MRI RF Inhomogeneity Artifact

RF inhomogeneity artifact, also known as shading artifact, is a type of MRI artifact that appears due to non-uniformity of the RF (radiofrequency) field during image acquisition. This causes a variation in the flip angle across the image, resulting in intensity variations and shading effects in the image.

The appearance of RF inhomogeneity artifact on MRI images can vary depending on the specific imaging sequence and body part being imaged. However, typical characteristics include areas of high signal intensity at the periphery of the image and areas of low signal intensity at the center.

Here are some strategies to minimize or avoid RF inhomogeneity artifact :

Using a multi-channel coil: Multi-channel coils can provide a more uniform RF field by using multiple transmit and receive elements. This can help to reduce RF inhomogeneity artifacts in the resulting images.

Use surface coil: Surface coils are often used to obtain higher signal-to-noise ratio (SNR) and better image quality, especially for small body parts. They can help reduce RF inhomogeneity artifacts because they are placed closer to the region of interest and have a more uniform sensitivity profile.

Shimming: Magnetic field shimming can be used to adjust the magnetic field homogeneity within the region of interest, which can help reduce RF inhomogeneity artifacts.

Using a higher field strength: Higher field strength can improve image quality and reduce RF inhomogeneity artifacts. However, it may not be feasible or safe for all patients or imaging applications.

Using a shorter echo time: A shorter echo time can reduce the impact of RF inhomogeneity on image quality.

References:

Franklin, K. M., Dale, B. M., & Merkle, E. M. (Year). Improvement in B1-inhomogeneity artifacts in the abdomen at 3T MR imaging using a radiofrequency cushion. Journal of Magnetic Resonance Imaging,