Ua. Ramadan et al., IMPROVEMENT OF BRAIN LESION DETECTION AT 0.1 T BY SIMULTANEOUS USE OFGD-DTPA AND MAGNETIZATION-TRANSFER IMAGING, Magnetic resonance in medicine, 37(2), 1997, pp. 268-274
Imaging parameters were optimized at 0.1 T to improve contrast-to-nois
e ratios (CNR) when combining magnetization transfer (MT) imaging and
the use of paramagnetic contrast medium. This was accomplished by imag
ing a phantom containing serial concentrations of Gd-DTPA in cross-lin
ked bovine serum albumin. With the use of simulations, the dependence
of CNR on imaging parameters was studied. Conventional and MT images w
ere obtained from 10 brain tumor patients with single and triple doses
of Gd-DTPA. Simulations demonstrated the importance of TR in postcont
rast sequences. The CNR in MT images is less sensitive to TR than in c
onventional images. A significant CNR improvement caused by MT remains
at longer TR when there is no contrast enhancement without MT. The cl
inical results indicate that a single dose of Gd-DTPA combined with MT
cannot replace imaging with a triple dose. However, MT significantly
improved the CNR after single and triple Gd-DTPA-doses on T-1-weighted
and proton-density images.