Chapter 18
The Urinary System
9/9/10 Classroom ed
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• Often called the excretory system
• Two kidneys
• Two ureters
• One urinary bladder
• One urethra

2 bean shaped bodies situated behind peritoneum
Asymmetrical - left is slightly longer and narrower than right
How come Rt kidney slightly lower than Lt kidney?
Liver
Lie in an oblique plane (opposite si jt direction)
Normally extend from T-12 to L3

Kidney Function
• Remove waste products from blood
• Maintain fluid and electrolyte balance
• Secrete substances that affect blood pressure
• How much urine excreted per day?
1 - 2 liters

(cont’d)
• Minor calyces unite to form major calyces
• Major calyces unite to form renal pelvis
• Renal pelvis then drains into ureters
• Hilum - longitudinal slit in medial border for transmission of blood vessels, nerves, lymphatic vessels, and ureter

(cont’d)
• Essential microscopic components of kidney called nephrons
• How many nephrons per kidney? about 1 million

Collecting ducts drain into minor calyx

Cannot be seen on plain radiographs
Not part of urinary system
Chiefly responsible for regulating stress response through adrenaline etc

• Two tubes 10 - 12 “ long
• Retroperitoneal
• Extend from renal pelvis
• Enter bladder at ureteral orifice
• How is urine moved through ureters?
– peristalsis

• Musculomembranous sac situated immediately posterior and superior to symphysis pubis of pelvis
• Serves as Urine reservoir

• How much fluid can bladder hold?
– up to 500 mL
• Urethral orifice located in bladder neck
• Area between ureteral openings and urethral orifices is trigone

• Carries urine from bladder to?
• exterior of body
• How long is it in females?
• About 1.5

• In males?
• About 7  to 8

• Sphincter at neck of bladder controls flow
• Male urethra contains following parts:
– Prostate
– Membranous area
– Spongy area

• Gland surrounding proximal part of male urethra
• Considered part of male reproductive system , but due to location, often described with urinary system
• Prostate secretes fluid that mixes with seminal fluid to create ejaculate

Radiography of Urinary System aka
Urography
Radiographic investigation of renal drainage or collecting system

Formerly erroneously known as IVP -
Intravenous pyelogram!
– pyelo refers to renal pelvis and calyces only
– study also shows ureters, bladder, and sometimes urethra

• Demonstrate physiologic function and structure of urinary system
• Evaluate abd. Masses, renal cysts and tumors
• Urolithiasis
(stones)
• Pyelonephritis
(Inflammation of kidney)
• Hydronephrosis
(distension of renal pelvis and calyces with urine)
• Effects of trauma
• Pre-op evaluation
• Renal hypertension

• Inability to filter contrast medium from blood
• Allergy to contrast
• Abnormal BUN and Creatinine levels

• Pt should follow low residue diet for 1-2 days prior to exam
• laxative taken day before
• NPO after midnight
• Pts with multiple myeloma, high uric acid levels, or diabetes should be well hydrated before IVP exam
– Dehydration leads to increased risk of renal failure

Contrast Media
• Must be used to visualize urinary tract
• Iodinated, water-soluble contrast administered intravenously to examine system
• Antegrade filling

• Excretory urography
(IVU) generally uses a 50 to
70% iodine solution
• Lower concentrations for bladder studies due to large amount required to fill bladder (30%)
• Non-ionic contrast is generally used
– More expensive, but-
– Patients less likely to have reactions with non ionic

Contrast Media and Adverse Reactions
• Crucial not to leave pt alone for first 5 minutes after injection!
• Mild reactions
– warmth
– flushing
– hives, Nausea/Vomiting, respiratory edema
(accumulation of fluid in lungs)
• Severe reactions
– Anaphylactic shock
(sudden allergic response associated with a sudden drop in blood pressure and difficulty breathing). Can lead to death in a matter of minutes)

• Obtain allergy history
• Explain exam to pt
• Prepare contrast and supplies
(sterile tech.)
• Assist radiologist as necessary
– or
• Perform injection if IVcertified

(cont.d)
• Tourniquet
• IV arm board
• Towels
• Emergency kit
• Emesis basin
• Alcohol wipes, hibiclens, or povidone iodine wipes or swabs
• Contrast
• 19-22 G needle, butterfly or angiocath for infusion
• Extension tubing
• Tape or clear-type dressing

• Scout – KUB
• Contrast is injected
• Timed sequence of films obtained until bladder begins to fill-
– Immediate image of kidneys
– 5 minute image of abd. or kidneys
– Compression applied

• Applied over distal ends of ureters
• Inhibits flow of urine into bladder
• Distends renal pelvis and calyces
• Compression device should be centered at
ASIS

(cont’d)
• As much compression as pt can tolerate!
• Should not be applied when:
– stones, abd. mass or aneurysm, colostomy, suprapubic catheter, recent abd. surgery or trauma
• (Because of improvement of contrast agents, compression no longer generally used)

cont’d
• Tomograms are obtained once bladder is filled
– Pt is measured, divide number by 3, cuts begin there
• Pt. measures 30cm, beginning cuts at 10cm
• Release compression slowly
• Have pt void, and obtain post-void film

