Merrill's Atlas of Radiographic Positions and Radiologic Procedures Vol 2 PDF

 T Mosby An Affiliate of Elsevier Science 1 1 830 Westline Industrial Drive S1. Louis. Missouri 63 1 46 MERRILL'S ATLAS OF RADiOORAPHIC POSITIONS AND ISBN (Set) 0-323-0 1 604-9 RADIOLOOIC PROCEDURES. ED \ 0...

 T Mosby An Affiliate of Elsevier Science 1 1 830 Westline Industrial Drive S1. Louis. Missouri 63 1 46 MERRILL'S ATLAS OF RADiOORAPHIC POSITIONS AND ISBN (Set) 0-323-0 1 604-9 RADIOLOOIC PROCEDURES. ED \ 0 (Volume Two) 0-323-01 607-3 Copyright e 2003, Mosby, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means. electronic or mechanical. including photocopying. recording. or any information storage and retrieval system. without permission in writing from the publisher. Permissions may be sought directly from Elsevier's Health Sciences Rights Department in Philadelphia. PA. USA: phone: (+ 1 ) 2 1 5 238 7869. fax : (+ 1 ) 2 1 5 238 2239. e-mail: [email protected]. You may also complete your request on-line via the Elsevier Science home page (http://www.elsevier.com). by selecting 'Customer Support' and then 'Obtaining Permissions'. Previous editions copyrighted 1 949. 1 959. 1 967. 1 975. 1 982. 1 986. 1 99 1. 1 995. 1 999 International Standard Book Number (Set) 0-323-01604-9 (Volume II) 0-323-01607-3 Publisher: Andrew Allen Executive Editor: Jeanne Wilke Developmental Editors: Jennifer Genett Moorhead. Carolyn Kruse Publishing Sen'ices Manager: Patricia Tannian Senior Project Manager: Melissa Mraz Lastarria Book Design Manager: Gail Morey Hudson Medicallllustrator: Jeanne Robertson Cover Design: Jen Brockett Printed in United States of America Last digit is the print number: 9 8 7 6 5 4 3 2 OUTUNE  I ntroduction Trauma i s defined as a sudden, unex­ day. A l evel l/center probably has all of Trauma radiography can be an excItIng pected, dramatic, forceful , or violent the same specialized care avai lable, but and challenging environment for the radi­ event. Trauma ranks as the leading cause differs in that it is not a research or teach­ ographer. For others, however, performing of death in the United States for persons I ing hospital and some specialty physi­ trauma procedures can be intimidating to 34 years of age. This statistic excludes cians may not be avai lable on site. Level and stressful. The difference depends on suic ide and homicide-related deaths. 11/ centers are usually located in smaller how prepared the radiographer is to han­ Trauma, homicide, and suicide rank first, communities where level I or level I I dle the situation. To reduce the stress as­ second, and third, respectively, as the care is not avai lable. I n general, level I I I sociated with trauma radiography, the ra­ leading causes of death in persons age 1 5 centers do not have all specialists avail­ diographer must be properly prepared for to 24 years. Emergency medical care of­ able, but are able to resuscitate, stabilize, the multitude of responsibilities encoun­ ten is the difference between life and asse , and prepare a patient for transfer tered in the emergency room (ER). death when intentional or unintentional to a larger trauma center. A level IV cen­ The goals of this chapter are to ( I ) assist inj uries occur. ter may not be a hospital at all, but rather the radiographer to develop an understand­ Many types of facil ities provide emer­ a clinic or outpatient setting. These faci l ­ ing of the imaging equipment utilized in gency medical care, ranging from major, ities usually provide care for minor i n ­ trauma, (2) explain the role of the radiogra­ metropol itan medical centers to small juries, a s w e l l a s offer stabilization and pher as a vital part of the ER team, and (3) outpatient clinics in rural areas. The term arrange for tran fer of more serious in­ pre ent the common radiographic proce­ trauma center signifies a specific level of j uries to a larger trauma center. dures performed on trauma patients. This e mergency medical care as defined by Several types of forces, including, blunt, chapter provides the information necessary the American Col lege of S urgeons penetrating, explosive, and heat, result in to improve the skills and confidence of all Commission on Trauma. Trauma centers injuries. Examples of blunt trauma are radiographers caring for trauma patients. are categorized into four levels of care. motor vehicle accidents (MVA), which in­ Level I is the most comprehensive and cludes motorcycles accidents and colli­ level IV the most basic. A level I center sions with pedestrians; falls; and aggra­ is usually a university-based center, re­ vated assaults. Penetrating trauma includes search faci l ity, or large medical center. It gunshot wounds, stab wounds, impalement provides the most comprehensive emer­ injuries, and foreign body ingestion or as­ gency medical care avai lable with com­ piration. Explosive trauma causes injury by plete i maging capabilities 24 hours a day. several mechanisms, including pressure All types of specialty physicians are shock waves, high velocity projectiles, and available on site 24 hours a day. Radi­ burns. B urns may be caused by a number ographers are also available 24 hours per of agents including fire, steam and hot wa­ ter, chemicals, electricity, and frostbite. A B 1 3- 1 A, Dedicated C-arm type trauma radiographic room with patient on the table. B, Fig. Dedicated conventional trauma radiographic room with vertical Bucky. (B, Courtesy of Fischer Imaging. Inc.) 2 Preliminary Mobile radiography is widely utilized Positioning aids are a necessity in in the ER. Many patients will have in­ trauma radiography. Sponges, sandbags, Considerations juries that prohibit transfer to a radio­ and the creative use of tape are often the SPECIALIZED EQU IPMENT graphic table, or their condition may be trauma radiographer's most useful tools. Time is a critical element in the care of a too critical to interrupt treatment. Trauma Most trauma patients are unable to hold trauma patient. To minimize the time re­ radiographers must be competent in per­ the required positions as a result of pain or quired to acquire diagnostic x-ray images, formi ng mobi le radiography on almost impaired consciousness. Other patients many ERs have dedicated radiographic any part of the body and be able to utilize cannot be moved into the proper position equipment located in the department or im­ accessory devices ( i.e., grids, air-gap tech­ because to do so would exacerbate their mediately adjacent to the department. nique) needed to produce quality mobile injury. Proper use of positioning aids as­ Trauma radiographs must be taken with a images. sist in quick adaptation of procedures to mini mal of patient movement, requiring Mobile fluoroscopy units, usually re­ accommodate the patient 's condition. more maneuvering of the tube and image ferred to as C-arms because of their shape, Grids and IR holders are necessities receptor (lR). Specialized trauma radio­ are becoming more commonplace in ERs. si nce many projections require the use of a graphic systems are available and are de­ C-arms are util ized for fracture reduction horizontal central ray. I nspect grids rou­ signed to provide greater flexibility in x-ray procedures, foreign body localization in tinely, because a damaged grid will often tube and I R maneuverability ( Fig. 1 3- 1 ). limbs, and for reducing joint dislocations cause image artifacts. I R holders enable the These specialized systems help to mini­ ( Fig. 1 3-2). radiographer to perform cross-table lateral mize movement of the injured patient projections (dorsal decubitus position) on while performing i maging procedures. numerous body parts with minimal distor­ Additionally, some ERs are equipped with tion. ER personnel should not hold the IR specialized beds or stretchers that have a to prevent unnecessary exposure. moveable tray to hold the l R. This type of stretcher al lows the use of a mobile radio­ graphic unit and eliminates the require­ ment and risk of transferring an injured pa­ tient to the radiographic table. Fig. 