Currents induced by rapid field changes in an MRI solenoid can, in some cases, heat tissue in the body, but under normal circumstances the heating is small. Consider a “loop" of muscle encircling the bone of your arm that is made up of a single strand 8.0 cm long and 1.0 cm in diameter. Muscle tissue is not a great conductor, but current will pass through it and so we can consider this a conducting loop with a rather high resistance. Suppose the magnetic field along the axis of the loop drops from 1.6 T to 0.0 T in 0.30 s, as it might in an MRI solenoid. Assume that the muscle tissue has resistivity of p = 13 Qm, density of D = 1.1 x 10³ kg/m³, and specific heat capacity of c= 3600 J/kg K.

Currents induced by rapid field changes in an MRI solenoid can, in some cases, heat tissue in the body, but under normal circumstances the heating is small. Consider a “loop" of muscle encircling the bone of your arm that is made up of a single strand 8.0 cm long and 1.0 cm in diameter. Muscle tissue is not a great conductor, but current will pass through it and so we can consider this a conducting loop with a rather high resistance. Suppose the magnetic field along the axis of the loop drops from 1.6 T to 0.0 T in 0.30 s, as it might in an MRI solenoid. Assume that the muscle tissue has resistivity of p = 13 Qm, density of D = 1.1 x 10³ kg/m³, and specific heat capacity of c= 3600 J/kg K.