Urology Residents’

Club

ByAhmad A. Al-

Sabbagh

Urological

Imaging

• Conventional radiography (including abdominal plain radiography, intravenous excretory urography, retrograde pyelography, loopography, retrograde urethrography, and cystography) has long been critical to the diagnosis of conditions of the kidneys, ureters, and bladder.

Introduction

• Urologists increasingly perform & interpret conventional radiography examinations in the office and operating room environments.

• Imaging plays an important role in the diagnosis and management of urologic diseases. Because many urologic conditions are difficult to be assessed by physical examination.

• The underlying physical principles of conventional radiography involve emitting a stream of photons from an x-ray source which travel through the air and strike tissue, imparting energy to that tissue.

Physics

• Some of the photons emerge from the patient with varying amounts of energy attenuation and strike an image recorder such as a film cassette or the input phosphor of an image intensifier tube, thus producing an image.

• Iodine is the most common element in general use as an intravascular radiologic contrast medium (IRCM) due to the property of Radio-Opacity.

Contrast Media

• Other elements are added to the IRCM to increase water solubility & decreases toxicity by preventing the contrast from entering the cells.

Plain Abdominal

Radiography

1. To be a preliminary film in anticipation of contrast administration.

2. To assess renal calculus disease before and after treatment.

3. To assess the presence of residual contrast from a previous imaging procedure.

4. To assess the position of drains and stents.

5. To help the investigation of blunt or penetrating trauma to the urinary tract.

Indications

• Plain films are widely used in the management of stone diseases.

1. Bowl gases or stools may obscure small stones.

2. Stones may be obscured by other structures such as bones or ribs.

3. Calcifications in pelvic veins or vascular structures may be confused with ureteral calculi.

4. Stones that are poorly calcified or composed of uric acid may be radiolucent.

Limitations

Examples

Examples

Intravenous Urography

1. Demonstrate the renal collecting systems and ureters.

2. Investigate the level of ureteral obstruction in renal units displaying delayed function.

3. Demonstrate intraoperative opacification of collecting system during ESWL or Per-cutaneous access to the collecting system.

4. Demonstrate renal function during emergent evaluation of unstable patients.

5. Demonstrate renal and ureteral anatomy in special circumstances (e.g., ptosis, after transureteroureterostomy, after urinary diversion).

Indications

1. Renal insufficiency for worsening of their renal function (contrast induced nephrotoxicit y).

2. Multiple consecutive contrast studies – less than 48 hours (increased possibility for CIN)

3. Documented allergic reaction to contrast such as urticaria, angioedema, laryngeal edema, bronchospasm, and hypotension with tachycardia.

4. cardiac disease as contrast administration can cause worsening of congestive hear t failure, due to the osmotic load.

5. Patients who are on metformin must stop the drug 48 hours before contrast injection as it can cause lactic acidosis which may be fatal.

Contraindications

Technique• Bowel prep may help to visualize the entire ureters and

upper collecting systems.

• A KUB to allow determination of adequate bowel preparation, confirms correct positioning, and exposes kidney stones or bladder stones.

• Contrast is administered IV as a rapid bolus injection; slow, steady injection; or drip infusion. (This is an individual preference rather than a scientific selection.) Contrast dose is 1 mL contrast per pound of body weight, to a maximum of 150 mL.

• A film is taken at 5 minutes and then additional films at 5-minute intervals until the question that prompted the IVU is answered.

• Postvoiding films are obtained to evaluate the presence of outlet obstruction, prostate enlargement, and bladder filling defects including stones and urothelial cancers.

Examples

History of Asthma & Previous reaction to contrast are the most concerning precipitating factors for adverse reaction to contrast

Complications

Minor Reactions

Intermediate Reactions

Major Reactions

Nausea, flushing, articaria, headache & Maybe Vomitting, pain at the site of injection

Worsening minor reactions, bronchospasm, Hypotension in 0.5-2%

Seizures,Laryngeal spasm, bronchospasm, pulmonary edema, Arrhythmia, respiratory collapse, or cardiac arrest are recorded in 1/1000Epinephrine

Diazepam + Hydrocortisone

H1 Blocker (diphenhydramine

)

Retrograde Pyelograph

y

1. Evaluation of congenital & acquired ureteral obstruction.

2. Elucidation of filling defects and deformities of the ureters or intrarenal collecting systems.

3. Opacification or distention of collecting system to assist percutaneous access.

4. In conjunction with ureteroscopy or stent placement.

5. Evaluation of hematuria.

6. Surveillance of transitional cell carcinoma.

7. In the evaluation of traumatic or iatrogenic injury to the ureter or collecting system.

Indications

Technique

• Usually done in the dorsal lithotomy position.

