Radiographic Textbook PDF

564 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY TRAUMA AND MOBILE IMAGING Introduction This chapter is divided into two primary sections; the first section involves trauma and mobile imaging, and the secon...

564 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY TRAUMA AND MOBILE IMAGING Introduction This chapter is divided into two primary sections; the first section involves trauma and mobile imaging, and the second section discusses surgical radiography. Student radiographers may feel anxious and intimidated by these types of procedures because of the nature of the patient’s condition, different equipment, unfamiliar surroundings, and working with personnel outside the radiology department. All of these factors can create a heightened perception of stress. To build confidence, reduce perceived stress, and perform these advanced exams with greater accuracy, it is important to view these experiences as an opportunity to build on knowledge previ- ously acquired. There are multiple facets to these areas that could be discussed in great detail; however, the purpose of this chapter is to provide a basic foundation. Experience is truly the greatest Fig. 15.1 Trauma radiography. resource in becoming prepared to face the challenges presented by these procedures. Maintaining an open mind, thinking critically, and accepting that learning is a product of effort and experience will allow for the development of the skills necessary to be proficient in trauma, mobile, and surgical radiography. Skeletal Trauma and Fracture Terminology The American Registry of Radiologic Technologists (ARRT) defines trauma as a serious injury or shock to the body, often requiring modifications that may include variations in positioning, minimal movement of the body part, and so on1 (Fig. 15.1). This may mean that patients cannot be brought to the radiology department for routine radiographic procedures as described in other sections of this text. Instead, a mobile (portable) x-ray unit must be taken to the emergency department (ED) or to the patient’s bedside (Fig. 15.2). Even if patients are brought to the radiology department, they may be immobilized in a number of ways. Some may present with one or more splints, indicating possible limb fractures or dis- locations. Others may be strapped to a backboard with a cervical collar in place. In these cases, a major adaptation of CR angles Fig. 15.2 Bedside mobile radiography. and image receptor placement is required. Radiographers must use their knowledge of anatomy, technical factors, and positioning to acquire diagnostic images in difficult circumstances. Skeletal trauma and surgical radiography require an understand- ing of terms that are unique to these situations, such as fracture- dislocation terminology. Knowing the terms used in patient histories or on examination requisitions allows the technologist to understand which type of injury or fracture is suspected and which projections are most important. It also is useful for knowing how to avoid positioning techniques or body positions that may result in addi- tional pain or injury. DISLOCATION Dislocation refers to the displacement of a bone that is no longer in contact with its normal articulation.2 Dislocations can frequently be clinically identified by the abnormal shape or alignment of the body parts. Any movement of these parts can be painful and must be avoided. As with fractures, dislocations should be imaged in two planes, 90° to each other, to demonstrate the degree of displace- ment. The most common dislocations encountered in trauma involve the shoulder (Fig. 15.3), fingers or thumb, patella, and hip. Fig. 15.3 Right shoulder dislocation (AP projection). If a bone has relocated itself following the injury, damage may still have occurred, and a minimum of two projections of the affected joint is required to assess for damage and/or possible avulsion fractures. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 565 SUBLUXATION Anterior vertebral line A partial dislocation is illustrated in Fig. 15.4, in which a vertebra is displaced posteriorly. Another example is nursemaid’s elbow C4 (so-called jerked elbow), which is a traumatic partial dislocation of the radial head of a child. This is caused by a hard pull on the hand and wrist of a child by an adult. It is frequently reduced when the C5 forearm is supinated for an AP elbow projection. SPRAIN C6 A sprain is a forced wrenching or twisting of a joint that results in a partial rupture or tearing of supporting ligaments, without disloca- tion. A sprain may result in severe damage to associated blood vessels, tendons, ligaments, and/or nerves. Severe swelling and discoloration resulting from hemorrhage of ruptured blood vessels Fig. 15.4 Subluxation of cervical vertebra (C5 vertebra displaced frequently accompany a severe sprain. A severe sprain can be posteriorly). painful and must be handled with great care during the radiographic examination. Symptoms are similar to those of fractures; radiographs aid in differentiating a sprain from a fracture. CONTUSION This is a bruise type of injury with a possible avulsion fracture. An example is a hip pointer, a football injury involving contusion of bone at the iliac crest of the pelvis. FRACTURE A fracture (fx) is defined as a disruption of bone caused by mechani- cal forces applied either directly to the bone or transmitted along the shaft of the bone.2 With any possible fracture, the technologist must use extreme caution in moving and positioning the patient so as to not cause further injury or displacement of fracture fragments. The technologist should never force a limb or body part into position. If the fracture is obvious, or if severe pain accompanies any movement, positioning should be adapted as needed. FRACTURE ALIGNMENT TERMINOLOGY Alignment refers to the associative relationship between long axes of the fracture fragments. A fracture is aligned if the long axes of the bone remain parallel to each other. Apposition Fig. 15.5 Lack of apposition. Fig. 15.6 Bayonet apposition. Apposition describes how the fragmented ends of the bone make contact with each other. Three types of apposition are known: 1. Anatomic apposition: Anatomic alignment of ends of fractured bone fragments, wherein the ends of the fragments make end- to-end contact. Body midline Body midline 2. Lack of apposition (distraction): The ends of fragments are aligned but pulled apart and are not making contact with each other (e.g., as from excessive traction; Fig. 15.5). 3. Bayonet apposition: The fracture fragments overlap and the shafts make contact, but not at the fracture ends (Fig. 15.6). Angulation Angulation describes loss of alignment of the fracture; apex is the direction of the angulation and is opposite in relation to the distal part of the fracture fragments (Fig. 15.7). The following three terms can be used to describe the type or direction of angulation, which Varus (lateral apex) Valgus (medial apex) uses the apex or distal fragments as its reference point: 1. Apex angulation: Describes the direction or angle of the apex Fig. 15.7 Varus versus valgus deformity. of the fracture, such as a medial or lateral apex, wherein the point or apex of the fracture points medially or laterally. 2. Varus deformity: The distal fragment ends are angled toward the midline of the body and the apex is pointed away from the midline. 3. Valgus deformity: The distal fragment ends are angled away 15 from the midline and the apex is pointed toward the midline. NOTE: The terms varus and valgus also are used as inversion and eversion stress movement terms (see Terminology, Chapter 1).  566 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY TYPES OF FRACTURES Many terms are used in describing fractures. Terms that technolo- gists are most likely to encounter are as follows. Simple (Closed) Fracture This is a fracture in which the bone does not break through the skin. Compound (Open) Fracture This is a fracture in which a portion of the bone (usually the frag- mented end) protrudes through the skin (Fig. 15.8). Incomplete (Partial) Fracture This fracture does not traverse through the entire bone. (The bone is not broken into two pieces.) It is most common in children. Two Fig. 15.8 Compound Fig. 15.9 Greenstick fx (ulna). major types of incomplete fractures are as follows: fx (tibia-fibula). 1. Torus fx: This buckle of the cortex (outer portion of the bone) is characterized by localized expansion or torus of the cortex, possibly with little or no displacement, and no complete break in the cortex. 2. Greenstick fx (hickory or willow stick fx): Fracture is on one side only. The cortex on one side of the bone is broken and the other side is bent. When the bone straightens, a faint fracture line in the cortex may be seen on one side of the bone, and a slight bulging or wrinkle-like defect is seen on the opposite side (Fig. 15.9). Complete Fracture In this fracture, the break is complete and includes the cross-section of bone. The bone is broken into two pieces. There are three major types of complete fractures. 1. Transverse fx: Fracture is transverse at a near right angle to the long axis of the bone. 2. Oblique fx: The fracture passes through bone at an oblique angle. 3. Spiral fx: In this fracture, the bone has been twisted apart and the fracture spirals around the long axis (Fig. 15.10). Comminuted Fracture In this fracture, the bone is splintered or crushed at the site of Fig. 15.10 Spiral fx (femur). Fig. 15.11 Comminuted fx (tibia). impact, resulting in two or more fragments (Fig. 15.11). Three types of comminuted (kom′-i-nu-ted) fractures have specific implications for treatment and prognosis because of the possible substantial disruption of blood flow: 1. Segmental fx: A type of double fracture in which two fracture lines isolate a distinct segment of bone; the bone is broken into three pieces, with the middle fragment fractured at both ends. 2. Butterfly fx: A comminuted fracture with two fragments on each side of a main, wedge-shaped separate fragment; it has some resemblance to the wings of a butterfly. 