1998 Fiscal Year Final Research Report Summary
Three-dimensional imaging of myocardial blood flow with microcomputed
| Project/Area Number |
09555133
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
計測・制御工学
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| Research Institution | Kawasaki College of Allied Health Professions |
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Principal Investigator |
JIKUYA Kazuaki Kawasaki College of Allied Health Professions Dept.of Applied Medical Engineering, Assistant Professor, 医用電子技術科, 助教授 (90206350)
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| Co-Investigator(Kenkyū-buntansha) |
TACHIBANA Hiroyuki Kawasaki College of Allied Health Professions Dept.of Applied Medical Engineerin, 医用電子技術科, 助手 (00241216)
HIRAMATSU Osamu Kawasaki College of Allied Health Professions Dept.of Applied Medical Engineerin, 医用電子技術科, 講師 (50208849)
MOCHIZUKI Seiichi Kawasaki College of Allied Health Professions Dept.of Applied Medical Engineerii, 医用電子技術科, 助教授 (60259596)
MATSUMOTO Takeshi Kawasaki College of Allied Health Professions Dept.of Applied Medical Engineerin, 医用電子技術科, 助教授 (30249560)
GOTO Masami Kawasaki College of Allied Health Professions Dept.of Applied Medical Engineerii, 医用電子技術科, 教授 (50148699)
OGASAWARA Yasuo Kawasaki Medical School Dept.of Medical Engineeriing, Associate Professor (10152365)
KAJIYA Fumihiko Kawasaki Medical School Dept.of Medical Engineering, Professor (70029114)
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| Project Period (FY) |
1997 – 1998
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| Keywords | myocardial blood flow / global heterogeneity / local homogeneity / molecular flow tracer / microregional ischemia |
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| Research Abstract |
The aim of this study was to characterize the spatial distribution of microregional blood flows in the left ventricular subendocardium. The within-layer myocardial flow distributions in subendocardium (Endo) and subepicardium (Epi) of anesthetized rabbit left ventricular free walls (n=6) were measured using high-resolution digital radiography combined with the ^3H-labeled desmethylimipramine deposition technique [sample size (SS)=0.1 mm]. The spatial pattern of flow distribution was quantitated by the coefficient of variation of regional flows (CV, related to global flow heterogeneity) and the correlation between adjacent regional flows (CA, related to local flow homogeneity). To evaluate the resolution-dependence of regional flows, CV and CA were also computed for several coarse-grained images reproduced from the original by increasing SS step by step from 0.1 to 1 mm. Both CV and CA were higher in Endo than in Epi at all levels of resolution (P<0.05, Wilcoxon test). Fractal nature of CV existed in both layer ; however the fractal dimension was lower in Endo than in Epi (P<0.05, Wilcoxon test). We conclude that globally, the microregional flow distribution is more heterogeneous but locally, more homogeneous in Endo than in Epi. The large global flow heterogeneity in Endo may be attributable to the high heterogeneity of coronary anatomy and myocardial stress distribution in Endo. The large local flow homogeneity and low fractal dimension in Endo may be related to the high oxygen demand in Endo. Furthermore, from the fact that CA increased with increasing SS and reached a plateau at SS=0.4 mm in both layers the minimum size of a regulatory unit is estimated to be 0.4 mm.
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