Urologic Imaging Examinations

Question 1

Indications for US of Kidneys

Answer 1

Vizualization of:
1. Renal Tumours
2. Renal Cysts
3. Nephrolithiasis
4. Hydronephrosis

Question 2

Indications for US of Bladder

Answer 2

1. Bladder Wall Thickening
2. Bladder Calculi
3. Tumours
4. Urinary Retention

Question 3

Indications for US of Prostate

Answer 3

1. Prostate volume [Usually Suprapublic but also Transrectal]
2. Prostate Shape
3. Prostate Echogenicity
4. Prostatic Abscesses or masses

Question 4

Indications for US of Scrotum and Penis

Answer 4

1. Testicular Torsion
2. Crpytorchidism
3. Trauma
4. Testicular Tumours
5. Varicocele
6. Epididymitis

Question 5

Indications for CT

Answer 5

1. Investigation of choice to detect Urinary calculi and renal masses
2. Vizualization of Urothelium in suspected malignancies and obstruction
3. CT angiography to evaluate Acute Pelvic Trauma and Tumour Blood supply; Dx of Renal Vascular Malformations

Question 6

Indications for MRI

Answer 6

1. Differentiate between Renal Cysts and Neoplasms
2. Accurate staging of Bladder and Prostate cancers
3. Alternative to CT Angiography to Iodine-based radiocontrast allergic patients

Question 7

Indications for Renal Scintigraphy

Answer 7

1. Assess for Renal Scarring and significant Urinary Obstruction
2. Estimation of differential Renal function
3. Screening for Renal Artery Stenosis
4. Monitoring of Renal Transplants

Assess anatomy and function of Kidneys

Question 8

The basic procedure and 2 subtypes of Renal Scintigraphy performed in Urology

Answer 8

Procedure - IV administration of Technetium [Tc-99m pertechnetate/gamma emitter] and measurement of its distribution in the body with a gamma camera

Subtype -
1. Static Renal Scintigraphy: Radiotracer is retained in the renal cortex and used to assess renal funciton as well as degree of structural damage to the renal cortex. Injection of Tc-99m DMSA [Dimercaptosuccinic acid, an injectable radioactive gamma-ermitter due that rapidly accumulates in renal parenchyma and very small amounts are eliminated]. Recording done 3 hours post injection
2. Dynamic Renal Scintigraphy: Radiotracer is exreted by the kidney and used to assess renal perfusion as well as urine flow in urinary tract. Injection of Tc-99m MAG3 [Mercaptoacetyltriglycine, a technetiim that rapidly accumulates in renal parenchyma and is cleared almost exlcusively by tubular excretion]. Recording done from time of injection up to 30 minutes

Question 9

Indications and Contraindications for Voiding Cystourethrography

Answer 9

Indications:
1. Abnormal US findings [in cases of Vesicoureteral reflux and Urinary tract obstructions causing hydronephrosis or hydroureter]
2. Recurrent UTIs
3. Suspected urethral stricture
4. Trauma

Contraindications:
1. UTI
2. Contrast allergy

Assess presence and severity of Vesicoureteral Reflux and detect anatomical abnormalities in Urinary bladder and below

Question 10

Basic Procedure of Voiding Cystourethrography

Answer 10

• Radiocontrast dye is injected into the bladder via urinary catheter [retrograde filling of bladder with contrast]
• Fluoroscopy is performed during voiding
• Increased bladder pressure during voiding may reveal previously undetected reflux

Complication: UTI

Question 11

Indications and Contraindications for Intravenous Urography

Answer 11

Indications:
1. Visualize Renal Excretion
2. Visualize course o Ureters

Contraindications:
1. Hyperthyroidism [Iodine contrast can cause Iodine storm]
2. Renal Insufficiency [Contrast directly toxic to tubule cells and vasoconstrictive effects leads to impaired perfusion of renal medulla]
3. Contrast medium allergy [Anaphylactic shock]
4. Multiple Myeloma [Contrast-induced Renal failure much more likely in MM]

Procedure involves IV contrast agent and X-rays to make images of Geniturinary tract

Question 12

Indications for CT urography

Answer 12

First-line imaging test to assess for genitourinary abnormalities [like malignancies and strictures]. Used to contrast assess the anatomy and to a certain degree, function of the urinary collecting system, renal calyces, ureters and bladder

CT with contrast dye injected IV

Question 13

Retrograde urethrography

Answer 13

A diagnostic test in which contrast agent is injected into the urethra to evaluate for urethral injuries and disorders via x-ray

Indications: suspected anatomical and/or functional urethral lesions, e.g.:
- Urethral strictures
- Urethral injuries
- Urethral fistulas

Findings:
- Intact urethra: no urethral extravasation with contrast in bladder
- Partial urethral disruption: urethral extravasation with contrast in bladder
- Complete urethral disruption: urethral extravasation and no contrast in bladder

Question 14

Retrograde cystography

Answer 14

An imaging modality in which contrast is injected into the bladder via a catheter to inspect bladder anatomy and assess for abnormalities via x-ray

Indications: suspected bladder injury, e.g., traumatic or iatrogenic injury

Contraindications: suspected urethral injury

Findings: contrast extravasation in bladder injuries