Final General Summary PDF

Departmental option: The head may be turned toward IR to a near-lateral position. This results in some rotation of upper vertebrae but may help to prevent superimposition of mandible on upper vertebrae.  If patient has a lateral curvature (scoliosis) of the spine (as determined by vie...

Departmental option: The head may be turned toward IR to a near-lateral position. This results in some rotation of upper vertebrae but may help to prevent superimposition of mandible on upper vertebrae.  If patient has a lateral curvature (scoliosis) of the spine (as determined by viewing the spine from the back, with the patient in the erect position and with hospital gown open), patient should be placed in whichever lateral position places the sag, or convexity of the spine, down to open the intervertebral spaces better. If waist is not supported suf ciently, resulting in sagging of the vertebral column, the CR must be angled 5° to 8° caudad to be parallel to the interiliac line (imaginary line between iliac crests High amounts of secondary or scatter radiation are generated as the result of the part thickness. Close collimation is essential, along with place- ment of lead masking on tabletop behind patient. This is especially important with digital imaging. note : High amounts of secondary and scatter radiation are generated. Close collimation is essential to reduce patient dose and obtain a high-quality image. fi  NOTE 1: Ensure that midsagittal plane is parallel to IR, which for slender but broad-shouldered patients results in hips and lower thorax not being against IR. NOTE 2: This increase in OlD of the lower chest results in the costophrenic angles of the lungs being projected lower because of divergence of the x-ray beam. Therefore, CR and IR should be lowered a minimum of 1 inch (2.5 cm) from the PA on this type of patient to prevent cutoff of costophrenic angles. NOTE: Always attempt to have patient sit completely erect in wheelchair or on cart if possible. However, if the patient’s condition does not allow this, the head end of the cart can be raised as nearly erect as possible with a radiolucent support behind the back (Fig. 2.63). All attempts should be made to get patient as nearly erect as possible Note on Centering and Exposure for Neck Region Centering should be to laryngeal prominence (C5) with exposure factors for a soft tissue lateral neck if the area of interest is primarily the larynx and upper trachea. Centring and Exposure for Distal Larynx and Trachea Region If the distal larynx and upper trachea and midtrachea are the primary areas of interest, the IR and CR should be lowered to place the CR at the upper jugular notch (T1-2) with exposure factors approxi- mately those for a lateral chest. NOTE: Patient should be upright a Anatomy Demonstrated: Air-filled stomach and minimum of 5 minutes, but 10 to 20 loops of minutes is desirable, if possible, before bowel and air-fluid levels where present. Should exposure for visualizing small include amounts of intraperitoneal air. If a bilateral diaphragm and as much of lower abdomen patient is too weak to maintain an erect as position, a lateral decubitus should be possible. Small free, intraperitoneal crescent- taken. For hypersthenic patients, two shaped air landscape IRs may be required to include bubble if present seen under right hemidiaphragm, the entire abdomen. away from gas in stomach  CERVICAL AND THORACIC SPINE C HAP TE R 8 315 CERVICOTHORACIC (SWIMMER’S) LATERAL POSITION: CERVICAL SPINE C5-T3 REGION Clinical Indications Cervical Spine Evaluation Criteria Pathology involving the inferior cervical SPECIAL spine, superior thoracic spine, and adjacent Cervicothoracic Anatomy Demonstrated: Vertebral bodies and soft tissue structures lateral intervertebral disk spaces of C5 to T3 are shown. The Various fractures (including compression humeral head and arm farthest from the IR are magnified and fractures) and subluxation 24 appear inferior to T4 or T5 (if visible) (Figs. 8.63 and 8.64). This is a good projection when C7 to T1 is not L Position: Minimal vertebral rotation indicated by visualized on the lateral cervical spine, or when superimposition of cervical zygapophyseal joints and articular the upper thoracic vertebrae are of special inter- 30 pillars, and posterior ribs. The humeral heads should be est on a lateral thoracic spine. separated vertically. Collimation to area of interest. Exposure: Clear demonstration of bony margins and Technical Factors trabecular markings of lower cervical and upper thoracic SID of 60 to 72 inches (152 to 183 cm) vertebrae. No motion. IR size—24 × 30 cm (10 × 12 inches), portrait Grid Specially designed compensating filter useful for obtaining uniform brightness (see Chapter 1 for more information on compensating filters) Analog—75 to 85 kV range Digital systems—90 ± 5 kV range Shielding Shield radiosensitive tissues outside region of interest. Patient Position—Erect or Recumbent Position Place patient in preferred erect position (sitting or standing). The radiograph may be performed in the recumbent position if the patient’s condition requires. 8 Part Position Align midcoronal plane to CR and midline of table and/or IR. Place patient’s arm and shoulder closest to the IR up, flexing elbow and resting forearm on head for support. Fig. 8.62 Cervicothoracic (swimmer’s) lateral. Position arm and shoulder furthest from the IR down and rotate slightly posterior, to place the remote humeral head posterior to Left vertebrae (Fig. 8.62). humerus Ensure that no rotation of thorax and head exists. CR CR perpendicular to IR (see Note). Direct CR to T1, which is approximately 1 inch (2.5 cm) above level of jugular notch anteriorly and at level of vertebra promi- nens posteriorly. Center IR to CR. Recommended Collimation Collimate on four sides to anatomy of interest. Respiration Suspend respiration on full expiration. NOTE: A slight caudad angulation of 3° to 5° may be necessary to help separate the two shoulders farthest from the IR. Optional Breathing Technique If patient can cooperate and C7 T1 Left clavicle remain immobilized, a low mA and 3- or 4-second exposure time can be used, with patient breathing short, even breaths during the Fig. 8.63 Cervicothoracic Fig. 8.64 Cervicothoracic exposure to blur out overlying lung structures. (swimmer’s) lateral. (swimmer’s) lateral.