Fetal MRI is the acquisition of high-quality images of the fetus using radiomagnetic radiation that does not have a damaging effect on tissues. The advantage of MRI is the absence of ionizing radiation, high tissue contrast, obtaining a multi-plane and three-dimensional image of the fetus, regardless of its position and gestational age. It is prescribed when fetal malformations, congenital and genetic diseases, pathology of the placenta and umbilical cord are detected according to the results of ultrasound screening. Allows you to make a forecast of fetal development and its viability, choose the tactics of pregnancy, childbirth and postpartum measures.
MRI is usually performed after ultrasound screening to confirm or supplement the information obtained during ultrasound examination. This is especially important for determining fetal abnormalities, clarifying the nature and extent of the prevalence of various pathological processes. Also, fetal MRI is prescribed if ultrasound diagnosis is impossible, for example, in patients with increased body weight, when the layer of adipose tissue is longer than the wavelength of the sound wave, as well as with a decrease in the volume of amniotic fluid, atypical fetal location that makes it difficult to visualize the desired areas, the presence of twins. Magnetic resonance imaging is recommended for examining the fetal brain at the final stage of pregnancy, since the density of the bones of the skull increases from the third trimester, and they stop transmitting an ultrasound signal.
Indications for tomography are burdened heredity (developmental abnormalities in older children, a history of stillbirth, etc.), decreased activity and a decrease in the number of heart contractions of the child. The doctor may recommend an MRI of the fetus in case of suspected injury or intrauterine infection. Multiple pregnancies have an increased risk of developing anomalies, the most dangerous defect is conjoined twins. Magnetic resonance imaging in these cases makes it possible to assess the possibility of survival of children, choose the optimal treatment and delivery tactics, and make an approximate plan for the operation to separate twins even before their birth. On the mother’s side, indications for fetal MRI are anatomical changes in the pelvis (narrow or flat pelvis, consequences of injuries, rickets suffered in childhood.).
Among the contraindications to magnetic resonance diagnostics are absolute and relative. The first include the presence of a pacemaker in the mother’s body, an electronic middle ear implant and any metal structures. Relative contraindications include fear of confined spaces, heart failure in the decompensation stage, prosthetic heart valves, the presence of tattoos made using a dye containing metal compounds.
A specialist conducting an MRI of the fetus must submit the available medical documentation: ultrasound results, extracts from medical records, etc. Before starting the study, the patient must remove all metal objects (watches, earrings, rings, hairpins, etc.), put credit cards and electronic devices (mobile phones and other gadgets). The procedure does not provide for restrictions on food intake and other specific preparation.
Methodology of conducting
Fetal MRI begins with the patient being placed on a table, which is moved inside the device. During the diagnosis, it is necessary to maintain complete immobility so as not to distort the image. If any problems arise, the patient can contact the laboratory assistant via a two-way communication system and suspend the study, the duration of which is on average 40 minutes. The time required to prepare a medical report depends on the severity of a particular clinical case. The conclusion is issued in printed or handwritten form together with images on film, disk or other electronic media.
Interpretation of results
During the procedure, you can study in detail the nervous system, ligaments, muscles, adipose tissue, blood vessels, parenchymal organs and other anatomical formations. According to the results of fetal MRI, the quantitative and qualitative composition of amniotic fluid, the size, location, structure and contours of the placenta are determined. With the help of tomography, the position and type of presentation of the child is assessed, the volume of the head is measured with the study of brain structures.
When visualizing the abdominal organs, their location and size are determined, as well as the correspondence of the obtained indicators to the period of pregnancy. An MRI of the fetus is completed by the preparation of a conclusion by a specialist who reflects all the identified changes in writing. Based on these data, the clinical picture and the results of other diagnostic procedures, the attending physician can make a final diagnosis, make a treatment plan or raise the question of termination of pregnancy.