3. Splintered fx: A comminuted fracture in which the bone is splintered into thin sharp fragments. Impacted Fracture In this fracture, one fragment is firmly driven into the other, such as the shaft of the bone being driven into the head or end segment. Fig. 15.12 Impacted fx (radius). These most commonly occur at distal or proximal ends of the femur, humerus, or radius (Fig. 15.12). SPECIFIC NAMED FRACTURES Following are some examples and descriptions of named fractures, usually named by the type of injury or after the person who identi- fied them. 15 Barton Fracture It is an intra-articular fracture of the distal radius often associated with dislocation or subluxation of the radiocarpal joint.  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 567 Baseball (Mallet) Fracture This fracture of the distal phalanx is caused by a ball striking the end of an extended finger. The distal interphalangeal (DIP) joint is partially flexed, and an avulsion fracture is frequently present at the posterior base of the distal phalanx. Bennett Fracture This longitudinal fracture, which occurs at the base of the first metacarpal with the fracture line entering the carpometacarpal joint, generally includes a posterior dislocation or subluxation. Boxer Fracture This fracture usually involves the distal fifth metacarpal, with an apex posterior angulation best demonstrated on the lateral view. It results from punching someone or something. Colles Fracture Fig. 15.13 Colles Fig. 15.14 Smith fx This fracture of the wrist, in which the distal radius is fractured with fx (radius). (reverse Colles fx). the distal fragment displaced posteriorly, may result from a forward fall on an outstretched arm (Fig. 15.13). Smith (Reverse Colles) Fracture This is a fracture of the wrist with the distal fragment of the radius displaced anteriorly rather than posteriorly, as in a Colles fracture. It commonly results from a backward fall on an outstretched arm (Fig. 15.14). Hangman Fracture This fracture occurs through the pedicles of the axis (C2), with or Fig. 15.15 Monteggia fx (ulna). without displacement of C2 or C3. Hutchinson (Chauffeur) Fracture This is an intra-articular fracture of the radial styloid process. (The name originates from the time when hand-cranked cars would backfire, with the crank striking the lateral side of the distal forearm.) Monteggia (mon-tej′-ah) Fracture This fracture of the proximal half of the ulna, along with dislocation of the radial head, may result from defending against blows with the raised forearm (Fig. 15.15). Pott Fracture Fig. 15.16 Pott fx (distal tibia-fibula). This term is used to describe a complete fracture of the distal fibula with major injury to the ankle joint, including ligament damage and frequent fracture of the distal tibia or medial malleolus (Fig. 15.16). ADDITIONAL FRACTURE TYPES Avulsion Fracture This fracture results from severe stress to a tendon or ligament in a joint region. A fragment of bone is separated or pulled away by the attached tendon or ligament. Blowout and/or Tripod Fracture These fractures, which result from a direct blow to the orbit and/ or maxilla and zygoma, create fractures to the orbital floor and lateral orbital margins. Fig. 15.17 Compression fx (body of vertebra). Chip Fracture This fracture involves an isolated bone fragment; however, this is not the same as an avulsion fracture because this fracture is not caused by tendon or ligament stress. Compression Fracture This vertebral fracture is caused by compression-type injury. The 15 vertebral body collapses or is compressed. Generally, it is most evident radiographically by a decreased vertical dimension of the anterior vertebral body (Fig. 15.17).  568 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY Depressed Fracture (sometimes called a is stable. In this scenario, a nurse may accompany the patient to Ping-Pong fracture) monitor his or her condition. In this fracture of the skull, a fragment is depressed. The appearance is similar to a Ping-Pong ball that has been pressed in by the finger, MOBILE X-RAY SYSTEMS but if the indentation can be elevated again, it can assume its Major advances have been made in mobile radiographic and fluo- near-original position. roscopic equipment. Examples of general types commonly used are described and illustrated in this chapter. Epiphyseal Fracture This is a fracture through the epiphyseal plate, the point of union of the epiphysis and shaft of a bone. It is one of the most easily fractured sites in long bones of children. Radiologists commonly use the Salter-Harris classification (Salter 1 to 5, with Salter 5 indicating the most complex) to describe the severity and reason- able indication of prognosis of these fractures. Pathologic Fracture These fractures are due to disease process within the bone, such as osteoporosis, neoplasia, or other bone diseases. Stellate Fracture In this fracture, the fracture lines radiate from a central point of Fig. 15.18 Stellate fx (patella). injury with a starlike pattern. The most common example of this type of fracture occurs at the patella and is often caused by knees hitting the dashboard in a motor vehicle accident (Fig. 15.18). Stress or Fatigue Fracture (sometimes called a “March” fracture) This type of fracture is nontraumatic in origin. It results from repeated stress on a bone, such as from marching or running. If caused by Fig. 15.19 Tuft fx (distal phalanx). marching, these fractures usually occur in the midshafts of meta- tarsals; if caused by running, they are in the distal shaft of the tibia. Stress fractures are frequently difficult to demonstrate radiographi- cally and may be visible only through subsequent callus formation at the fracture site or on a nuclear medicine bone scan. Trimalleolar Fracture This fracture of the ankle joint involves the medial and lateral malleoli as well as the posterior lip of the distal tibia. Tuft or Burst Fracture This comminuted fracture of the distal phalanx may be caused by a crushing blow to the distal finger or thumb (Fig. 15.19). POSTFRACTURE REDUCTION Closed Reduction Fracture fragments are realigned by manipulation and are immobi- lized by a cast or splint. A closed reduction is a nonsurgical proce- dure; however, it may be done with the aid of fluoroscopy. Open Reduction For severe fractures with significant displacement or fragmentation, a surgical procedure is required. The fracture site is exposed and screws, plates, or rods are installed as needed to maintain align- ment of the bony fragments until new bone growth can take place. Fig. 15.20 GE Image Optima XR220amx. (Courtesy GE Healthcare.) This is called an open reduction with internal fixation (ORIF), as described later (see “Surgical Radiography”). Mobile X-Ray Equipment A study of trauma and mobile radiography requires an understand- ing of the functions and operations of the equipment being used. Trauma radiography may be performed with a conventional over- head tube in a dedicated trauma bay located in the ED or with mobile (portable) units that are brought to the ED, the patient’s 15 bedside, or the operating room (OR) for surgical procedures (Fig. 15.20). Radiographic examinations may also be performed in the radiology department if the physician has deemed that the patient  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 569 Battery-Driven, Battery-Operated, Mobile X-Ray Units 2. Accurate centering: It is important that the body part and the These systems are powered by 10 to 16 rechargeable, sealed, lead central ray be centered to the IR. acid-type 12-volt batteries connected in series. The self-propelled 3. Exposure factors: With regard to exposure to the patient, it is systems of these units are also battery-powered and have variable important that the ALARA (as low as reasonably achievable) travel speeds up to an average walking speed of 2.5 to 3 mph with principle be followed and the lowest exposure factors required a maximum incline of 7°. They have a driving range of up to 10 to obtain a diagnostic image be used. This includes the highest miles on a level surface after a full charge. kV and the lowest mAs that would result in desirable image These units are driven and maneuvered by dual-drive motors quality. It may be necessary to increase kV over that used for that operate the two drive wheels. They also have a lower speed analog (film-screen) imaging for larger body parts, with 50 kV forward and reverse for maneuvering in close quarters. Parking as the minimum used on any procedure (exception is brakes are automatically engaged when the control levers are not mammography). in use; this is known as dead man’s control. If the technologist 4. Post-processing evaluation of exposure indicator: The expo- releases the control levers, the mobile unit will come to an sure indicator value on the final processed image must be abrupt halt. checked to verify that the exposure factors used were in the The unit can be plugged in for recharging when it is not being correct range to ensure optimal quality with the least radiation used and can be recharged at 110 or 220 V. The parking brakes to the patient. If the index is outside of the acceptable range, are also used during charging. With 110-V, 5-amp outlets, the the technologist must adjust kV or mAs or both accordingly for charging time is about 8 hours when fully discharged (Fig. 15.21). any repeat exposures. Standard