1997 Fiscal Year Final Research Report Summary
Assessment of vascularity andviability of the liver and liver tumors using the liver specific contrast agent in MR imaging
| Project/Area Number |
08671014
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Radiation science
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| Research Institution | Fukui Medical University |
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Principal Investigator |
KAWAMURA Yasutaka Fukui Medical University, Medical Hospital, Lecturer, 医学部附属病院, 講師 (30214703)
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| Project Period (FY) |
1996 – 1997
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| Keywords | MRI / Liver, Neoplasm / Liver, Reticuloendothelial System / Contrast Media / Perfusion / 血流 |
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| Research Abstract |
PURPOSE : Although SPIO-enhanced MRI is excellent for detecting small liver tumors, its lack of tumor vascularity makes it difficult in evaluating tumor viability of follow-up cases. We applied dynamic SPIO-MRI to obtain perfusion data of the liver and liver tumors.
MATERIALS AND METHODS : Seven patients with hepatocellular carcinoma, five with liver metastases and two with cholangiocarcinoma were enrolled in this study. SPIO-MRI was performed with a 1.5 Tesla unit (Signa Horizon, GE : WI), dynamic contrast-enhanced CT (High Speed Advantage, GE : WI) and liver angiography were performed on all patients. The dynamic SPIO-MRI was performed in eight cases.
The SPIO (Nihon Schering, Japan) has a size of 4.2 nm (core) and 55 nm (whole particle) Its T1-and T2-relaxitivities are 9.48 and 229.5 mM-1・sec-1 on our GE 1.5-T Signa. T2-weighted images (Fast SE : TR/TE=4100/80-90), breath-holding gradient echo images (TR/TE=100/2.7 ; Flip Angle=20ﾟ) were obtained before and after the dynamic SPIO-MRI.
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The T1-weighted dynamic MRI were performed with the bolus injection of 8 mmol Fe/kg of SPIO (FMP SPGR : TR/TE=110/2.7-4.1 ; Flip Angle=90ﾟ ; 12 seconds/11 slices).
The number and the delineation of tumors and the pattern of enhancement (homogeneous or inhomogeneous) were assessed on each images with no knowledge of patient history and image sequences. Results obtained from angiography were used as the gold standard for the tumor number.
RESULTS : Out of 32 nodules confirmed by the angiography, 24 (75%) and 17 (53%) were detected on SPIO-MRI and dynamic-CT,respectively. However, seven false-positive lesions were noticed on SPIO-MRI,possibly due to regeneration nodules associating liver cirrhosis.
Five hepatocellular carcinoma patients and two metastases patients had been treated by trans arterial chemoembolization therapy more than one month prior to this study. In those cases, CT clearly demonstrated central high density due to effective lipiodol accumulation within the nodules and peripheral enhancement indicating viable tumor. However, SPIO-MRI showed tumors as homogeneous hyperintensity nodules in which tumor viability could not be assessed.
Dynamic SPIO-MRI revealed tumor perfusion in 14 major lesions otherwise tumor necrosis and viable portion could not be differentiated on SPIO-MRI.
DISCUSSION : The use of SPIO could improve the detectability of small liver tumors on MRI,however, false-positive results and its insensitivity of tumor vascularity might cause problem in screening liver disease. To apply the dynamic SPIO-MRI could supply perfusion data of the liver and liver tumors and helped diagnostic quality. Less
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