In a small study of 51 patients, a combination of DWI and T2-weighted images increased the accuracy for the diagnosis of appendicitis, with decreased ADC values correlating with appendicitis. The presence of low ADC in the peri-appendiceal fat was also notable in the presence of complicated appendicitis [63]. That is contrary to the study of 125 pregnant patients in which the addition of DWI showed no significant improvement to MRI detection of appendicitis [45]. MRI performed similarly to abdominal US, followed by abdominal and pelvic CT if findings on US were negative or inconclusive for the detection of perforated appendicitis with low sensitivities (57% for MRI and 48% for US followed by the conditional CT). The missed diagnoses of perforated appendicitis were misclassified as simple appendicitis [64]. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of 13 Acute Pelvic Pain in the Reproductive Age Group appendicitis and renal obstruction. MR urogram without IV contrast was shown to have a 95% sensitivity and 100% specificity for the detection of hydronephrosis, and it has good agreement to determine the level of obstruction as compared to IV urography. The correct diagnosis was made in 94% of patients with MR urogram without IV contrast [65]. US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible.
Acute Pelvic Pain in the Reproductive Age Group. In a small study of 51 patients, a combination of DWI and T2-weighted images increased the accuracy for the diagnosis of appendicitis, with decreased ADC values correlating with appendicitis. The presence of low ADC in the peri-appendiceal fat was also notable in the presence of complicated appendicitis [63]. That is contrary to the study of 125 pregnant patients in which the addition of DWI showed no significant improvement to MRI detection of appendicitis [45]. MRI performed similarly to abdominal US, followed by abdominal and pelvic CT if findings on US were negative or inconclusive for the detection of perforated appendicitis with low sensitivities (57% for MRI and 48% for US followed by the conditional CT). The missed diagnoses of perforated appendicitis were misclassified as simple appendicitis [64]. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of 13 Acute Pelvic Pain in the Reproductive Age Group appendicitis and renal obstruction. MR urogram without IV contrast was shown to have a 95% sensitivity and 100% specificity for the detection of hydronephrosis, and it has good agreement to determine the level of obstruction as compared to IV urography. The correct diagnosis was made in 94% of patients with MR urogram without IV contrast [65]. US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible.