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The Urinary System. Chapter 18. 9/9/10 Classroom ed. Urinary System. Often called the excretory system Two kidneys Two ureters One urinary bladder One urethra. Kidneys. 2 bean shaped bodies situated behind peritoneum Asymmetrical - left is slightly longer and narrower than right
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The Urinary System Chapter 18 9/9/10 Classroom ed.
Urinary System • Often called the excretory system • Two kidneys • Two ureters • One urinary bladder • One urethra
Kidneys 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
Kidneys (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
Kidneys (cont’d) • Essential microscopic components of kidney called nephrons • How many nephrons per kidney? about 1 million
Neprons Collecting ducts drain into minor calyx
Adrenal Glands Cannot be seen on plain radiographs Not part of urinary system Chiefly responsible for regulating stress response through adrenaline etc
Ureters • Two tubes 10 - 12 “ long • Retroperitoneal • Extend from renal pelvis • Enter bladder at ureteral orifice • How is urine moved through ureters? • peristalsis
Urinary Bladder • Musculomembranous sac situated immediately posterior and superior to symphysis pubis of pelvis • Serves as Urinereservoir
Urinary Bladder • How much fluid can bladder hold? • up to500 mL • Urethral orifice located in bladder neck • Area between ureteral openings and urethral orifices is trigone
Urethra • 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
Prostate • 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 akaUrography Radiographic investigation of renal drainage or collecting system
IVU- Intravenous Urogram ! Formerly erroneously known as IVP-Intravenous pyelogram! • pyelo refers to renal pelvis and calyces only • study also shows ureters, bladder, and sometimes urethra
Indications For Urography • 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
Contraindications • Inability to filter contrast medium from blood • Allergy to contrast • Abnormal BUN and Creatinine levels
Preparation Of Pt • 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 intravenouslyto examine system • Antegrade filling
Contrast Media • 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 havereactions with nonionic
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)
Injection Procedure • Obtain allergy history • Explain exam to pt • Prepare contrast and supplies (sterile tech.) • Assist radiologist as necessary • or • Perform injection if IVcertified
Injection Supplies (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
IVU Procedure • 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
Ureteral Compression • Applied over distal ends of ureters • Inhibits flow of urine into bladder • Distends renal pelvis and calyces • Compression device should be centered at ASIS
Ureteral Compression (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)
IVU Procedure 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
Radiation Protection • 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
Radiation Protection • Shield females when IR centered over kidneys • Rule out chance of pregnancy before examination (Emergency cases may not allow time)
AP Projection-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
Time Delay - IVU 3 minute 6 minutes
Time delay- IVU With compression 9 minutes
AP Projection Variations • 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)
AP Oblique Projections - RPO/LPO • 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
Nephrotomography • Best method for visualizing renal parenchyma (neprons and collecting tubules) • Ability to visualize kidneys free of intestinal content superimposition
Retrograde Urography What does retrograde mean? Opposite normal flow
Retrograde Urography • Considered an operative procedure • Pt may be under general anesthesia • Sterile technique is used • Nurse responsible for set-up of exam and pt. care
Retrograde Urography • 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
Cystography • Radiologic exam of urinary bladder • Contrast administration usually performed retrograde(against normal flow of urine)
Excretory Cystogram Retrograde Cystogram
Cystography Indicated for: 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)
Cystography indicationscont’d • Bladder trauma • Prostate enlargement • Lower urinary tract fistulae • Urethral stricture • Posterior urethral valves (obstructive congenital defect of the male urethra)
Cystography • Contraindications – anything related to catheterization of urethra!