1 3-2 A mobile fluoroscopic C-arm. (Courtesy of OEC Diasonics. Inc.) 3  EXPOSURE FACTORS POSITIONING OF THE PATIENT Patient motion is always a consideration in The primary challenge of the trauma radi­ trauma radiography. The shortest possible ographer is to obtain a high quality, djag­ exposure time that can be set should be used nostic image on the first attempt when the in every procedure, except when a breathing patient is unable to move into the desired technique is desired. Unconscious patients position. Many methods are available to are not able to suspend respiration for the adapt a routine projectjon and obtain the exposure. Conscious patients are often in desired i mage of the anatomical part. To extreme pain and unable to c ooperate for the minjmize risk of exacerbating the patient's procedure. condition, the x-ray tube and lR should be Radiographic exposure factor compen­ positioned, rather than the patient or the sation may be required when making expo­ part. For example, position the stretcher sures through immobilization devices, like adjacent to the vertical Bucky or upright a spine board or backboard. Most trauma table as often as the patient's condition al­ patients arrive at the hospital with some lows (Fig. 1 3-4). This location enables ac­ type of immobilization device (Fig. 1 3-3). curate positionjng with mjnimal patient Pathologic changes should also be consid­ movement for cross-table lateral i mages ered when setting technical factors. For in­ (dorsal decubitus positions) on numerous stance, internal bleeding in the abdomjnal parts of the body. Addjtionally, the grid in cavity would absorb a greater amount of the table or vertical B ucky is usually a radiation than a bowel obstruction. higher ratio than those used for mobile ra­ diography, so i mage contrast is improved. Another technique to increase efficiency, while minimizing patient movement, is to take all of the AP projections of the re­ quested examinations, moving superiorly to inferiorly. Then perform all of the lat­ eral projections of the requested examina­ tjons, moving inferiorly to superiorly. This method moves the x-ray tube in the most expeditious manner. A B Fig. 1 3-3 A, Typical backboard and neck brace used for trauma patients. B, BaCkboard. brace. and other re­ straints are used on the patient throughout transport. c C, All restraints will remain with and on the patient until all x-ray examinations are completed. 4  When taking radiographs to localize a DIAGNOSTIC IMAGI NG Radiographer's Role as PROCEDURES penetrating foreign object, such as metal or glass fragments or bullets, the entrance Part of the Trauma Team Producing a high quality, diagnostic im­ and/or exit wounds should be marked with The role of the radiographer within the ER age is one of the more obvious roles of a radiopaque marker that is visible on all ultimately depends on the department proto­ any radiographer. A radiographer in the projections (Fig. 1 3-5). Two exposures at col and staffing, as well as the extent of trauma environment has the added respon­ right angles to each other will demon­ emergency care provided at the facility. sibility to perform that task efficiently. strate the depth, as well as the path, of the Regardless of the size of the facility, the pri­ Efficiency and productivity are common projectile. mary responsibilities of a radiographer in an and practical goals for the radiology de­ emergency situation include the following: partment. In the ER, efficiency is often Perform quality diagnostic i maging crucial to sav i ng the pat ient's l i fe. procedures as requested Diagnostic imaging in the ER is para­ Practice ethical radiation protection mount to an accurate, timely, and often Provide competent patient care li fe-saving diagnosis. It is i mpossible to rank these responsi­ bil ities because they occur simultane­ ously, and all are vital to quality care in the ER. Fig. 1 3-4 Stretcher positioned adjacent to vertical Bucky to expedite positioning. Note x-ray tube in position for lateral projections. Fig. 1 3-5 Proper placement of radiopaque markers (inside red circles) on each side of a bullet entrance wound. The red circles are "stickies" that contain the radiopaque marker. 5  RADIATION PROTECTION PATIENT CARE The fam i l iar "ABCs" of Airway, One of the most essential duties and ethi­ As with al l i maging procedures, trauma Breathing, and Circulation of basic life cal re ponsibilities of the trauma radiogra­ procedures require a patient history. The support techniques must be constantly as­ pher is radiation protection of the patient, patient may provide this, if he or she is sessed during the radiographic procedures. the members of the trauma team, and self. conscious, or the attending physician may Visual inspection and verbal questioning I n highly critical care situations, members inform you of the i njury and the patient's enables the radiographer to detennine if of the trauma team cannot leave the pa­ status. If the patient is conscious, explain the status of the patient changes during the tient while imaging procedures are being what you are doing in detail and in terms procedure. Table 1 3- 1 serves as a guide for performed. The trauma radiographer must the patient can under tand. Listen to the the trauma radiographer regarding changes ensure the other team members are pro­ patient 's rate and manner of speech, in status that should be reported immedi­ tected from unnecessary radiation expo­ which may provide insight into his or her ately to the attending physician. The table sure. Common practices should mini­ mental and emotional status. Make eye includes only the comm.on injuries in mally incl ude the fol lowing: contact with the patient to provide com­ which the radiographer may be the only Clo e col l imation to the anatomy of in­ fort and reassurance. Keep in mind that a health care professional with the patient terest to reduce scatter trip to the ER is an emotional ly stressful during the i maging procedure. Patient Gonadal shielding for the patients of event, regardless of the severity of the in­ with mUltiple trauma injuries or those in child-bearing age (when doing so does jury or illness. respiratory or cardiac arrest usually are not interfere with the anatomy of interest) Radiographers are often responsible for i maged with a mobile radiographic unit Lead aprons for al l personnel that re­ the total care of the trauma patient while while emergency personnel are present in main in the room during the procedure performing diagnostic imaging procedures. the room. I n these situations, the primary Expo ure factors that minimize patient Therefore it is critical that radiographers responsibility of the trauma radiographer dose and scattered radiation constantly assess the patient's condition, is to produce quality images in an efficient Announcement of impending exposure recognize any signs of decline or distress, manner while practicing ethical radiation to al low unnecessary personnel to exit and report any change in the status of the protection measures. the room patient's condition to the attending physi­ Consideration must also be given to pa­ cian. The trauma radiographer must be tients on nearby stretchers. I f there is less well ver ed in taking vital signs and know­ than 6 feet of distance from the x-ray tube, ing normal ranges, competent in cardiopul­ appropriate shielding hould be provided. monary resuscitation (CPR), administra­ Some of the greatest exposures to patients tion of oxygen, and dealing with all types and medical personnel are from fluoro­ of medical emergencies. Tne radiographer scopic procedures. If the C-arm fluoro must be prepared to perform these proce­ unit is used in the ER, special precautions dures when covered by a standing physi­ should be in place to ensure that fluoro ex­ cian's order or as departmental policy al­ posure time is kept to a minimum and that lows. Additionally, the radiographer should all personnel are wearing protective be familiar with the location and contents aprons. A recent study on incidental preg­ of the adult and pediatric crash carts, and nancy in trauma patients noted that fe­ understand how to use the suctioning males are very often unaware of their devices. pregnancy status or are unable to respond to questions regarding menses. I The re­ search recommends i mplementation of routine abdominal shielding during radio­ graphic evaluation of females of chi ld­ beari ng age for trauma diagno is. Additionally, the authors recommend re­ quiring a urine screen in addition to serum beta human chorionic gonadotrophin ( I3HCG) for females of childbearing age with traumatic injuries. ( Refer to Chapter 2 for a detailed explanation of the princi­ ples radiation protection.) ' Bochicchio G, Napolitano M. Haan J , Champion H, Scalea T: Incidental pregnancy in trauma patients, J Am Coli Surg 192(5):566, 200 1. 