Radiology of Ureter and Urinary Bladder PDF

Dr Syed Faizan Raza Jafri MBBS,MD MEDICINE Medical specialist Radiology of ureter and urinary bladder  URETER The ureters are paired tubular structures that convey urine from the renal pelvis to the urinary bladder. They are approximately 25–30 cm in length and have characteristic a...

Dr Syed Faizan Raza Jafri MBBS,MD MEDICINE Medical specialist Radiology of ureter and urinary bladder  URETER The ureters are paired tubular structures that convey urine from the renal pelvis to the urinary bladder. They are approximately 25–30 cm in length and have characteristic anatomical landmarks and constrictions that are clinically significant.  Imaging Features: Plain Radiography (KUB X-ray): The ureter is not typically visible unless calcifications or stones are present. A contrast study (IVU/IVP) highlights the ureters. Intravenous Urography (IVU): Outlines the ureters after contrast administration. Demonstrates normal peristaltic contractions. Ultrasound: Non-invasive but limited for visualizing normal ureters unless dilated (e.g., due to obstruction). Appears as tubular, anechoic structures with posterior acoustic enhancement.  CT: CT urography provides detailed cross-sectional imaging of the ureter. Ureteric stones, strictures, and tumors can be identified. Three segments are identifiable: Proximal: Renal pelvis to the sacroiliac joint. Middle: Sacroiliac joint to the pelvic brim. Distal: Pelvic brim to bladder insertion. MRI: Rarely used for ureter imaging but can provide excellent soft-tissue contrast. MR urography is helpful in identifying congenital anomalies or masses.  Key Constrictions of the Ureter: Ureteropelvic junction (UPJ): Where the renal pelvis narrows into the ureter. Pelvic brim: Where the ureter crosses the iliac vessels. Ureterovesical junction (UVJ): Where the ureter enters the bladder wall.  BLADDER The urinary bladder is a hollow, muscular organ situated in the pelvis, with the primary role of storing urine.  Imaging Features: Plain Radiography: Visible only with the introduction of contrast (e.g., cystography). Can outline the bladder's shape and detect filling defects, diverticula, or rupture. Ultrasound: Bladder appears as an anechoic structure when filled with urine. Bladder wall thickness and any intraluminal masses or stones can be assessed. Doppler can evaluate vascularization in tumors.  CT: Offers excellent visualization of the bladder wall, surrounding structures, and pathologies (e.g., bladder masses, trauma, or diverticula).Contrast-enhanced CT helps delineate tumors and inflammatory conditions. MRI: Superior for soft-tissue contrast; useful for staging bladder cancer. Differentiates bladder tumors from surrounding tissues. Cystoscopy and Retrograde Cystography: Invasive but allows direct visualization and imaging of the bladder. Retrograde cystography with contrast is valuable in detecting rupture or fistulae.  Normal Anatomy on Imaging: Shape: Pyramid-like in infants. Ovoid in adults when distended. Wall Thickness: Normal: 3–5 mm when distended. Thickened in conditions like infection, inflammation, or neoplasms. Trigone Area: Located between the ureteric orifices and internal urethral opening. Smooth on imaging compared to the rest of the bladder. Radiopathology of the Ureter and Urinary Bladder Ureteric Obstruction Causes: Stones, strictures, tumors, or external compression (e.g., lymphadenopathy, retroperitoneal fibrosis). Imaging Features: Ultrasound: Hydroureter and hydronephrosis (anechoic dilation of the renal pelvis and calyces). Echogenic shadowing stones may be seen. CT (Non-contrast and Contrast-enhanced): Best for detecting ureteric stones (high-density foci with or without obstruction). Dilated ureter upstream from obstruction. Strictures: Irregular narrowing of the ureteral lumen. IVU/IVP: Delayed contrast excretion and tapering at the site of obstruction.  