Coil shading and uneven signal in MRI
One side of the image is brighter than the other. Check the coil and the intensity correction before repeating the scan.
Coil shading / signal non-uniformity
Signal is bright near the coil elements and fades with depth, or one region is dark.
Surface coil sensitivity falls with distance. A dark region can also mean a failed element, an unplugged connector, or the wrong coil selected.
- Turn on intensity correction (PURE / CLEAR / Prescan Normalize)
- Check coil selection, connection and position
- Centre the anatomy inside the coil
Correction evens brightness but not SNR: deep tissue stays noisier.
This page is one entry from the MRI Technologist Reference
The full reference has 31 protocols, 9 dynamic study timelines, 19 artifacts, 16 scanner problems and 15 safety topics, as a PDF in English and Arabic plus an interactive tool.
Educational reference. It does not replace your site protocols, the radiologist's instructions, the MR safety officer, or the manufacturer's instructions for any implant, device or contrast agent. Parameter values are typical starting points at 1.5 T and must be adapted to the scanner, coil and patient.