CYSTOGRAPHY

What examination commonly uses AP, posterior oblique, and lateral bladder projections?

Cystography.

What are the clinical indications for cystography?

Cystitis, obstruction, vesicoureteral reflux, and bladder calculi.

What may lateral cystography images demonstrate?

Possible fistulas.

What SID is recommended for cystography?

40 inches (100 cm).

What IR size is recommended for cystography?

14 × 17 inches (35 × 43 cm), portrait.

Is a grid used for cystography?

Yes.

What kVp range is recommended for cystography?

80–90 kVp.

How is the patient positioned for the AP cystography projection?

Supine with legs extended.

How should the MSP be positioned for an AP cystography projection?

Aligned to the center of the table and IR.

What body rotation is used for posterior oblique cystography projections?

45° to 60°.

Why are posterior oblique cystography projections performed?

To visualize the posterolateral aspect of the bladder.

What condition is especially evaluated with posterior oblique cystography views?

Vesicoureteral reflux (VUR).

What should be done with the downside leg in posterior oblique positioning?

Partially flex it for stabilization.

Why should the elevated-side leg not be flexed excessively?

To prevent superimposition over the bladder.

Why is the lateral bladder projection considered optional?

Because of the high gonadal radiation dose.

How should the patient be positioned for a lateral bladder projection?

True lateral with no rotation.

Where is the CR centered for the AP bladder projection?

2 inches (5 cm) superior to the symphysis pubis.

What CR angle is used for the AP bladder projection?

10°–15° caudad.

Why is a 10°–15° caudad angle used for AP cystography?

To project the symphysis pubis inferior to the bladder.

What structure is demonstrated when centering at the level of the iliac crest?

Urinary reflux.

Where is the CR centered for posterior oblique bladder projections?

2 inches (5 cm) superior to the symphysis pubis and 2 inches (5 cm) medial to the ASIS.

Where is the CR centered for the lateral bladder projection?

2 inches (5 cm) superior and posterior to the symphysis pubis.

How should collimation be applied during cystography?

Collimate on all four sides to the anatomy of interest.

What respiration instruction is given during cystography?

Suspend respiration after expiration and expose.

What should be done to the bladder before filling it with contrast?

Unclamp and drain the bladder.

How should contrast medium be introduced into the bladder?

Under pressure but allowed to fill slowly by gravity in the presence of an attendant.

What anatomy should be demonstrated on cystography images?

Distal ureters and urinary bladder.

What anatomy should be included on all cystography images?

Optimal image exposure and contrast of the urinary anatomy.

What indicates correct AP bladder positioning?

The urinary bladder is not superimposed by the pubic bones.

What indicates correct posterior oblique positioning?

The urinary bladder is not superimposed by the downside leg.

What indicates correct lateral positioning?

The hips and femurs are not superimposed.

What indicates proper collimation on cystography images?

Proper collimation to the anatomy of interest.

What structure should be included distal to the pubis in older men?

The prostate area.

What is vesicoureteral reflux (VUR)?

The backward flow of urine from the bladder into the ureters.

What is a bladder calculus?

A stone located within the urinary bladder.

What is cystitis?

Inflammation of the urinary bladder.

What is the main purpose of the AP cystography projection?

To demonstrate the urinary bladder free of superimposition by the pubic bones.

Which cystography projection best demonstrates the posterolateral bladder wall?

Posterior oblique (45°–60°).

Which cystography projection best demonstrates possible fistulas?

Lateral bladder projection.

Which projection is most useful for evaluating vesicoureteral reflux?

Posterior oblique cystography projection.