Non contrast:

  • Nodules
  • Abnormal chest x-ray
  • Small airways infection
  • Bronchiectasis
  • Emphysema

Contrast:

  • Adenopathy
  • Staging malignancy
  • Sarcoid –may want to ask for thin section inspiration 1mm ( not always necessary to do HRCT unless ordered by Pulmonologist)

CTA: Aorta, PE. No need to do pre unless looking for acute intramural hematoma or looking at stent grafts.

HRCT: Ideally for assessment of ILD

  • Asbestosis
  • UIP
  • NSIP
  • HP
  • Use HRCT questionnaire if you feel unsure.

Low dose:

  • Want to know that there is a documented prior showing nodules
  • Follow-up nodules
  • If there is anything else: i.e. nodules + adenopathy: may need routine dose.

Lung cancer screen: specific protocol Smokers for screening (i.e. 29+ pack years)

NB: Can always get retro recon thin sections,

Ideally ALARA on dose that means no non-contrast UNLESS there is a need:

We need non cons:

  • CT renal mass where you need non contrast to make a decision on enhancement.
  • CT adrenals
  • CT IVU: here the pre is done low dose with routine dose post.

So based on ACR AC criteria and LI-Rads we are going away from doing pres on

  1. Pancreas mass
  2. Liver mass

We are also going towards MR for the following:

  • Liver mass: characterization is best with MR.
  • For F/U cystic pancreatic lesions: MR pancreas which includes thin section MRCP for pancreatic duct.
  • For renal masses: solid/ cystic: MRI best to evaluate for solid nodules within cystic lesions and getting tumor/cortex SI ration may help differentiate clear cell, papillary and chromophobe, nuance in that chemotherapy differs for each.
  • MRE: ideally if the patient is young and has known Crohn Dz.

# of phases: portal phase is sufficient on most CRC, breast, lung, bladder, prostate, testicularmets etc. Rarely, you can do 2 phases for hypervascular primary lesions: art/ portal phase for carcinoid, melanoma, neuroendocrine tumor metastases.

CTE

  • Single phase: Crohn disease: adults or in acute phase.
  • To evaluate bowel when EGD and colonoscopy negative but complains of diarrhea/ abdominal pain.
  • Double phase: occult GI bleed/ Fe deficiency anemia.

CTIVU

  • Split bolus technique is best for assessment and keeps dose down. Caoili (U Michigan)

Low dose CT KUB

Ideally, only want this on patients who have a DOCUMENTED imaging study CT, US or KUB with stones and are following stone burden.