Fetal magnetic resonance imaging: indications, technique, anatomical considerations and a review of fetal abnormalities

Abstract

Fetal MR imaging often poses a diagnostic challenge for the radiologist. Both fetal anatomy and pathology differ decidedly from pediatric and adult MR imaging. While ultrasound remains the method of choice for screening examinations of the fetus, MR imaging is playing an increasingly important role in the detection and classification of malformations not diagnosable by ultrasonography alone. Recently, advances in fast single-shot MR sequences have allowed high-resolution, high-quality imaging of the moving fetus. Preferable sequences to be applied are a true fast imaging steady precession (true-FISP) or a half-Fourier acquired single-shot turbo spin-echo (HASTE) sequence. Premedication is generally no longer required. In all fetal MR imaging, every aspect of fetal anatomy has to be scrutinized. Subsequently, any abnormalities need to be described and classified. A close collaboration with the referring obstetrician is of paramount importance.

MR assessment of fetal lung development using lung volumes and signal intensities

“…The introduction of ultrafast sequences has rapidly expanded the indications for fetal magnetic resonance imaging (MRI) [4][5][6][7][8][9][10]. MRI is a valuable adjunct to ultrasound in the prenatal diagnosis of fetal chest masses [11][12][13][14].…”

The selective use of magnetic resonance imaging in prenatal diagnosis

“…Thus, primary tumors of the liver, albeit rare, such as hamartomas, hepatoblastomas and hemangioendotheliomas, would be expected to be detectable and differentiable by MRI 13,14 .…”

MR Imaging of Fetal Omphalocele: A Case Report

“…5 In contrast to ultrasound, MR imaging is not suitable for fetal screening but is useful for detailed imaging when an abdominal wall defect is detected by ultrasound, and MR imaging aids diŠerential diagnosis. 6,7 In addition, chromosomal and congenital anomalies are more frequent for an omphalocele than for a gastroschisis. Compared to abdominal ultrasound, MR imaging is useful for prenatal diagnosis as well as diŠerential diagnosis in evaluating factors such as size of the abdominal wall defect, quantity of extruded bowel, presence of intestinal atresia, and presence of other congenital anomalies.…”

“…[2][3][4][5] Although magnetic resonance (MR) imaging clearly delineates the hernia sac of a fetal omphalocele and facilitates diŠerential diagnosis, 6,7 its use in imaging the hernia's internal structure has not been described. We report a case of an omphalocele and detail the internal structure of the hernia sac.…”