Lecture 21 Imaging of the Urinary System Flashcards
How large are the kidneys
10- 12 cm long
Are kidneys larger in women or men
Men
At what age do the kidneys stop increasing and start decreasing
20 years
What are the 3 points of narrowing in the ureters
o PUJ
o Pelvic brim
o VU junction
Name indications for renal imaging
Renal colic Renal stone disease Haematuria Renal mass UTIs
What are the advantages of Plain films
Cheap and readily available
Historically US and Renal isotope
What are the disadvantages of plain films
o Low sensitivity and specificity for urological diseases
o Radiation
What are the advantages of ultrasound
o Cheap and readily available
o No radiation
o Contrast is not nephrotoxic
o Real time imaging
What are the disadvantages of ultrasound
o Limited by body habitus and gas
o Poor visualisation of ureters
o Operator dependant
o No functional information
What are the advantages of CT
o Currently the imaging modality of choice for detection of renal stones, staging renal tumours, investigation of hematuria
o Good spatial resolution with capability of multi planar reformat
What are the disadvantages of CT
o Radiation dose
o Cost
o Contrast resolution less than MR
o Contrast reaction and nephrotoxicity
What are the advantages of MR
o Multiplanar imaging
o Excellent contrast resolution
o Imaging of urothelium without contrast injection (MRU)
What are the disadvantages of MR
o Poor spatial resolution
o Poor detection of calcification and stones
o Cost
o Contraindications: pace maker, claustrophobia,etc
o Contrast reaction and other side effects
What is the use of the isotope scan DMSA
To look for renal scarring
What is the use of isotope scan MAG3
Asess renal function and drainage
