Imaging for Pelvic Pain Radiating to the Leg

Initial Imaging Approach

The American College of Radiology recommends ultrasound as the initial imaging modality for evaluating pelvic pain radiating to the leg, especially when gynecological causes are suspected, due to its excellent visualization of pelvic structures and no radiation exposure 1, 2
Ultrasound provides excellent visualization of pelvic structures with no radiation exposure and is widely regarded as the initial imaging study of choice, with color and spectral Doppler included as standard components to evaluate internal vascularity of pelvic structures 1, 2

The American College of Radiology suggests that CT with IV contrast has higher sensitivity than ultrasound for urgent diagnoses in adults with abdominopelvic pain, with a sensitivity of 89% versus 70% 3
CT provides approximately 88% overall accuracy compared with surgical diagnosis, and is superior for detecting non-gynecological causes such as diverticulitis, with a sensitivity of 81% versus 61% for ultrasound 3, 4
MRI should be considered as a problem-solving examination after initial imaging with ultrasound or CT, particularly when endometriosis or fistulizing disease is suspected, due to its excellent soft tissue contrast 1

The American College of Radiology recommends starting with ultrasound if gynecological etiology is suspected, patient is of reproductive age, or pregnancy is possible or confirmed, and pain is well-localized to the pelvis 1, 3, 7
CT abdomen and pelvis with IV contrast should be started if non-gynecological cause is strongly suspected, pain involves both abdomen and pelvis, or patient has risk factors for diverticulitis or other gastrointestinal pathology 3, 4, 6

Relying solely on plain radiographs, which have very limited utility in evaluating pelvic pain, is not recommended by the American College of Radiology 1, 2
Failing to consider vascular causes of pelvic pain radiating to the leg, which may require specific imaging protocols, is a common pitfall to avoid 2
Not using IV contrast for CT when evaluating most non-urolithiasis causes of pelvic pain significantly limits diagnostic capability, according to the American College of Radiology 3