Power Source, Capacitor-Discharge, Non-Motor-Driven Units A second type of mobile x-ray unit without battery power is now available. These models are much lighter in weight and usually are not motor-driven. They operate with a 110-V, 15-amp power source or a 220-V, 10-amp power source. These units generally incorporate a capacitor discharge system, which stores electrical charges when plugged in and then discharges this electrical energy across the x-ray tube when exposure is initiated. This increases the electrical power (voltage) from the standard 110- or 220-V power source. Other systems offer a dual power source with both battery power and plug-in electrical power for increased output. These generally also have a battery-assisted motor drive for easier trans- porting (Fig. 15.22). The controls on these units may include some type of optional programmed memory system that is based on anatomic parts, or they may have operator-selected kV and mAs technique controls. Fig. 15.21 Carestream DRX Revolution Mobile X-ray System. (Courtesy Carestream Health.) NOTE: These are only two examples of available mobile systems. Other manufacturers offer various modifications, features, and options. Digital Imaging Considerations The widespread use of digital imaging into mobile systems is the most notable advancement in mobile equipment. As discussed in Chapter 1, digital imaging includes both computed radiography (CR) and digital radiography (DR). Digital imaging is especially well suited for trauma and mobile imaging in the ED, in the OR, and for bedside (mobile/portable) examinations. These procedures frequently are performed under difficult but urgent conditions in which opportunities for repeats are limited. The wide exposure lati- tude of digital images has improved the consistency of these images and has greatly reduced the need for repeat exposures due to positioning and technical variables. Another advantage of digital imaging for trauma and mobile radiographic examinations is the ability to transfer these images electronically to more than one location simultaneously for inter- pretation or consulting. Radiologists can view the images and arrive at a diagnosis in a very short time and can communicate those findings to the ED physician, who then is able to create a plan of care for the trauma patient. In some instances, the images can be viewed directly on the mobile unit. Following is a summary of guidelines that should be followed when digital imaging technology (computed radiography or digital radiography) is used for the lower limbs: 1. Four-sided collimation: Collimate to the area of interest with a 15 minimum of two collimation parallel borders clearly demon- Fig. 15.22 Siemens Mobilett Plus—dual power source, battery and/ strated in the image. Four-sided collimation is always preferred or standard power, capacity discharge. (Courtesy Siemens Medical if the study permits. Solutions, Malvern, PA.)  570 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY Positioning Principles for Trauma and Mobile Radiography Positioning principles for trauma and mobile radiography are similar to those applied for routine general radiography, as described in Chapter 1 of this text. The primary difference can be summarized by the word adaptation. Each trauma patient and situation is unique, and the technologist must evaluate the patient and adapt CR angles and IR placement as needed. However, all images must be as true to those of routine general radiography as possible. The technologist must keep the following three principles in mind when performing trauma or mobile radiography: 1. Two projections 90° to each other with true CR-part-IR alignment 2. Entire structure or trauma area included on image receptor 3. Maintain the safety of the patient, health care workers, and the Fig. 15.23 AP foot (trauma adaptation positioning). public PRINCIPLE 1: TWO PROJECTIONS 90° TO EACH OTHER WITH TRUE CR-PART-IR ALIGNMENT Trauma radiography generally requires orthogonal views, two projections taken at 90° (or right angles to each other) while true CR-part-IR alignment is maintained. The preferences for the two projections are a true AP or PA and a true lateral achieved by turning the body part (standard positioning) or angling the CR and IR as needed (trauma adaptation positioning). In this way, the CR-part-IR alignment can be maintained even if the patient cannot be turned or rotated. An example is shown in Figs. 15.23 and 15.24, in which true AP and lateral foot images are obtained without flexing or moving the lower limb. The AP projection is achieved by angling the CR and IR in relation to the foot, thus maintaining a true CR-part-IR alignment. When adaptations are made during the performance of any Fig. 15.24 Lateral foot. radiographic image, it is important to include as much information as possible as to how the image was achieved. This information includes CR angle, projection of the beam (AP, PA, lateral, oblique, cross-table), and upright, semiupright, or supine position. Exception to True Anteroposterior (AP) and Lateral Principle Because of the patient’s condition, occasionally it may not be possible to maintain this standard CR-part-IR relationship for true anteroposterior (AP) and lateral projections. This may be due to unavoidable obstructions such as large splints, back supports, trac- tion bars, or other apparatus. In this case, the technologist should still attempt two projections as near 90° to each other as possible, even if the anatomic part is partially rotated. Only as a last resort should just one projection be taken. When these exceptions are unavoidable, a note that explains the reason for this variance in routine should be left in the patient’s record and/or examination requisition. Fig. 15.25 Trauma AP axial oblique C-spine exception. The IR is not Exception to CR-Part-IR Alignment perpendicular to the CR. Generally, this principle involves placing the IR at right angles or perpendicular to the CR for minimal part distortion. However, in situations such as shown in Fig. 15.25, the CR-part relationship can be maintained, but not the part-IR relationship. In this example, the AP axial oblique cervical spine is obtained with the patient supine and the IR flat on the table under the patient. This will result in some part distortion but, in trauma radiography, it may be an acceptable option. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 571 PRINCIPLE 2: ENTIRE STRUCTURE OR TRAUMA AREA INCLUDED ON IMAGE RECEPTOR Trauma radiography mandates that the entire structure being examined should be included on the radiographic image to ensure that no pathology is missed. This requires selection of sufficiently large IRs or the use of more than one IR if needed. If an examination request on a trauma patient includes the long bones of the upper or lower limbs, both joints should be included for possible secondary fractures away from the primary injury. An example is a post-trauma examination request for a leg (tibia-fibula) with injury to the distal region. This may require a second, smaller IR of the knee to include the proximal tibia-fibula region if the patient’s leg is too long to be included on a single image. Fractures of the distal tibia also may involve a secondary fracture of the proximal fibula. This principle of including both joints is true for AP and lateral projections. For all upper and lower limb follow-up examinations, always include a minimum of one joint nearest the site of injury. Few if any exceptions to this rule exist, even if the obvious fracture shown on previous images is in the midshaft region. The joint nearest the fracture site should always be included (Figs. 15.26 and 15.27). Fig. 15.26 AP distal lower leg Fig. 15.27 Lateral distal lower The principle of including the entire structure, or trauma region, and ankle. leg and ankle. also applies to these larger body areas. For example, the abdomen on a large patient may require two IRs placed landscape to include the entire abdomen. This may also be true for the chest or bony thorax. Trauma patients often arrive in a supine position, and horizontal beam (cross-table) projections are commonly required for the lateral projections. Care must be taken to ensure that the divergent x-ray beam does not project the body part off the IR, especially when the IR is placed on edge directly beside the patient. This is true for the spine, skull, and other parts that rest directly on the tabletop. Examples of a horizontal beam, lateral skull projection, with and without a possible spine injury, are shown in Figs. 15.28 and 15.29. With a questionable spinal injury, the head and neck cannot be moved or elevated. Therefore, no support or pad can be placed between the head and tabletop. If the IR is placed on edge next to the patient’s head, the divergent x-ray beam will project the posterior part of the skull off the IR. Fig. 15.28 Horizontal beam lateral skull without possible spine injury To avoid cutoff of the posterior skull in this example, the patient (head raised from tabletop). can be moved to the edge of the table or cart and the IR placed below the level of the tabletop (see Fig. 15.29). This may result in an increase in the object image receptor distance (OID), with resultant magnification. In these cases, this is an acceptable option. If cervical spine radiographs have ruled out cervical fracture or subluxation, the head may be raised and supported by a sponge to prevent posterior skull cutoff (see Fig. 15.28). Fig. 15.29 With possible spine injury, head cannot be raised or moved (cassette is placed below tabletop level to prevent posterior skull cutoff). 