Imaging Recommendation for Multi-Site Right-Sided Abdominal Pain
Order CT abdomen and pelvis with IV contrast as the single initial imaging study to evaluate this constellation of symptoms, as it will simultaneously assess for appendicitis, urolithiasis, biliary pathology, and other intra-abdominal causes with high diagnostic accuracy. 1, 2
Rationale for CT with IV Contrast
This patient's symptom complex—RLQ pain, urinary symptoms with pressure, RUQ pain, and flank pain—suggests multiple potential diagnoses that require comprehensive evaluation:
CT abdomen and pelvis with IV contrast achieves 95% sensitivity and 94% specificity for appendicitis while identifying alternative diagnoses in 23-45% of cases, including urolithiasis, diverticulitis, bowel obstruction, and gynecologic pathology. 1, 2
The American College of Radiology rates CT with IV contrast as the gold standard for RLQ pain evaluation, with 94.3% concordance between CT diagnosis and final clinical diagnosis for non-appendiceal conditions. 1
IV contrast is essential for detecting critical findings like gallbladder wall enhancement, hepatic parenchymal hyperemia, and vascular emergencies that cannot be visualized without contrast. 3
Why Not Ultrasound First
While ultrasound is first-line for isolated RUQ pain, this multi-site presentation requires broader evaluation:
Ultrasound has significant limitations with 20-81% non-visualization rates for the appendix and sensitivity ranging from 21% to 95.7% depending on operator experience and patient body habitus. 2
Equivocal ultrasound results require CT anyway, resulting in diagnostic delay without avoiding radiation. 2
For flank pain evaluation, unenhanced helical CT detects ureteral stones with 98-100% sensitivity and specificity regardless of size, location, or chemical composition, far superior to ultrasound. 4, 5
Essential Pre-Imaging Step
- Obtain beta-hCG in all women of reproductive age before imaging to exclude ectopic pregnancy, which is a life-threatening "can't miss" diagnosis requiring urgent intervention. 3, 1
What This Single CT Study Will Evaluate
The contrast-enhanced CT will simultaneously assess:
- Appendicitis and right colonic diverticulitis (RLQ pain source) 1
- Urolithiasis causing ureteral obstruction (flank pain and urinary symptoms) 4, 5
- Acute cholecystitis, choledocholithiasis, or cholangitis (RUQ pain source) 3
- Bowel obstruction, mesenteric ischemia, and other vascular emergencies 3, 2
- Gynecologic pathology including ovarian cysts or masses that can cause referred RUQ pain 3
Critical Pitfalls to Avoid
Do not order CT without IV contrast for this presentation—critical findings like gallbladder wall enhancement and vascular pathology cannot be detected without contrast. 3
Do not delay CT for oral contrast administration, as IV contrast alone provides equivalent diagnostic accuracy for appendicitis and avoids treatment delays. 1
Do not limit imaging to pelvis only, as this misses 7% of surgical pathology located in the abdomen. 1
Do not assume normal laboratory values exclude serious pathology—many tests are nonspecific and may be normal despite serious infection or perforation. 2
Alternative Imaging Scenarios
If the patient is pregnant, MRI abdomen and pelvis without contrast is preferred over CT to avoid radiation exposure while maintaining diagnostic capability. 3
If CT shows equivocal biliary findings and cholangitis is suspected (jaundice, fever/chills, RUQ pain), proceed to MRCP to evaluate bile ducts. 3