The role of CT Urography in the evaluation of Bladder Cancer

Dr Mohamed El Safwany, MD.

Intended learning outcome The student should learn at the end of this

lecture principles of CT in bladder cancer.

What is CT Urography (CTU)?

CTU is a term used to describe high-spatial-resolution imaging of the urinary tract by using contrast material administration, a multidetector CT scanner with thin collimation and imaging in the excretory phase .

CTU Indications

Hematuria

Patients at increased risk for having upper or lower tract

urothelial neoplasms

Urinary diversion procedures following cystectomy

Hydronephrosis, chronic symptomatic urolithiasis or planning of

percutaneous nephrolithotomy (PCNL)

Traumatic and iatrogenic uretheral injury, and complex urinary tract infections.

CTU: technique

2 Phase- single bolus CTU: - Oral hydration (700 ml of water, 30 min ) - Low dose diuretic (Furosemide): 0.1mg/kg, 1-3 min, before CM - Single bolus of 100 -[320] IV CM - Arterial phase - Nephrographic phase@ 100 sec - Excretory phase @ 12 min (7-15 min)

Unenhanced phase?

1.- Ultrasound is widely used. 2.-Using Furosemide there is an improvement in lithiasis diagnosis.

Furosemide decrease the urine attenuation value (< 500 HU) *.

Lithiasis HU

Calcium oxalate monohydrateCalcium oxalate dihidrateCystineStruviteUric acid

1645+ 2381417 + 234711 + 228666 + 87

409 + 118

Portal versus nephrographic phase?

Bladder cancer tends to show peak enhancement with the 60- second (portal Phase) scanning delay *.

Portal phase CTU offers high accuracy detecting BC:

- Sensitivity: 89%–92% in per lesion analysis 95% in per patient analysis

- Specificity: 88%– 97% in per lesion analysis 91%–93% in per patient analysis

CTU: Image review, image reconstruction and reformatted images

CTU image review and postprocessing: Using a workstation and/or a picture archiving and communication system (PACS): Creation of multiplanar reformatted images and 3D reconstructed images by using:

- Maximum intensity projection techniques (MIP 5-50mm)

- Volume-rendering (VR 5-50 mm)

- Narrow and wide windows and thin sections with MPR and axial images review (improve the detection rate for tumors smaller than 5 mm)

Homogeneous bladder opacification: Voiding the bladder before examination or mixing bladder contents: patient rolls over supine- prone on the CT table or walks around the CT room.

All the excretory system must be included in the exam: Since the urothelium of the entire urinary system is at risk of developing cancer.

CTU may allow staging of deeply invasive tumors, detection of metastases and other extra-genitourinary pathology.

Bladder cancer CTU

Bladder cancer

Background• Is the most common malignancy of the urinary tract. • Is a disease of older patients (>65).• Represents the 6.6% of the total cancers in men and

2.1% in women, with an estimated male-to-female ratio of 3.8:1*.

Bladder cancer

Risk factors• Cigarrete smoking: Smokers have a two to sixfold increased risk of

cancer compared to non-smokers. • Occupational exposures: Exposition to aromatic amines

(petrochemical, textile, printing industries), hairdressing, firefighting, truck driving, plumbing…

• Exposures to certains medications: Phenacetin, Cyclophosphamide.• Others: Arsenic in drinking water, prior pelvic irradiation and lower

urinary tract inflammation (schistosomiasis).

Bladder cancerCell type

•I.- Epithelial tumors:•Urothelial (transitional cell) cancer (90%). Is the most common urinary tract cancer in the United States and Europe. • Has a propensity to be multicentric (30-40% ) with synchronous and metachronous bladder and upper tract tumors.

• Squamous cell (5-8 %)• Adenocarcinoma (2%)

•II.- Non-epithelial tumors: Leiomyosarcomas, lymphoma: Rare

Staging

Ta: Non invasive CIS: high- grade flat Urothelial

cancer T1: Invade lamina propria T2a and T2b: bladder wall

musculature T3a and T3b: perivesical space

extension T4: Adyacent organs or pelvic sidewall invasion.

GRADE: Grade 1: Well differentiated: papillary/

superficial Grade 2: Poorly differentiated:

infiltrative/Invasive

Symptoms

Microscopic or gross hematuria, but only 13-28% patients with gross hematuria have bladder cancer.

CTU Assesment in Bladder cancer

Tumor appearance

Tumor enhancement

CTU appearance of BC

Asymmetric diffuse or focal wall thickening

Male, 75 year-old.Tumor right bladder wall

Male 70 year old.Tumor at left UVJ

Focal enhancing masses

Small filling defects

Soft tissue window (W:400, L:40) Wide windows (W:1990, L:362)

67 year-old man. Previous transurethral BC resection.CTU: Asymetric enhancing right wall thickeningCystoscopy: Fybrosis

CTU reasons for false negative diagnosis

Flat tumors Bladder lesions located at the bladder base

(near prostate and urethra) The most problematic group: Patients

have already undergone local treatment for non-invasive bladder tumors .

72 year-old man. CTU: Prostatic hypertrophy and diffuse wall thickening and small polipoid nodule in the posterior bladder wallCystoscopy: BC in small nodule

75 year-old man. Previous transurethral resectionCTU: Small bladder, diffuse wall thickening and small enhancing nodule at bladder domeCystoscopy: BC

T3a or T3b ?

T4

Text Book David Sutton’s Radiology Clark’s Radiographic positioning and

techniques

Assignment Two students will be selected for

assignment.

Question Define value of VRT in urinary tract

examination ?

Thank You