Neck Flashcards
Soft Tissue (ST) Neck studies include what superior anatomy and what inferior anatomy?
superior: superior orbital rim
inferior: through lung apices
For a ST Neck, the gantry should be angled to avoid what possible streaking artifact?
streaking from dental hardware
The ST Neck CT may be split into two scans. The superior scan is angled to run parallel with what structure? The inferior scan is angled to parallel with what structure?
superior scan // with the hard palate
inferior scan // with the mandibular body
What are the slice thicknesses for: ST Neck and CTA Neck and/or Laryngeal studies?
ST Neck: 3-5 mm
CTA and/or Laryngeal: 0.5-2 mm
What is the DFOV, soft tissue WL and WW, and bone WL and WW for the neck?
18-25 cm (varies based on patient size)
ST: WL 50, WW 400
Bone: WL 300, WW 2000
What is the patient position for CT of the Larynx?
supine with the head extended until the larynx is perpendicular to the CT image. Gantry is angled to be parallel with the true vocal cords
For CT Larynx, what superior and inferior anatomy are included and what is the slice thickness?
superior: hyoid bone
inferior: circoid cartilage
0. 5 - 2 mm slice thickness
What is an example WL and WW for CT Larynx?
WL -300, WW 1000
Why is the thyroid is hyperdense on CT?
the thyroid is inherently high in iodine content
For CTA of the Neck, what direction is the scan performed?
caudocranial; the contrast is traveling superiorly through the carotid artery
What is the recommended volume and flow rate of contrast for a CTA Neck?
50-75 mL at 4 mL per second (with a 12-15 second delay)
What is the collimation size? The slice overlap?
a. 0.625 mm collimation
b. 0.75 x 0.5 mm overlap
Why would the kVp be reduced from 140 to 120 for a CTA Neck?
it can improve visualization of the vessel opacification by the contrast
