Urinary System Lecture 1

Introduction The kidneys lie in retroperitoneal space , opposite to the upper three lumber , surrounded by perinephric fat. Bean-shaped with their concave aspect pointed medially . Each kidney consist of cortex &medulla . The PCS consist of minor calyces which drain into major calyces via a neck (infundabulum).

Introduction The ureter run retroperitonealy anterior to the tip of transverse process of lumbar vertebra separated from them by psoas muscle , it descend along the lateral pelvic wall to the level of ischial spine ,from where it run anteromedialy until it enter the superolateral angle of the UB base ,the ureter run obliquely through the bladder wall for 2cm . UB lie immediately posterior to the pubic bones. located in the center of the pelvis ,it surround by perivesical fat ,the base of the UB receive the ureters and give rise to the urethra . UB may have smooth upper indentation in female by uterus ,while in male there is smooth lower indentation by prostate .

Radiological investigation of urinary system . The 4 basic examinations for urinary system: 1. US 2. IVU(intravenous urography). 3. CT 4.Radionuclide examination . Arteriography &other invasive investigations are limited to highly selected patients .

Ultrasound: It’s important investigation in renal system as its available , harmless , repeatable & non invasive . INDECATION OF US 1-Renal calculi. 2-Evaluation of renal masses &localization of cyst for rupture. 3-Investigation of renal failure or non functioning kid. at IVU. 4-Measurment of renal size to follow the renal size in both acute & chronic disease 5-diagnosis of polycystic kid. 6-Investigation of perinephric abscess. 7-Assessment of bladder tumor

In normal US The kidney is smooth in outline , hypoechoic parenchyma surrounding a central hyperechoic region (renal sinus) which consist of PC system with surrounding fat &blood vessels . Normally ureters are not usually visible . UB is examine in distended state ( full bladder )

EU ( excretory Urography ) IVU IVP It provides both functional & anatomical information . It has advantage ,that whole urinary tract can be seen on a few films .

Method of examination : 1.Plain film ( KUB ) : for Assess patient preparation . Detect bone and soft tissue abnormality. To identify urinary tract calcification. Determine exposure factors. The main categories of calcification are : calculi nephrocalsinosis localized renal paranchymal calcification (renal TB or tumor) bladder calcification prostatic calcification

Films following the injection of water soluble iodinated contrast media , dose = 300mg/kg body weight . 2.1min film (conned view):nephrogram for renal parenchyma, particularly renal outline , size & position . 3.5min film (conned view) :pyelogram.excretion of contrast to PCS. 4.10 min film :full length (C.M fill the PCS) 5. 15-20min film to show the contrast in the ureters & probably show the bladder full with opacified urine . 6.post voiding film. To asses the residual volume

Interpretation of films taken after injection of contrast media: 1.Renal size 2. Renal position 3.Renal outline It provide both functional &anatomical information . Adult renal size is 10-16cm,a difference of 1.5cm is acceptable between 2 side. Small kidney could be unilateral or bilateral.

  1.Renal size. Causes of unilateral small kidney : Chronic pylonephrites , TB , Obstructive uropathy (late stage) , renal artery stenosis , renal hypoplasia and radiation nephritis. Causes of bilateral small kidneys : Chronic GN , DM , analgesic nephropathy, hypertensive nephropathy, collagen vascular disease . Causes of unilateral large kidney : Compensatory hypertrophy Bifid collecting system Renal vein thrombosis Hydronephrosis Causes of bilateral large kidneys : Acute GN polycystic kid. Amyloidosis

2. Renal position : Rt kid. is lower than Lt. kid 2. Renal position : Rt kid. is lower than Lt. kid. , renal axis parallel to the psoas muscle and extend from lower border of D12 to lower border of L3. Abnormal axis occur in : Ectopic kidney Displacement by mass Nephroptosis

3.Renal outline: renal parenchyma should be smooth, symmetrical and uniform , measurement 2-2.5cm with no indentation .   4.Renal calices : Normal calicies have well define cup shape ,in dilated PCS shape of calices change from cupping to flat or to clubbing . 5.renal pelvis : varies in position ,size and shape. normally its homogenous , any filling defect within renal pelvis may caused mainly by one of 3 most common causes 1.radiolucent stone . 2.urothelial tumor. 3.blood clot.

6. Only part of ureter is seen due to peristalsis, , 7mm is maximum accepted diameter . Its normal course along the transverse processes of lumber vertebra 7.UB In full bladder view , the UB have smooth outline &centrally located Trabeculated outline is due to chronic outlet obstruction in ( large prostate , other pelvic mass ). Any filling defect should be detected which is due to vesical stone , urothelial tumor (transitional cell ca .) or blood clot .

Urethrography : Either ascending or descending approach. Ascending urethrography used for anterior urethra up to distal sphincter , it done by special catheter. Descending exam. shows the detail of post. urethra by filling the U.B with contrast by catheter &films taken during voiding( to the urethra and bladder base. ) .

Ascending urethrography

Cystography : in micturating cystogram the entire process should be observed flourpscopically. The major indication for micturating cystogram: 1.identify and quantify vesico-ureteric reflex. 2. UB injury . 3. investigate the anatomy of the bladder neck & urethra ( to show obstruction such as stricture or urethral valve). 4. to demonstrate emptying bladder &the control of micturation.

Cystography

Percutaneouse Antegrade pyelography Done by inserted needle into PCS under US or fluoroscopic guide, urine specimen is obtained and inject the contrast media , this procedure is done under local anesthesia. It used to evaluate the cause &level of obstruction to patient in whom non-invasive imaging has not provide the information . This procedure used to demonstrate ureteric fistula and leak .

Other direct contrast studies: Retrograde pyelography Nephrostograpy . Cyst puncture

COMUTED TOMOGRAPHY : CT has a wide variety of indication including: 1. characterization of renal masses . 2. staging of urinary tract tumors. 3. assessment of inflammatory and traumatic processes.

RADIONUCLIDE EXAMINATION: There are two main radionuclide technique for studying the kidneys : 1.the renogram (Tc DTPA) which measure renal function ( excretion ). 2.scan of renal morphology (Tc DMSA) to investigate renal mass or detect cortical scar.  

THANK YOU