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Spine
General Hints
• Topogram: Lateral, 512 mm for thoracic and lumbar
spine and 256 mm for the C-spine.
• Patient positioning for thoracic and lumbar spine
studies:
Patient lying in supine position, arms positioned
comfortably above the head in the head-arm rest,
lower legs supported.
• Patient positioning for cervical spine studies:
Patient lying in supine position, hyperextend neck
slightly, secure head well in head holder.
– Patient respiratory instruction: do not breathe, do
not swallow.
Any possible injuries to the spinal column should be
determined before beginning the examination and
taken into account when repositioning the patient.
• In case of 3D study only, images should be recon-
structed with at least 50% overlapping and kernel
B10.
• In case of SSD study only, mAs value can be reduced
by 50%. Use kernel B10 and 50% overlapping image
reconstruction.
• For lumbar studies, place a cushion under the
patient’s knees. This will reduce the curve in the
spine and also make the patient more comfortable.
• For image reconstruction of bone study, use kernel
B60.
• The CT scan following myelography must be per-
formed within 4-6 hours of the injection, otherwise,
the contrast density in the spinal canal will be too
high to obtain artifact-free images. Also, if possible,
it is a good idea to roll the patient once, or scan in a
prone position. This will prevent the contrast from
pooling posterior to the spinal cord.
• If a prone scan is performed, breathing instructions
are recommended to avoid motion artifact in axial
source and MPR images.
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