Imaging

Question 1

__?__ images are acquired using a rotating X-ray tube and opposing detectors which collect data based on the X-ray attenuation of the tissues and is then reconstructed by a computer.

Answer 1

CT

Computed Tomography

Question 2

What slice sized can generally be obtained from

Answer 2

1mm to 10mm sections can be obtained, depending on the application.

Question 3

True or false: Standard contrast agents can be nephrotoxic and should be used with caution in patients known to have renal impairment.

Answer 3

True

Question 4

The principle concern about CT is __?__.

Answer 4

the dose of radiation involved.

Question 5

What is the estimated risk of developing malignancy from CT?

Answer 5

Often cited as one additional cancer per 1000-2000 scans performed

Question 6

True or false: Always consider pregnancy before requesting X-ray investigations for women of child-bearing age.

Answer 6

True

Question 7

__?__ is the gold standard for imaging neurospinal, rectal, prostate and MSK tumours.

Answer 7

MRI

Magnetic resonance imaging

Question 8

True or false: There is thought to be a very slight risk of toxicity related to exposure to the magnetic field of an MRI scanner.

Answer 8

False.

There is no known toxicity resulting from exposure to the non-ionising magnetic field as an adult, child or in utero.

Question 9

True or false: Metallic prosthetic joints are an absolute exclusion for MRI.

Answer 9

False.

Prosthetic joints are sufficiently fixed in place so as not to be a problem.

Question 10

True or false: Metallic foreign bodies in the eye or brain are an absolute exclusion for MRI.

Answer 10

True.

Foreign bodies in the eye or brain (typically vascular clips, surgical staples, metallic shards following trauma) are an absolute exclusion.

Question 11

__?__ generates images from the reflection of high-frequency sound waves at soft-tissue interfaces.

Answer 11

Ultrasound

Question 12

__1__ detects high-energy photons emitted by short-lived radioisotopes, which can be chemically tethered to molecules such as __2__ or somatostatin to form a __3__ (e.g. fluorine 18 deoxyglucose; FDG-18)..

Answer 12

1. PET, positron emission tomography
2. glucose
3. tracer

Question 13

A patient with lung cancer has a Positron Emission Tomography (PET) scan to evaluate possible metastatic disease. What does this type of scan demonstrate?

A) Apoptotic activity
B) Cellular proliferation
C) Glucose uptake
D) Vascular supply
E) Tyrosine kinase activity

Answer 13

C) Glucose uptake

Positron Emission Tomography (PET) is a form of nuclear imaging which uses fluorodeoxyglucose (FDG) as the radiotracer. This allows a 3D image of metabolic activity to be generated using glucose uptake as a proxy marker.