Urinary Imaging Flashcards
Kidney function
Removes metabolic waste from blood
Maintains fluid and water levels
Regulates acid-base and electrolyte balance
Secretes substances that affect blood pressure
The urinary system includes:
Two kidneys
Two ureters
One urinary bladder
One urethra
Kidney location
Retroperitoneal cavity
Surrounded by fat
Encapsulated by a fibrous capsule (gerota’s fascia)
Adrenal glands
Suprarenal glands, not part of the urinary system.
Endocrine structures
Calyces
Cup shaped recesses in the center of each kidney that receive the urine from the collecting ducts
The beginning branches of the urinary collecting system are called
Minor calyces
Minor calyces unite to form the
Major calyces
The major calyces unite to form the
Renal pelvis
The renal pelvis exits the kidneys and transitions into the
Ureter
Ureters
Connects kidneys to the bladder.
- very narrow in diameter, collapsible tubing
Kidneys produce how much urine per day?
1-2 liters
Epinephrine is secreted by the
Suprarenal glands
The left kidney is
Longer, narrower, and located higher than the right kidney due to the size of liver causing displacement.
The kidneys will drop about 2” when
Moving from the supine to upright
The average kidney is approximately
4.5” long
2.5” wide
A little over 1” thick
Nephroptosis
The abnormal fall of the kidneys, normally suspended in the abdomen.
With failure of suspensory tissues, kidneys will fall sometimes into pelvis.
The ureters enter the bladder along the
Posterior wall.
Ureteral valves
One way flow from ureteral into bladder
UVJ
Ureterovesicular junction
The female urethra is about 1-2” long, males about 7-8” making
Females more susceptible to UTI
The urinary bladder serves as a reservoir and can hold about
500cc of urine
Rugae
Numerous mucosal folds located within the urinary bladder
Trigone
Area of the bladder formed by its 3 openings:
2 ureters
1 urethra
Micturition
Act of urinating/voiding
Detrusor muscle
Surrounds bladder, contracts in order to expel urine
Bladder
U/V junction
Ureteral valve
Trigone
Urethra
Males bladder also includes
Prostate gland
IVP
Intravenous pyelogram.
The most commonly ordered radiographic study of the urinary system.
IVU
Intravenous urogram.
The proper term for the examination of the entire urinary system.
Nephrotomogram phase
Phase filtering of blood in the cortex of an IVP/IVU exam
Collection/transport phase
Movement of urine into calyces, renal pelvis, ureters, and into bladder during a IVP/IVU image
Antegrade
During an IVU, the contrast is traveling in the normal excretory direction of flow.
Retrograde
Against the normal flow.
Method requires catheterization or endoscopy and can be used to demonstrate the bladder, urethra, and lower ureters.
Sample IVU routine:
Scout (KUB) Injection - note time 1 min. Nephrogram or nephrotomography 3 min. AP supine 5 min. AP supine 10 min. AP supine 15 min. AP supine 20 min. Posterior obliques Post-void (prone or erect)
IVP or IVU demonstrates
Both function and structures of the urinary system by kidneys ability to filter contrast medium from the blood, collect, contrast as urine, and pass urine to bladder
Purpose of IVU/IVP
Visualize the collecting portion of the urinary system
Assess the functional ability of the kidneys
Assess the movement of urine through system
Bolus injection
The rapid introduction of contrast agents into the vascular system
50-100cc
The most common contrast dosages used for a adult patient.
Why do a scout abdomen.
Contour and location of kidneys Presence of stones Pre contrast comparison Success of prep - NPO Perfection of technique
Contrast medium usually becomes visible in the pelvicalyceal system within
2-3 minutes of injection
What is seen on an IVU/IVP AP projection?
Entire urinary system K - U - B
No rotation/motion
On an IVU/IVP posterior oblique exam
The side up kidney is seen parallel to the IR and the side down is seen perpendicular to the IR
In the AP supine position the kidneys
Do not sit flat and square in the abdomen
In the RPO position the left kidney is ? to the IR and the right is ? to the IR
Left is parallel to the IR and right is perpendicular to the IR.
In the LPO position the right kidney is ? to the IR and the left is ? to the IR
The right kidney is parallel to the IR and the left is perpendicular to the IR.
Ureteric Compression
Used to enhance filling of the pelvicalyceal system and proximal uterus. Allows the renal collecting system to retain contrast medium longer. Applied over the distal ends of the ureters at the level of the ASIS but just medial to the ASIS.
Tomography
Exam where a slice of anatomy is imaged rather than the entire body part using a higher contrast, blurring away unfocused tissues. Tissue is in focus visualized without superimposition.
Tomographic movements
Tube and Bucky move together
Fulcrum is the focal point of motion - anatomy at level of fulcrum is best visualized.
The more tomographic movement
Results in finer focus anatomy.
Linear tomography
As the tube and film move in opposite directions, blurring occurs in structures outside the focal plane
Tomographic angle
The angle determines the thickness of the slice.
As the tomo angle increases
Thinner slice or section of anatomy imaged
As the tomo angle decreases
A thicker slice or section of anatomy will be imaged.
Cystography
Retrograde urological study of the urinary bladder, performed to evaluate trauma, calculi, tumor, or inflammatory disease.
Contrast with a cystography exam
Delivered through a catheter into the bladder which flows in by gravity pressure only.
Voiding cystography is performed to assess
Ureteral valves and reflux of contrast up ureters
Patency of the urethra
VCUG
VCUG
Voiding cystourethrogram
Retrograde study of the bladder and urethra to determine cause of urinary retention and to evaluate for possible ureteral reflux.
Cystography contrast
Very low concentration water soluble iodine
18-20%
Ureteral reflux
Failure of the ureteral valves to prevent back flow of urine from bladder into ureters and kidney during mucturition
BPH
Benign prostatic hyperplasia
Male stricture of the urethra
Can be accompanied by the backflow of urine into the prostate gland,leading to chronic and recurrent prostatitis.
