Formative mock exam questions 40 marks Flashcards
Q1. Describe the difference between the terms “window width” and “window level” (2 x 1 mark).
WW- the number/range HU units displayed on an image. Window level, the centre Hounsfield value within the WW
Q2. With reference to CT, describe the difference between Axial and Helical scan modes. (2 x 1 mark).
Helical scans (the main one will use now) the scanner spins, and the table moves (spiral scan)
Axial scan, take one slice, then the table moves a little bit, then another slice.
2 b. Give an advantage and disadvantage of each of axial and helical scanning. (4 x 1 mark)
Helical scan pros, faster, single breath hold, good quality data is overlapping, good spatial resolution. Good in trauma due to speed
Cons, more dose than axial, can be prone to interpolation/partial volume artefact (the computer makes up data)
Axial scan mode scans a single slice, then move and repeat,
Advantage, less dose than helical, better spatial resolution
Dis, takes longer, may require more breath holds, inappropriate in many clinical sceneries, not useful in contrast
- Give 4 considerations that need to be made before administering iodine based contrast intravenously. (4 x 0.5 marks)
Any allergies,
if they have had contrast recently and why,
if they have the correct cannula in for the flowrate,
eGFR,
LMP for contrast as the baby will get more contrast.
Asthma,
heart failure.
Hypertension,
any nephrotoxic drugs like NSAIDS.
Q1. What pathology is demonstrated in the image above? (1 mark)
Subarachnoid
Q2. What could cause this pathology? (1 mark)
Trauma eg Basal skull fracture, reputed amasysem
Q.3 Name 3 symptoms a patient like this may have? (3 x 0.5 mark)
subarachnoid bleed
Thunderclap headache, fainting, vomiting, photophobic, unconsciousness, nausea, neck stiffness
Q4. State the technical protocol of this scan. (3 x 0.5 marks)
Non-enhanced CT brain
Q5. You are about to perform the scan above. As you press the “start scan” button the patient starts seizing on the table. The team who have escorted the patient are with you in the control room. What actions would you take? (5 marks)
Stop the scan so that it is safe to go into the CT room, tell the team its safe to go in, (1)
move the bed out of the aperture so you can move the patient, (1)
get the crash trolley for the team, (if it isnt already in the room) (1)
Call trash team (1)
put the patient into recovery position (on their side), tell the team what contrast you gave the patient if you gave them contrast (1)
Get the suction tube ready in case the patient vomits so they dont choke, or point out where it is as the team may not know where it is (1)
Ask for help from radiology staff to support, (1)
You are called to theatre to perform some intraoperative imaging on a 25 year old female patient having a spinal fixation.
Q1. How would you confirm the pregnancy status of this patient? (2 x 1 mark)
The patient is asleep, ask nurse/assesthinca/surgeon to see a recent pregnancy test (1) or check medical records for record of sterilisation (1), check consent form section regarding pregnancy (1), ask the radiologist (1)
Q.2. What is the radiation controlled area in an operating theatre? (2 x 1 mark).
The 2 metres from the x-ray tube (1)
Q.3. You are unable to ascertain the pregnancy status of this patient and inform the surgeon that you cannot proceed until you speak to a radiologist. The surgeons becomes angry and tells you to “just get on with it”. How would you handle this situation? (3 marks)
Dont procedure with the surgery (1)
tell them its required by law IR(ME)R (1)
and I would just go and ring the radiologist (1)
Q4. You are eventually permitted to perform the imaging having confirmed the pregnancy status. One of the scrub staff refuses to wear lead protection. What do you do? (3 marks)
Dont procedure with the surgery (1)
Tell them its required by law IR(ME)R (1)
Tell them to leave if they wont wear it, tell them im going to leave with the c-arm if they don’t put lead protection on. (1)
Q.1 What is structure ‘A’? (1 mark)
lipohemarthrosis
Q.2 What causes this appearance? (3 marks)
Trauma, fracture, fat floats on blood, causing a fluid level to be visible
