Will a computed tomography (CT) scan kidney protocol show the bladder in an adult female patient with pelvic pain?

CT Kidney Protocol and Bladder Visualization

Yes, a standard CT kidney protocol will show the bladder, though it may not provide optimal bladder evaluation depending on the specific protocol used.

Understanding CT Kidney Protocols

The term "CT kidney protocol" is not standardized and varies significantly between institutions. The bladder visualization depends on which specific protocol is performed:

Standard CT Abdomen and Pelvis

• A contrast-enhanced CT abdomen and pelvis includes imaging from the diaphragm through the pelvis, which encompasses the bladder 1
• This protocol will show the bladder but is not specifically tailored for detailed bladder evaluation 1
• The bladder is typically imaged during the portal venous phase (approximately 70 seconds post-contrast), which allows visualization of the organ but may miss subtle bladder pathology 1

CT Urography (CTU)

• CTU is specifically designed to evaluate the entire urinary tract including kidneys, ureters, and bladder 1
• This multi-phase protocol includes unenhanced images, nephrographic phase, and excretory phase (at least 5 minutes post-contrast) 1
• CTU provides detailed anatomic depiction of the bladder along with the rest of the urinary system 1
• The excretory phase allows for comprehensive bladder visualization with contrast-opacified urine 2

Non-Contrast CT (Stone Protocol)

• Non-contrast CT for renal stones typically extends from the upper kidneys to the pubic symphysis, which includes the bladder 3
• This protocol can detect bladder stones and gross bladder abnormalities 4
• However, it lacks contrast enhancement, limiting evaluation of bladder wall pathology and soft tissue detail 1

Important Caveats for Bladder Evaluation

When Standard Protocols Are Insufficient

• If dedicated bladder evaluation is needed (such as for suspected bladder rupture or bladder cancer), specialized protocols are required 1
• CT cystography involves retrograde instillation of diluted contrast into the bladder and is the gold standard for traumatic bladder injuries 1
• Standard CT with only excreted contrast cannot reliably diagnose bladder rupture, even with a clamped catheter 1

Field of View Considerations

• Some "renal protocols" may be limited to the kidneys only and not extend to the pelvis 1
• Always verify that the scan range extends to the pubic symphysis to ensure complete bladder visualization 3
• The optimal scan range for complete urinary tract imaging is from T10 vertebral body to the pubic symphysis 3

Clinical Application for Pelvic Pain

In your specific scenario of an adult female with pelvic pain:

• If the CT protocol includes the pelvis (which most kidney protocols do), the bladder will be visible 1
• However, for optimal evaluation of bladder pathology as a cause of pelvic pain, CTU would be superior to a standard CT 1
• The bladder may be inadequately distended on routine imaging, potentially missing pathology 1
• Consider requesting CTU specifically if urinary tract pathology is suspected, as it provides comprehensive evaluation of kidneys, ureters, and bladder in a single examination 5, 2