tailieunhanh - Fetal MRI: An approach to practice: A review

MRI has been increasingly used for detailed visualization of the fetus in utero as well as pregnancy structures. Yet, the familiarity of radiologists and clinicians with fetal MRI is still limited. This article provides a practical approach to fetal MR imaging. Fetal MRI is an interactive scanning of the moving fetus owed to the use of fast sequences. Single-shot fast spin-echo (SSFSE) T2-weighted imaging is a standard sequence. T1-weighted sequences are primarily used to demonstrate fat, calcification and hemorrhage. Balanced steady-state free-precession (SSFP), are beneficial in demonstrating fetal structures as the heart and vessels. Diffusion weighted imaging (DWI), MR spectroscopy (MRS), and diffusion tensor imaging (DTI) have potential applications in fetal imaging. Knowing the developing fetal MR anatomy is essential to detect abnormalities. MR evaluation of the developing fetal brain should include recognition of the multilayered-appearance of the cerebral parenchyma, knowledge of the timing of sulci appearance, myelination and changes in ventricular size. With advanced gestation, fetal organs as lungs and kidneys show significant changes in volume and T2-signal. Through a systematic approach, the normal anatomy of the developing fetus is shown to contrast with a wide spectrum of fetal disorders. The abnormalities displayed are graded in severity from simple common lesions to more complex rare cases. Complete fetal MRI is fulfilled by careful evaluation of the placenta, umbilical cord and amniotic cavity. Accurate interpretation of fetal MRI can provide valuable information that helps prenatal counseling, facilitate management decisions, guide therapy, and support research studies. | Journal of Advanced Research 2014 5 507-523 Cairo University Journal of Advanced Research REVIEW Fetal MRI An approach to practice A review CrossMark Sahar N. Saleem Department of Radiology Kasr Al Ainy Faculty of Medicine Cairo University Cairo Egypt ARTICLE INFO ABSTRACT Article history Received 19 March 2013 Received in revised form 3 June 2013 Accepted 4 June 2013 Available online 11 June 2013 Keywords Fetal MRI Anomalies Prenatal MRI has been increasingly used for detailed visualization of the fetus in utero as well as pregnancy structures. Yet the familiarity of radiologists and clinicians with fetal MRI is still limited. This article provides a practical approach to fetal MR imaging. Fetal MRI is an interactive scanning of the moving fetus owed to the use of fast sequences. Single-shot fast spin-echo SSFSE T2-weighted imaging is a standard sequence. T1-weighted sequences are primarily used to demonstrate fat calcification and hemorrhage. Balanced steady-state free-precession SSFP are beneficial in demonstrating fetal structures as the heart and vessels. Diffusion weighted imaging DWI MR spectroscopy MRS and diffusion tensor imaging DTI have potential applications in fetal imaging. Knowing the developing fetal MR anatomy is essential to detect abnormalities. MR evaluation of the developing fetal brain should include recognition of the multilayered-appearance of the cerebral parenchyma knowledge of the timing of sulci appearance myelination and changes in ventricular size. With advanced gestation fetal organs as lungs and kidneys show significant changes in volume and T2-signal. Through a systematic approach the normal anatomy of the developing fetus is shown to contrast with a wide spectrum of fetal disorders. The abnormalities displayed are graded in severity from simple common lesions to more complex rare cases. Complete fetal MRI is fulfilled by careful evaluation of the placenta umbilical cord and amniotic cavity. Accurate interpretation of fetal MRI can