Although uterine atony is a clinical diagnosis, CT can be helpful by detecting a hematoma within the cavity of an enlarged uterus [13] and excluding other causes of PPH. However, it can be difficult to differentiate blood products from RPOC [12]. CT can detect vascular complications such as bladder flap, subfascial, or perivaginal space hematoma and delineate relationship to adjacent organs (supralevator versus infralevator location in the perivaginal space) [14,15]. Small (<4 cm) subfascial and bladder flap hematomas may not be clinically significant [15]. A >5 cm bladder flap Postpartum Hemorrhage hematoma should raise suspicion for uterine dehiscence, characterized by disruption of the endometrial and myometrial layers with an intact serosal layer [15,16]. Low correlation between clinical and radiologic findings of dehiscence have been noted, and it is important not to interpret hypodense edema at the cesarean incision site as dehiscence in the first postpartum week [15]. Presence of gas in the myometrial defect extending from the endometrium to the parametrial tissue along with hemoperitoneum are findings suggestive of uterine rupture [15]. CTA Abdomen and Pelvis Persistent hemorrhage after empiric embolization is an indication for CTA [12]. Active extravasation is seen in 41% to 74% cases of PPH on CTA [17] and multiphasic CT, including a noncontrast arterial and portal venous phases, has excellent accuracy of 97% [18] for detection of the site of active extravasation, similar to that of gastrointestinal hemorrhage [17,18]. CTA can be falsely positive because of dilated tortuous hypertrophic uterine arteries mimicking extravasation and be falsely negative in atony because of slow intermittent hemorrhage [12,18]. CTA also enables comprehensive evaluation of abdominopelvic vasculature, including vessels not often evaluated on routine angiography such as the ovarian and inferior epigastric arteries [18].
Postpartum Hemorrhage. Although uterine atony is a clinical diagnosis, CT can be helpful by detecting a hematoma within the cavity of an enlarged uterus [13] and excluding other causes of PPH. However, it can be difficult to differentiate blood products from RPOC [12]. CT can detect vascular complications such as bladder flap, subfascial, or perivaginal space hematoma and delineate relationship to adjacent organs (supralevator versus infralevator location in the perivaginal space) [14,15]. Small (<4 cm) subfascial and bladder flap hematomas may not be clinically significant [15]. A >5 cm bladder flap Postpartum Hemorrhage hematoma should raise suspicion for uterine dehiscence, characterized by disruption of the endometrial and myometrial layers with an intact serosal layer [15,16]. Low correlation between clinical and radiologic findings of dehiscence have been noted, and it is important not to interpret hypodense edema at the cesarean incision site as dehiscence in the first postpartum week [15]. Presence of gas in the myometrial defect extending from the endometrium to the parametrial tissue along with hemoperitoneum are findings suggestive of uterine rupture [15]. CTA Abdomen and Pelvis Persistent hemorrhage after empiric embolization is an indication for CTA [12]. Active extravasation is seen in 41% to 74% cases of PPH on CTA [17] and multiphasic CT, including a noncontrast arterial and portal venous phases, has excellent accuracy of 97% [18] for detection of the site of active extravasation, similar to that of gastrointestinal hemorrhage [17,18]. CTA can be falsely positive because of dilated tortuous hypertrophic uterine arteries mimicking extravasation and be falsely negative in atony because of slow intermittent hemorrhage [12,18]. CTA also enables comprehensive evaluation of abdominopelvic vasculature, including vessels not often evaluated on routine angiography such as the ovarian and inferior epigastric arteries [18].