Pathology Demonstrated:
- The range of motion of the vertebral column is assessed.
Technical Factor:
- Cassette size is 35 x 43 cm (14 x 17 inches), lengthwise, or 35 x 92 cm or 14 x 56 inches film.
- Moving or stationary grid.
- Erect markers for erect patient position.
- Use of compensating filters to help obtain a more uniform density along the vertebral column.
- kV 80
- mAs 15
Shielding:
AP Right Bending |
- Place lead shielding over gonads without obscuring area being examine.
Patient Position:
- Patient can erect or lying (recumbent) as an AP or PA with its arm on side.
Part Position:
- Midsagittal plane is align or centered to cassette or table.
- Ensure no rotation of pelvis area and torso if possible.
- The lower part of cassette must be 1 to 2 inches below iliac crest.
- With the pelvis acts as a fulcrum, ask patient to bend laterally, as far as possible to either side.
- If patient is in lying position, move both the upper torso and the legs to achieve maximum lateral flexion.
- Repeat above steps when doing opposite side.
Central Ray:
- CR perpendicular, and directed to center of cassette or image receptor.
- SID of 40 to 60 inches, and longer SID for larger film used (35 x 90 cm) to acquire adequate collimation.
Collimation:
- Four- sided collimation to near borders of image receptor, and donot cut any portion of vertebrae column.
Respiration:
- Suspend respiration on expiration.
Note: The pelvis must remain as stationary as possible during positioning, Pelvis acts as fulcrum (pivot point) during changes in position.
Radiograph may be done as PA projection if taken erect, to significantly reduce exposure to radiation-sensitive organs.
Radiographic Criteria | Right or Left Bending Scoliosis Series | Spinal Fusion Series
Structure Shown:
- An AP or PA projection of the thoracic and lumbar spine, with the patient in lateral position; minimum of 2.5 cm of the iliac crests is visible on the image.
AP Right Bending |
Position:
- Thoracic and lumbar vertebrae should be demonstrated in lateral flexion (bending to the left and right)
- Rotation of pelvis or thorax may be seen because scoliosis often is accompanied by rotation of involved vetebrae.
Collimation and Central Ray:
- Vertebral column should be in the middle of the image or collimated field.
Exposure Criteria:
- Optimal density and contrast help to clearly demonstrate the lumbar and thoracic vertebrae.
- A compensating filters may be useful for obtaining uniform density along the vertebral column.
- Sharp bony margins indicate no motion.
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