• Radiographer is responsible!
• Gonadal shield - if it does not interfere with examination objective
• Close collimation
• Avoid repeat exposures
• Shield males for all urinary studies, except when urethra is of primary interest

• Shield females when IR centered over kidneys
• Rule out chance of pregnancy before examination
(Emergency cases may not allow time)

Radiographic Positions IVU

• KUB
• ( All exposures at end of expiration for any urinary system study)

AP Projection- IVU
(cont’d)
Must include entire
KUB region
Should include prostatic region on older males

3 minute
6 minutes

9 minutes
With compression

• Trendelenberg
– Lower head 15 - 20 degrees
– Helps demonstrate lower ureters
• Upright
– Center lower - organs change position
• Prone
– Demonstrates ureteropelvic region
– Fills obstructed ureter in cases of hydronephrosis
(distension of renal pelvis and calyces with urine)

• Patient is supine
• Patient rotated to
30 degrees
• CR to iliac crest, 2 in. lateral to midline
– Center to side up

AP Oblique Projections - RPO/LPO
• Elevated kidney will be parallel to cassette
• Kidney closest to cassette will be perpendicular
• Entire KUB region must be included

• Best method for visualizing renal parenchyma
(neprons and collecting tubules)
• Ability to visualize kidneys free of intestinal content superimposition

What does retrograde mean?
Opposite normal flow

• Considered an operative procedure
• Pt may be under general anesthesia
• Sterile technique is used
• Nurse responsible for set-up of exam and pt. care

• Requires catheterization of ureters
• Contrast injected directly into pelvicaliceal system via cathethers
• Provides improved opacification of renal collecting system

Retrograde Urography (cont’d)
• Contrast does not enter blood stream
• Used for patients with renal insufficiency or contrast sensitivity
• Ureters, and collecting systems can be selectively imaged and sampled
• Little physiologic information provided

• Radiologic exam of urinary bladder
• Contrast administration usually performed retrograde
(against normal flow of urine)

Excretory Cystogram
Retrograde Cystogram

Vesicoureteral reflux
(backward flow of urine into ureters)
Recurrent lower urinary tract infection
Neurogenic bladder: ( dysfunction due to disease of central nervous system or peripheral nerves)

cont’d
– Bladder trauma
– Prostate enlargement
– Lower urinary tract fistulae
– Urethral stricture
– Posterior urethral valves
(obstructive congenital defect of the male urethra)

“Retrograde”
• Contrast will be dripinfused via a catheter
• Bladder will be filled to capacity
• Fluoro-spot and overhead films will be obtained

Scout filled AP
Cystography Routine Series both obliques lateral voiding post-void

• CR
( similar to coccyx projection)
– Angled 10 to 15 degrees caudad to center of IR
– Enters 2  above upper border of pubic symphysis

(excretory method)

(prone)
CR
– Angled 10 to 15 degrees cephalad
– Enters about 1”distal to coccyx
– Exits just above superior border of pubic symphysisPatient prone
– Arms out of anatomy of interest
– IR centered to CR

• Pt position
– 40- to 60-degree
– RPO or LPO depending on physician preference

CR
– Perpendicular to center of
IR
– CR 2  above upper border of pubic symphysis and 2
 medial to upper ASIS
– If bladder neck and proximal urethra is of interest, 10-degree caudal angle of CR will project pubic bones below them

• Patient position
– Lateral recumbent, right or left side
• Part position
– Knees flexed
– MCP aligned to midline
• CR to midcoronal plane at 2 in. above symphysis pubis

– Demonstrates anterior/posterior bladder walls
– Base of bladder
– Any vesicovaginal or vesicorectal fistulae

• Retrograde study to visualize bladder and urethra
• Contrast does not enter blood stream
• Sterile technique must be used
• Nurse will generally perform catheterization

• AP Oblique Projection - RPO/LPO
• Patient is supine, rotated 35 - 40 degrees
• Urethral syringe (or Brodney clamp?) is used to introduce contrast
Cunningham Penile Clamp: device used to help control male urinary incontinence.

• Images are obtained as contrast is injected
• Entire urethra must be visualized
• Bladder can be filled to obtain antegrade voiding study
• Why is this antegrade if its injected into urethra?

• Retrograde
• AP Projection
(maybe obliques)
• Bladder can be filled and patient void for antegrade studies
• Cassette should be centered as for cystography
• Abduct thighs to prevent superimposition of bone or soft tissue

• Positioning is same as retrograde cystography
• On lateral films, pt. asked to strain to demonstrate any prolapse or incontinence

Metallic Bead Chain Cystourethrography
• To evaluate stress incontinence in females only
• Beaded chain inserted in
Urethra
• Shows anatomic changes in shape and position of anatomic floor
• Valsalva tech. applied for comparison

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Voiding Cystourethrogram
X-ray images of bladder and urethra during urination
Follows cystogram - urinary catheter removed
Pt. urinates into special radiolucent urinal as images taken

Voiding Cystourethrogram cont’d
• Shows size and shape of bladder under stress caused by urination
• Demonstrates urethra functioning
• Most commonly used for young girls with history of recurrent bladder infections