Radiology of Renal Tract Flashcards
Advantages of plain films e.g. x-ray?
Cheap, readily available
Functional and anatomical information
Disadvantages of plain films e.g. x-ray in urinary/renal?
Low sensitivity and specificity for urological diseases
Radiation
Advantages of Ultrasound?
Cheap, readily available
No radiation
Contrast is not nephrotoxic
Real time imaging
Disadvantages of Ultrasound in urinary/renal?
Limited by body habitus and gas
Poor visualisation of ureters
Operator dependant
No functional information
Advantages of CT for imaging of urinary/renal system?
Currently imaging of choice for renal stones, staging renal tumours and investigating haematuria.
Disadvantages of CT for imaging of urinary/renal system?
Radiation dose
Cost
Reaction to contrast and nephrotoxicity
What are isotope scans most commonly used in the investigation of?
Prostate cancer
What is DMSA isotope scanning used to look at?
Renal scarring
What is MAG3 isotope scanning used to look at?
Assess renal function and drainage
What are bone isotope scanning used to look at?
Metastatic disease e.g. prostate cancer
What imaging modality of choice in the staging of renal tumours?
CT
How long is each kidney?
10-12cm
When do kidneys stop increasing in size?
20yrs
->they become smaller in later life
How long are the ureters?
25-30cm
Where are the three points of narrowing in the ureters?
Utero-pelvic junction
Pelvic brim
Where ureter enters bladder
Trigone of bladder?
Triangular area between the ureteric and urethral orifices
What are some indications of renal imaging?
Renal colic and renal stone disease
Haematuria
Suspected renal mass
UTIs
Hypertension
Pyelography?
Contrast study involving the injection of contrast into the ureters
Micturating cystourethrography is a another type of contrast study. When may it be used?
To assess vesico-ureteric reflux and it’s grade
Advantages of MRI in the urinary/renal system?
Multiplanar imaging
Excellent contrast resolution
Imaging of urothelium without contrast injection
Disadvantages of MRI in the urinary/renal system?
Poor spatial resolution
Poor detection of calcification and stones
Cost
Longer time
Contraindications e.g. pacemaker, claustrophobia
Reaction to contrast and other side effects
PET CT has limited use in the staging of urological malignancies, why is this?
High uptake in urine and variable uptake by tumours
What is the best imaging modality to diagnose renal tract stones?
CT
What is the least helpful imaging modality in assessment of patient with suspected renal artery stenosis?
Ultrasound