6 TABLE 13-1 Guide for reporting patient status change Noted symptom Possible cause When to report to physician immediately Cool. clammy skin Shock> Other symptoms of shock present Vasovagal reactiont Excessive sweating (diaphoresis) Shock> Other symptoms of shock present Slurred speech Head injury Stroke (cerebrovascular accidenti) Accompanied by vomiting. especially Drug or ethanol inftuence§ if vomiting stops when patient is moved to different position Agitation or confusion Head injury Accompanied by vomiting. especially if Drug or ethanol inftuence§ vomiting stops when patient is moved to different position Vomiting (without abdominal Head injury Position of patient abruptly stimulates vomiting complaints) (hyperemesis) Hyperglycemia'i or abruptly stops vomiting Drug or ethanol overdose Increased drowsiness (lethargy) Shock> Other symptoms of shock present or Head injury accompanied by vomiting Hyperglycemia" Loss of consciousness Shock> Immediately (unresponsive to voice Head injury or touch) Hyperglycemiall Pale or bluish skin pallor (cyanosis) Airway compromise Immediately Hypovolemic shock Bluish nail beds Circulatory compromise Immediately Patient complaints of thirst Shock> Other symptoms of shock present Hyperglycemia'i Hypoglycemia Patient complaints of tingling Spinal cord injury Accompanied by any symptoms of shock or numbness (paresthesia). Peripheral nerve impairment or altered consciousness or inability to move a limb Seizures Head injury Immediately Patient states cannot feel Spinal cord injury Accompanied by any symptoms of shock or your touch (paralysis) Peripheral nerve impairment altered consciousness Extreme eversion of foot Fracture of proximal femur or hip joint Report only if x-ray request speCifies "frog-leg" lateral projection of hip. This movement will exacerbate patient's injury. as well as cause intense pain. Surgical lateral position should be substituted. Watch for changes in abdominal size and firmness. Increasing abdominal distention Internal bleeding from pelviC Immediately and firmness to palpation fracture or organ laceration Hypovolemic or hemorrhagic shock is a medical condition where there are abnormally low levels of blood plasma in the body. such that the body is unable to properly maintain blood pressure. cardiac output of blood. and normal amounts of fluid in the tissues. It is the most common type of shock in trauma patients. Symptoms include diaphoresis. cool and clammy skin. decrease in venous pressure. decrease in urine output. thirst. and altered state of consciousness. tVasovagal reaction is also called a vasovagal attack or situational syncope. as well as vasovagal syncope. It is a reflex of the involuntary nervous system or a normal physiologic response to emotional stress. The patient may complain of nausea. feeling flushed (warm). feeling lightheaded. and they may appear pale before they lose consciousness for several seconds. !Cerebrovascular accident (CVA) is commonly called a stroke and may be caused by thrombosis. embolism or hemorrhage in the ves­ sels of the brain. §Drugs or alcohol. Patients under the influence of drugs and/or alcohol are common in the ER. ln this situation. the usual symptoms of shock and head injury are unreliable. Be on guard for aggressive physical behaviors and abusive language. NHyperg/ycemia is also known as diabetic ketoacidosis. The cause is increased blood sugar levels. The patient may exhibit any combina­ tion of symptoms noted. and will have fruity-smelling breath. Pelvic fractures have a high mortality rate (open fractures are as high as 50%). Hemorrhage and shock are very often associated with this ty p e of injury. Emergency cystograms are often ordered on patients with known pelviC fractures. 7  IV. Positioning-Careful precautions V III. Attention to detail-NEVER "Best Practices" in must be taken to ensure that perfor­ leave a trauma patient (or any pa­ Trauma Radiogra phy mance of the imaging procedure does tient) unattended during i maging Radiography of the trauma patient seldom not exacerbate the patient's injuries. procedures. The patient's condition allows the use of "routine" positions and The "golden rule" of two projections may change at any time, and it is projections. Additional ly, the traumatized at right angles from one another still the radiographer's responsibility to patient requires special attention to patient applies. As often as possible, position note these changes and report them care techniques while performi ng difficult the tube and the I R, rather than the immediately to the attending physi­ i maging procedures. The fol lowing best patient, to obtain the desired projec­ cian. If you are unable to process practices provide some universal guide­ tions. i mages while maintaining eye con­ l ines for the trauma radiographer. V. Practice Standard Precautions­ tact with your patient, call for help. l. Speed- Trauma radiographers Exposure to blood and body fluids Someone must be with the injured must produce quality i mages in the should be expected in trauma radi­ patient at all times. shortest amount of time. Rapidity in ography. Wear gloves, mask, and I X. Attention to department protocol performing a diagnostic examina­ gown when appropriate. Place IR and scope of practice-Know de­ tion is critical to saving the patient's and sponges in nonporous plastic to partment protocols and practice l ife. Many practical methods that protect from body fluids. Wash only within your competence and increase examination efficiency hands frequently, especially be­ abilities. The scope of practice for without sacrificing image quality tween patients. Keep all equipment radiographers varies from state to are introduced in this chapter. and accessory devices clean and state and from country to country. ll. Accuracy - Trauma radiographers ready for use. Be sure to study and understand the must provide accurate i mages with a V I. Immobilization-NEVER remove scope of your role in the emergency minimal amount of distortion and any immobilization device without setting. Do not provide or offer a the maximum amount of recorded physician's orders. Provide proper patient anything by mouth. A lways detail. Alignment of the central ray, immobi lization and support to in­ ask the attending physician before the part, and the I R applies in trauma crease patient comfort and mini­ giving the patient anything to eat or radiography, too. Using the shortest mize risk of motion. drink no matter how persistent the exposure time minimizes the possi­ VD. Anticipation- Anticipating re- patient may be. bility of i maging involuntary and/or quired special projections or diag­ x. Professionalism-Ethical conduct uncontrollable patient motion. nostic procedures for certain in­ and professionalism in all situations III. Q Uality-Quality does not have to juries makes the radiographer a vital and with every person is a requirement be sacrificed to produce an image part of the ER team. For example, of all health care professionals, but the quickly. Do not fall into the trap of patients requiring surgery generally conditions encountered in the ER can using the patient's condition a an ex­ require an x-ray of the chest. be particularly complicated. Adhere to cuse for careless positioning and ac­ Fractures of the pelvis often require Code of Ethics for Radiologic cepting less than high quality images. a cystogram to determine the status Technologists (see Chapter 1 ) and the of the urinary bladder. Being pre­ Radiography Practice Standards. Be pared to perform these examina­ aware of the people present or nearby tions quickly and understanding the at all times when discussing a patient's necessity of these additional images care. The ER radiographer is exposed instills confidence in, and creates an to a myriad of tragic condition. appreciation for, the role of the radi­ Emotional reactions are common and ographer in the emergency setting. expected, but must be controlled until the emergency care of the patient is complete. 