CT Protocols: (Brain, ENT, Spine, Vascular) - Department of Radiology

27 Revised 7/22/09 (Gentry/Ranallo)
Orbit: (Routine) (Protocol – Adult: # 2.1 – Pediatric: # 12.1 & 12.2)
Billing:
Setup:
DFOV:
Contrast:
Patient Age:
1. CT Orbit without, or with, or with and without
2. Contrast if used
1. Patient Supine, AP and lateral scouts, no gantry angle.
2. Extend the scouts to include aortic arch for smart prep.
3. Patient Positioning: Tilt the patients head so that a line connecting the lateral canthus
of the eye and the EAC is perpendicular to the CT tabletop (see head CT protocol).
You may need to put a foam pad under the occiput to get the head in this position.
4. Ask the patient to look straight ahead and hold their eyes in a very still position.
5. Start the scans at the infraorbital rim and scan through the top of the orbit
Preferred 14 cm (Range 14-16 cm)
1. Adults: 75 ml of 240 mg/ml nonionic contrast media (use 150ml of 240mg/ml if a CT
of the head will also be obtained)
2. Pediatrics: 1 ml / pound (2 ml/kg) of 240 non-ionic contrast media
3. Injection Rate: Adults: 3 ml/sec; Pediatric: 2 ml/sec
4. Smart prep over the cavernous sinus (adults) or aortic arch (peds). Begin scanning
10 seconds (adults) or 6 seconds (pediatric) after arrival of contrast.
Choose the CT scan factors on the scanner for the proper age range of the patient
1. Child: (3 – 6 years)
2. Infant: (0 – 3 years)
Recons & Reformats:
1. All 2-D reformats described below are to be done as 2 mm x 2 mm reformats. Do them in
the coronal and bilateral oblique sagittal planes as shown in the image below.
2. If this is an exam solely with contrast or solely without contrast: Do 2D-reformats using
both the standard 1.25 mm images (Recon 1) AND the bone 0.625 mm images (Recon 3)
3. If this is a “with & without” contrast study: Do not do Recons 2 and 3 on the contrast scan.
Do 2D-reformats using the 1.25 mm standard algorithm images (Recon 1) only from the
contrast series AND also do 2 mm x 2 mm reformats using the bone 0.625 mm images
from the non-contrast series (Recon 3).
4. Do not send the 0.625 mm (Recon 3) bone images to PACS.