Quantification of muscle involvement by MRI in familial amyloid polyneuropathy.

These observations suggest that FF and MTR could be interesting biomarkers in TTR-FAP. In asymptomatic patients, the FF in gastrocnemius lateralis muscle could be used as a good indicator of the transition from an asymptomatic to a symptomatic form of the disease. Of interest, MTR could be an early biomarker of muscle alterations.