By Smruti Munshi
MRI or Magnetic Resonance Imaging has been a life saving technique for many ailments. One of the budding areas for MRI is its application in obstetrics. Obstetrics is the specialty which focuses on woman and fetus care during pregnancy, childbirth and puerperium, the period after delivery of the baby. During pregnancy, the woman undergoes lot of physiological changes. Hence, it becomes very important to watch the various stages in the pregnancy to ensure proper fetal development and avoid complications during child birth. Imaging is one of the most convenient ways to monitor the pregnancy. The commonly used imaging methods are X-Rays. Computerized Tomography (CT) and Ultrasound (US). However, CT and X-rays are not preferred due to the harmful ionizing radiation which has teratogenic effects on the fetus. MRI is scoring over Ultrasound due to some of the "can't be ignored" and some "nebulous" benefits it provides.
One of the most difficult challenges in the pregnant patients is acute abdominal pain. The reason of pain may be obstetric in nature or may be caused by an abnormality in intraabdominal or intrapelvic structures. In such a scenario, MRI provides high intrinsic soft-tissue contrast and clear topographic display with benefits from lack of ionizing radiation. MRI has been shown to be a useful imaging technique for imaging the adrenal gland, diagnosis of appendicitis and inflammatory bowel disease. It has been proved that MRI is a better method for evaluating the fetus in obese patients and in patients whose pregnancies are complicated by low amniotic fluid volume. Unlike ultrasound, MRI provides clear visualization, multiplanar imaging and large field of view facilitating examination of fetuses with large or complex anomalies. Moreover, MR images are easily understood by patients and clinical practitioners as compared to ultrasound. MRI has some of the disadvantages as well. It is more expensive, can be more difficult for patients suffering from claustrophobia, and is not as popular. Furthermore, MRI is quite sensitive to fetal motion. It is a general practice to perform ultrasound prior to MRI to check the fetal position which helps determine the coil selection and position. One of the emerging applications of MRI is to evaluate central nervous system abnormalities in the fetus. The fetal scalp, neck and airway cannot be fully evaluated with ultrasound because of fetal position and artifacts related to adjacent bony structures. MRI helps in diagnosing abnormalities related to these structures and can provide information complementary to ultrasound.