Contents. Review anatomy of the urinary tract Imaging modalities

Contents Review anatomy of the urinary tract Imaging modalities

The Urinary Tract

Kidneys

ตาแหน งไต (position) อย ใน retroperitoneum ระด บ T12-L3 โดยไต ขวาจะม ระด บตากว าไตซ ายเล กน อย ร ปร าง (shape) คล ายร ปถ ว ด านเว าห นเข าทาง medial ท ศทางการวางต ว Long axis ของไตเอ ยงขนานไปก บเงาของ (axis) psoas muscle ขนาด (size) ยาวประมาณ 10-16 cm. กว าง 6 cm. หนา 4 cm. หร อประมาณ 3-4 lumbar vertebral bodies ขนาดของไตสองข างต างก นได ไม เก น 1.5 cm. ความหนาของ renal ประมาณ 1.5-2 cm. cortex (cortical thickness) ขอบ (outline) ขอบเร ยบเสมอก น

Kidneys 1. Renal capsule Gerota s capsule Adipose capsule Fibrous capsule 2. Renal parenchyma Cortex Medulla 3. Renal sinus Renal pelvis Artery, vein lymph, nerves Fat

Renal Capsule Renal capsule: 3 layers I. Gerota s capsule II. Adipose capsule III. Fibrous capsule

Renal Parenchyma

Renal Sinus

Associations

Renal Vessels

Film KUB

IVP 5 MINS IVP/IVU

Ultrasound

Computed Tomography (CT scan)

Magnetic resonance imaging (MRI)

Ureters

Film KUB IVP 10 Minutes

Physiologic narrowing of ureter I. Ureteropelvic junction (UPJ) II. Distal ureter that cross bifurcation of iliac vessels III. Ureterovesical junction (UVJ)

Physiologic Narrowing (1)

Physiologic Narrowing (2)

Physiologic Narrowing (3)

Urinary Bladder

Urethra

Normal male urethrogram

Investigations 1. Plain KUB 2. Intravenous pyelography (IVP) 3. Retrograde pyelography (RP) 4. Cystography 5. Voiding cystourethrography (VCUG) 6. Ultrasonography 7. CT scan 8. Magnetic resonance imaging 9. Renal angiogram 10. Renogram

Plain KUB

Plain KUB 1. Soft tissue shadow 2. Abnormal calcification 3. Free air or free fluid 4. Bony structure

Soft tissue shadows: Kidneys Psoas muscles Uterus Bladder Liver Spleen

Soft tissue shadows: Kidneys Psoas muscles Uterus Bladder Liver Spleen 1. Position 2. Shape 3. Axis 4. Size 5. Cortical thickness 6. Outline

Soft tissue shadows: Kidneys Psoas muscles Uterus Bladder Liver Spleen

Soft tissue shadows: Kidneys Psoas muscles Uterus Bladder Liver Spleen Retroperitoneal mass?

Right psoas abscess

Intraperitoneal mass

? DDx. - Urinary tract stone - Calcified granuloma - Tumor - Gallstone - Appendicolith - Costochondral calcification - Atherosclerosis - Phlebolith - Prostatic calculi - Calcified uterine fibroid

? Example: There is an ovalshaped calcification at left L1-L2 paravertebral level, overriding lateral margin of left psoas muscle. These findings are suspected of left UPJ stone.

UPJ stone

Calyceal stone

Staghorn stone

Emphysematous pyelonephritis

I. Spine II. Lower ribs III. Sacrum IV. Pelvis V. Hip & SI joints Look for - Fracture - Congenital bony defect - Bony destruction

สร ป: การอ าน Plain KUB 1. Soft tissue shadow 2. Abnormal calcification 3. Free air or free fluid 4. Bony structure

Intravenous Pyelography (IVP)

IVP *** Intravenous injection of iodinated contrast medium to evaluate for renal anatomy and function 1. Standard IVP (50 ml contrast medium) 2. Double dose IVP (100 ml contrast medium)

Factors 1. Kidney function GFR 2. Intrarenal concentration: State of hydration, osmotic diuresis 3. Exit of contrast from kidney (collecting system dynamics): Rate of urine flow, volume of collecting system, ureteral dynamics

IVP: Preparation Fluid restriction Increase visualization of contrast media Except for patients with poor renal function, DM, multiple myeloma, trauma, young child Bowel preparation To clear fecal content Not absolutely needed

IVP: Contraindication 1. Allergy to iodinated contrast media 2. Renal insufficiency (Creatinine Clearance < 30) Pregnancy Note: Cr Clearance = (140-age)xBW(kg) 72xserum Cr (mg/dl) If female (x0.85)

IVP: Evaluation 30 min, full bladder 3 min. Post void 10 min. 5 min.

Scout Film

Normal Nephrogram 3 min.

