Comprehensive Radiographic Positioning and Technical Parameters Guide

Lumbar, Sacral, Coccygeal, and Sacroiliac Radiographic Procedures

For the lumbar spot projection, the central ray is angled 5^\ncirc - 8^\ncirc caudal and directed $2''$ posterior to the anterior superior iliac spine (ASIS) and $1.5''$ inferior to the iliac crest. The source-to-image distance (SID) is set to $40''$. Proper close collimation must be applied to isolate the anatomical region extending from L5 down through the upper sacrum.

For the anteroposterior (AP) axial sacrum radiograph, respiration is suspended during exposure. The SID is maintained at $40''$, utilizing an image receptor (IR) size of $8 \times 10''$ or $10 \times 12''$. The central ray is angled 15^\ncirc cephalic and directed $2''$ inferior to the ASIS.

For the AP axial coccyx projection, the patient suspends respiration during exposure. The central ray is directed 10^\ncirc caudal to a point $2''$ inferior to the ASIS at an SID of $40''$. An IR sized $8 \times 10''$ or $10 \times 12''$ is utilized.

For the lateral coccyx radiograph, the central ray is directed perpendicular to the level of the ASIS and $3 - 4''$ posterior to it. The SID is set to $40''$, and a $10 \times 12''$ image receptor is positioned lengthwise.

For the AP axial sacroiliac (SI) joint projection, the central ray is directed 30 - 35^\ncirc cephalic to a landmark $2''$ inferior to the ASIS. An SID of $40''$ is required with a $10 \times 12''$ lengthwise image receptor, ensuring that both SI joints are completely included in the field of view.

For the AP oblique sacroiliac joint projection, the patient's body is rotated 25 - 30^\ncirc. The central ray is directed perpendicular to a point $1''$ medial to the upside ASIS. The SID is $40''$, and collimation/IR size is set to 6 \times 12''$.\n\n# Thoracic and Abdominal Radiographic Procedures\n\nFor chest radiograph procedures in PA and Lateral projections, the top of the image receptor is positioned 1 \frac{1}{2}''$above the patient's shoulders. The standard SID is$72''$. Image receptor sizing for the AP view is$14 \times 17'' depending on body habitus, while a portrait orientation is used for the lateral view. The central ray is directed perpendicular to T7, and respiration is suspended on full inspiration.\n\nFor bilateral decubitus chest radiography, the IR is placed 1 \frac{1}{2}''$above the shoulders with the central ray perpendicular to T7. Respiration is suspended on full inspiration. An SID of$40''$minimum is required, though an SID of$60 - 72'' is preferred. To accurately assess pathology, fluid evaluation requires positioning the affected side down, whereas air evaluation requires placing the unaffected side up.\n\nFor the AP supine abdomen (KUB) examination, respiration is suspended on expiration. The central ray is directed perpendicular to the iliac crest at an SID of 40''. Coverage must extend from the pubic symphyses to the upper abdomen.\n\nFor the AP upright abdomen projection, the central ray is aimed perpendicular to a level 2''$above the iliac crest with an SID of$40''. The exposure is performed with suspended expiration, capturing anatomical structures from the diaphragms down to the lower abdomen.\n\nFor AP/PA left lateral decubitus abdomen radiography, the patient is placed in the left lateral decubitus position. The central ray is directed perpendicular to 2''$above the iliac crest at an SID of$40'', ensuring that the diaphragm is fully included in the radiograph.\n\n# Cervical, Thoracic, and Lumbar Spine Radiographic Procedures\n\nFor the AP axial cervical spine projection, the central ray is angled 15 - 20^ circ$cephalic through C4 at an SID of$40''$. The anatomical coverage must open C3 through T2 across a$10''$length, with collimation set to$1'' on the sides of the skin shadow.\n\nFor the lateral cervical spine procedure, the central ray is directed perpendicular to C4 using a 72''$SID and an$8 \times 10'' image receptor.\n\nFor the open mouth projection of C1-C2, the occlusal plane and mastoid tips must be placed in a horizontal level plane. The central ray is directed perpendicular to the center of the open mouth at an SID of 40''$, utilizing a$5 \times 5'' collimated field.\n\nFor the AP thoracic spine projection, respiration is suspended on expiration. The central ray is centered at T7, aligned with the 17\times$nipple line at an SID of$40''$.

