Imaging Flashcards
if pyelonephritis is suspected, what investigation should be done
US
- to exclude ureteric obstruction
Then Contrast-CT
if a gynaecological disease is suspected, what investigation should be done
US
- to visualise uterine, ovarian and uterine tubal pathology
when is an US (or MRI) done instead of a CT
patient is pregnant
- avoid radiation exposure to foetus
Renal colic Ix
1st - Non contrast CT
2nd - KUB x-ray
If CT contraindicated then MRI
what is the normal ureter course
Pass inferiorly over the psoas muscles
Descend anterior to the tips of the lumbar transverse processes
Cross the iliac bifurcation and enter the pelvis
Pass posteromedially and enter the posterior aspect of the bladder
where do ureteric calculi often get stuck at
pelviureteric junction (PUJ) pelvic brim vesicoureteric junction (VUJ)
what are the flaws in KUB x-ray
lacks specificity
- phleboliths, lymph nodes, uretine fibroids and arterial calcification are also shown
what are phleboliths
calcification within a vein
- of no clinical importance
what is the definitive test to confirm SYMPTOMATIC ureteric calculus
Non-contrast enhanced CT
when is CT avoided
In pregnant females
if possible, non-preganant young females
contrast induced nephropathy
how can renal colic be followed up
by using the simplest test that showed the calculus at presentation
what is the aim in macroscopic haematuria investigation
to examine the whole urinary tract by simplest means possible
Ix of frank haematuria in the over 50s
1 - CT urography (CTU)
2 - Cystoscopy
what does the CTU look at
the kidneys, collecting systems and ureters
what does the cystoscopy examine
the bladder and urethra
what is the CTU technique
First CT scan before contrast
Administration of IV contrast (wait 15 mins)
Top up dose of IV contrast
Second CT scan
what can be seen in the first CT scan before contrast
renal or ureteric calculi
what can be seen in the second CT scan with contrast
renal parenchymal tumours
urothelial tumours of the collecting systems or ureters
what is an advantage of finding a tumour on a CT scan with contrast
any tumour detected can be staged at the same time
Ix of the under 50s with macroscopic haematuria
US of kidneys to detect calculi and renal parenchymal tumours
Cystoscopy to look for occasional bladder TCC, bladder calculi, other bladder tumours or evidence of urethritis/prostatitis
when is a CTU done in under 50s with macroscopic haematuria
only when US and cystoscopy are normal and macroscopic haematuria persists
when is MR urography useful
as it does not require contrast or radiation, useful in patients who have;
- contrast allergy
- renal impairment
- pregnancy
when is MR urography used
when CTU contra-indicated
how are most renal masses detected
incidentally when imaging for another reason
