PT  - JOURNAL ARTICLE
AU  - Yousem, D M
AU  - Ihmeidan, I
AU  - Quencer, R
AU  - Atlas, S W
TI  - Paradoxically decreased signal intensity on postcontrast short-TR MR images.
DP  - 1991 Sep 01
TA  - American Journal of Neuroradiology
PG  - 875--880
VI  - 12
IP  - 5
4099  - http://www.ajnr.org/content/12/5/875.short
4100  - http://www.ajnr.org/content/12/5/875.full
SO  - Am. J. Neuroradiol.1991 Sep 01; 12
AB  - Seven lesions are presented in which short TR/short TE images obtained immediately after IV administration of gadopentetate dimeglumine demonstrated an apparent decrease in signal intensity compared with precontrast short TR/short TE images. All seven lesions were hyperintense on precontrast short TR/short TE images. In four cases in which long TR/long TE scans were also obtained, the lesions were hypointense. This phenomenon may be due to a dominant T2 shortening effect by the contrast material that "overwhelms" T1 shortening even on short TR/short TE scans. Other compounding factors may include variations in scanning variables, receive and transmit attenuations, or a photographic phenomenon due to window widths and center levels.