Flashcards in Radiology Deck (72):
Where do the kidneys lie in the retroperitoneum?
What is the level of the hila for each kidney?
Left -> L1
Right -> L1/L2
Why is the left renal vein longer than the right?
Passes across the aorta anteriorly to join to the right sided IVC
What CT phase is best to depict calculi?
After the injection of contrast, how long should be waited for the corticomedullary phase of CT?
After the injection of contrast, how long should be waited for the Nephrographic phase of CT?
After the injection of contrast, how long should be waited for the excretory phase of CT?
Which of the following is not a risk factor for contrast nephropathy:
- Renal impairment - +/- diabetes mellitus
- Congestive heart failure
- LV ejection fraction > 40%
- Acute MI (within 24 hours)
- Nephrotoxic drugs
LV ejection fraction > 40%
If it is
What are the hydration protocols to prevent contrast nephropathy?
1-1.5 ml/kg/h 0.9% normal saline 6-12hrs before and after contrast administration
Sodium bicarbonate instead of sodium chloride – urine alkalinization – prevention of oxygen free radicals
Bicarbonate administered from 1 hour pre-procedure to 6 hrs post
How do cysts appear on MRI in the following phases:
T1 -> Low/no signal
T2 -> High signal
What causes nephrogenic systemic sclerosis?
Exposure to gadolinium containing contrast medium used in MRI
What is a CT urogram used to image?
What is the commonest imaging modality for viewing the bladder?
What does a bladder USS allow us to see?
Internal calculi (if Calcium)
Bladder wall irregularities
What condition needs met for a bladder USS to be most useful?
Bladder must be full
What is cystography the gold standard investigation for?
Bladder wall tears
What tumour staging is CT best for?
What tumour staging is MRI best for?
Local staging of bladder wall tumours
What is a retrograde urethrogram used for?
What is the modality of choice for imaging the testes, uterus, ovaries and prostate?
What is the modality of choice for imaging infertility (tubal patency) and uterine abnormalities?
What is the mediastinum testis?
Infolding of tunic albuginea
What is the first line investigation is pyelonephritis or a gynaecological condition is thought to be the source of renal colic?
If a patient with renal colic is pregnant, what investigations should be done?
USS and/or MRI
Which calculi can be seen on x-ray?
What is the first line investigation for suspected renal colic?
Where do the ureters pass in relation to the psoas muscles?
Anteriorly over them
Where do the ureters descend in relation to the tips of the lumbar transverse processes?
How can we visualise the collecting systems, ureters and bladder on x-ray?
IV urogram (contrast)
Where do ureteric calculi often get stuck?
Where do renal calculi mimics tend to lie?
More lateral in the pelvis
How can you tell the difference between a renal stone and a phlebolith?
- Lie more laterally
- Calcified but have a slightly radiolucent centre
-> Calculi are completely radio-opaque
What are phleboliths?
How does USS help diagnose renal stones?
Can't see stone itself due to bowel obscuring image, but it will show associated hydronephrosis
What is the definitive test to confirm a symptomatic ureteric calculus?
Non-contrast enhanced CT
What will a CT alo show in renal calculi?
Signs of obstruction:
- Perinephric stranding
What are some potential differentials for renal calculi that will be seen on CT?
Where does macroscopic haematuria tend to arise from?
If the source of haematuria is suspected to be from the kidneys, collecting system or ureters, what modality is the first line if the patient is older than 50?
If the source of haematuria is suspected to be from the bladder or urethra, what modality is the first line if the patient is older than 50?
What is the most sensitive way to detect renal parenchymal tumours or urothelial tumours of the collecting systems or ureters?
In patients younger than 50 with macroscopic haematuria, why are USS and cystoscopy preferred?
Incidence of urothelial tumours is low, so routine CTU which gives a double dose of radiation is unjustified
When is a CTU used in patients younger than 50 with macroscopic haematuria?
If USS and cystoscopy are normal and haematuria persists
In what patients is an MR urography useful?
How would an angiomyolipoma appear on CT?
- High fat content
-> Less dense than surrounding parenchyma
When would a CT scan be taken if there is a suspected renal cortex tumour?
100 seconds after contrast
What is the 'density' or normal fluid on CT?
If the 'density' of a substance inside a cyst on CT is >20 what might you suspect?
What are features of complex cysts on CT?
Fluid density filled cysts and uniform cysts are usually what?
Solid (non-cystic) masses >3cm are usually what?
'Cannon ball' mets
Renal tumours mets in the lungs
What investigation can be used to diagnose renal artery stenosis?
If the kidney appears small on imaging, what process is occurring?
A chronic cause
What will a USS of hydronephrosis show?
Dilated renal pelvis and calyces
If the kidney appears normal/large on imaging, what process is occurring?
On an US doppler of epididymo-orchitis, how will the testis appear?
Hypervascular (lots of colour)
On an US doppler of testicular torsion, how will the testis appear?
Hypovascular (no/very little colour)
Which of the following is not a common cause of painless testicular swelling:
- Epididymal cyst
What is a varicocoele?
Dilated scrotal venous plexus with tortuous veins usually >2mm in diameter
Why do varicocoeles typically occur on the left?
Renal tumour may extend into left renal vein, which can result into the left gonadal vein being occluded
What else must also be scanned in a varicocoele?
How does a hydrocoele appear on USS?
Black anechoic fluid surrounding the testicle
How does an epididymal cyst appear on USS?
Anechoic uni/multilocular lesion typically arising within the epididymal head
A testicular mass with vessels inside is probably what?
How is renal trauma best assessed?
What type of bladder rupture is most common and how is it treated?
What type of bladder rupture is rarer and how is it treated?
- Due to compression of full bladder
How is bladder trauma diagnosed?
or CT cystography:
- Contrast leaks into intra- or extraperitoneal space
If you have clinical suspicion of urethral trauma (meatal bleeding, anuria) what must NOT be done?
How can a urethral stricture be imaged?