Method to automatically tune MRI RF coils

A flexible coil for magnetic resonance imaging comprising:

• a continuous belt having a first layer of insulating material and a second layer comprising an rf coil for generating or receiving an rf MRI imaging signal, the belt comprising a series of joined segments including a first active segment that establishes a minimum active length and one or more serial intermediate segments that extend the active length of the belt between a minimum physical length and a maximum physical length;
• the first segment having an inductance and a capacitance that establishes a resonant frequency for said minimum physical length;
• means for adjusting the active length of the belt to an intermediate length compatible with the circumference of a sample, said intermediate length including one or more serial segments of the belt;
• each serial segment being electrically connected in series with the first segment and with any intervening segments, each serial segment providing an incremental inductance and an incremental capacitance that substantially cancel one another so that the resonant frequency of the coil at each intermediate length and at the maximum length is substantially the same as the resonant frequency for the minimum length.