Will a computed tomography (CT) scan of the abdomen and pelvis without contrast show the kidneys and bladder in a female patient with kidney and pelvic pain?

Will CT Abdomen and Pelvis Without Contrast Show the Kidneys and Bladder?

Yes, a CT scan of the abdomen and pelvis without contrast will clearly visualize both the kidneys and bladder, making it an appropriate imaging modality for evaluating kidney and pelvic pain in this clinical scenario. 1

Anatomic Visualization Capabilities

• Noncontrast CT provides excellent visualization of kidney anatomy, including renal parenchyma, collecting systems, and can detect hydronephrosis with high accuracy 1
• The bladder is readily visible on noncontrast CT, allowing assessment of bladder wall thickness, masses, and intraluminal contents 1
• Noncontrast CT achieves sensitivity up to 97% for detecting urolithiasis (kidney stones), which is a common cause of kidney and pelvic pain in females 1
• Secondary signs of urinary tract pathology are well-demonstrated, including periureteral inflammation, perinephric stranding, and ureteral dilatation 1

Clinical Context and Diagnostic Performance

• For suspected kidney stones, noncontrast CT ("stone protocol") is the reference standard because IV contrast can obscure small renal calculi 1
• Low-dose noncontrast CT maintains diagnostic accuracy with pooled sensitivity of 97% and specificity of 95% for stone detection while reducing radiation exposure 1
• Noncontrast CT can visualize hydronephrosis with comparable accuracy to standard-dose CT, making it effective for detecting urinary obstruction 1

Important Limitations to Consider

• Lack of IV contrast limits evaluation of soft tissue pathology including renal masses, pyelonephritis, renal abscesses, and detailed assessment of the urothelium 1
• Noncontrast CT has reduced sensitivity for detecting causes of pelvic pain beyond urolithiasis, as it cannot optimally evaluate pelvic organs, inflammatory processes, or vascular abnormalities 1
• In patients without history of kidney stones and negative urinalysis, 15% have nonrenal stone diagnoses when presenting with flank pain, suggesting contrast-enhanced CT may be more appropriate in this subset 1
• For comprehensive evaluation of recurrent complicated UTIs or suspected pyelonephritis, contrast-enhanced imaging is preferred to assess for abscesses, anatomic abnormalities, and inflammatory changes 1

Clinical Decision Algorithm

If kidney stones are suspected (history of stones, positive urinalysis for blood, acute colicky pain):

• Noncontrast CT abdomen/pelvis is the optimal first-line study 1

If other causes are suspected (infection, mass, inflammatory disease, no stone history):

• Consider contrast-enhanced CT or ultrasound as initial imaging, as noncontrast CT will show anatomy but miss critical pathology 1

For female patients with acute pelvic pain of unclear etiology:

• Transvaginal ultrasound should be considered first-line to evaluate gynecologic causes before proceeding to CT 1, 2, 3