8  This section provides trauma position­ PATIENT PREPARATION Radiogra phic ing instructions for radiography projec­ It is important to remember that the pa­ Procedu res in Trauma tions of the following body areas. tient has endured an emotional ly disturb­ A recent telephone survey of level Cervical spine ing and distressing event in addition to the trauma centers indicated that the common Lateral (dorsal decubitus position) physical i njuries he or she may have sus­ radiography projections ordered for initial Cervicothoraci c (dorsal decubitus tained. If the patient is conscious, speak trauma surveys are as follows ': position) calmly and look directly in the patient 's Cervical spine, dorsal decubitus posi­ AP axial eye while explaining the procedures that tion (cross-table lateral) AP axial oblique have been ordered. Do not assume that the Chest, AP (mobile) Thoracic and lumbar spine patient cannot hear you even if he or she Abdomen, AP ( KU B and acute abdom- Lateral (dorsal decubitus position) cannot or will not respond. inal series) Chest Check the patient thoroughly for items Pelvis, AP AP that might cause an artifact on the images. Cervical spine, AP and obliques Abdomen Explain what you are removi ng from the Lumbar spine AP patient and why. Be sure to place all re­ Lower limb AP ( left lateral decubitus position) moved personal effects, especially valu­ Upper limb Pelvis ables, in the proper container used by the On reviewing the l ist, the reader should AP facil ity (i.e., plastic bag), or in the desig­ note that skull radiography is not in­ Skull nated secure area. Every facility has a pro­ cluded. Most level I trauma centers have Lateral (dorsal decubitus position) cedure regarding proper storage of a pa­ replaced conventional trauma skull radi­ AP or PA tient's personal belongings. Be sure to ographs ( A P, lateral, Towne, reverse AP axial (Towne Method) know the procedure and fol low it carefully. Waters, etc. ) with computed tomography Facial bones (CT) of the head. The usefulness of con­ Acanthioparietal ( Reverse Waters BREATHING I NSTRUCTIONS ventional radiographs of the skull in Method) Most injured patients have difficulty fol­ trauma has been controversial for over a Limbs lowing the recommended breathing in­ decade. Research articles have debated Special procedures structions for routine projections. For the advantages of CT i maging of the cra­ In addition to the dorsal decubitus posi­ these patients, exposure factors should be nium over than plain fil m. However, the tions, AP projections of the thoracic and set using the shortest possible exposure survey also revealed that some hospitals lumbar spine are usually required for time to minimize motion on the radi­ sti ll perform conventional skull radiogra­ trauma radiographic surveys. The AP pro­ ograph; necessitating use of the large fo­ phy. Additionally, many smal ler facilities jections of this anatomy vary minimally i n cal spot. The decreased resolution of the may not have CT readily available; there­ the trauma setting, and therefore are not large focal spot produces greater resolu­ fore trauma skull positioning remains as discussed in detai l. Critical study and clin­ tion than the significant loss of resolution valuable knowledge for the radiographer. ical practice of these procedures should from patient movement. If a breathing adequately prepare a radiographer for technique is desired, this can be explained 'Thomas Wolfe, Methodist Medical Center, work in the ER. to the conscious trauma patient in the Memphis, TN, conducted the survey as a part of his Certain criteria apply in every trauma usual manner. If the patient is unconscious graduate practicum for Midwestern State University. i maging procedures, and therefore are ex­ or unresponsive, then careful attention plained here and not included on each should be paid to the rate and degree of procedure in detai l. chest wall movement. If inspiration is de­ sired on the image, then time the exposure to correspond to the highest point of chest expansion. Conversely, if the routine pro­ jection cal ls for exposure on expiration, then the exposure should be made when the patient's chest wall falls to its lowest point. 9  IMMOBI LIZATION DEVICES IMAGE RECEPTOR SIZE IMAGE EVALUATION A wide variety of immobilization devices The IR sizes used in trauma procedures Ideally, trauma radiographs should be of are used to stabilize i njured patients. are the same as those specified for the rou­ optimum quality to ensure prompt and ac­ Standard protocol is to perform radio­ tine projection of the anatomy of interest. curate diagnosis of the patient's i njuries. graphic images without removing immo­ Occasionally, the physician may request Evaluate i mages for proper positioning bilization devices. Once i njuries have been that more of a part be incl uded, and then a and technique as i ndicated in the routine di agnosed or ruled out, the attending larger I R is acceptable. projections. Al lowances can be made physician gives the order for immobiliza­ when true right angle projections (APfPA tion to be removed, changed, or continued. CENTRAL RAY, PART, IMAGE and lateral) must be altered as a result of Many procedures necessitate the use of RECEPTOR ALIGNM ENT patient condition. some sort of immobil ization to prevent in­ Unless otherwise i ndicated for the proce­ voluntary and vol untary motion. Prudent dure, the central ray should be directed DOCUME NTATION use of such is discussed in many patient perpendicular to the midpoint of the grid Deviation from routine projections is a ne­ care textbooks. The key i ssue in the use of and/or IR. Tips for minimizing distortion cessity in many i nstances. It is important to immobi lization in trauma is not to exacer­ are detailed on those procedures in which document the alterations in routine projec­ bate the patient's injury nor increase his or distortion i s a potential threat to i mage tions for the attending physician and radi­ her discomfort. quali ty. ologist so that they can properly interpret the images. Additionally, the radiographer often has to determine if the anatomy of in­ terest has been adequately demonstrated, and perform additional projections (within the scope of the ordered examination) on an injured part to aid in proper diagnosis. Notations concerning additional projec­ tions are extremely helpful for the i nter­ preting physicians. 10  Cervical Spine.. LATERAL PROJECTlONl Patient position considerations Structures shown Dorsal Decubitus Position Patient general ly is immobil ized on a Entire cervical spine, from sella turcica to Trauma positioning tips backboard and in a cervical collar. the top of T I , must be demonstrated in Always perform this projection first, be­ Have patient relax. his or her shoulders profi le with minimal rotation and distor­ fore any other projections. as much as possible. tion (Fig 13-7). The attending physician or radiologist Ensure patient is looking straight ahead NOTE: If all 7 cervical vertebrae, including the must review this image before perform­ without any rotation of the head or spinous process of C7 and the C7-T I inter­ i ng other projections. neck. space, are not clearly visible, a lateral projec­ Use a 72 i nch SID whenever attainable. Place l R in a holder at top of shoulder tion of the cervicothoracic region must be Move the patient 's head and neck as lit­ (Fig. 1 3-6). performed. tle as possible. Check that the l R i s perfectly vertical. Shield gonads and other personnel in Central ray is horizontal and centered the room. to midpoint of l R. 