15  572 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY PRINCIPLE 3: MAINTAIN THE SAFETY OF THE PATIENT, SONOGRAPHY HEALTH CARE WORKERS, AND THE PUBLIC Sonography (medical ultrasound) is indicated in the early assess- When trauma or mobile radiography is performed, it may be neces- ment of certain trauma patients, such as those who have experi- sary to move room equipment and side rails to provide access to enced blunt abdominal injury. It is a noninvasive technique used the patient. The technologist must take note of the equipment that to detect free fluid or blood in the abdomen. Sonography is also is moved to make sure that it is not attached to the patient. Often, the modality of choice for imaging emergency conditions of the the technologist will be able to move equipment only a short female reproductive system (e.g., ectopic pregnancy). Sonography distance because of space constraints. Side rails may have to be is used as required for specific emergency situations when other lowered to allow the technologist to place an IR under the patient. abdominal organs are imaged. This must take place as quickly and as safely as possible. Never assume that a patient is unable to move. All side rails must be NUCLEAR MEDICINE returned to the upright position, regardless of whether or not the Nuclear medicine is useful for the evaluation of specific emergency patient already had the rails up. All equipment must be returned conditions, such as pulmonary embolus, testicular torsion, and to its original location as well. gastrointestinal (GI) bleeding. Blood flow to the areas under inves- When performing mobile studies, technologists are also tigation is assessed through injection of the radionuclide. responsible for ensuring the safety of the other health care workers in the immediate area. In a trauma situation, time is of ANGIOGRAPHY AND INTERVENTIONAL PROCEDURES the essence. Although it is important that the technologist obtain Angiography is indicated for studies of the aortic arch in the trauma trauma images while physicians, nurses, and other staff are attend- patient, although the use of these procedures has declined because ing to the patient, under no circumstances should an exposure take of the increased use of CT angiography. Interventional procedures place with an unshielded person in the vicinity of the primary beam. performed on the trauma patient, as described in Chapter 17, The ALARA principle (exposure to patient as low as reasonably include transcatheter embolization to occlude hemorrhaging achievable) applies to other health care workers and the public, as vessels. well as to the patient. Routine and Special Projections Alternative Modalities Certain routine and special projections for trauma, mobile, and COMPUTED TOMOGRAPHY surgical radiography are demonstrated and described on the fol- The increased speed of computed tomography (CT) scanners has lowing pages and listed in Appendix B as suggested standard contributed to their increased use for emergency imaging. CT is routine and special departmental routines or procedures. commonly used for accurate diagnosis of a wide range of traumatic conditions that affect all body systems, thus replacing some of the traditionally ordered diagnostic examinations, such as spine and skull radiography. The three-dimensional reconstruction capability of CT is useful for fully assessing skeletal trauma. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 573 TRAUMA AND MOBILE POSITIONING AP CHEST WARNING: With possible spinal injury or severe trauma, do not attempt to move the patient. Clinical Indications Respiration Expose at end of second full inspiration. According to the American College of Chest Optional lateral chest (not demonstrated here): A lateral image Radiology (ACR), the AP chest radiograph TRAUMA can be obtained with a horizontal beam CR if patient can raise arms is a standard part of the trauma workup at AP at least 90° from body. Place IR parallel to midsagittal plane (MSP), most level I trauma centers across the OPTIONAL with top of IR 2 inches (5 cm) above level of shoulders. Support Lateral United States.3 Lateral decubitus patient on radiolucent pad to center chest to IR and center hori- Approximately 25% of deaths from blunt (AP) zontal CR to level of T7. trauma arise from chest injuries, although up to 50% of death are at least partially related to thoracic injuries.2 Chest injuries include acute aortic injury, pulmonary injury, pneumothorax, hemothorax, extrapleural hematoma, large airway rupture, hemidiaphragmatic rupture, and musculoskeletal injury.3 Ensure proper placement of lines and tubes. Technical Factors Minimum SID—40 (102 cm). Use 72 inches (183 cm) if possible. IR size—35 × 43 cm (14 × 17 inches), landscape, for average to large patients (see Note 1) Grid (see Note 2) Analog and digital systems—90 to 125 kV, depending on whether grid is required Patient Position AP Chest Fig. 15.30 AP supine chest, bedside (IR landscape), CR 3° to 5° Patient is supine on cart; if patient’s condition allows, the head caudad, perpendicular to sternum. end of the cart should be raised into an erect or semierect position. Rotate arms internally, if patient’s condition allows, to move scapulae out of lung fields. Part Position AP Chest Enclose the IR in a plastic cover and place under or behind patient; place top of IR about to 2 inches (4 to 5 cm) above the shoulders, aligning CR to IR. Ensure no rotation (coronal plane parallel to IR). (Place supports under parts of IR as needed.) CR AP Chest Direct CR 3 to 4 inches (8 to 10 cm) below jugular notch, level Fig. 15.31 AP semierect chest, bedside. of T7. Angle CR 3° to 5° caudad, or raise head end of bed slightly, to place the CR perpendicular to long axis of sternum (unless grid prevents this). This simulates the PA projection and prevents the clavicles from obscuring the apices of the lungs (Fig. 15.30). If patient is able to attain only a semierect position, the CR must be angled to maintain the perpendicular relationship with the IR (Fig. 15.31). Radiation Safety Exposure factor selection should be optimized in accordance with ALARA. Collimate on four sides to anatomy of interest. 15 Shield radiosensitive tissues outside area of interest.  574 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY Lateral Decubitus AP Projection To determine air-fluid levels when the patient cannot be elevated sufficiently for an erect posi- tion, a lateral decubitus can be taken in bed with the IR placed behind the patient or on a stretcher in front of the IR holder, as shown in Fig. 15.32. Place radiolucent pads under the thorax and shoulders, and raise the arms above the head. CR-part-IR alignment and centering are similar to supine AP, with necessary adaptations for the decubitus position. NOTE 1: Costophrenic angle cutoff is a problem with recumbent chest positions taken with a shorter source image receptor distance (SID) because of the divergence of the x-ray beam. Therefore, unless the patient is quite small, a landscape IR placement is recommended. NOTE 2: Focused grids generally are difficult to use for mobile chests because of the problems of grid cutoff. Fig. 15.32 Lateral decubitus (AP) chest, horizontal beam for detecting possible air-fluid levels. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 575 AP SUPINE AND DECUBITUS: ABDOMEN WARNING: With possible spinal injury or severe trauma, do not attempt to move the patient. Clinical Indications Abdomen Radiation Safety Evaluate for fracture, free intraperitoneal TRAUMA Exposure factor selection should be optimized in accordance air, abnormal fluid or gas.4 AP supine with the ALARA. Decubitus Chest radiograph may be ordered along Collimate on four sides to anatomy of interest. with an abdominal series. Shield radiosensitive tissues outside area of interest. Technical Factors Minimum SID—40 inches (102 cm) IR size—35 × 43 cm (14 × 17 inches), portrait (see Note 1) Grid Analog systems—70 to 80 kV range Digital systems—80 to 90 kV Include decubitus and upside markers if applicable Patient Position AP Supine (Fig. 15.33) Place IR into plastic cover if taken at bedside. Align IR portrait to MSP. Arms placed at side, away from the body. Left Lateral Decubitus AP (or PA) Projection (Fig. 15.34) This projection allows determination of air-fluid levels (see Note 2) and possible free intra-abdominal air when an upright image is not possible. The lateral decubitus can be taken in bed, on a stretcher in the ED, or on a stretcher in the radiography room in front of an upright wall bucky. Place supports or a positioning board under hips and thorax as needed to center abdomen to IR for lateral and dorsal decubitus projections, if performed bedside. This will create a flat surface, thus preventing the patient from sinking into the mattress and Fig. 15.33 Supine AP abdomen, bedside. cutting off downside anatomy on the image. Raise arms up near head and partially flex the knees to stabilize patient. Part Position AP Supine Center IR to CR at level of iliac crest. Ensure that both sides of upper and lower abdomen are at equal distances from lateral IR margins. Place supports under parts of IR if needed to ensure that IR is level and perpendicular to CR (prevents patient rotation and grid cutoff on soft bed surfaces). Left Lateral Decubitus AP (or PA) Projection Ensure that diaphragm and upper abdomen are included. Place center of IR 1 to 2 inches (3 to 5 cm) above level of iliac crests. Ensure no rotation and that the IR plane is perpendicular to CR. Fig. 15.34 Left lateral decubitus (AP) abdomen, bedside. CR AP Supine Position CR perpendicular to level of iliac crest and to center of IR. Left Lateral Decubitus AP (or PA) Projection Direct horizontal CR to center of IR, 2 inches above level of iliac crests. 