|Tests and Services
Fetal MRI and Ultrasound
Children’s National Medical Center is one of the few centers nationally that provides combined fetal ultrasound and MR imaging. This test is only performed at Children's National Medical Center-Main Hospital location.
The Division of Diagnostic Imaging and Radiology performs fetal MRIs and prenatal ultrasounds in conjunction with the Center for Prenatal Evaluation.
David Wessel, MD, Senior Vice President of the Center for Hospital-Based Specialties and Raymond Sze, MD, Chief of Diagnostic Imaging and Radiology are pleased to announce that the American College of Radiology’s (ACR) Commission on Quality and Safety has granted accreditation to the following diagnostic imaging programs:
Attaining the ACR Gold Seal of Accreditation is an arduous process that involves submission of physician and staff credentials, safety policies, detailed quality assurance records for each scanner, radiation dose calibrations for the ionizing radiation-producing scanners, and multiple samples of actual clinical images from each scanner. All data and images submitted are analyzed by a group of expert radiologists and medical imaging physicists who determine if the site meets the highest standards of quality and safety.
Children’s Division of Diagnostic Imaging and Radiology (Sheik Zayed campus location) achieved this high honor and is now ACR Accredited for a 3-year term. Congratulations to the faculty and staff for their commitment to high quality patient care, patient safety, and overall excellence in imaging.
What is a prenatal ultrasound?
A prenatal ultrasound scan is a diagnostic technique which uses high-frequency sound waves to create an image of the fetus, placenta, and uterus. Ultrasounds may be performed in the first, second, or third trimester.
How is an ultrasound scan performed?
Although the specific details of each procedure vary slightly, generally, ultrasounds follow the following process.
- Abdominal ultrasound—To perform the exam, the ultrasound technologist passes a hand-held transducer across the woman’s belly. Inaudible, high-frequency sound waves are emitted by the ultrasound transducer. As these sound waves pass into the body, they are reflected back at different strengths and frequencies by the different anatomic structures of both the mother and the fetus. The same transducer receives these reflected sound waves and a computer reconstructs them into real time-images. A woman may need to have a full bladder for abdominal ultrasounds in early pregnancy. This helps move the uterus into better view.
- Transvaginal ultrasound—In a transvaginal ultrasound, a small ultrasound transducer is inserted into the vagina and rests against the back of the vagina to create an image. A transvaginal ultrasound produces a sharper image and is often used in early pregnancy.
- Three-dimensional (3D) and 4D ultrasound can produce images of the fetus that are as detailed as a photograph. This type of imaging may be used when examining a particular fetal abnormality.
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What are the risks and benefits of ultrasound?
There is no known evidence of risk to the fetus with ultrasound. The mother may experience some discomfort from the pressure of the ultrasound transducer or from having a full bladder, which may be needed in early pregnancy exams. Given its long record of safety, utility, and cost-effectiveness, ultrasound is the first modality used for screening a fetus.
What is fetal MRI?
(Magnetic Resonance Imaging) is a diagnostic technique for taking pictures of the inside of the body. MRI uses a strong magnetic field and radio waves to obtain the pictures. At times it can provide useful additional information about the fetal brain, chest, and abdomen.
Images are quickly obtained without the use of sedation and provide exquisite detail that multiple experts can review. Children’s National Medical Center is one of the few centers nationally that provides combined fetal ultrasound and MR imaging.
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How is a fetal MRI performed?
During a MRI scan, pictures are taken from different angles and a computer processes the information to produce a detailed image of the baby. The MRI scanner looks like a big square box with a tunnel through the middle. During a MRI scan the mother must lie still on her back in the tunnel. If it is not possible for her to lie on her back, she may be able to lie on her side.
Foam cushions and soft straps are used to help keep the mother still. A soft flexible wrap goes over the stomach and records the radio waves for the pictures. Earplugs are worn to muffle the loud knocking noise of the machine.
There is a microphone in the scanner so the mother can talk to the MRI technologist performing the scan. The scan usually takes 30 to 40 minutes.
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Is fetal MRI safe?
The magnetic field and radio waves are believed to be safe and no adverse effects on unborn babies have been reported with normal use. There is no ionizing radiation (which is used for x-rays) used in MRI.
Are there any special precautions with fetal MRI?
All people entering the MRI room are required to complete a MRI questionnaire prior to the scan. It asks the patient’s medical history and helps the MRI team ensure the safety of all patients in the scanning room.
Because the machine is a large magnet, no metal can be brought into the room. All body piercing must be removed. The following items are affected by the magnet and are not permitted into the scanning room for safety reasons: watches, pens, keys, jewelry, hair pins, safety pins, mobile phones, credit cards, pagers, radios, and CD players.
A downloadable PDF is available for assistance with metal screening.
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