NONSPECIFICITY OF SHORT INVERSION TIME INVERSION-RECOVERY (STIR) AS ATECHNIQUE OF FAT-SUPPRESSION - PITFALLS IN IMAGE INTERPRETATION

Short inversion time inversion recovery (STIR) and the rapid acquisiti on with relaxation enhancement (RARE) version of STIR are commonly use d pulse sequences that are sensitive enough to detect a broad range of pathologic conditions. In addition to suppressing the signal from fat , the STIR sequence achieves additive T1-weighted, T2-weighted, and pr oton density-weighted contrast to facilitate lesion conspicuity [1, 2] . Fat suppression with STIR sequences is based on short T1 relaxation rates and therefore is not tissue specific. The signal from any tissue with a short T1, similar to that of fat, may be nulled as well. The s ignal from tissues that accumulate paramagnetic contrast agents also m ay be suppressed with STIR sequences when an appropriate degree of T1 shortening results.