  The low cost and high resolution Multi-gap Resistive Plate Chamber (MRPC)
opens up a new possibility to find an efficient alternative detector for the
Time of Flight (TOF) based Positron Emission Tomography, where the sensitivity
of the system depends largely on the time resolution of the detector. In a
layered structure, suitable converters can be used to increase the photon
detection efficiency. In this paper results of the cosmic ray test of a
four-gap bakelite-based prototype MRPC operated in streamer mode and six-gap
glass-based MRPC operated in avalanche mode are discussed.
