Switched surface coil system for bilateral MR imaging.

A method is presented for acquiring magnetic resonance (MR) images in parallel from both members of a pair of organs, such as the temporomandibular joint (TMJ), with use of two surface coil receivers. Interleaved sagittal sections are broken into two groups, one on each side of the head, and the MR receiver is toggled between the two coils. The surface coil that is not receiving at a given time is decoupled from the other surface coil by the active gating of a diode blocking network located across the coil input. This method produces effective decoupling independent of coil loading and positioning and makes it possible to use the same surface coils already employed for single-coil MR reception. Clinical application in 95 patients (190 joints) with symptoms of internal derangement of the TMJ demonstrated a 24% average decrease in total patient examination time, even after the addition of coronal imaging to the procedure. In no case was there a sacrifice in diagnostic quality.