15  576 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY Respiration AP Supine and Left Lateral Decubitus AP (or PA) Projection Make exposure at end of expiration. NOTE 1: For patients with a large body habitus, two 35 × 43-cm (14 × 17-inch) IRs may be needed to ensure that the entire anatomy is included. These IRs should be placed landscape, one for imaging the upper abdomen and diaphragm and the other for imaging the lower abdomen and sym- physis pubis. Two separate exposures are necessary (see Chapter 3). NOTE 2: For lateral decubitus projections, have patients lie on the side for a minimum of 5 minutes before taking exposure to allow air to rise to highest position within the abdomen. Dorsal Decubitus, Lateral Position (Fig. 15.35) This is not a common bedside projection. The dorsal decubitus is a useful position for demonstrating a possible abdominal Fig. 15.35 Dorsal decubitus (lateral) abdomen, on stretcher in front aortic aneurysm, or it may be used as an alternative to the lateral of erect bucky. decubitus position if the patient cannot be moved. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 577 UPPER LIMB WARNING: With possible spinal injury or severe trauma, do not attempt to move the patient. Clinical Indications Upper Limb Fractures, dislocations, and subluxations TRAUMA due to trauma. AP or PA Lateral Hand and wrist fractures and dislocations OPTIONAL are more common than those of any other Oblique part of the body.5 Delayed diagnosis due to persistent clinical findings. Technical Factors Minimum—40 inch (102 cm) SID IR size—Smallest IR possible Grid—if part is thicker than 10 cm Analog—50 to 60 kV range Digital—60 to 70 kV range Patient Position The patient will present in a multitude of positions. Some may Fig. 15.36 PA forearm to include wrist and elbow. be able to sit upright for their exam, while others may be supine on a back board. Because of the wide variance in patient posi- tions, it is difficult to describe a specific protocol to follow in regard to patient positioning. The technologist must assess the patient’s status and limitations to determine how to proceed in the best interest of the patient. Part Position Obtain a minimum of two projections 90° to each other with true CR-part-IR alignment (Figs. 15.36 and 15.37). Do not attempt to rotate a severely injured part. Do not remove splints or other immobilization devices. Be cautious working around foreign bodies that may be protrud- ing from the area of interest. When placing the IR, minimally raise the affected limb while supporting both joints. CR Include the entire structure or trauma area, including both joints for long bones. Fig. 15.37 Lateral forearm to include wrist and elbow. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. 15  578 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY UPPER LIMB POSITIONING EXAMPLES Figs. 15.38 to 15.50 provide examples of how radiographs can be produced when encountering a trauma situation involving the upper limb. Fig. 15.38 AP proximal metacarpals and wrist. Fig. 15.42 Lateral wrist and hand. Fig. 15.39 AP hand and fingers for distal phalanges. Fig. 15.43 PA thumb. Fig. 15.40 AP hand. Fig. 15.44 Lateral thumb. 15 Fig. 15.41 Oblique—fingers, hand, and/or wrist.  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 579 Fig. 15.45 PA horizontal beam elbow, CR perpendicular to Fig. 15.48 Lateral for coronoid process, elbow flexed 80°, CR angled interepicondylar plane. 45° distally (from shoulder). Fig. 15.46 Lateral elbow partially flexed, CR angled as needed to be Fig. 15.49 AP humerus; should include both joints. parallel to interepicondylar plane. Fig. 15.47 Lateral for radial head, elbow flexed 90°, CR angled 45° Fig. 15.50 Lateral, mid- and distal humerus to include elbow. proximally (toward shoulder). 15  580 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY SHOULDER WARNING: Do not attempt to rotate the arm if a fracture or dislocation is suspected; leave affected arm as presented. NOTE: Local protocols for radiographic evaluation Shoulder of the shoulder for trauma vary widely. However, TRAUMA the shoulder trauma protocol should have at least AP three views, two of which are orthogonal.6 Scapular Y lateral Inferosuperior axial Transthoracic lateral Clinical Indications Fractures, dislocations, and subluxations due to trauma. Technical Factors Minimum SID—40 inches (102 cm) IR size—24 × 30 cm (10 × 12 inches) portrait Grid Analog—70 to 80 kV range with grid Fig. 15.51 AP shoulder. Digital systems—75 to 85 kV range with grid Patient Position AP Shoulder and Scapular Y Lateral—AP Oblique (Lateromedial Scapula) (Figs. 15.51 and 15.52) Patient will most likely be supine; however, an erect position is usually more comfortable. Inferosuperior Axial (Fig. 15.53) Patient supine, with shoulder raised approximately 2 inches (5 cm) from the cart or tabletop. Place support under arm and shoulder to place area of interest near center of IR. Transthoracic Lateral (Fig. 15.54) Patient will most likely be supine in case of trauma; however, an erect position is usually more comfortable. Place the affected shoulder closest to the IR. Fig. 15.52 AP oblique, scapular Y, lateromedial projection of scapula. Part Position AP Shoulder Affected arm in neutral rotation, position at side. Center IR (grid IR under patient if on stretcher) to shoulder joint and to CR. Scapular Y Lateral—AP Oblique (Lateromedial Scapula) Palpate borders of scapula by grasping medial and lateral borders of body of scapula with fingers and thumb. Carefully adjust body rotation as needed to bring the plane of the scapular body perpendicular to the IR (approximately 25° to 30° away from IR). Center scapulohumeral joint to CR and center of IR. Inferosuperior Axial Place IR as close to the neck as possible. Abduct affected arm 90° from body or as much as the patient can tolerate. Care should be taken when abducting the arm; support should be provided under arm. Transthoracic Lateral Raise unaffected arm above head, elevating the unaffected shoulder. Center surgical neck of affected arm to center of IR. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 581 CR AP Shoulder CR perpendicular to IR, directed to midscapulohumeral joint. Scapular Y Lateral—AP Oblique (Lateromedial Scapula) Project CR perpendicular to IR, or if patient cannot be turned up sufficiently, angle CR as needed to be parallel to scapular blade (place grid horizontal to prevent grid cutoff) (See Note 1). Center CR to scapulohumeral joint (2 or 2 12 inches [5 or 6 cm] below top of shoulder). Inferosuperior Axial Direct CR medially 15° to 30° (less angle is required with less Fig. 15.53 Inferosuperior axial (transaxillary) shoulder. abduction of the arm). Center the CR horizontally to axilla and humeral head. Transthoracic Lateral CR perpendicular to IR, directed through thorax exiting at surgi- cal neck of affected arm (see Note 2). Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration A breathing technique may be preferred for the transthoracic lateral to blur out ribs and lung structures. Fig. 15.54 Lateral, transthoracic proximal humerus. NOTE 1: Some distortion will occur with this medial CR angle if it is needed to achieve a lateral position of the scapula. NOTE 2: A 10° to 15° cephalad angle may be required if superimposition of the shoulders occurs. 15  582 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY LOWER LIMB WARNING: With possible spinal injury or severe trauma, do not attempt to move the patient. NOTE: Radiographs are the mainstay of initial Lower Limb medical imaging in the setting of acute foot trauma. TRAUMA Initial foot imaging typically consists of a three-view AP study with the possibility of additional views as Lateral indicated by the clinical setting.7 An evaluation of OPTIONAL the traumatized ankle should consist of AP, lateral, Oblique and mortise views of the ankle.8 Several studies have found that the knee radiograph is commonly obtained after trauma but has the lowest yield for diagnosing clinically significant fractures.9 Clinical Indications Fractures, dislocations, and subluxations due to trauma. Technical Factors Minimum—40 inch (102 cm) SID IR size—Smallest IR possible Fig. 15.55 AP knee, CR parallel to long axis of foot lateromedially. Grid—if part is thicker than 10 cm (No cephalic angle is required on average patients.) Analog—50 to 80 kV range Digital—55 to 85 kV range Patient Position The patient will present in a multitude of positions. Because of the wide variance in patient positions, it is difficult to describe a specific protocol to follow in regard to patient positioning. The technologist must assess the patient’s status and limitations to determine how to proceed in the best interest of the patient. Part Position Obtain a minimum of two projections 90° to each other with true CR-part-IR alignment (Figs. 15.55 and 15.56). Do not attempt to rotate a severely injured part. Do not remove splints or other immobilization devices. Be cautious working around foreign bodies that may be protrud- ing from the area of interest. Fig. 15.56 Lateromedial knee, horizontal CR. When placing the IR, minimally raise the affected limb while supporting both joints. CR Include the entire structure or trauma area, including both joints for long bones. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 583 LOWER LIMB POSITIONING EXAMPLES Figs. 15.57 to 15.67 provide examples of how radiographs can be produced when encountering a trauma situation involving the lower limb. Fig. 15.57 AP foot and/or toes—CR perpendicular to IR. Fig. 15.60 Optional—AP ankle, CR perpendicular (parallel to long axis of foot). Fig. 15.58 Optional—oblique foot, CR cross-angled lateromedially Fig. 15.61 AP mortise projection—CR 15° to 20° lateromedial angle, 30° to 40°. perpendicular to intermalleolar plane. Fig. 15.59 Lateral foot or calcaneus. Fig. 15.62 Lateral ankle—CR horizontal. 