US performance for the evaluation of appendicitis in pregnant patients appears to be similar to the same-age nonpregnant patients, as shown in a case-control study with 67 pregnant patients compared with 133 nonpregnant young patients. PPV was 94% in the pregnant group and 91% in the nonpregnant group, with corresponding NPV of 40% and 43% [49]. This is even though the appendix is not visualized on US in 68% to 97% of patients [40]. US with graded compression of the appendix has similar accuracy to nonenhanced CT; however, it is more limited in the third trimester due to the large size of the gravid uterus [39]. This may be a useful initial imaging approach if pregnancy location and gestational age are unknown at the time of an acute presentation. US Duplex Doppler Adnexa A combined transabdominal and TVUS approach is typically used for pelvic US imaging. This document considers Doppler imaging to be a standard component of pelvic US. In a recent single-center retrospective study of 790 patients, CT of the abdomen and pelvis with IV contrast demonstrated a statistically significant improved yield (ie, a study with no indeterminate findings) of 97.5% compared with US of 15.8%. The negative appendectomy rate was also significantly lower at 3.3% for the CT group in comparison with 17.7% with US diagnosis [51]. With the increased interest in nonoperative antibiotic management of uncomplicated appendicitis, appendicoliths are important to detect. Higher failure rates of conservative management are seen in the presence of appendicoliths. Furthermore, appendicoliths are associated with increased inflammation and risk of perforation. Appendicoliths are readily identified with CT and found in nearly 40% of adults with proven appendicitis, compared with slightly more than 4% of those without appendicitis [52].
Acute Pelvic Pain in the Reproductive Age Group. US performance for the evaluation of appendicitis in pregnant patients appears to be similar to the same-age nonpregnant patients, as shown in a case-control study with 67 pregnant patients compared with 133 nonpregnant young patients. PPV was 94% in the pregnant group and 91% in the nonpregnant group, with corresponding NPV of 40% and 43% [49]. This is even though the appendix is not visualized on US in 68% to 97% of patients [40]. US with graded compression of the appendix has similar accuracy to nonenhanced CT; however, it is more limited in the third trimester due to the large size of the gravid uterus [39]. This may be a useful initial imaging approach if pregnancy location and gestational age are unknown at the time of an acute presentation. US Duplex Doppler Adnexa A combined transabdominal and TVUS approach is typically used for pelvic US imaging. This document considers Doppler imaging to be a standard component of pelvic US. In a recent single-center retrospective study of 790 patients, CT of the abdomen and pelvis with IV contrast demonstrated a statistically significant improved yield (ie, a study with no indeterminate findings) of 97.5% compared with US of 15.8%. The negative appendectomy rate was also significantly lower at 3.3% for the CT group in comparison with 17.7% with US diagnosis [51]. With the increased interest in nonoperative antibiotic management of uncomplicated appendicitis, appendicoliths are important to detect. Higher failure rates of conservative management are seen in the presence of appendicoliths. Furthermore, appendicoliths are associated with increased inflammation and risk of perforation. Appendicoliths are readily identified with CT and found in nearly 40% of adults with proven appendicitis, compared with slightly more than 4% of those without appendicitis [52].