3 min: Nephrogram 1. Position 2. Shape 3. Axis 4. Size 5. Cortical thickness 6. Outline

Normal Excretion 3 min. 5 min.

5 min: Excretion 1. Minor/major calyx 2. Renal pelvis Abnormalities - Clubbing calyx/ hydronephrosis - Filling defect - Anomaly - Dense nephrogram

10 min: Pelvocalyeal system and ureter 5

Scout film Findings of UPJ obstruction 3 mins 5 mins 10 mins

Scout 5 min 10 min

Hydronephrosis

Double collecting system

10 mins 30 mins

Right UVJ stone causing obstruction scout 10 mins post void

Bilateral hydronephrosis & hydroureters 1. Bladder cause 2. Urethra cause

Filling Defects

30 min: Full bladder 1. Size 2. Shape 3. Position 4. Architecture 5. Density

Irregular bladder outline Multiple bladder diverticulum Bladder trabeculation

Bladder filling defects

Post voiding film 1. Residual urine 2. Small tumor 3. Small stone

IVP: Indication 1. Renal and ureteric calculi 2. Colicky abdominal pain 3. Persistent or frank hematuria 4. Complicated urinary tract infection 5. Urothelial tumors 6. Abnormal US or renogram

IVP 1. Can evaluate renal function 2. Can demonstrate urothelium 3. Can visualize the ureter 1. Unable to identify renal parenchymal abnormality 2. Need IV contrast renal failure

Retrograde Pyelography (RP)

RP: Indication 1. Poor kidney excretion 2. Evaluate pelvocalyceal system if uncertainty from IVP 3. Unexplained hematuria

RP: Contraindication 1. Urinary tract infection

RP: Complication 1. Infection 2. Trauma to urethra

Cystography

Retrograde Cystography

Cystography: Indication 1. Evaluate size and contour of urinary bladder 2. Bladder carcinoma 3. Trauma: rupture bladder 4. Low-pressure vesicoureteral reflux 5. Vesical fistula

Voiding Cystourethrography (VCUG)

VCUG: Indication 1. Urinary tract infection in children: - Urethral abnormality: posterior urethral valve - Vesicoureteral reflux (VUR) 2. Cause of urinary incontinence

Urethrography 1. Descending (antegrade) urethrography 2. Ascending (retrograde) urethrography

Descending Urethrography Urethrography was performed during voiding

Ascending/Retrograde Urethrography

Urethral stricture at bulbous portion

Urethrograpy: Indication 1. Urethral trauma 2. Urethral stricture or anomaly

Ultrasonography (US)

1. Liver 2. Right kidney 3. Right diaphragm 4. Hepatorenal pouch Longitudinal scan of right kidney

Normal kidney Liver parenchyma Normal renal parenchyma, slightly hypoechoic Hepatorenal pouch, no free fluid Normal renal fat = hyperechoic No dilatation of collecting system

Normal renal pyramids: medulla triangular-shaped, hypoechoic structures

Renal parenchymal disease Normal kidney Increased renal echogenicity

Obstruction hydronephrosis Renal parenchyma, hypoechoic Dilated collecting system, anechoic (fluid) Compressed renal fat, hyperechoic

Renal mass: solid / cystic

Bladder, uterus, prostate gland

US: Indication 1. Renal mass 2. Creatinine rising Renal disease or obstruction 3. Infection of kidney Renal abscess, perinephric abscess 4. Renal transplant patients 5. Urinary bladder lesion 6. Renal biopsy

US-KUB 1. No radiation 2. Can be used in pts with renal failure 3. No need to NPO 4. Image guided biopsy 1. Cannot evaluate renal function 2. Limit evaluation of ureter 3. Operator dependent

Computed Tomography (CT KUB)

CT Renal Protocol I. Precontrast phase II. Corticomedullary phase (30-60 sec) III. Nephrographic phase (60-100 sec) IV. Excretory or delayed phase (180-300 sec)

Non contrast

Corticomedullary phase

Nephrographic phase

Excretory phase

Ureter

Bladder

CT: Indication 1. Renal mass: diagnosis, staging 2. Tumor of urinary system 3. Renal trauma 4. Infection 5. Renal artery stenosis 6. Renal stone protocol

CT KUB 1. Can evaluate renal function and anatomy 2. Good detail study 1. Radiation 2. Contrast administration

Magnetic Resonance Imaging (MRI)

MRI 1. No radiation 2. Risk of Gadolinium allergy < iodinated CM 3. Good for evaluating renal artery stenosis 1. Long scan time 2. Metallic / motion artifact 3. Not sensitive for stone or calcification 4. Expensive

Renal Angiography

Renogram

Summary Normal radiographic anatomy Kidney, Ureter, Bladder, urethra Investigation of the KUB system Indication Contraindication Complication Interpretation

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