A.    Gradient magnetic fields may stimulate 

nerves or muscles.

B.    Peripheral nerve stimulation is 

perceptible as ‘tingling’ or ‘tapping’ 

sensations.

C.    At gradient magnetic field exposure 

levels 50% to 100% above perception 

threshold, patients may experience pain.

D.    The majority of radiofrequency (RF) 

power transmitted for MR imaging is 

transformed into sound.

2.  Which of the following 
statements associated with aortic 
rupture is true?

CPD QUESTIONNAIRE

Give ONE correct answer for each 
question.

56         SA JOURNAL OF RADIOLOGY • July 2008

Instructions:
1. CPD questionnaires must be completed 

online via www.cpdjournals.org.za. After 
submission, you can check the answers 
and print your certificate. Questions 
may be answered up to 6 months after 
publication of each issue.

2. Read the articles in the journal to find the 
answers to the questions.

3. Go to www.cpdjournals.org.za to answer 
the questions.

1.  Regarding magnetic resonance, 
choose one false answer.

A.    CT is the gold standard for evaluating 

aortic rupture.

B.    The negative predictive value of a 

normal chest radiograph is high.

C.    There is a low mortality rate for major 

aortic surgical repair.

D.    Best selection criterion for endovascular 

repair is rupture immediately adjacent 

to the left subclavian artery (LSA) 

origin.

3.  Which of the following 
statements is false?

A.    The covered portion of stent grafts 

should cross the lesion and at least 1.5 

cm of the normal aorta at either end.

B.    When there is less than 15 mm of 

normal aorta between the aneurysm and 

the normal LSA, the covered part of the 

stent will not necessarily occlude the 

origin of the LSA in ensuring adequate 

length of the proximal landing zone.

C.    Closure of the tear in post-traumatic 

arch rupture often occurs spontaneously 

after stent graft insertion.

D.    The most common complication after 

stent graft implantation is leakage into 

the aneurysm.

5.  Which of the following 
statements is false?

A.    The use of a standard breast phantom 

for entrance dose estimation does not 

reflect the true skin dose for larger or 

smaller breasts.

B.    A well-defined square root relationship 

that exists between SAL and AGD is 

dependent on the kilovoltage used.

C.    In computed radiography, the displayed 

image density is automatically adjusted 

by system image processing and is 

dependent on the applied dose.

D.    In conventional radiography, the 

amount of exposure is directly related 

to the average optical density whilst in 

computed radiography it determines the 

signal-to-noise ratio.

6.  Identify the correct statement in 
the following choices.

A.    Protein-losing enteropathy is defined as 

a condition in which excess protein loss 

into the gastrointestinal lumen is severe 

enough to produce hypoproteinaemia.

B.    There are no benefits in using a Tc-99m 

labelled tracer.

C.    Peutz Jeghers syndrome is not 

associated with protein-losing 

gastroenteropathy.

D.    Faecal clearance of alpha 1-antitrypsin 

is an expensive and unreliable test of 

protein-losing enteropathy.

7.  Regarding Conn’s syndrome, all 
the following is false except:

A.    Conn’s syndrome is a common entity 

among hypertensive patients.

B.    Adrenal adenomas are usually 3 cm or 

less in size.

C.    For adenomas measuring close to 1 cm 

or more, MRI is the modality of choice.

D.    The disease is more common in males 

who present between the third and sixth 

decades of life.

8.  Identify the false statement 
among the following:

A.    Cholesteatomas are non-neoplastic but 

destructive lesions containing layers of 

keratin in a cavity lined by squamous 

epithelium.

B.    They occur mainly in the middle 

ear cleft but have also been reported 

intracranially and in the external 

auditory canal.

C.    Traumatic cholesteatomas occur as a 

complication with different types of 

injury to the temporal bone.

D.    The time interval between injury 

9.  Regarding PET-CT, identify a 
single false statement:

A.    PET has the ability to demonstrate 

abnormal metabolic activity (at the 

molecular level) in organs that as yet 

do not show an abnormal appearance 

based on morphologic criteria.

B.    PET-CT scanners are applied in 

imaging in which precisely co-registered 

functional and anatomic images are 

obtained by performing a PET study 

and a CT study on different scanners 

without moving the patient.

C.    FDG is a radiopharmaceutical analog of 

glucose that is taken up by metabolically 

active tumour cells using facilitated 

transport similar to that used by 

glucose.

D.    PET is based on the detection of 

annihilation photons released when 

radionuclides, such as F-18, C-11 and 

O-15, emit positrons (ß+) that undergo 

annihilation with electrons.

10. If you cannot answer question 9:

A.    Phone a friend.

B.   Phone George Bush.

C.    Don’t worry, Worldcup 2010 is more 

important.

D.   Read the next issue of SAJR.

4.  Which of the following 
radiological signs is not associated 
with meconium peritonitis?

A.    Highly echogenic material creating 

‘snowstorm’ appearance on ultrasound.

B.    Dense calcifications in the scrotum.

C.    Meconium peritonitis results from 

prenatal intestinal perforation nearly 

always involving the large bowel.

D.    On plain films, calcifications are 

amorphous and irregular.

and diagnosis of post-traumatic 

cholesteatomas is approximately 3 

months.

CPD.indd   56 8/1/08   2:24:22 PM