'See mobile lateral projection in Volume 3. page 257. Horizontal C R to C4 Fig. 1 3-6 Patient and IR positioned for a trauma lateral projection of the cervical spine us­ ing the dorsal decubitus position. A B Fig. 1 3-7 Dorsal decubitus position lateral projection of the cervical spine performed on a trauma patient. A, Dislocation of the C3 and C4 articular processes (arrow). Note that C7 is not well demonstrated and a lateral projection of the cervicotho­ racic vertebrae should also be performed. B, Fracture of the pedicles with disloca­ tion of C5 and C6. Note superior portion of C7 shown on this image. 11  Cervicothoracic Region '" LATERAL PROJECTION Patient position considerations Structures shown Dorsal Decubitus Position Supine, usual ly on backboard and in a The lower cervical and upper thoracic ver­ Trauma positioning tips cervical collar. tebral bodies and spinous processes should This projection should be performed if Have patient depress the shoulder clos­ be seen in profile between the shoulders. the entire cervical spine, including C7 est to the tube as much as possible. Do Contrast and density should demonstrate and the interspace between C7 and Tl, not push on patient's shoulder. bony cortical margins and trabeculation is not demonstrated on the dorsal decu­ Instruct the patient to raise arm opposite (Fig. 1 3-9). bitus lateral projection. The patient the tube over his or her head. Assist pa­ NOTE: A grid i s required to i mprove image must be able to move both a rms. Do not tient as needed, but do not use force or contrast. I f a breathing technique cannot be move the patient's arms without per­ move the limb too quickly (Fig. 1 3-8). used, then make the exposure with respiration mission from the attending physician Ensure patient is looking straight ahead suspended. Special compensating filters can be and review of the lateral projection. without any rotation of the head or neck. used to i mprove image quality. Coll imate the width of the x-ray beam Central ray is horizontal and perpendic­ closely to reduce scatter radiation. ular to the IR entering the side of the If the patient is in stable condition, po­ neck just above the clavicle, passing sition his or her stretcher adjacent to the through the C7-T I interspace. vertical B ucky to increase efficiency I nstruct patient to breathe normally, if and obtain optimum i mage quality. he or she is conscious. Shield gonads and other personnel in If possible, use a long exposure time the room. technique to blur the rib shadows. Horizontal CR to C7-Tl Fig. 1 3-8 Patient and IR positioned for trauma lateral projection of Fig. 1 3-9 Dorsal decubitus position lateral projection the cervicothoracic vertebrae using the dorsal decubitus position. of the cervicothoracic region performed on a trauma patient. Negative examination. Note excel­ lent image of the C7-Tl joint (arrow). 12  Cervical Spine.. AP AXIAL PROJECTION1 Patient position considerations Structures shown Trauma positioning tips Supine, usually on backboard and in a C3 through T I or T2 including interspaces Do not peifo rm this projection until the cervical collar. and surrounding soft tissues should be attending physician has reviewed the Have patient relax his or her shoulders demonstrated with minimal rotation and lateral projection. as much as possible. distortion. Density and contrast should This projection is usually performed af­ Ensure the patient is 100 lUng straight demonstrate cortical margins and soft tis­ ter the lateral projection. ahead without any rotation of the head sue shadows (Fig. 1 3- 1 1 ). If patient is on a backboard, either on a or neck. NOTE: I f the patient is not on a backboard or an stretcher or an x-ray table, gently and Place the IR under the backboard, if x-ray table, then preferably, the attending slowly lift the backboard and place I R present, centered to approximately C4 physician should lift the patient's head and in position under the patient's neck. (Fig. 1 3- 1 0). neck while the radiographer positions the I R Move patient's head and neck as little Central ray is directed 1 5 t o 2 0 degrees under the patient. as possible. cephalad to the center of the IR and en­ Col li mate the width of the x-ray beam tering at C4. closely to reduce scatter radiation. Shield gonads and other personnel in the room. ' See slandard projeclion, Volume I, page 420. Bucky Fig. 1 3 - 1 0 Patient and IR positioned for a trauma AP axial Fig. 1 3- 1 1 AP axial projection of the cervical vertebrae projection of cervical vertebrae. performed on an l l -year-old trauma patient. Note cervi­ cal spine completely dislocated between C-2 and C-3 (arrow). The patient died on the x-ray table after the x-ray examinations were performed. 13  Cervical Spine.& AP AXIAL OBLIQUE Patient position considerations Structures shown PROJECTION Supine, usually on backboard and in a Cervical and upper thoracic vertebral bod­ Trauma positioning tips cervical collar. ies, pedicles, open intervertebral disc Do not peiform this projection until the H ave patient relax his or her shoulders spaces, and open intervertebral foramjna attendillg physician has reviewed the as much as possible. of side opposite of central ray entrance lateral projection. Ensure patient is looking straight ahead point. This projection provides excellent If patient is on a backboard, gently and without any rotation of the head or detail of the facet joints and it is important slowly lift the board and place the IR in neck. in detecting subluxations and di slocations position. Place the IR under the immobil ization (Fig. 1 3- 1 3). If the 1 5 degree cephalic an­ Move patient's head and neck as little device, if present, centered at the level gie is not used the i ntervertebral foramina as possible. of C4 and the adjacent mastoid process will be foreshortened. Do not use a grid IR because the com­ (about 3 inches lateral to mjdsagittal NOTE: If the patient is not on a backboard or an pound central ray angle results in grid plane of neck) (Fig. 1 3- 1 2). If a grid IR x-ray table, then preferably, the attending cut-off. However, many radiography is used with one central ray angle, the physician should l ift the patient's head and machines do not allow the x-ray tube­ grid lines should be perpendicular to neck while the radiographer positions the I R head to move in a compound angle. On the long axis of the spine. under the patient. these machines only the 45 degree an­ Central ray is directed 45 degrees lat­ gie is utilized and a grid IR may then be eromedially. When a double angle is used to improve contrast. used, angle 15 to 20 degrees cephalad. Coll i mate the width of the x-ray beam The central ray enters sl ightly lateral to closely to reduce scatter radiation. midsagittal plane at the level of the thy­ Shield gonads and olher personnel in roid cartilage and passing through C4. the room. The central ray exit point should coin­ cide with center of IR. Fig. 1 3- 1 2 Patient and IR positioned for a Fig. 1 3- 13 AP axial oblique projection of the cervical vertebrae performed on a trauma trauma AP axial oblique projection of the patient using a 45 degree angle. Radiograph was made using a non-grid exposure tech­ cervical vertebrae. The CR is positioned 45 nique. Negative image. Note excellent alignment of the vertebral bodies and interverte­ degrees mediolaterally and if possible. 15 bral foramen. to 20 degrees cephalad. 