• A KUB film is taken to confirm correct positioning, and exposes kidney stones or bladder stones.

• Cystoscopy is performed and a catheter is inserted in the ureteral orifice through which the contrast medium is injected

• Documentary still images or “spot films” may be saved for evaluation during peristalsis & for future comparison

1. Urinary tract infections

2. Patients who cannot or should not be cystoscoped (e.g. patients recover ing from recent bladder or urethral surger y).

Contraindications

1. Difficult identification of the orifice in case of inflammatory or neoplastic bladder changes (Helped by IV injection of Methylin Blue)

2. Changes associated with Bladder outlet obstruction causes angulation of the intramural part of the ureter which may result in trauma during canulation of the orifice

Limitations

Backflow of contrast which may cause upward introduction of Infection & absorption of contrast.

Complications

A. Pyelotubular Backflow: Injection under pressure → Opacification of medullary pyramids.

B. Pyelosinus Backflow: Calyceal tear → leakage to the renal sinus

C. Pyelovenous Backflow: contrast enters the venous system → visualization of the renal vein

Examples

Loopography

1. Evaluation of infection, hematuria, renal insufficiency, or pain after urinary diversion

2. Surveillance of upper urinary tract for obstruction

3. Surveillance of upper urinary tract for urothelial neoplasia

4. Evaluation of the integrity of the intestinal segment or reservoir

Indications

Historically the term “loopogram” has been associated with ileal conduit diversion but may be used in reference to any bowel segment serving as a urinary conduit (Pouch-o-gram is a more accurate discription)

Technique

• Supine position.

• A KUB film is taken to confirm correct positioning, and exposes kidney stones or bladder stones.

• A small-gauge catheter is inserted into the ostomy of the loop, advancing it just proximal to the abdominal wall fascia. The balloon can then be inflated to 5 to 10 mL of sterile water.

Examples

Retrograde Urethrogra

phy

1. Evaluation of ureteral stricture disease

2. Assessment for foreign bodies

3. Evaluation of penile or urethral penetrating trauma

4. Evaluation of traumatic gross hematuria

Indications

Technique

• The patient is usually positioned slightly obliquely to allow evaluation of the full length of urethra.

• A KUB film is taken to confirm correct positioning, and exposes kidney stones or bladder stones.

• The penis is placed on slight tension.

• A small catheter may be inserted into the fossa navicularis with the balloon inflated to 2 mL .

• Contrast is then introduced via catheter-tipped syringe.

• Alternatively, a penile clamp may be used to occlude the urethra around the catheter.

Examples

Static Cystograp

hy

1. Evaluation of intravesical pathology

2. Evaluation of bladder diverticula

3. Evaluation of inguinal hernia involving the bladder

4. Evaluation of colovesical or vesico-vaginal fistulae

5. Evaluation of bladder or anastomotic integrity after surgical procedure

6. Evaluation of blunt or penetrating trauma to the bladder

Indications

Technique

• The patient is usually positioned in supine position

• A KUB film is taken to confirm correct positioning, and exposes kidney stones or bladder stones.

• The bladder is filled with 200 to 400 mL of contrast depending on bladder size and patient comfort.

• Oblique films should be obtained because posterior diverticula or fistulae may be obscured by the full bladder.

• A postdrainage film completes the study.

Examples

Voiding Cystourethrog

raphy

1. Evaluation of structural and functional bladder outlet obstruction.

2. Evaluation of reflux.

3. Evaluation of the urethra in males and females.

Indications

Technique

• The patient is usually positioned in supine position

• A KUB film is taken to confirm correct positioning, and exposes kidney stones or bladder stones.

• The bladder is filled with 200 to 400 mL of contrast depending on bladder size and patient comfort.

• The catheter is removed and a voiding film is obtained, AP and oblique films are obtained.

• Oblique films should be obtained because posterior diverticula or fistulae may be obscured by the full bladder in addition determination of the grade of reflux

• A postdrainage film completes the study.

Examples

Thank You

To Be Continued…