1992 Fiscal Year Final Research Report Summary
Research on MRI Contrast Agents for the Liver.
| Project/Area Number |
02454282
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | University of Tsukuba, Institute of Clinical Medicine (1991-1992)
The University of Tokyo (1990) |
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Principal Investigator |
ITAI Yuji Univ. of Tsukuba, Radiology, Professor, 臨床医学系, 教授 (30010268)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Tokuko Univ. of Marine Science, Chemistry, Professor, 教養学部, 教授 (40092382)
SHIGA Junji Univ. of Tokyo, Pathology, Associate professor, 医学部, 助教授 (10110694)
OHTOMO Kuni Yamanashi Medical College, Associate professor, 放射線部, 助教授 (80126010)
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| Project Period (FY) |
1990 – 1992
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| Keywords | MR imaging / Liver / Contrast agent / Gd-DTPA / Ferrite / Experimental liver cancer / Large dose administration of contrast agent |
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| Research Abstract |
1. Nonspecific Contrast Agents Using Gd-DTPA, we evaluted its differential diagnostic accuracy among liver tumors and investigated the evaluation of treatment in hepatocellular carcinoma (HCC). In delayed phase of spin echo, differentiation of HCC from hepatic cavernous hemangioma (HCH) was achieved with accuracy of 94%. In order to evaluate the diagnostic role of subtle ehancement noted in the late phase, the dose of Gd-DTPA administered was increased from 0.05 to 0.2m mol/kg. However, HCC revealing the typical HCH pattern was in creased from 7% to 15%. Comparing dynamic MRI with dynamic CT, both studies were essentially same and only 3% of lesions had different diagnoses despite different scanning interval and time as well as different direction of imaging used. Thus MRI was superior to CT in the detection of feebly enhanced areas and in less frequent and severe adverse effects. However, we failed to confirm the advantage over CT in the early detection of recurrence in treated HCC an
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d the evaluation of treatment effect so far. The utility of MRI contrast agent was also evaluated in diffuse liver diseases such as liver cirrhosis and radiation hepatitis. Regenerating nodules of non-iron deposit type appeared as relatively hyperintense on plain Tl-weighted image and became isointense or hypoinse after contrast enhancement because of prominent enhancement of Glisson's sheath. However, due to inferior spatial resolution, MRI did not have anything adding to findings obtained with CT. Radiation hepatitis showed gradual, prominent enhancement behind the enhancement peak of HCC. The time and degree of enhancement peak were varying and were inferred to be related with radiation dose, period after irradiation and histological state of hapatitis.
2. Specific Contrast Agents We first reported the presence of reticulo-endothelisl system in well-differentiated HCC of woodchuck with MRI using iron oxide, and later, this phenomenon was also noted in human subjects, Iron oxide and Glutal were compared in terms of dose and peak time using rat having hepatic tumors induced by DAB. Less
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