14  Thoracic and Lumbar Spine.. LATERAL PROJECTIONS Structures shown NOTE: A lateral projection of the cervicotho­ Dorsal Decubitus Positions For the thoracic spine, the image should racic spine must be performed to visualize the Trauma positioning tips include T3 or T4 to L I. The lumbar spine upper thoracic spine in profi le. Always perform these dorsal decubitus image shou ld, at a minimum, include T 1 2 positions before the AP projections of to the sacrum. The vertebral bodies should the spine. be seen in profi le with mini mal rotation The attending physician should review and di stortion. Density and contrast the dorsal decubitus lateral projections should be sufficient to demonstrate corti­ before performing other projections. cal margins and bony trabeculation (Fig. Move patient as little as possible. 1 3- 1 5 ). Use of a grid is necessary to i mprove i mage contrast. Utilize the vertical B ucky if possible to maximize posi­ tioning and for optimal image qual ity. Shield gonads and other personnel in the room. Patient position considerations Patient generally is immobilized and on a backboard. Have patient cross arms over chest to remove them from anatomy of interest. Place the IR I Y2 to 2 inches (3.8 to 5 cm) above the patient's relaxed shoulders for thoracic spine and at the level of il iac Horizontal CR to top crests for lumbar pine (Fig. 13- I 4). of iliac crest If not using the vertical Bucky, ensure Fig. 1 3- 14 Patient and IR positioned for trauma lateral projection of the lumbar spine that IR is perfectly vertical. using the dorsal decubitus position and utilizing a vertical Bucky device. Central ray is horizontal, perpendicular to the longitudinal center of the JR, and goi ng through the spine. Col l i mate closely to the spine to reduce scattered radiation and patient dose. A B Fig. 1 3- 1 5 Dorsal decubitus position lateral projection of the lumbar spine performed on a trauma patient. A, Fracture and dislocation of L2 (black arrow). Note backboard (white ar­ row). B, Compression fracture of the body of L2 (arrow). This coned-down image provides better detail of the fracture area. 15  Chest.. AP PROJECTION 1.2 Patient position considerations Trauma positioning tips o Position the top of I R about l 'li to 2 o Most trauma patients must be radi­ inches (3.8 to 5 cm) above the patient's ographed in the supine position. I f it is shoulders. necessary to see air-fluid levels a cross­ o Move the patient's arms away from tho­ table lateral x-ray beam (dorsal decubi­ rax and out of col l imated field. tus position) can be performed. o Ensure patient is looking straight ahead o Obtain help in l ifting the patient to po­ with chin extended out of the colli­ sition the I R if the stretcher is not mated field. equipped with an I R tray. o Check for rotation by determining if the o Check for signs of respiratory distress shoulders are equidistant to I R or or changes in level of consciousness stretcher. This position places the mid­ during radiographic examination and coronal plane parallel to the I R, mini­ report any changes to the attending mizing i mage distortion. physician immediately. o Central ray should be directed perpen­ o A sess abi lity of patient to fol low dicular to the center of the I R at a point breathing instructions. 3 inches (7.6 cm) below the jugular o Use the maximum SID possible to min­ notch (Fig. 1 3- 16). imize magnification of the heart shadow. o Use universal precautions if wounds and/or bleeding are present and protect the IR with plastic covering. o Mark entrance and/or exit wounds with radiopaque indicators if evaluating a penetrating injury. o Use of a grid improves image contrast. o Shield gonads and other personnel in the room. 'See standard projection, VolumeI, page 550. 2See mobile projection, Volume 3, page 242. CR to center of IR Fig. 1 3- 16 Patient and IR positioned for a trauma AP projection of the chest. 16  Chest Structures shown An AP projection of the thorax is demon­ strated. The lung fields should be included in their entirety with minimal rotation and distortion present. Adequate aeration of the lungs must be imaged to demonstrate the lung parenchyma ( Fig. 1 3- 1 7). NOTE: Ribs are somewhat visible o n a n AP projection, necessitating the use of a grid l R to increase image contrast. Use proper breathing instructions and techniques to ensure adequate visualization of ribs of interest. A B Fig. 1 3- 1 7 AP upright projection of the chest performed on a trauma patient. A, Multiple buckshot in chest caused a hemopneumothorax. Arrows show the margin of the col­ lapsed lung with free air laterally. Arrowhead shows fluid level at the costophrenic angle, left lung. B, Open safety pin lodged in esophagus of a 1 3-month-old baby. 17  Abdomen.. AP PROJECTION 1.2 Patient position considerations Trauma positioning tips Ask ER personnel to assist in transfer­ Use of a radiographic table and a B ucky ring patient to radiographic table, if provides optimum image quality. Before possible. moving the patient, verify transfer to I f transfer is not advisable, obtain assis­ table with the attending physician. tance to carefully lift the patient to po­ If transfer is not possible, use of a grid sition the grid IR under the patient. IR is required. Center the grid I R at the level of the il­ Determine the possibil ity of fluid accu­ iac crests and ensure that the pubic mulation within the abdominal cavity to symphysis is included (Fig. 1 3- 1 8). On determine appropriate exposure factors. patients with a long torso a second AP For patients with blunt force or projec­ projection of the upper abdomen may tile injuries, check for signs of internal be required to demonstrate the di­ bleeding during radiographic examina­ aphragm and lower ribs. tion and report any changes to the at­ If the patient is on a stretcher, check tending physician immediately. that the grid IR is parallel with the pa­ Mark entrance and/or exit wounds with tient's midcoronal plane. Correct tilting radiopaque markers if evaluating pro­ with sponges, sandbags, rolled towels, jectile injuries. etc. The grid I R must be perfectly hori­ Assess the abi l ity of the patient to fol­ zontal to prevent grid cut-off and i mage low breathing instructions. distortion. If unable to correct tilt on Use standard precautions if wounds or grid IR, then angle CR to maintain part­ bleeding are present and protect IR J R-CR alignment. with plastic covering. Central ray is directed to the center of Shield gonads, if possible, and other the JR. personnel in the room. 'See standard projection Volume 2, page 80. 'See mobile projection Volume 3, page 246. Bucky Fig. 1 3- 1 8 Patient and IR positioned for a trauma AP projection of the abdomen. 18  Abdomen Structures shown An AP projection of the abdomen is demonstrated. The entire abdomen, in­ cluding pubic symphysis and diaphragm should be i ncluded without distortion or rotation. Density and contrast should be adequate to demonstrate tissue interfaces, such as lower margin of liver, kidney shadows, psoas muscles and cortical mar­ gins of bones (Fig. 1 3- 1 9). A B Fig. 1 3- 1 9 AP projection of abdomen performed on a trauma patient. A, Table knife in the stomach along with other small metallic foreign bodies swallowed by the patient. B, Coin in the stomach swallowed by patient. 