Urinary System

Question 1

parts of the urinary system

Answer 1

Kidneys
Ureters
bladder
urethra

Question 2

Kidney

Answer 2

• retroperitoneal; 20 degrees to MSP and 30 degrees to the coronal plane
• blood supply: L&R renal veins and Arteries (one on each side)
• functions: (1) remove waste, (2) regulate water levels in the body, (3) regulate acid/base + electrolyte levels

Question 3

Urine Production

Answer 3

• 180L of blood flows through the kidneys a day
• 99% of filtrate returned
• produces 1.5L of urine a day

Question 4

Path of Filtrate

Answer 4

• afferent arterioles supply blood to the glomeruli; efferent take blood away
• glomerular capsule –> proximal convoluted tubule (PCT) –> descending limb –> loop of Henle –> ascending limb –> distal convoluted tubule (DCT) –> collecting tubule –> minor calyx

Question 5

Pathology: staghorn Kidney

Answer 5

A term used to describe a large stone that takes up more than one branch of the collecting system in the renal pelvis of the kidney

Question 6

3 sites at risk for Kidney stones

Answer 6

UP junction (Kidney)
Pelvic Brim 
UV junction (bladder)

Question 7

Percutaneous Nephrolithotomy

Answer 7

• Kidney is accessed percutaneously through the patient’s back
• needle inserted into kidney using U/S and fluoro guidance
• it is known that needle is in the kidney when urine is seen exiting the needle
  -contrast injected to confirm needle tip in the kidney; guidewire inserted; dilators of increasing size are advanced
  over the guidewire to increase the size of the access site
  -stones removed through the site using scope/extraction
  catheters

(Done if stones are too large for ESWL)

Question 8

Retrograde Urography: Indications

Answer 8

Indications: hydronephrosis, filling defects, stones, strictures, neoplasms

Question 9

Retrograde Urography: procedure

Answer 9

• done via ureteroscope
• lithotomy position
• select a ureter and inject contrast
• visualization to at least the renal pelvis
• basket extraction or stent insertion from here
• Done in OR or urology clinic

Question 10

Cystography: Indications

Answer 10

recurrent UTIs, suspected vesicoureteral reflux, bladder diverticula, suspected rupture, fistulae, bladder outlet obstruction, incontinence, hematuria, neoplasm, evaluation of post-void residual volume

Question 11

Cystography: procedure

Answer 11

• imaging of the bladder after retrograde administration of contrast
• patient is catheterized (nurse or radiologist)
• sterile procedure
• water soluble iodonated contrast hung by IV; NEVER INJECTED (could rupture bladder)

Question 12

Cystography: Positioning and CR

Answer 12

CR: 2in (5cm) above pubic synthesis 
positions: 
AP 
45-60 degree obliques 
lateral (optional)

Question 13

voiding cystography

Answer 13

• usually done
• patient voids under fluroscopy
• includes the urethra

Question 14

Urethrography: indications

Answer 14

Trauma and obstruction

Question 15

Uerthrography: Procedure

Answer 15

• Imaging of the urethra following retrograde administration of contrast media
• typically only male patients
• a few mLs of contrast injected using a device such as a Brodney clamp, catheter or syringe

Question 16

Urethrography: CP and Positioning

Answer 16

CP: level of pubic synthesis

position : 30 degrees RPO

Question 17

Intravenous Urography (IVU): Indications

Answer 17

• Shows anatomy and function of the urinary system
• contrast injected (antegrade delivery) via peripheral IV
• images taken at intervals (1,5 10, 20 minutes) to see the entire urinary system enhanced with water-soluble, iodinated contrast
• replaced with CT (more efficient, better visualization, no need for contrast)

Question 18

Extracorporeal Shockwave Lithotripsy (ESWL)

Answer 18

• done with sedation (Anesthetist +urologist)
• uses shockwaves to break apart stones
• 2000-3000 shock waves administered in a single treatment (approx. an hour)
• shockwaves constantly hit the calculi and fragment it
• calculi are located by fluroscopy

Question 19

Pathology: Prostatic Hypertrophy

Answer 19

-radiographic signs
elevation + smooth impression on the floor of the bladder
-MRI, CT, US are also useful
- prostate cancer has similar symptoms

Question 20

Seeding

Answer 20

seeds implanted into the prostate
two types:
radioactive- administers radiation
gold- localization; guidance for radiation therapy