Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool that uses a powerful magnetic field and radio waves to generate detailed cross-sectional pictures of the body’s internal structures. Unlike X-rays or CT scans, this technology excels at visualizing soft tissues, including ligaments, tendons, cartilage, and muscles in the wrist. Because patients often worry about entering a large machine, this article clarifies the physical positioning and experience specific to a wrist MRI scan.
Answering the Question: Positioning for a Wrist MRI
The short answer to whether your whole body goes in for a wrist MRI is no. The primary requirement for a successful scan is ensuring the area of interest—the wrist—is perfectly centered within the machine’s magnetic field, known as the isocenter. For a standard closed-bore scanner, the patient is positioned on a table that slides into the machine, but only the arm and wrist need to be fully enclosed.
One common positioning method is for the patient to lie on their stomach in the “superman position,” with the affected arm extended forward into the bore. Alternatively, the patient may lie on their back, with the arm extended alongside the body or bent across the abdomen, placing the wrist into a specialized coil. In both scenarios, the head, chest, and lower body remain largely outside the narrow tube. This minimizes the feeling of being completely confined while ensuring the wrist coil is centered to produce the clearest possible images.
Understanding Different MRI Machines
The physical experience of a wrist scan depends significantly on the type of machine used. The most common is the standard closed-bore MRI, a tube-shaped scanner that delivers high-quality images due to its strong and uniform magnetic field. Even with this system, since the wrist is positioned first, the patient’s head usually remains near the entrance or entirely outside the bore.
A more accommodating option is the open MRI, designed with open sides or a wider bore to alleviate anxiety. These machines use magnets positioned above and below the patient, offering a less enclosed environment. However, the image quality may occasionally be lower than that of high-field closed systems.
The least confining option is the dedicated extremity scanner, a much smaller machine built specifically for imaging limbs like the wrist, ankle, or knee. With this scanner, the patient’s head and torso remain completely outside the machine, as only the arm needs to be inserted into the small opening. These specialized systems are highly patient-friendly, significantly reducing anxiety and noise levels compared to a full-body unit. While offering a superior patient experience, the standard closed-bore scanner remains a common setting for a wrist MRI because extremity scanners are not universally available.
What to Expect During the Scan
Once positioned, the technologist places the wrist into a specialized receiver coil, a padded device designed to maximize image clarity. Immobilization is achieved using pads, supports, or straps, as any slight movement during the scanning sequences can blur the resulting pictures. The technologist then moves to a separate control room to operate the equipment and begin the procedure.
The scan typically takes between 20 and 45 minutes, depending on the complexity of the required images and whether a contrast agent is necessary. During this time, the machine produces very loud, repetitive tapping and thumping sounds as the magnetic gradients rapidly turn on and off. To protect the patient’s hearing, the technologist provides earplugs or noise-canceling headphones, often with the option to listen to music.
The patient is given an emergency call button to hold throughout the duration of the scan. This device allows the patient to instantly alert the technologist if they experience discomfort or anxiety during the procedure. Communication with the technician is also maintained through a two-way intercom system, ensuring the patient is supported and can report any issues without having to move.