For the lateral thoracic spine radiograph, an orthostatic breathing technique is employed during the exposure. The procedure requires an SID of $72''$ and an IR size of 7 \times 17''$.\n\nFor the cervicothoracic lateral (Swimmers) projection, respiration is suspended on expiration. The central ray centers at the C7-T1 junction with an SID of 72''$, using an$8 \times 10'' image receptor with close collimation.\n\nFor AP and Lateral lumbar spine radiographs, the central ray is directed at the L4 iliac crest, and exposure occurs during suspended expiration at an SID of 40''. The view must demonstrate the area from T12 down to the sacrum and coccyx.\n\n# Lower Extremity and Pelvic Radiographic Procedures\n\nFor knee radiography (AP, Medial/Lateral Oblique, and Lateral), the central ray is directed \frac{1}{2}''$inferior to the patella or$1''$distal to the medial epicondyle with a$5^ circ$cephalic angle. The procedure is conducted at an SID of$40'', demonstrating open joint spaces and extending from the distal femur to the proximal tibia and fibula.\n\nFor the AP femur radiograph, the foot is internally rotated 15 - 20^ circ$. The central ray is perpendicular to the mid-part of the femur at an SID of$40'', capturing both the hip and knee joints.\n\nFor the lateral femur radiograph, the epicondyles are aligned parallel to the image receptor, the knee is flexed 45^ circ$, and the central ray is directed perpendicular to the mid-part at an SID of$40'', fully including both the hip and knee joints.\n\nFor the AP hip projection, the foot is internally rotated 15 - 20^ circ$. The central ray is centered$1 - 2''$medial and$3 - 4''$distal to the ASIS at an SID of$40'', capturing the ASIS and pubic symphyses.\n\nFor the lateral hip projection, the knee is flexed and abducted 45^ circ$. The central ray is targeted$1 - 2''$medial and$3 - 4''$distal to the ASIS with an SID of$40'', covering the ASIS and pubic symphyses.\n\nFor the AP pelvis radiograph, the feet are internally rotated 15 - 20^ circ$. The central ray is aimed perpendicular to$2''$inferior to the ASIS, with the top of the image receptor positioned$1 - 1.5''$above the iliac crest at an SID of$40'' to include the entire pelvis.\n\nFor foot radiography (AP Axial, Oblique, Lateral), the central ray for the axial projection is angled 10^ circ$toward the heel or directed perpendicular to the base of the 3rd metatarsal. At an SID of$40'', collimation covers from the distal phalanges to the distal tibia and fibula.\n\nFor ankle radiography (AP, Mortise, Lateral), the central ray is perpendicular to the mid-malleoli or medial malleolus at an SID of 40''$. Collimation must extend$1'' on all sides, including the heel.\n\nFor tibia and fibula (Tib/Fib AP and Lateral) radiographs, the central ray is perpendicular to the mid-part of the leg. The SID is set to 40 - 48'', with collimation enclosing the anatomical extent from the ankle to the knee.\n\n# Upper Extremity and Shoulder Girdle Radiographic Procedures\n\nFor finger radiography (PA, Lateral, Oblique), the central ray is directed perpendicular to the proximal interphalangeal (PIP) joint at an SID of 40''. Collimation extends from the distal phalange to the metacarpophalangeal (MCP) joint.\n\nFor thumb radiography (AP, Oblique, Lateral), the central ray is directed perpendicular to the MCP joint at an SID of 40'', with collimation encompassing the distal tip through the trapezium.\n\nFor hand radiography (PA, Oblique, Lateral), the central ray is perpendicular to the 3rd MCP joint (and the 2nd MCP joint for lateral views) at an SID of 40''. The collimated field spans from the phalanges to the distal radius and ulna.\n\nFor wrist radiography (PA, Oblique, Lateral), the central ray is directed perpendicular to the mid-carpals at an SID of 40''. Collimation includes the proximal metacarpals as well as the distal radius and ulna.\n\nFor the axial wrist projection targeting the scaphoid, the central ray is angled 10 - 15^ circ$to the scaphoid at an SID of$40'' to present the scaphoid without foreshortening.\n\nFor forearm radiography (AP, Lateral), the central ray is perpendicular to the mid-forearm at an SID of 40'', with collimation covering from the wrist to the distal humerus.\n\nFor elbow radiography (AP, Medial/Lateral Rotation, Lateral), the central ray is perpendicular to the elbow joint at an SID of 40'', capturing the proximal radius/ulna and distal humerus.\n\nFor humerus radiography (AP, Lateral), the central ray is perpendicular to the mid-humerus at an SID of 40'', fully showing both the elbow and shoulder joints.\n\nFor shoulder AP radiography (Internal and External rotation), the central ray is perpendicular to 1''$inferior to the coracoid process at an SID of$40''$using a$10 \times 12'' field size.\n\nFor the shoulder Y projection (Scapular Y), the central ray is perpendicular to the scapulohumeral joint at an SID of 40''$, utilizing a$10 \times 12'' field size.\n\nFor clavicle radiography (AP, Axial), the central ray is directed either perpendicular or angled 15 - 30^ circ$cephalic to the mid-clavicle at an SID of$40''$$. Collimation must cover from the sternoclavicular joint to the acromioclavicular joint.