15  584 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY Fig. 15.63 AP lower leg—CR cross-angled lateromedially (parallel to Fig. 15.66 AP mid- and distal femur. long axis of foot). Fig. 15.64 Lateral lower leg. Fig. 15.67 Lateral mid- and distal femur. Fig. 15.65 Optional medial oblique knee—CR 45° lateromedial cross-angle, grid landscape (crosswise). 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 585 PELVIS WARNING: Do not attempt to rotate leg internally if hip fracture is suspected. NOTE: An AP pelvic radiograph is often combined Pelvis with an AP chest and a lateral horizontal beam TRAUMA cervical spine radiograph to quickly assess the AP patient for emergent injuries and to triage patients.3 Clinical Indications Fractures, dislocations, and subluxations due to trauma. Technical Factors Minimum SID—40 inches (102 cm) IR size—35 × 43 cm (14 × 17 inches), landscape Grid Analog—80 ± 5 kV range Digital systems—85 ± 5 kV range Patient Position AP Pelvis Patient supine, with arms removed from area of interest (Fig. 15.68). Direct CR perpendicular to center of IR and pelvis. Part Position AP Pelvis Fig. 15.68 AP pelvis—bedside mobile. (Right leg is not rotated Place plastic cover over IR and slide under pelvis, IR landscape, internally in this example.) centered to patient. Top of IR will be about 1 inch (2.5 cm) above iliac crest. Ensure no rotation and equal distances from anterior superior iliac spine (ASIS) to IR. Rotate feet internally 15° if possible (see Warning, above). CR AP Pelvis CR is perpendicular to IR, directed midway between level of ASIS and the symphysis pubis. This is approximately 2 inches inferior to the level of ASIS. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration during exposure. 15  586 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY HIP WARNING: Do not attempt to rotate leg internally if hip fracture is suspected. NOTE: Radiography is the established initial Hip imaging study of choice for assessing the acutely TRAUMA painful hip. As with any trauma-related musculo- AP skeletal radiographic studies, orthogonal projections Lateral-axiolateral- inferosuperior (two or more views of the anatomy at right angles hip—Danelius-Miller to each other) are considered standard.10 method Clinical Indications Fractures, dislocations, and subluxations due to trauma. Technical Factors Minimum SID—40 inches (102 cm) IR size—35 × 43 cm (14 × 17 inches) or 24 × 30 cm (10 × 12 inches), portrait Grid Analog—80 ± 5 kV range Digital systems—80 to 90 kV range Patient Position AP Hip and Axiolateral-Inferosuperior Hip—Danelius-Miller Method (Figs. 15.69 and 15.70) Patient supine, with arms removed from area of interest. Part Position Fig. 15.69 AP hip. AP Hip Place 35 × 43-cm (14 × 17-inch) portrait under hip with the top of the IR at the level of the iliac crest. Ensure no rotation and equal distances from anterior superior iliac spine (ASIS) to IR Rotate leg 15° internally, if possible (see Warning, above). Axiolateral-Inferosuperior Hip–Danelius—Miller Method Place IR against patient’s side just above iliac crest and adjust so that it is parallel to femoral neck. Rotate leg 15° internally, if possible (see Warning, above). Elevate opposite leg as much as possible. CR AP Hip CR is perpendicular to IR, directed 1 to 2 inches (2.5 to 5 cm) Fig. 15.70 Inferosuperior lateral—bedside mobile (Danelius-Miller distal to midfemoral neck. method). Axiolateral-Inferosuperior Hip—Danelius-Miller Method Direct horizontal CR perpendicular to femoral neck and to plane of IR. Ensure that CR is centered to the midline of the grid to prevent cutoff. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration during exposure. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 587 CERVICAL SPINE WARNING: Do not remove cervical collar or move patient’s head or neck until cervical fractures have been ruled out. NOTE: A meta-analysis of seven studies that met Cervical Spine Radiation Safety strict inclusion criteria revealed that the pooled TRAUMA Exposure factor selection should be optimized in accordance sensitivity of radiography for detecting cervical spine Lateral, horizontal with the ALARA. injuries (CSI) was 52%, while the combined sen- beam Collimate on four sides to anatomy of interest. sitivity of CT was 98%. Screening the cervical spine OPTIONAL Shield radiosensitive tissues outside area of interest. with multidetector CT (MDCT) is faster than per- Cervicothoracic (swimmer’s) lateral forming radiography, with far fewer technical fail- ures. The ACR panel concluded that thin-section Respiration Suspend respiration on full expiration. MDCT, and not radiography, should be the primary screening study for NOTE 1: It is estimated that, for a small body part (10 cm or 4 inches), a suspected CSI. When motion artifacts are significant enough to prevent 10-inch (25-cm) air gap will clean up scatter as well as a 15 : 1 grid. The adequate evaluation of vertebral integrity, a single lateral view will suffice cleanup is not as efficient for a larger body part (20 cm or 8 inches).12 to show that there is normal alignment and no evidence of fracture.11 NOTE 2: Traction on arms will help depress shoulders but should be done Clinical Indications only by a qualified assistant and/or with the consent or assistance of a Fractures, dislocations, and subluxations due to trauma. physician. If the C7-T1 junction cannot be visualized on the initial horizontal beam lateral C-spine image, a horizontal beam swimmer’s lateral should be performed. Technical Factors SID—60 to 72 inches (153 to 183 cm) NOTE 3: A 5° CR caudal angle may be required if patient cannot depress IR size—24 × 30 cm (10 × 12 inches), portrait shoulder opposite IR. Grid or without grid (see Note 1) Specially designed compensating filter useful for obtaining uniform brightness on the swimmer’s lateral (see Chapter 1 for more information on compensating filters, p. 41) Analog—70 to 80 kV range; lateral, horizontal beam Analog—75 to 85 kV range; cervicothoracic (swimmer’s) lateral Digital systems—75 to 85 kV range; lateral, horizontal beam Digital systems—80 to 95 kV range; cervicothoracic (swimmer’s) lateral Patient Position Lateral, Horizontal Beam (Fig. 15.71) and Cervicothoracic (Swimmer’s) Lateral (Fig. 15.72) Patient supine with potential spinal injury Part Position Lateral, Horizontal Beam Vertical IR against shoulder, parallel to MSP, with top of IR 1 to 2 inches (3 to 5 cm) above level of EAM. Ensure that C7-T1 Fig. 15.71 Horizontal beam lateral, C spine. region is included. Have patient relax and depress shoulders as much as possible (see Note 2). Cervicothoracic (Swimmer’s) Lateral Vertical IR placement is similar to lateral, horizontal beam placement. Elevate arm and shoulder closest to IR and depress opposite shoulder as much as possible (see Note 3). CR Lateral, Horizontal Beam Direct CR horizontal to C4 (upper thyroid cartilage) and to center of grid to prevent grid cutoff, or turn grid with centerline vertical to prevent grid cutoff if necessary. Cervicothoracic (Swimmer’s) Lateral Direct CR horizontal, centered to C7-T1 (≈1 inch [2.5 cm] above level of jugular notch). Center the center of grid to CR to prevent grid cutoff (grid lines vertical). Fig. 15.72 Swimmer’s lateral—C7-T1. 15  588 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY THORACIC AND LUMBAR SPINE WARNING: With possible spinal injury or severe trauma, do not attempt to move the patient. Lateral projections are typically reviewed by a Thoracic and Lumbar physician prior to obtaining additional spine Spine TRAUMA images as described in Chapters 8 and 9. Lateral, horizontal beam NOTE: Currently, MDCT is the imaging procedure OPTIONAL of choice for evaluating trauma patients with pos- Cervicothoracic sible spinal fractures or injuries.11 (swimmer’s) lateral (previous page) Clinical Indications Fractures, dislocations, and subluxations due to trauma. Technical Factors Minimum SID—40 inches (102 cm) IR size—35 × 43 cm (14 × 17 inches), portrait Grid (see Note 1) Analog—80 to 90 kV range Fig. 15.73 Horizontal beam lateral—thoracic spine. Digital systems—85 to 95 kV range; lateral thoracic spine Digital systems—90 to 95 kV range; lateral lumbar spine Patient Position Lateral Thoracic Spine, Horizontal Beam (Fig. 15.73) and Lateral Lumbar Spine, Horizontal Beam (Fig. 15.74) Patient supine, raise arms sufficiently so as to not obscure anatomy of interest. Part Position Lateral Thoracic Spine, Horizontal Beam and Lateral Lumbar Spine, Horizontal Beam Build up patient with backboard (see Fig. 15.73) or move patient to edge of table and place vertical IR below level of tabletop. Use IR holder or tape and/or sandbags to support IR (see Note 2). CR Lateral Thoracic Spine, Horizontal Beam Fig. 15.74 Horizontal beam lateral—lumbar spine. Center horizontal CR to vertebral column (midway between midcoronal plane and posterior aspect of thorax); near centerline of grid at level of T7, 3 to 4 inches (8 to 10 cm) inferior to jugular notch. Lateral Lumbar Spine, Horizontal Beam Center horizontal CR centered to vertebral column (midcoronal plane); near centerline of grid at level of L4 or the iliac crest. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration on full expiration. NOTE 1: A decubitus-type grid with lead strips aligned horizontal can be used to prevent grid cutoff. The grid then may be placed landscape to patient, for better centering of CR to near centerline of grid. This applies to both horizontal beam thoracic and lumbar spine projections. NOTE 2: Both lateral thoracic and lumbar examinations can be performed with the patient remaining on the gurney. The stretcher can be moved to an upright bucky and the CR aligned with the patient positioned 15 appropriately.  