عن�ایت کن�ف در دانش جوین�ده اس�������ت. خداون�������د
پيامبر اكرم )ص( می : فرمایند
بسم الله الرحمن الرحیم
Computer TomographyTechnique
Lecture 7:CT scan Vertebrals
September, 2012
Prepared by:
Behzad OmmaniMaster of Medical Engineering
Instructor Radiology Group
The Lumbar Spine
The two commonest reasons for imaging the lumbar spine are:
Lumbar disc disease, most commonly at L5/S1 and L4/L5;
Spinal stenosis, i.e. narrowing of either or both the spinal canal and lateral recesses
Lumbar
Patient position :
• Supine, Both arms should be raised above the head. This is the planning scan and is usually an anteroposterior (AP) view and lateral.
Start position : Zero to symphysis pubis
End position : Commence 35 cm
Lumbar
• Slice thickness 3-5 mm• Table increment 3-5 mm• Algorithm Standard• Kilovoltage 120-140 kV• mAs per slice 250-400 mAs• Scan field of view 48 cm• Display field of view 15 cm• Window width (WW) 500/1500• Window level (WL) 60/250
Lumbar Protocol
Lumbar Disc
• From the lateral scan projection radiograph, plan three axial sections through each disc space, from L5/S1 up to L1/L2, with the middle section passing through the middle of and parallel to each disc space.
• The axial scans should be 5 mm in thickness and separated using a table increment of 10 mm
Lumbar Stenosis
Lumbar Stenosis
• MR imaging should always be used to investigate cervical disc disease but, due to the lack of signal from bone, it is often very difficult to assess the degree of encroachment on cervical nerve roots from osteophyte formation within the intervertebral foramen.
Cervical
Patient position :
• Supine, Both arms should be raised above the head. This is the planning scan and is usually an anteroposterior (AP) view and lateral.
Start position : Zero to 5 cm above orbitomeatal baseline
End position : Length, 25 cm
Cervical Spine
• Axial scans (helical)• Slice thickness 1-3 mm• Table pitch 1-1.5• Algorithm Standard• Kilovoltage 120 kV• mAs per slice 200-400 mAs• Scan field of view 25 cm• Display field of view 15 cm• Window width 500/1500• Window level 60/250
Cervical Spine Protocol
postnasal space scan
Patient position :
• Supine with head in head cushion on table top• Lateral scan projection radiograph is optional
• Start position Skull base• End position : Epiglottis• Gantry angle : Parallel to infraorbital meatal line
• Slice thickness 5 mm• Table increment 5 mm• Kilovoltage 120 kV• mAs per slice 250 mAs• Algorithm Soft/standard• Scan field of view 25 cm• Display field of view 22 cm• Window width 400• Window level 20
Protocol for postnasal space scan
Recommended