Radiology Flashcards
What causes renal colic?
ureteric calculus
Why must you ensure the history and exam are consistent with renal colic, before requesting imaging?
Tests used to detect calculi give a high radiation dose
What diseases mimic renal colic?
pyelonephritis or gynaecological disease
What imaging modality should be used to visualise pyelonephritis or gynaecological disease?
Ultrasound
What imaging modalities should be used to minimise radiation exposure to a foetus during pregnancy?
US and/or MRI
What substance is found in high density vs low density calculi?
Dense calculi = calcium
lower density = urate
What forms of imaging can be used to visualise renal calculi?
KUB X-ray
CT
MRI
What is involved in a KUB X-Ray?
Kidney, Ureter, Bladder
Photo taken of Upper Urinary tract and separate photo of Lower Urinary tract
Describe the course of the ureters?
- Pass inferiorly over the psoas muscles
- Descend anterior to the lumbar transverse processes
- Cross the iliac bifurcation and enter the pelvis
- Pass posteromedially and enter the posterior aspect of the bladder
What are the predictable sites where ureteric calculi will get stuck?
pelviureteric junction
pelvic brim
vesicoureteric junction
Why is contrast not usually used to visualise renal calculi?
The contrast is dense, as are most calculi
=> the contrast would obscure visualisation of calculi
What other causes of calcification may simulate renal calculi?
Phleboliths
Lymph nodes
Uterine fibroids
Arterial calcification
Aside from the calculus itself, what other signs of obstruction can be seen on CT?
perinephric stranding (oedema in perinephric fat)
hydroureteronephrosis (widening of ureter above blockage)
Most calculi pass spontaneously. TRUE/FALSE?
TRUE
What are the potential causes of macroscopic haematuria?
Calculi Infection Tumour Urethritis/prostatitis Trauma Clotting disorders
At what age does Renal cell carcinoma present vs transitional cell carcinoma?
RCC - any age
TCC - over 50
What is the difference between Cystoscopy and ureteroscopy?
Cystoscopy = camera inserted to visualise the bladder and urethra Ureteroscopy = passed further up to visualise ureters also
Describe how CT urography is carried out?
- First CT scan before contrast
- Administration of IV contrast
- This is excreted by kidneys over 15 minutes
- Top up dose given 60 seconds before 2nd CT (to enhance renal parenchyma)
- Second CT scan following contrast
What is CT urography particularly sensitive in detecting?
- renal parenchymal tumours
- urothelial tumours of the collecting systems or ureters
What is meant by a multifocal TCC?
Present in multiple parts of urinary tract
e.g. in kidney and in bladder
Why is CT urography less commonly carried out in patients under 50 who develop macroscopic haematuria?
urothelial tumours of kidney or ureter = very low at this age
CTU imparts a double radiation dose which is unjustified
How are patients <50 investigated for macroscopic haematuria?
US of kidneys
Cystoscopy
CTU only when US and cystoscopy are normal and macroscopic haematuria persists
Over what size are kidney tumours more likely to be malignant?
3cm
How are renal masses characterised?
size
density (fat, fluid, soft tissue, calcified)
uniformity (varying density?)
internal morphology (nodules, septa)
What mass in the kidney contains fat?
benign angiomyolipomas
Masses in the kidney filled with fluid are what?
cysts (of which the uniform ones are benign)
What type of cysts would you worry about being malignant?
if they contain solid areas or thick septa
What is CT used to asses when staging a cancer?
local spread:
- extracapsular
- adjacent organs
- involvement of renal vein or IVC
Lymph node Involvement
Metastatic disease
lung, bone
In pre-renal disease, what imaging modality is used to visualise renal artery stenosis?
MR angiography
Fluid is dark on US. TRUE/FALSE?
TRUE
A hypervascular testis on Doppler US with colour may indicate what disease?
epididymo-orchitis
An avascular testis on Doppler US with colour may indicate what?
Testicular torsion
What are common causes of painless scrotal swellings?
hernia
varicocoele (distended vein)
hydrocoele
epididymal cyst
What is a rare but serious differential in a painless scrotal swelling?
testicular tumour
Epididymal cysts are usually benign. TRUE/FALSE?
TRUE
Testicular lump = malignant
Epididymal lump = Benign
What imaging modality is the most useful in kidney trauma?
CT
What investigation is most useful in bladder trauma?
cystography or CT cystography
After filling bladder, contrast leaks through into the intra or extraperitoneal space
What are the two possible types of bladder rupture?
Intraperitoneal (due to compression)
Extraperitoneal (more common)
Urethral disruption is associated with what injuries?
anterior pelvic fracture/dislocation
OR straddle injury
What are the 2 main types of urethral disruption?
complete or incomplete
Should you attempt catheterisation in urethral disruption?
No - call urologist if concerned that urethra has been damaged
What is a long term complication of urethral trauma?
Stricture formation
What non-vascular interventions can radiology perform in the urinary system?
- relief of ureteric obstruction (nephrostomy, ureteric stent)
- drainage of abscess/cyst
- biopsy of renal masses
- guided ablation of renal tumours (e.g. cryoablation)
What vascular interventions can radiology perform in the urinary system?
- correction of renal artery stenosis
- control of arterial bleeding sites (embolisation)
- varicocoele embolisation
