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
