Magnetic resonance imaging (MRI) is a non-ionizing imaging modality. The MRI machine uses an electromagnetic field to align certain atoms in the tissue in a particular direction. Then a radiofrequency is applied to interrupt this alignment. This would lead to a magnetic rotation of the atomic nuclei, which can be detected and recorded in order to reconstruct an image. MRI can provide a great contrast between adjacent soft tissue with high resolution making this modality a potentially attractive candidate for skin imaging.
Detection of primary (local) or matastatic skin tumor
Conventional MRI has been shown to be helpful in detecting local skin tumors. MRI is also able to show invasion of the tumor to underlying and/or adjacent structures. Perineural invasion of skin tumors including BCC and SCC are reported to be seen on MR images. The extent of tumor infiltration in Dermatofibrosarcoma Protruberans (DFSP) is reported to be detected by MRI. This information can distinctly facilitate surgical planning.
Eosinophilic fasciitis
MRI is a superior modality in evaluation of pathologies affecting the musculoskeletal structure. Eosinophilic fasciitis shows characteristic features on MR images such as symmetrical thickening and hyperintensity signal of the involved superficial muscle fasciae. Follow up images after treatment shows normalization of the above features.
Fibrosing Diseases and and Cutaneous Scleroderma
MRI is also a modality of choice to study fibrosing processes. In cutaneous Scleroderma, deep/sub-cutaneous structural involvement can be evaluated by MRI images.
Future Directions
There is a rich body of literature showing successful in-vivo skin imaging with MR machines at various Tesla unites. However, creating a commercially applicable skin dedicated coil that can address some of the limitations and differences in MR imaging of the skin is still the subject of research and development. Once an appropriately designed skin dedicated MR coil is available, whether applied as a high resolution anatomical imaging or function imaging, MRI modality can contribute significantly to “primary skin imaging”.