Magnetic Resonance Imaging as an Adjunct to Ultrasound in Evaluating Cesarean Scar Ectopic Pregnancy

Abstract

Cesarean scar pregnancies (CSPs) are a relatively rare form of ectopic pregnancy in which the embryo is implanted within the fibrous scar of a previous cesarean section. A greater number of cases of CSPs are currently being reported as the rates of cesarean section are increasing globally and as detection of scar pregnancy has improved with use of transvaginal ultrasound (TVUS) with color Doppler imaging. Delayed diagnosis and management of this potentially life-threatening condition may result in complications, predominantly uterine rupture and hemorrhage with significant potential maternal morbidity. Diagnosis of a cesarean scar pregnancy (CSP) requires a high index of clinical suspicion, as up to 40% of patients may be asymptomatic. TVUS has a reported sensitivity of 84.6% and has become the imaging examination of choice for diagnosis of a CSP. Magnetic resonance imaging (MRI) has been used in a small number of patients as an adjunct to TVUS. In the present report, MRI is highlighted as a problem-solving tool capable of more precisely identifying the relationship of a CSP to adjacent structures, thereby providing additional information critical to directing appropriate patient management and therapy.

Identifying risk factors for cesarean scar pregnancy: a retrospective study of 79 cases

“…1A) [18]. Intraoperative findings revealed that the bladder was densely adhered to the lower uterine segment and the gestational sac implanted through the cesarean scar.…”

Magnetic Resonance Imaging in Addition to Ultrasound in the Diagnosis of Cesarean Scar Ectopic Pregnancy

“…MRI is very helpful in showing sac characterization, localization and whether there is an invasion of adjacent organs because it is a multiplanar imaging method and it has a high soft tissue resolution. Another advantage of the MRI is that it gives critical information for further treatment plan and guidance to surgeons [10].…”

Difficulties in evaluating the pregnant patient with abdominal pain: A complicated case of uterine rupture

“…MRI, compared to ultrasound, is more sensitive for the detection of placental invasion into the uterine wall. 9 Once uterine rupture has occurred it is best diagnosed based on clinical findings rather than with imaging due to the limited time available before irreversible physiologic damage occurs to the mother and fetus. Based on case reports, the most common conditions associated with uterine rupture include: prolonged deceleration in fetal heart rate or bradycardia, [10][11][12][15][16][17] abnormal pattern in fetal heart rate, [10][11][12][15][16][17] previously scarred uterus, [13][14][15] oxytocin stimulation of labor, 13,14 cephalopelvic disproportion, 13,14 grand multiparity, [13][14][15] abruptio placentae, 13 10,15 In most cases of acute uterine rupture there is little time to perform diagnostic imaging, and there is currently no strong evidence to support one imaging modality over another.…”

“…Given these limitations, ultrasound is considered to be the first line imaging tool to evaluate the status of a cesarean scar. 4,9 Magnetic Resonance Imaging (MRI) and Computed Topography (CT) are also useful imaging modalities. MRI is hypothesized to be superior to CT for evaluating the status of a cesarean scar because of its superior ability to evaluate soft tissue structures.…”

“…MRI is hypothesized to be superior to CT for evaluating the status of a cesarean scar because of its superior ability to evaluate soft tissue structures. 4,9 Principle limitations of MRI are length of acquisition time and sensitivity to patient movement. 4 CT images can be obtained more rapidly but are used sparingly in pregnancy, especially early in pregnancy, due to ionizing radiation.…”