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 589 CRANIUM LATERAL, HORIZONTAL BEAM WARNING: Cervical spine fractures and subluxations or dislocations must be ruled out before attempts are made to move or manipulate the patient’s head or neck. NOTE: Rapid CT scanning is readily available in Cranium most hospitals that treat head-injured patients; thus TRAUMA the routine use of CT has been advocated as a Lateral, horizontal screening tool to triage patients with minor or mild beam AP head injuries who require hospital admission or AP axial surgical intervention from those who can be safely discharged without hospital admission.13 Clinical Indications Calvarial fractures, penetrating injuries, and radiopaque foreign bodies. Technical Factors Minimum SID—40 inches (102 cm) IR size—24 × 30 cm (10 × 12 inches), landscape (aligned to the anterior to posterior dimension of the skull). Fig. 15.75 Trauma lateral after cervical injury has been ruled out. Grid Place support under elevated head. Analog—70 to 80 kV range Digital systems—80 ± 5 kV range Patient Position Patient supine; remove all metal, plastic, or other removable objects from head. Part Position AP Lateral, Horizontal Beam If patient’s head can be manipulated (see Warning above), carefully elevate skull on a radiolucent sponge (Fig. 15.75). If you cannot manipulate head, move patient to edge of table and then place grid IR at least 1 inch (2.5 cm) below tabletop and occipital bone, as shown in Fig. 15.76. The divergent beam then will not project the posterior skull off the IR. Place the side of interest closest to the IR. Place head in true lateral position by ensuring that the MSP is parallel to the IR, the image plate (IP) is perpendicular to the Fig. 15.76 Trauma lateral without head manipulation. IR, and the infraorbitomeatal line (IOML) is perpendicular to the tabletop (see Warning above). Adjust IR to ensure that the entire skull will be included on image and center of grid is centered to CR. Ensure not to cut off the top of the skull. If required, use a larger IR to include the entire skull. CR AP Lateral, Horizontal Beam A horizontal beam (essential for visualization of intracranial air-fluid levels) is directed perpendicular to IR. Center to a point 2 inches (5 cm) superior to the EAM. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration during exposure. REMINDER: On patient with a cervical spine injury, do not attempt to raise and place support under head or to move any portion of the head or neck, 15 as shown in Fig. 15.75, until cervical pathology has been ruled out with a horizontal beam lateral cervical.  590 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY CRANIUM AP, AP AXIAL 15° (REVERSE CALDWELL METHOD) WARNING: Cervical spine fractures and subluxations or dislocations must be ruled out before attempts are made to move or manipulate the patient’s head or neck. NOTE: Rapid CT scanning is readily available in Cranium most hospitals that treat head-injured patients; thus TRAUMA the routine use of CT has been advocated as a Lateral, horizontal screening tool to triage patients with minor or mild beam AP head injuries who require hospital admission or AP Axial surgical intervention from those who can be safely discharged without hospital admission.13 Clinical Indications Calvarial fractures, penetrating injuries, and radiopaque foreign bodies. Technical Factors Minimum SID—40 inches (102 cm) IR size—24 × 30 cm (10 × 12 inches), portrait Grid Analog—75 to 85 kV range Digital systems—80 to 90 kV range Patient Position Fig. 15.77 AP CR parallel to OML, centered to glabella. Patient supine; remove all metal, plastic, and other removable objects from head. Part Position AP and AP Axial 15° Align MSP perpendicular to midline of grid or table (see Warning above) Center IR to CR CR AP to Orbitomeatal Line Projection (Fig. 15.77) Angle CR parallel to orbitomeatal line (OML): With patient in a cervical collar, this often occurs approximately 10° to 15° caudad, but each patient and situation will be different. Center CR to glabella; then center IR to projected CR. AP Axial 15° Reverse Caldwell Method Projection (Fig. 15.78) Angle CR 15° cephalad to OML: To accomplish this, first find the OML on the patient; this varies in patients in cervical collars with the neck extended. Then, angle the CR 15° cephalic to the patient’s OML. Center CR to nasion; then center IR to projected CR. Fig. 15.78 AP axial 15° reverse Caldwell method—CR 15° cephalad to OML, centered to nasion. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration during exposure. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 591 CRANIUM AP 30° AXIAL (TOWNE METHOD) WARNING: Cervical spine fractures and subluxations or dislocations must be ruled out before attempts are made to move or manipulate the patient’s head or neck. NOTE: Rapid CT scanning is readily available in Cranium most hospitals that treat head-injured patients; thus TRAUMA the routine use of CT has been advocated as a Lateral, horizontal screening tool to triage patients with minor or mild beam AP head injuries who require hospital admission or AP Axial surgical intervention from those who can be safely discharged without hospital admission.13 Clinical Indications Calvarial fractures, penetrating injuries, and radiopaque foreign bodies. Technical Factors Minimum SID—40 inches (102 cm) IR size—24 × 30 cm (10 × 12 inches), portrait Grid Analog—75 to 85 kV range Digital systems—80 to 90 kV range Fig. 15.79 AP axial Towne—CR 30° caudad to OML, centered to Patient Position midpoint between EAMs. Patient supine; remove all metal, plastic, and other removable objects from head. Part Position AP Axial (Towne Method) Projection Align MSP perpendicular to midline of grid or table (see Warning above) Center IR to CR CR AP Axial (Towne Method) Projection (Fig. 15.79) Angle CR 30° caudad to OML, or 37° caudad to the IOML. (Once again, note that a patient in a cervical collar with the neck extended will have OMLs and IOMLs that vary from the conven- tional parallel and perpendicular relationships formed through routine positioning; see Note). Center CR to pass midway between EAMs and exiting the foramen magnum. This centers CR to midsagittal plane 6 cm (inches) above superciliary arch; then center IR to projected CR. NOTE: The CR for the AP axial should not exceed 45° or excessive distor- tion will hinder the visualization of essential anatomy. NOTE: If the CR cannot be angled 30° to the OML (before the maximum angle of 45° is reached), the dorsum sella and posterior clinoids will be visualized superior to the foramen magnum. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration during exposure. 15  592 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY FACIAL BONES LATERAL, HORIZONTAL BEAM WARNING: Cervical spine fractures and subluxations or dislocations must be ruled out before attempts are made to move or manipulate the patient’s head or neck. NOTE: Rapid CT scanning is readily available in Facial Bones most hospitals that treat head-injured patients; thus TRAUMA the routine use of CT has been advocated as a Lateral, horizontal screening tool to triage patients with minor or mild beam Acanthioparietal head injuries who require hospital admission or (reverse Waters surgical intervention from those who can be safely method) discharged without hospital admission.13 AP (see previous pages) OPTIONAL Clinical Indications Modified Acanthioparietal Fractures, penetrating injuries, and radi- (Modified Reverse opaque foreign bodies. Waters Method) Technical Factors Fig. 15.80 Trauma horizontal beam lateral—facial bone projection. Minimum SID—40 inches (102 cm) IR size—24 × 30 cm (10 × 12 inches), portrait Grid Analog—75 to 85 kV range Digital systems—80 ± 5 kV range Patient Position AP Lateral, Horizontal Beam Patient supine; remove all metal, plastic, or other removable objects from head. Part Position AP Lateral, Horizontal Beam Place head in true lateral position by ensuring that the MSP is parallel to the IR, the image plate (IP) is perpendicular to the IR, and the infraorbitomeatal line (IOML) is perpendicular to the tabletop (see Warning above). CR AP Lateral, Horizontal Beam A horizontal beam (essential for visualization of intracranial air-fluid levels) is directed perpendicular to IR. Center CR to the zygoma, midway between the outer canthus and EAM (Fig. 15.80). Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Respiration Suspend respiration during exposure. 