Sinuses, Facial Bones, Cerebral Vasculature

Question 1

What are indications for Sinus CT

Answer 1

Inflammatory sino/nasal disease, Chronic sinusitis, roadmapping for surgery

Question 2

What is the focus of sinus CT anatomically

Answer 2

Frontal, ethmoid, sphenoid, and maxillary sinuses as well as nasal passages, turbinates, and septum

Question 3

What are the benefits of Sinus CT

Answer 3

Screening is inexpensive, low radiation, and accurate

Question 4

What is the more common scan plane for sinuses: Coronal or Axial

Answer 4

Axial supine

Question 5

What is the scan range for sinuses

Answer 5

From above the frontal sinus to below the hard palate including from mid sella through frontal sinus

Question 6

How do you position a patient for sinuses

Answer 6

Supine (sometimes prone), extend the chin and drop head as far back as possible in a special head holder.
Align hard palate perpendicular to the table (OML line) OR angle the gantry if not possible

Question 7

Do you use CM for sinuses

Answer 7

no

Question 8

What are you trying to demonstrate in chronic sinusitis coronal axial image

Answer 8

air-fluid level

Question 9

What is the preferred modality for imaging of the face

Answer 9

CT. It is most sensitive for fracture detection

Question 10

What is a disadvantage of CT imaging for the face

Answer 10

It has potential to miss a subtle tooth fracture along the axial plane

Question 11

What are some indications for a non-enhanced face ct

Answer 11

facial fractures and soft tissue injury

Question 12

What are some indications for an enhanced ct scan of the face

Answer 12

Infection and masses

Question 13

Is face CT axial or helical

Answer 13

Helical: crucial to make accurate reconstructions!

Question 14

If contrast IS used, will it be single or split bolus

Answer 14

Split

Question 15

Romans says position patient head how

Answer 15

chin tucked

Question 16

How will some techs opt to position patient

Answer 16

angle gantry parallel to the IOML

Question 17

What is the most likely vasculature of interest for CTA of the face/head

Answer 17

Circle of Willis (COW)

Question 18

When performing CTA of COW how many scans will be performed

Answer 18

2 sets:
1 non contrast head
second arterial phase CTA with 80ml @ 4ml/s OR 60ml if the concentration is higher than 370 with 20ml of saline

Question 19

For a timed bolus of COW CTA what level will you place the ROI

Answer 19

Carotid artery at C4

Question 20

What is the scan range for CTA COW

Answer 20

Level of C1 to just above skull vertex (may differ in clinical)

Question 21

What will happen if one of the main arteries making the COW is occluded

Answer 21

The distal smaller arteries may begin receiving collateral circulation

Question 22

What are some indications for CT Venography (CTV)

Answer 22

Cerebral venous disorders, dural sinus thrombosis

Question 23

What is the contrast required for CTV

Answer 23

100ml at 4ml/s on a 45 s delay

Question 24

What is the scan range for CTV

Answer 24

just below skull base to just above vertex

Question 25

How do you position the patient for CTV

Answer 25

Hard palate perpendicular to the table top