Radiographic Techniques - Lumbar Vertebrae

Radiographic Techniques - Lumbar Vertebrae

• Antero-posterior (AP) Projection (Basic):
  • Patient positioning: Supine on Bucky table, median sagittal plane aligned with the table's midline and perpendicular to the Bucky. Anterior superior iliac spines equidistant from the tabletop. HIPS and knees flexed, feet on tabletop to flatten the lumbar arch.
  • Image receptor: Large CR cassette including the lower thoracic vertebrae and sacro-iliac joints centered at the lower costal margin.
  • Exposure: Made during arrested expiration to prevent diaphragm movement, which would cause density differences between upper and lower lumbar vertebrae.

Lateral Projection (Basic):

• Patient Positioning: Patient lies on either side of the Bucky table. Raise and rest patient's arms on the pillow in front of head; knees and hips are flexed for stability.
• Image Receptor Alignment: The coronal plane of the spine should coincide and be perpendicular to the Bucky's midline, non-opaque pads may be necessary to align the vertebral column parallel to the image receptor.
• Image Receptor Centering: The image receptor is centered at the level of the lower costal margin.
• Exposure: Exposure should be made during arrested expiration.
• Additional Projection: This projection can be performed with the patient standing or sitting.

Lateral - Flexion and Extension Projections

• Patient positioning:
  • Patient positions: Erect, seated on a stool with either side against the vertical Bucky.
  • First exposure: patient leans forward, flexing the lumbar region as much as possible grip front of seat for stability.
  • Second exposure: patient leans backward, extending the lumbar region as far as possible and grips the back of the seat or a support. The Bucky is positioned at the lower costal margin.
• Note: Exposure is during arrested expiration in both flexion and extension.

Sacroiliac Joints (AP Axial):

• Patient Positioning: Supine on Bucky table, median sagittal plane aligned with table's midline and perpendicular to the Bucky.
• Pelvic Rotation: No rotation of the pelvis. ASIS (Anterior Superior Iliac Spine) should be the same distance from the tabletop.
• X-ray Beam: Collimated vertical beam directed cephalad. 5 cm below the ASIS.

Essential Image Characteristics (General):

• Image Inclusion: Include entire area of interest (e.g., T12 downward to sacral junction) in both projections.

• Exposure Time: Short exposure for patient stability is desirable.

• Density: Ensure sufficient density for diagnosis (e.g., bone detail throughout the region), including all bony structures

• Rotation: Sacroiliac joints equidistant from spine.

• Common Image Faults and Solutions:

  • Missing sacroiliac joint: Additional projection of the sacroiliac joint is needed.
  • High-contrast image/poor density: Software application to correct image density of overexposed areas is needed.
  • Poor superimposition of anterior/posterior margins : This could mean the patient was positioned improperly (rolled too far in either direction).
  • Spinous processes missing from image: Check collimation and ensure enough exposure.
  • Failure to demonstrate intervertebral disc space: Ensure adequate space for visibility