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

70 Revised 7/22/09 (Gentry/Ranallo)
Temporal Bone: (Vascular Mass): (Protocol – Adult: # 2.11 – Pediatric: #12.20 & 12.21)
Billing:
Setup:
DFOV:
1. CT Temporal Bone (without and with)
2. Contrast
1. Patient Supine, AP and lateral scouts, no gantry angle
2. Extend the scouts to include aortic arch for smart prep.
3. Only use 16 and 64 slice scanners
4. Patient Positioning: Tilt the patient’s 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).
5. The dynamic portion is a monitored exam by an ENT radiologist or ENT Fellow.
1. Posterior Fossa: Preferred 20 cm (Range 18-22 cm)
2 TB: 9.6 cm
Exam: Part 1: Temporal Bone CT Without Contrast
1. Use the same protocol as described in the Temporal Bone W/O Contrast protocol
2. This includes axial Recon 1, 2 and 3; the additional Retro recons of soft tissue and of
bone; and all the reformatted 1 x 1 cm images of the temporal bones.
Part 2: Dynamic Contrast Enhanced Exam Through the Vascular Mass (as described below)
1. Select eight 2.5 mm scans through the vascular mass of posterior fossa (per radiologist)
2. 1 image per sec X 5 (Using Cine Mode), then 1 image every 3 sec. X 3, then 1 image
every 10 seconds X 2 (5 groups using Axial Mode with a Prep Group Delay of 2 sec and
9 sec respectively) (scan time = 34 sec).
3. Use 100 kV; 300 mA for adults, 150 mA for peds less than 6 y/o.
4. Standard algorithm only
5. Inject Contrast: Adults: Inject 150 ml of 240mg/ml at 4.0 ml per sec (Injection time = 37.5
sec). Pediatrics: Inject 1 ml/lb (2 ml/kg) of 240 mg/ml contrast at 2 ml per sec
6. Smart prep over superior vena cava; begin scanning with arrival of contrast in the
superior vena cava
7. As soon as all contrast has been injected immediately start Part 3
Part 3: Temporal Bone Examination With Contrast
1. Inject contrast and then obtain standard algorithm 1.25 mm scans with a 0.75 mm
interval from the bottom of C1 to 1 cm above the top of temporal bone.
2. Reconstruct the 1.25 mm axial slices into 2 mm x 2 mm images of the posterior fossa
(axial, coronal, and sagittal) using an 18-22 cm DFOV with standard algorithm only.
Patient Age: Choose the CT scan factors on the scanner for the proper age range of the patient
2D Reformats:
1. Child: (3 – 6 years)
2. Infant: (0 – 3 years)
1. Part 1: Do 1 mm by 1 mm 2D-reformations in the coronal, Stenver’s, and Pöschl planes
2. Part 3: Do 2 mm by 2 mm 2D-reformations in the axial, coronal, and sagittal planes