Ureteric Stones Imaging Features: KUB X-ray: Radio-opaque calculi in the ureter’s anatomical course (calcium, struvite stones). Uric acid and cystine stones are radiolucent. CT (Non-contrast): Gold standard for stone detection (hyperdense focus with acoustic shadowing).  Ureteric Tumors Types: Urothelial carcinoma (most common), metastases. Imaging Features: CT Urography: Irregular filling defects in the contrast-filled lumen. Wall thickening or irregular enhancement. MRI: Soft-tissue mass with hyperintense signal on T2-weighted images. IVU: Filling defects and delayed excretion.  Ureteric Trauma Imaging Features: CT Urography: Extravasation of contrast from the ureter. Associated perirenal hematoma or urinoma. Retrograde Pyelography: Precise location of leak or disruption.  URINARY BLADDER Bladder Stones Imaging Features: KUB X-ray: Radio-opaque stones in the bladder (calcium-based). Radiolucent stones require CT or ultrasound. Ultrasound: Hyperechoic structures with posterior acoustic shadowing. CT: Clear visualization of stones, including radiolucent ones  Bladder Tumors Types: Urothelial carcinoma (most common), squamous cell carcinoma, adenocarcinoma. Imaging Features: Ultrasound: Hypoechoic or mixed echogenic masses projecting into the lumen. CT Cystography: Irregular, enhancing masses. Thickened wall and invasion of surrounding structures. MRI: Tumor staging: Hyperintense on T2-weighted images, with irregular wall thickening and infiltration into adjacent fat.  Bladder Trauma Types: Intraperitoneal or extraperitoneal rupture. Imaging Features: Retrograde Cystography: Contrast extravasation. Intraperitoneal rupture: Contrast outlines bowel loops. Extraperitoneal rupture: Contrast limited to perivesical space. CT Cystography: Preferred for trauma evaluation. Clearly shows extravasation patterns.  Bladder Infections (Cystitis) Causes: Bacterial, tuberculosis, fungal. Imaging Features: Ultrasound: Thickened, irregular bladder wall. Echogenic debris or gas in severe cases (emphysematous cystitis). CT: Wall thickening, stranding in the perivesical fat. Gas bubbles in the bladder wall or lumen in emphysematous cystitis. MRI: Diffuse wall thickening and increased signal intensity on T2-weighted images.  Bladder Diverticula Imaging Features: Ultrasound: Anechoic outpouchings from the bladder. CT Cystography: Contrast filling diverticula. Assess for stones or tumors within diverticula. Radiology of Benign Prostatic Hyperplasia (BPH) BPH refers to the non-cancerous enlargement of the prostate gland, often causing lower urinary tract symptoms (LUTS). Radiologic evaluation helps assess prostate size, bladder effects, and complications like obstruction or infection.  Ultrasound (US) Transabdominal: Enlarged prostate (>30 mL volume). Median lobe protrusion into the bladder (intravesical prostatic protrusion). Post-void residual volume to assess obstruction severity. Transrectal (TRUS): More accurate measurement of prostate volume. Hypoechoic or heterogeneous nodules in the transition zone. Detects complications (e.g., bladder wall thickening, stones).  MRI Best for detailed anatomy and staging (if needed). Features: Enlarged prostate, predominantly in the transition zone. T2-weighted images: Heterogeneous signal intensity due to nodules. Compression of the peripheral zone and central gland by hypertrophy.  CT Rarely used specifically for BPH but may show: Enlarged prostate gland with bladder wall thickening or trabeculations. Secondary findings like hydronephrosis from chronic obstruction. Voiding Cystourethrography (VCUG) Demonstrates bladder outlet obstruction: Elongated and narrowed prostatic urethra. Post-void residual urine.  Key Findings: Enlarged prostate (>30 g). Secondary changes in the bladder: Wall thickening, trabeculations, diverticula. Retained urine (post-void residual). Complications: Bilateral hydronephrosis or hydroureter from chronic obstruction.