15  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 593 FACIAL BONES ACANTHIOPARIETAL (REVERSE WATERS METHOD) AND MODIFIED ACANTHIOPARIETAL (MODIFIED REVERSE WATERS) WARNING: Cervical spine fractures and subluxations or dislocations must be ruled out before attempts are made to move or manipulate the patient’s head or neck. NOTE: Rapid CT scanning is readily available in Facial Bones most hospitals that treat head-injured patients; thus TRAUMA the routine use of CT has been advocated as a Lateral, horizontal screening tool to triage patients with minor or mild beam Acanthioparietal head injuries who require hospital admission or (reverse Waters surgical intervention from those who can be safely method) discharged without hospital admission.13 AP (see previous pages) OPTIONAL Clinical Indications Modified Fig. 15.81 Acanthioparietal (reverse Waters method)—CR parallel to acanthioparietal MML, centered to acanthion. Fractures, penetrating injuries, and radi- (modified reverse opaque foreign bodies. Waters method) Technical Factors Minimum SID—40 inches (102 cm) IR size—24 × 30 cm (10 × 12 inches), portrait Grid Analog—70 to 80 kV range Digital systems—75 to 85 kV range Patient Position Acanthioparietal (Reverse Waters Method) Patient supine; remove all metal, plastic, or other removable objects from head. Part Position Acanthioparietal (Reverse Waters Method) Position MSP perpendicular to midline of grid or table (see Fig. 15.82 Acanthioparietal (reverse Waters method). Warning above). CR Acanthioparietal (Reverse Waters Method) Angle CR cephalad as needed to align CR parallel to MML (Fig. 15.81). NOTE: This projection best visualizes facial bone structures and the maxil- lary region by projecting the maxilla and maxillary sinuses above the petrous ridges (see arrows, Fig. 15.82). Fig. 15.83 Modified acanthioparietal (modified reverse Waters Center to acanthion; then center IR to projected CR. method)—CR parallel to LML, centered to acanthion. Modified Acanthioparietal (Modified Reverse Waters Method) Angle CR cephalad as needed to align CR parallel to LML (Fig. 15.83). NOTE: This projection best demonstrates the floor of the orbits and pro- vides a view of the entire orbital rims. Petrous ridges are visualized in midmaxillary sinus region (Fig. 15.84). Center to acanthion; then center IR to projected CR. Radiation Safety Exposure factor selection should be optimized in accordance with the ALARA. Collimate on four sides to anatomy of interest. Shield radiosensitive tissues outside area of interest. Fig. 15.84 Modified acanthioparietal (modified reverse Waters method). 15 Respiration Suspend respiration during exposure.  594 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY SURGICAL RADIOGRAPHY Radiography in surgery is one of the most demanding challenges The technologist must communicate radiation safety concerns encountered by a radiologic technologist. The technologist will be with the surgical team, including failure to wear aprons, overuse of called on to perform procedures quickly and accurately in a sterile C-arm real-time imaging, and placement of hands into the radiation environment, with a minimum number of repeat exposures (Fig. field. In these situations during surgery, the technologist is the 15.85). For most surgical procedures, the patient is under general radiation safety expert and must minimize exposure for the anesthesia and time is of the essence, because the less time a surgical team. patient spends under general anesthesia, the less likely it is that complications will occur. Therefore, the surgeon expects the tech- PROBLEM-SOLVING SKILLS nologist to perform any requested procedure without error or delay. Even when the technologist has used the best knowledge and These added pressures may create uncertainty and anxiety for preparation, unexpected problems can occur during surgery. C-arms the radiography student or recent graduate. However, with a can cease to work, reliable exposure factors may fail to produce a solid knowledge of the surgical procedure and operation of the diagnostic image, or the sterile field may be violated. Although it is imaging equipment, the technologist can function effectively in the difficult to predict every situation that might occur in the OR, surgical suite. the radiologic technologist must be able to find solutions to Through supervised observations with an experienced surgical these problems quickly. Perhaps the most important skill of the technologist, the student can become comfortable and confident technologist is the ability to problem-solve unforeseen situations in the surgical environment. It is essential that the student technolo- immediately. gist be kept under the direct supervision of an experienced tech- nologist in the OR until he or she has achieved competency for a MASTERY specific procedure. Mastery of all aspects of radiography, including use of the C-arm This section of the chapter identifies essential skills and com- and mobile radiographic equipment, is essential. The technologist monly used equipment, and previews the surgical environment to must be able to operate and troubleshoot conventional and digital provide the student radiographer with a baseline knowledge. More equipment. The technologist must also know reliable exposure commonly performed procedures are discussed at the end of this factors for patients of different sizes and for various procedures. chapter; however, it is important for student radiographers to understand that they will participate in a variety of surgical proce- dures based on their clinical setting. Rather than focus on specific surgical procedures, student radiographers should focus their efforts on developing the essential skills and transfer their newly acquired skills from one procedure to the next. Essential Attributes of the Radiologic Technologist in Surgical Radiography Although confidence and knowledge of procedures are needed in all aspects of radiography, certain personal attributes, skills, and insight are the trademark of a competent radiologic technologist in the surgical setting. CONFIDENCE Although no one can teach a technologist confidence, it is the first attribute that the other members of the surgical team expect to see in the technologist. Confidence is judged by the technologist’s level of comfort and ease in the OR suite, including the skilled Fig. 15.85 Radiography in the surgical suite. use of imaging equipment, ability to problem-solve situations, and respect for the sterile field. The surgical team expects the technologist to be confident in his or her abilities to perform the procedure quickly and accurately, with a minimum of repeat expo- sures. However, confidence comes only with experience and knowledge of all aspects of radiography. As the technologist gains experience and success in the OR, confidence will grow. COMMUNICATION It is essential that the technologist be an excellent communicator. He or she must communicate with other members of the surgical team regarding any concerns that arise during the procedure. Clear communication between the technologist, surgeon, and anes- thesiologist is paramount for most radiographic procedures. For example, during operative cholangiography, the technologist must 15 coordinate the exposure with the surgeon who is injecting the contrast medium and with the anesthesiologist who is suspending respiration. Without this team approach, motion may result and the quality of the exposure may be compromised.  TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY C HA PTE R 15 595 Surgical Team The composition of the surgical team will vary, depending on the surgeon, institutional policy, type of procedure, and other factors. A typical surgical team consists of the following members (Fig. 15.86). SURGEON The surgeon is a physician licensed and trained in general surgery or a specialty such as cardiovascular or orthopedic procedures. She or he has the primary responsibility for the entire surgical procedure and for the well-being of the patient prior to, during, and immedi- ately following surgery. ANESTHESIOLOGIST A physician anesthesiologist or a certified nurse anesthetist special- izes in administering anesthetic drugs to induce and maintain anesthesia to the patient during surgery. This person has the responsibility of ensuring the safety of the patient and monitoring Fig. 15.86 Surgical team—surgeon, certified surgical technologist physiologic functions and fluid levels of the patient during surgery. (CST), and radiologic technologist discussing procedure with patient. SURGICAL ASSISTANT A physician, physician’s assistant, certified surgical technologist (CST), or registered nurse (RN) assists the surgeon. This person’s range of responsibilities may include suctioning, tying and clamping blood vessels, and assisting in cutting and suturing tissue. CERTIFIED SURGICAL TECHNOLOGIST A CST is a health professional who prepares the OR by supplying it with the appropriate supplies and instruments. Other CST respon- sibilities include preparing the patient for surgery and helping connect surgical equipment and monitoring devices. During surgery, CSTs have the primary responsibility for maintaining the sterile field. CIRCULATOR A circulator is a nonsterile CST or RN who assists in the OR by responding to the needs of scrubbed members in the sterile field before, during, and after the surgical procedure. Duties may include Fig. 15.87 Scrub preparing and maintaining sterile surgical field. recording of pertinent information, retrieval of additionally needed items, and connecting nonsterile surgical equipment. SCRUB A scrub is a CST or RN who prepares the sterile field scrubs, gowns the members of the surgical team, and prepares and sterilizes the instruments before the surgical procedure is begun (Fig. 15.87). NOTE: During OR cases, the radiologic technologist receives instructions from a physician (surgeon, anesthesiologist). 15  596 C H A P T E R 15 TRAUMA, MOBILE, AND SURGICAL RADIOGRAPHY Surgical Radiography Imaging Equipment The technologist must be familiar with the location of power outlets to be used for a procedure. Ideally, all imaging equipment should be in place and checked for correct operation before the procedure is begun. Although most surgical equipment remains in the surgical area, it must be cleaned and checked frequently for correct opera- tion. Once the procedure has begun, there is no time to troubleshoot equipment or fix problems. Daily, weekly, and monthly quality control protocols should be followed for all surgical radiographic equipment. Even a small problem such as a frayed electrical cord must be addressed before it results in an equipment failure. CLEANING Mobile (portable) units and C-arm equipment should be cleaned before and after use in the surgical area. An approved antiseptic cleaner should be used to wipe down the equipment. A liquid-type cleaner rather than an aerosol is recommended to prevent the introduction of airborne contaminants into the surgical area. The technologist