Introduction To Abdominal Urinary Imaging Flashcards
What do radiographs require/contain in order to work?
X-ray generators that generates X radiation from a torch-like machine and they can go on to spread/fan out
- Detector which is now usually electronic rather than film
What are the 2 directions radiographs are commonly taken in?
- Anterior-posterior (AP) - front of patient facing X-ray source
- Posterior-anterior (PA) - back of patient facing X-ray source
What are the 5 densities shown by X-ray?
- Black: gas
- Dark grey: fat
- Grey: fluid/soft tissue
- White: calcified structures e.g. bone
- Bright white: metallic objects
What are the 7 steps to reading a abdominal image systemically?
- Check demographics e.g. patient ID, DOB & name
- Modality (X-ray/CT/MRI/US?) & view (AP/PA)/orientation (use spinal processes)
- Rotation (use spinal processes), inspiration (breath in) & penetration (exposure)
- Bowel loops and gas - small & large
- Extra-intestinal gas (abnormal)
- Areas of calcification (bones e.g. ribs, fractures, cancers that decalcify bone)
- Skeletal abnormalities
- Other soft tissue outline e.g. kidneys, liver, spleen
What can be given for e.g. when viewing the kidneys in imaging to aid viewing?
A contrast medium (be careful if patient has renal problems though)
What will be shown in imaging if there is reflex of urine back up ureters?
The ureters will be dilated along with the kidneys at T12 (12th rib)-L3 and calyx’s will not be seen as clearly due to damage as a result of backflow/pressure
If the kidney was not visible at the normal vertebral level, where would you check next and why?
You would check/track downwards because in embryology the kidneys originate from the pelvic cavity and ascend up so kidneys may not have descended properly
If the vertebra of the spinal cord look like frogs heads and there is gaps in the bones, who is this image of?
A child because the gaps in bones are growth plates
If the liver was shown to extend down to the right iliac fossa on imaging, would this be problematic?
This is a normal variant of the liver; it can drop down to pelvic cavity and obstruct view of kidneys
What vertebral level does the duodenum sit between?
L1 (transpyloric region) is where transpylorus leads in 1st part of duodenum -> L3 classically
What does the jejunum typically look like on imaging with contrast?
It is not a solid white pipe but a fluffy mucosa thrown into folds is shown
If you can see all of the gut tube structures very clearly on imaging, what does this mean?
That the gut tube is filled with gas which is abnormal
What is an artefact on imaging?
A zip, buttons if a patient is clothed, the coil, sterilisation clips etc. (sometimes can help identify gender in the latter 2 cases) - can be confusing
Is the positions/sizes of organs the same in a child in comparison to an adult?
No
What would a pneumothorax look like in imaging?
Pocket of air will be shown in the peritoneal cavity above the liver and under the diaphragm in a crescent moon shape - the patient must be stood up to allow the gas to rise - this can be due to perforation of bowel as gas can escape for e.g.
What is Rigler’s sign?
Also called the double wall sign where there is gas inside AND outside the intestines (abnormal) - tubes of SI and LI can be seen very clearly
What is a calcification in a vein in the pelvis called and what will it be seen as?
Phlebolith - small white stone in pelvic cavity
What are faecoliths and what would they look like?
Stones made up of faecal matter; can arise in right iliac fossa where the caecum and appendix normally sit - shown as runs of little white circles in a line
What is a caecal volvulus and what would it look like?
Caecum has twisted on itself and blocked intestine causing a build up of gas there and in proximal gut tube so you would see gas in the SI & caecum, but not in the LI due to obstruction
What is a sigmoid colon volvulus and what would it look like?
Sigmoid has twisted back on itself and caused a blockage so you will see a large white line running along S-shape of sigmoid colon as it has dilated massively (coffee bean sign)
Give an example of where and why gas could be seen in imaging that wasn’t coming from the GI tract/peritoneal cavity.
The kidneys will look enlarged and black due to gas in kidney infections which produce gas. The gas will be in the fascial layers covering the kidney so will communicate to both sides across retroperitoneal route making it harder to identify them and their internal structures.
What is the characteristic appearance of a bladder stone?
Big white circle that has layers like an onion
What is a Computed Tomography (CT) scan and what does it do?
- Uses X-rays and detects them electronically i.e. a fancy X-ray
- Machine spirals around patient gathering volumetric information
- Coordinate pixels in 3D space so can chop up data in whatever way you wish e.g. axial, longitudinal
What is the standard view of a CT image?
Patient is lying on back and you are standing at the foot of the bed looking up their body
