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]. Serpiginous myometrial vessels and prominent parametrial vessels can be a sign of VUA [19], whereas the presence of a pseudoaneurysmal sac is a more specific finding [14,20,21]. CTA can also identify and localize the feeding arteries of AVM for treatment planning [14]. However, CTA cannot reliably distinguish acquired VUA from failure of obliteration/subinvolution of the placental bed vessels, assess its severity, or need for intervention [19]. MRI Pelvis In clinically suspected endometritis, MRI can identify associated findings such as abscess or infected hematoma that may require drainage and other complications such as ovarian vein thrombosis [14]. RPOC can be seen as a variably enhancing intracavitory mass with variable degree of myometrial thinning [13,14]. MRI is superior to CT and US in detecting the myometrial defect with intact serosal layer in uterine dehiscence because of superior soft- tissue contrast [14,15]. However, in the immediate postpartum period, the cesarean section incision can be T1 and T2 hyperintense and may mimic a dehiscence [22]. Noncontrast MRI can be used to identify bladder flap, subfascial, and deep-seated pelvic hematomas, which depending on the time since delivery, may demonstrate variable T1 and T2 signal characteristics [14,23] and a low T2 signal rim after >2 weeks due to hemosiderin deposition. The superior spatial resolution of MRI compared to Postpartum Hemorrhage
Postpartum Hemorrhage. 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]. Serpiginous myometrial vessels and prominent parametrial vessels can be a sign of VUA [19], whereas the presence of a pseudoaneurysmal sac is a more specific finding [14,20,21]. CTA can also identify and localize the feeding arteries of AVM for treatment planning [14]. However, CTA cannot reliably distinguish acquired VUA from failure of obliteration/subinvolution of the placental bed vessels, assess its severity, or need for intervention [19]. MRI Pelvis In clinically suspected endometritis, MRI can identify associated findings such as abscess or infected hematoma that may require drainage and other complications such as ovarian vein thrombosis [14]. RPOC can be seen as a variably enhancing intracavitory mass with variable degree of myometrial thinning [13,14]. MRI is superior to CT and US in detecting the myometrial defect with intact serosal layer in uterine dehiscence because of superior soft- tissue contrast [14,15]. However, in the immediate postpartum period, the cesarean section incision can be T1 and T2 hyperintense and may mimic a dehiscence [22]. Noncontrast MRI can be used to identify bladder flap, subfascial, and deep-seated pelvic hematomas, which depending on the time since delivery, may demonstrate variable T1 and T2 signal characteristics [14,23] and a low T2 signal rim after >2 weeks due to hemosiderin deposition. The superior spatial resolution of MRI compared to Postpartum Hemorrhage