Orientation Lecture: Abdominal Imaging

Question 1

What kind of contrast can be used in x-rays?

Answer 1

• Iodinated (for cardiac)
• Barium
• Gadolinium

Question 2

What was pneumoencephalography used for?

Answer 2

Diagnosing brain cancer

The air passed to the ventricles and could be seen on x-ray. Ventricle shifting suggests a mass.

Question 3

Conventional tomography is ______________.

Answer 3

moving x-rays to blur the image

Question 4

__________ can be used as contrast on ultrasound.

Answer 4

Air (as in an agitated saline study)

Question 5

You are given an ultrasound image and are trying to decide if it’s a stone or soft tissue. What can you do to differentiate the two?

Answer 5

A stone will cast a posterior acoustic shadow, while soft tissue will not.

Question 6

Describe new research on contrast-induced nephropathy.

Answer 6

While it’s long been thought that contrast could cause renal failure, a study in 2013 showed that there was no difference in rates of renal failure in groups admitted to the hospital who got a NCCT compared to a CCT.

“Intravenous Contrast Material Exposure Is Not an Independent Risk Factor for Dialysis or Mortality
Author List”
–Robert J. McDonald, MD, PhD Jennifer S. McDonald, PhD Rickey E. Carter, PhD Robert P. Hartman, MD Richard W. Katzberg, MD David F. Kallmes, MD Eric E. Williamson, MD

Question 7

How can you tell if a CT image was taken with contrast?

Answer 7

Look at the aorta. It should be roughly the same shade as muscle. If it is brighter than muscle then the image was taken with contrast.

Question 8

Describe diffusion imaging.

Answer 8

MRI can detect water movement. If water is restricted from moving –such as from an abscess, edema (post-ischemic), or even within a neuron –then it shows up differently.

Question 9

How thick should the gallbladder be?

Answer 9

3 mm

Question 10

The splenic vein joins the _____________ vein.

Answer 10

inferior mesenteric

Question 11

The colon wall should be no thicker than ____________.

Answer 11

3 mm

Question 12

The appendix should be no thicker than __________________.

Answer 12

6 mm (because 2 walls x 3 mm/wall)

Question 13

The hepatic vein connects the _______________.

Answer 13

liver and the IVC

Question 14

The _____________ CT is the initial CT done without rotating the scanner. It is done to evaluate the range of the image.

Answer 14

scout

Question 15

The _____________ ligament connects to the top of the liver. It is a remnant of the _______________.

Answer 15

falciform; umbilical vein

Our radiology Bar Lab professor said it is a remnant of the vitelline duct, but that is incorrect. The vitelline duct becomes Meckel’s diverticulum.