[Fundamental study of magnetization transfer contrast (MTC) effect: optimization of MT pulse condition using experimental phantom].
Magnetization transfer contrast (MTC) was evaluated by changing the off-set frequency and pulse intensity of MTC with the spoiled gradient echo (SPGR) sequence (T2*-weighted image) using an experimental phantom that included olive oil, protein, fiber, collagen, and pure water. The intensity of pure water reached a constant level just above the off-set frequency (1200 Hz) regardless of MT pulse power. The contrast-to-noise ratio (CNR) in each of the phantom materials was maximal at the MT pulse power of 2500 degrees (equivalent flip angle). The CNR and image noise obtained by body coil were inferior to those obtained with an extremity coil. In clinical application, the MTC effect on chondrosarcoma was higher (MT ratio, ROI-1:0.448, ROI-2:0.382) than those of other cases in this study. Since the image contrast was improved between the malignant fibrous histiocytoma (MFH, MT ratio, ROI-1:0.282, ROI-2:0.289) and peripheral tissues, extraskeletal extension could be observed more easily than without MTC imaging. In conclusion, the effects of MTC might be in providing useful information, in presuming composed tissues, differential diagnoses, and extent to the surrounding structures because of changing the image contrast to surrounding tissues corresponding to the rate of included bound water.
Kawata
Hidemichi
H
Center for Diagnostic Imaging, Kurume University Hospital.
Nishimura
Hiroshi
H
Nagata
Syuji
S
Matsuda
Tsuyoshi
T
Takada
Kimiyoshi
K
Hayabuchi
Naofumi
N
D001859:Bone Neoplasms / Q000175:diagnosis; D002813:Chondrosarcoma / Q000175:diagnosis; D005069:Evaluation Studies as Topic; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000592:standards*; D019047:Phantoms, Imaging / Q000592:standards