CLINICAL UTILITY OF A NEW CONTRAST OPTION FROM MAGNETIZATION-TRANSFERCONTRAST

Two magnetization transfer (MT) contrast effects, a T2-like effect and the improved contrast observed when gadolinium is used with MT, are c ombined in a single sequence, Forty patients (22 males:18 females; mea n age, 45 years (23-87)) with suspected intracranial pathology underwe nt MRI on a 1.5 Tesla system, Of 46 lesions; seven were ischemic, five infective, seven neoplastic, four hemorrhagic, four multiple sclerosi s, seven human immunodeficiency virus (HIV) leukoencephalopathy, nine normal/miscellaneous, and three gliosis. A conventional spin-echo sequ ence (TR 900 TE 15) was used with on-resonance binomial MT pulses, The sequence was performed postgadolinium +/- MT, The signal intensity ra tios +/- MT were: white matter, 0.62 +/- 0.03; gray matter, 0,75 +/- 0 .04; ischemia, edema, and demyelination, 0.75 (0.57-0.86); and gadolin ium/methemoglobin, 0.85 (0.81-0.98), Areas which exhibited MT had TP-l ike contrast and those that did not maintained expected contrast for t he given parameters, The result was a combination of Ta-like contrast, gadolinium enhancement, and dark cerebrospinal fluid (CSF) providing both increased sensitivity to lesions which exhibited both contrast fe atures and improved delineation of periventricular lesions, Furthermor e, the differential signal between Ta-like contrast of edema and gadol inium enhancement in neoplastic or infective lesions was maintained.