Brain tumors: detection and typing by use of CPMG sequences and in vivo T2 measurements.

A spin-echo sequence with 24 echoes (Carr-Purcell-Meiboom-Gill sequence) was evaluated to determine the usefulness of magnetic resonance (MR) in detecting and typing brain tumors. The TEs in these examinations were between 28 and 346 msec, and the TR was 860, 1260, or 1660 msec. The results of the MR examination of 32 histopathologically proved tumors are presented. All but one tumor could be detected by MR. Tumors generally were obvious on MR due to the higher contrast enhancement of these lesions, especially with a TE longer than 100 msec. T2 values calculated from an eight-point fit, however, did not allow discrimination of different tumors, nor did they allow differentiation between tumor, inflammatory tissue, and demyelination.