19  Abdomen.. AP PROJECTION 1.2 Patient position considerations NOTE: A lateral projection using the dorsal de­ left lateral Decubitus Position o Carefully and slowly turn the patient cubitus position may be substituted for this Trauma positioning tips into the recumbent left lateral position. projection i f patient is too ill or injured to be o Use of the vertical B ucky provides op­ Flex the knees to provide stability. properly positioned in a left lateral position. If the i mage is being taken for visual­ (Position will be identical to the dorsal decubi­ timum i mage quality. If patient must be o tus position, lateral projection of the l umbar i maged using a mobile radiographic ization of fluid, carefully place a block spine. See Fig. 1 3- 1 4. ) unit, a grid IR is required. under the length of the abdomen to en­ o Verify with the attending physician that sure that the entire right side is visual­ the patient movement is possible and if ized. the image is needed to assess fluid accu­ o Ensure that the midcoronal plane is ver­ mulation or free air in abdorrunal cavity. tical to prevent i mage distortion. o The left lateral decubitus position o Center the IR 2 i nches (5 cm) above the demonstrates free air i n abdorrunal cav­ il iac crests to i nclude the diaphragm ity because the density of the liver pro­ (Fig. 1 3-20). vide good contrast for visualization of o The patient should be in the lateral po­ any free air. sition at least 5 rrunutes before the ex­ o If fluid accumulation is of primary in­ posure to allow any free air to rise and terest, the side down, or dependent side, be visual ized. must be elevated off of the stretcher or o Central ray is directed horizontal and table to be completely demonstrated. perpendicular to the center of the IR. o Check for signs of internal bleeding during radiographic exarrunation and Structures shown report any changes to the attending Air and fluid levels within the abdominal physician immediately. cavity are demonstrated. This projection o Use universal precautions if wounds or is especially helpful in assessing free air bleerung are present and protect the I R in the abdomen when an upright position with plastic covering. Mark a l l entrance cannot be used. Density and contrast and exit wounds with radiopaque mark­ should be adequate to demonstrate tissue ers when imaging for penetrating injuries i nterfaces, such as lower margin of liver, o Shield gonads, if possible, and person­ kidney shadows, psoas muscles, and corti­ nel in the room. cal margins of bones (Fig. 1 3-2 1 ). I See standard projection Volume 2, page 82. 2See mobile projection Volume 3, page 248. Horizontal CR to center of IR Fig. 1 3-20 Patient and I R positioned for a trauma A P projection of Fig. 1 3-21 Left lateral decubitus position AP projection of the abdomen using the left lateral decubitus position and utilizing a abdomen performed on a trauma patient. Free intraperi­ vertical Bucky device. toneal air is seen on the upper or right side of the abdomen (arrow). The radiograph is slightly underexposed to demon­ strate the free air more easily. 20  Pelvis '" AP PROJECTlON l ·2 Patient position considerations Structures shown Trauma positioning tips The patient is supine, possibly on back­ The pelvis and proximal femora should be Up to 50% of pelvic fractures are fatal board or in trauma pants. demonstrated i n their entirety with mini­ as a result of vascular damage and Carefu lly and slowly transfer the pa­ mal rotation and distortion. Femoral shock. The mortality risk increases with tient to radiographic table to allow use necks will be foreshortened and lesser the energy of the force and the health of of Sucky. trochanters will be seen. Optimum density the victim. If unable to transfer, use a grid IR posi ­ and contrast should demonstrate bony tra­ Pelvic fractures have a high incidence tioned under the immobilization device beculation and soft tissue shadows (Fig. of internal hemorrhage. A lert the at­ or patient. Ensure that grid is horizontal \ 3-23). tending physician immediately if ab­ and parallel to the patient's midcoronal NOTE: Diagnosis of pelvic fractures in the ER domen becomes distended and firm. plane to minimize distortion and rota­ is often immediately fol lowed by an emer­ Hemorrhagic shock is common with tion. Carefully al igned to the central ray gency cystogram procedure. The necessary an­ pelvic and abdominal injuries. Reassess to mini mize di tortion and rotation. cillary equipment and contrast media should patient's level of consciousness repeat­ Position the I R so the center is 2 i nches be readily avai lable. edly while performing radiographic (5 cm) inferior to the ASIS or 2 inches examinations. (5 cm) superior to the pubic symphysis. Do not attempt to internally rotate Central ray is directed perpendicular to l imbs for true AP projection of proxi­ the center of the IR (Fig. 1 3-22). mal femurs on thjs projection. Check colli mated field to ensure that Col l i mate closely to reduce scatter radi ­ the il iac crests and hip joints are in­ ation. cl uded. Shield gonads, if possible, and other personnel in the room. 'See standard projection Volume I , page 355. 2See mobile projection Volume 3, page 250. Bucky Fig. 1 3-22 Patient and IR positioned for a trauma AP projection of the pelvis. A B Fig. 1 3-23 AP projection of the pelviS performed on a trauma patient. A, Entire right limb torn off after be­ ing hit by a car. The pelvic bone was disarticulated at the pubic symphysis and S-I joint. The patient sur­ vived. B, Separation of the pubic bones (arrowheads) anteriorly and associated fracture of the left ilium (arrow). 21  Cranium.. LATERAL PROJECTIONl Patient position considerations Dorsal Decubitus Position o Have the patient relax his or her shoul­ Trauma positioning tips ders. o Since the scalp and face are very vascu­ o After cervical spine injury has been l ar, these areas tend to bleed profusely. ruled out, the patient's head may be po­ Protect IRs with plastic covering and sitioned to align i nterpupillary l i ne per­ practice universal precautions. pendicular to the I R and the midsagittal o A grid IR is used for this projection. plane vertical. Elevate the patient' s head on radiolu­ o If patient i s wearing a cervical collar, cent sponge only after cervical injury carefully minimize rotation and tilt of such asfracture or dislocation has been cranium. ruled out. o Ensure that the IR is vertical. o Vomiting is a ymptom of intracranial o Central ray is directed horizontal enter­ i njury. If patient begins to vomit, log i ng perpendicular to a point 2 i nches roll to lateral position to prevent aspi­ (5 cm) above the EAM (Fig. 1 3-24). ration and alert the attending physician immediately. o Alert attending physician immediately if there is any change in the patient 's level of consciousness or if pupils are unequal. o Col li mate closely to reduce scatter radi ­ ation. o Shield gonads and other personnel in the room. 'See standard projection Volume 2, page 306. Horizontal CR 2 inches above EAM Fig. 1 3-24 Patient and IR positioned for a trauma lateral projection of the cranium using the dorsal decubitus position. Note sponge in place to raise head to demonstrate poste­ rior cranium (after checking lateral cervical spine radiograph). 22  Cranium Structures shown A profi le image of the superimposed halves of the cranium is seen with detail of the side closest to the lR demonstrated (Fig. 1 3-25 ). With some i njuries, airlfluid levels can be demonstrated in the sphe­ noid sinuses. NOTE: The supine lateral position may be used on a patient without a cervical spine injury. See Volume 2. page 306. A B Fig. 1 3-25 Dorsal decubitus position lateral projection of the cranium performed on a trauma patient. A, Two gunshot wounds entering at the level of C l and traveling forward to the face and lodging in the area of the zygomas. Note bullet fragments in the EAM area. B, Multiple frontal skull fractures (arrows) caused by hitting the windshield during an auto accident. 23  Cranium.. AP PROJECTlON l Patient position considerations AP AXIAL PROJECTION­ If available and the patient's condition TOWNE METHOD 2 allows, carefully and slowly transfer the Trauma positioning tips patient to the x-ray table using the im­ Profuse bleeding should be anticipated mobilization device and proper transfer with head and facial i njuries. Use uni­ technique. Transfer allows the use of versal precautions and protect IRs and the B ucky and minimizes risk of injury sponges with plastic. to the patient when positioning the IR. Cervical spine injury should be ruled out I f the patient is not transferred to the ra­ before attempting to position the head. diographic table, the grid IR should be AP projection is used for injury to the placed under the immobi lization de­ anterior cranium. AP axial projection, vice. If no such device is present, the Towne method demonstrates the poste­ attending physician should carefully rior cranium. lift the patient's head and neck while Vomiting i s a symptom of an intracra­ the radiographer positions the grid I R nial injury. If patient begins to vomit, under the patient. log roll patient to lateral position to After a cervical spine injury has been prevent aspiration and alert attending ruled out, the patient's head may be po­ physician immediately. sitioned to place the OML or IOML A Lert attending physician if patient's and midsagittal plane perpendicular to LeveL of consciousness decreases or if the I R. pupiLs are unequal. If the patient is wearing a cervical col­ Collimate closely to reduce scatter radi­ lar, the OML or IOML cannot be posi­ ation. tioned perpendicular. For the AP axial A grid IR or B ucky should be used to projection, Towne method, the central ensure proper i mage contrast. ray angle may have to be increased up ShieLd gonads and other personneL in to 60 degree caudad-maintaining a the room. 30 degree angle to the OML. ISee standard projection Volume 2, page 3 1 2. 