From the Guidelines
You should not eat for 4-6 hours before an MRI scan, but follow your doctor's specific instructions. For most MRI scans, you'll be asked to fast for 4-6 hours beforehand. This is especially important if you're having an abdominal MRI or if contrast dye will be used. Fasting helps reduce motion in the digestive tract, which can improve image quality. It also reduces the risk of nausea if contrast dye is administered. Although the provided evidence does not directly address MRI scans, general guidelines for medical imaging and procedures suggest avoiding heavy meals before procedures, as seen in the context of CT simulation and treatment planning 1. You can usually drink clear liquids like water up until 2 hours before the scan, unless instructed otherwise. Take any regular medications as usual with small sips of water, unless your doctor says otherwise. Some studies suggest that a light meal may be acceptable before certain tests, such as the six-minute walk test 1, but this may not apply to MRI scans. For some types of MRI scans, particularly those not involving the abdomen, you may be allowed to eat normally. Always check with your healthcare provider or the imaging center for specific instructions, as requirements can vary based on the type of scan and individual patient factors.
From the Research
Eating Before an MRI Scan
- There is no strict requirement to fast before undergoing a Magnetic Resonance Imaging (MRI) scan, as evidenced by studies 2, 3, 4, 5.
- A study on fetal MRI found that neither fasting nor specific food consumption was associated with significant differences in fetal motion 2.
- Another study examined the effects of meal intake on flow velocities in the superior mesenteric artery and aorta using 2D phase-mapping MRI, but did not address the requirement for fasting before an MRI scan 3.
- Research on abdominal ultrasound preparation found that patient preparation, such as fasting for 8 hours, is common practice to avoid digestive motility and gases, but did not directly relate to MRI scans 6.
- An MRI study investigated gastric emptying after intake of a high-caloric, high-fat standard meal and found that gastric content volume decreased constantly after a lag phase, but this study was focused on food-effect bioavailability and fed bioequivalence studies 4.
- A study on detecting the effects of a standardized meal challenge on small bowel motility with MRI found that a caloric challenge produced an observable increase in motility in unprepared bowel, but this was not directly related to the requirement for fasting before an MRI scan 5.