Differential Diagnosis for Lower Abdominal Pain with Prolonged Cramping

Primary Differential Diagnoses

The American College of Radiology suggests that transvaginal ultrasound has a sensitivity of 98% and specificity of 100% for rectosigmoid and retrocervical endometriosis, which is a common cause of secondary dysmenorrhea in reproductive-aged women 1
Pelvic ultrasound with Doppler is the first-line imaging modality to assess for ovarian cysts, masses, or torsion, with the American College of Radiology recommending its use 2
The American College of Radiology recommends that thick tubal wall and "cogwheel" sign on ultrasound are sensitive markers (100% and 86% respectively) of acute pelvic inflammatory disease (PID) 1
Tubo-ovarian abscess has 93% sensitivity and 98% specificity on pelvic ultrasound, according to the American College of Radiology 1

The American College of Radiology states that pregnancy test (urine or serum β-hCG) is mandatory in all reproductive-aged women with pelvic pain 1
Transvaginal and transabdominal pelvic ultrasound with Doppler is the first-line imaging modality for suspected gynecologic causes, as recommended by the American College of Radiology 1
MRI pelvis without and with IV contrast is the next appropriate step for equivocal ultrasound findings, with the American College of Radiology recommending its use for detecting endometriosis and characterizing complex adnexal masses 2

The American College of Radiology warns that starting with CT instead of ultrasound in reproductive-aged women exposes patients to unnecessary radiation when gynecologic causes are most likely 1
Plain radiographs have very limited utility in evaluating pelvic pain and should not be used, according to the American College of Radiology 5