Radiology of the Renal Tract Flashcards
What is hydronephrosis?
Swelling of a kidney due to a build-up of urine (obstruction of lower parts of urinary tract)
What are the three points of narrowing of the ureters?
- PUJ
- Pelvic brim
- VUJ
What are the indications of renal imaging?
- Renal colic and renal stone disease
- Haematuria
- Suspected renal mass
- UTIs
- Hypertension
Name different imaging techniques
• Plain film • Contrast studies: - IVU - Pyelography: antegrade, retrograde, ileal conduit - Cystography • Ultrasound +/- contrast • CT and CTU • MR and MRU • Isotope scans • PET-CT
What are the advantages and disadvantages of plain films/
Advantages:
• Cheap and readily available
• Functional and anatomical information (IVU)
Disadvantages:
• Low sensitivity and specificity for urological diseases
• Radiation
What are different types of plain films?
- KUB (of abdomen)
* IVU
What is a pyelography?
Injection of contrast into the ureters
What is micturating cystourethrography?
Fluoroscopic study of the lower urinary tract in which contrast is introduced into the bladder via a catheter.
The purpose is to assess the bladder and urethra, and measure vesicle-ureteric reflex and its grade.
What are the advantages ad disadvantages of USS?
Advantages: • Cheap and readily available • No radiation • Contrast not nephrotoxic • Real time imaging
Disadvantages: • Limited by body habits and gas • Poor visualisation of ureters • Operator dependent • No functional info
What can USS show?
Congenital:
• Horseshoe kidney
• Ureterocele (prolapse of the female urethra into the vagina)
• Megaureter (dilated ureter)
- Renal tumour
- Urothelial tumours
What are the advantages and disadvantages of CT?
Advantages
• Imaging modality of choice for detection of renal stones, staging renal tumours, investigation of hematuria
• Good spatial resolution with capability of multi planar reformat
Disadvantages • Radiation dose • Cost • Contrast resolution less than MR • Contrast reaction and nephrotoxicity
What can CT show?
- Renal stone
- Renal tumours +/- IVC thrombus
- Bladder tumour
- Ureteric tumour
What are the advantages and disadvantages of MRI?
Advantages
• Multiplanar imaging
• Excellent contrast resolution
• Imaging of urothelium without contrast injection (MRU)
Disadvantages
• Poor spatial resolution
• Poor detection of calcification and stones
• Cost
• Contraindications: pace maker, claustrophobia,etc
• Contrast reaction and other side effects
Name different isotope scan?
- DMSA - to look for renal scarring
- MAG-3 - assess renal function and drainage
- Bone scan - metastatic disease i.e. prostate cancer
What is the indication for PET-CT use?
Extra-urological metastatic disease if other imaging modalities are equivocal or in poor surgical candidates
What is the best imaging modality to diagnose renal tract stones?
CT
What imaging modality of choice in staging of renal tumours
CT
What is the least helpful imaging modality in assessment of patient with suspected renal artery stenosis
USS
