Ultrasound vs MRI in Diagnosis of Fetal and Maternal Complications

Abstract

Ultrasound is the screening modality of choice for the fetal imaging. However, there are circumstances in which an alternative imaging technique is needed for additional information regarding fetal anatomy and pathology as well as different maternal conditions. Magnetic resonance imaging (MRI) is being increasingly used as correlative imaging modality in pregnancy because it uses no ionizing radiation, provides excellent soft-tissue contrast, and has multiple planes for reconstruction and large field of view, allowing better depiction of anatomy in fetuses with large or complex anomalies. In this review, we attempted to identify strengths and weaknesses of each modality both from the literature and our own working experience, and to propose to some practical recommendations on when to use which imaging modality. Both ultrasonography and MRI are operator-dependant and neither technique obviates the need for thorough knowledge of normal and abnormal anatomy. In early pregnancy, and where repeated assessment is needed, ultrasound has the obvious advantage. In circumstances where ultrasound examination is difficult, as in the obese patient or severe oligohydramnion, better images might be obtained by MRI examination. MRI might also identify early fetal ischemic lesions after an insult, such as maternal trauma or death of a monochorionic co-twin. From the published literature, it would appear that MRI may provide additional diagnostic information to that given by ultrasound in 25 to 55% of cases, which in turn may have influence on parental counseling and/or management of affected pregnancies. Individual circumstances and expertise influence the accuracy of both modalities. Ultrasound and MRI should be performed to the highest possible standard, and the final diagnosis should be made in a multidisciplinary setting.

Fetal and Perinatal Lymhangiomas - A Spectrum of MR and CT Findings

“…However, recently there is an expansion of the use of MRI due to the limited sonographic anatomical orientation in some pathology. Although US is first method of choice in fetal and perinatal age, MRI MR is more sensitive for detecting fluid levels, could be beneficial in cases of complex extension due to the large field of view englobing different anatomic regions -ex.from neck to mediastinum and is less operator dependant [3,5]. MRI could be used preoperatively to evaluate engagement of vital structures (aorta, trachea, nerve bundles, etc.).…”

“…According to those authors, MR imaging may play a role in prenatal imaging to provide early comprehensive information about both the anatomy and the extension of cystic hygromas [4]. Some authors like Ljubic et al describe an extensive comparison between MR and US in the diagnosis of fetal and maternal complications [5].…”

Spina Bifida;

“…[60][61][62][63] Urologic abnormalities Urologic abnormalities associated with spina bifida are vesicouretral reflex (21-25%), cryptorchidism (10-30%), bladder exostrophy (6.8%), hypospadias (0.1%), unilateral renal agenesis (2-8%), uretropelvic junction obstruction (1-3%), multicystic dysplastic kidney (7-13%) and horseshoe kidney (2-7%). [64][65][66][67][68][69][70][71][72][73][74] Cardio-Metabolic Dysfunction: People having SB have increased body mass index (BMI) and percent body fat than that of people without SB. Young adults and children having SB have decreased muscular strength and aerobic fitness in addition to having increased body fat.…”

A Spectrum of Ultrasound and MR Imaging of Fetal Gastrointestinal Abnormalities: Part 2 Anorectal Malformation, Liver, and Abdominal Wall Anomalies

“…Ultrasound (US) continues to be the modality of choice in prenatal fetal screening 1 due to its high availability, lack of radiation, and excellent spatial resolution. Nonetheless, application of US is limited by some factors such as being operator dependent, low image contrast, and maternal and fetal complications (eg, obesity, oligohydramnios, fetal position) 2 …”

“…Nonetheless, application of US is limited by some factors such as being operator dependent, low image contrast, and maternal and fetal complications (eg, obesity, oligohydramnios, fetal position). 2 Magnetic resonance imaging (MRI) can be utilized as a supplementary tool because it has better soft tissue contrast, wider field of view and software image processing, 1 providing multi-planar image reconstruction and more detailed anatomy. Specific advantages of MRI over US in alimentary tract and abdominal wall anomalies have also been described, including better depiction of fetal GI tract, localizing the level of obstruction, showing meconium, detection of microcolon, 3,4 and evaluation of the abdominopelvic and mural extension of masses 5 providing prognostic information and better therapeutic management.…”