'See standard projection Volume 2, page 3 1 4. Bucky Fig. 1 3-26 Patient and IR positioned for a Fig. 1 3-27 AP projection of the cranium performed on a trauma patient. Fracture of the trauma AP projection of the cranium. occipital bone (arrow). 24  Cranium For a n AP projection, the central ray Structures shown enters perpendicular to the nasion (Fig. The AP projection demonstrates the ante­ 1 3-26). An AP axial projection with the rior cranium (Fig. 1 3-28), The AP axial central ray di rected 1 5 degrees cepha­ projection, Towne method, demonstrates lad is sometimes performed in place of, the posterior cranium and foramen mag­ or to accompany the AP projection. num (Fig. 1 3-29). For the AP axial projection, Towne method, position the top of the IR at the level of the cranial vertex. The central ray is then directed 30 degrees caudad to the OML or 37 degrees to [OML (Fig. 1 3-27). The central ray passes through the EAMs and exits the fora­ men magnum. Bucky Fig. 1 3-28 Patient and IR positioned for a Fig, 1 3-29 AP axial projection, Towne method, performed on a trauma patient. Gunshot trauma AP axial projection Towne method, wound to the head. Metal clip (upper arrow) indicates entrance of the bullet on the an­ of the cranium using a 30 degree CR an­ terior cranium. Flattened bullet and fragments (lower arrow) lodged in the area of C2. gulation. 25  Facial Bones.. ACANTHIOPARI ETAL Patient position considerations Structures shown PROJECTlON l The superior facial bones are demon­ If available and the patient's condition REVERSE WATERS M ETHOD allows, carefully and slowly transfer the strated (Fig. 1 3-3 1 ). The image hould be Trauma positioning tips patient to the x-ray table using the im­ similar to the parietoacanthial projection Anticipate profuse bleeding with facial mobilization device and proper transfer or routine Waters method and demonstrate trauma. Protect I Rs with plastic cover­ techniques. Transfer allows the use of symmetry of the face. ing and practice universal precautions. the Bucky and minimizes risk of injury Cervical spine i njury should be ruled out to the patient when positioning the IR. before attempting to position the head. I f the patient is not transferred to the ra­ A Lert attending physician if patient 's diographic table, the grid I R should be C.R. I LeveL of consciousness decreases or if placed under the immobilization de­ pupiLs are unequal. v ice. If no such device is present, the A grid IR or B ucky is used to ensure attending physician should carefully proper image contrast. lift the patient's head and neck while Coll i mate closely to reduce scatter radi­ the radiographer position the grid IR ation. under the patient. ShieLd gonads and other personnel in If possible, the IOML should be posi­ the room. tioned approxi mately perpendicular to the I R. Note angle of MML. ' See standard projection Volume 2, page 364. The midsagittal plane should be per­ pendicular to prevent rotation. Bucky Central ray is angled cephalad until parallel to MML. The central ray enters Fig. 1 3-30 Patient and IR positioned for a the acanthion (Fig. 1 3-30). trauma acanthioparietal projection, Center the IR to the central ray. Reverse Water's method of the cranium. A B Fig. 1 3-31 Acanthioparietal projections, reverse Water's method, performed on trauma patients for demonstration of the facial bones. A, Fracture of the right orbital floor (arrow) with blood-filled maxillary sinus (note, no air in the sinus). Patient hit face on steering wheel during auto accident. B, Blowout fracture of the left orbital floor (arrow) with blood-filled maxillary sinus (note, no air in the sinus). Patient was hit with a fist. 26  Upper limb Trauma positioning tips o Check the patient's status during radio­ Patient position considerations Use standard precautions and cover I Rs graphic examination. Be aware that I f possible, demonstrate desired posi­ and positioning aids in plastic if shock can occur from crushing injuries tion for the conscious patient. Assist the wounds are present. to extremities. patient in attempting to assume the po­ o When lifting an injured limb, support at o Long bone radiographs must incl ude sition, rather than moving the injured both joints and lift slowly. Lift only both joints on the image. limb. enough to place the IR under the part­ o Separate examinations of the adjacent o If the patient is unable to position the sometimes ollly I to 2 inches (2.5 to 5 joints may be required if injury indi­ limb close to that required, move the I R cm). Always obtain help in lifting in­ cates. Do not attempt to "short cut" by and x-ray tube t o obtain desired projec­ jured limbs and positioning the I Rs to only performing one projection of the tion (Figs. 1 3-32 to 1 3-35). mini mize patient di comfort. long bone. o If the limb is severely injured, do not at­ o Shield gonads and other personnel in tempt to position for true AP or lateral the room. projections. Expose the two projec­ tions, 90 degrees apart, moving the in­ jured limb as little as possible. CR to center of IR 2 inch block Horizontal CR to center of IR Fig. 1 3-32 Patient and IR positioned for a Fig. 1 3-33 Patient and IR positioned for a trauma "cross table" lateral projection of trauma AP projection of forearm. forearm. 27  Upper limb Shoulder injuries should be initially i m­ aged "as is" without rotating the l imb. The "reverse" PA oblique projection of the scapular Y (an AP oblique) is useful in demonstrating dislocation of the glenohumeral joint with minimal pa­ tient movement. The patient is turned up 45 degrees and supported in position (Figs. 1 3-36 and 1 3-37. ) I f i maging while the patient is sti l l on a stretcher, check to make sure the I R is perfectly horizontal to minimize image distortion. Central ray must be directed perpendic­ ular to the IR to minimize distortion. I mmobilization techniques for the I R and upper l i mb are very useful i n ob­ taining optimal i mage with minimal pa­ tient discomfort. Fig. 1 3-34 A P projection o f the forearm performed o n a trauma patient. Fracture of the mid-portion of the radius and ulna (arrows). C.R. 1 4S" wedge Bucky Fig. 1 3-35 'Cross-table- Iateral projection of the forearm performed on a trauma patient. Fig. 1 3-36 Patient and IR positioned for Gunshot wound to the forearm with fracture of the radius and ulna and extensive soft tis­ a trauma AP oblique projection of the sue damage. shoulder to demonstrate the scapular Y. (Reverse of the PA oblique. scapular Y. see Chapter 5.) 28  Upper Limb Structures shown I mages of the anatomy of interest, 90 de­ grees from one another, should be demon­ strated. Density and contrast should be sufficient to visualize cortical margins, bony trabeculation, and surrounding soft tissues. Both joints should be included in projections of long bones. Projections of adjacent joints must be centered to the joint to properly demonstrate the articular ends ( Figs. 1 3-38 and 1 3-39). CR to center of IR Fig. 1 3-38 Patient and IR positioned for a trauma AP projection of humerus. Fig. 1 3-37 AP oblique projection of the shoulder (reverse of the Fig. 1 3-39 AP projection of the humerus performed on a trauma PA oblique, scapular Y)