on May 13, 2002
Published online before print May 13, 2002, doi: 10.1161/01.CIR.0000017200.47342.10
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Submitted on December 31, 2001
From the Second Department of Internal Medicine, Gifu University School of Medicine (M.K., H.T., T.N., K.S., Y.I., K.H., K.T., M.A., K.N., G.T., S.M., H.F.), Gifu, and the Department of Food Science, Kyoto Women's University (T.F.), Kyoto, Japan. * To whom correspondence should be addressed. E-mail: gifuim-gif{at}umin.ac.jp.
Background—The purpose of the present study was to define whether integrated backscatter (IB) combined with conventional intravascular ultrasound (IVUS) makes tissue characterization of coronary arterial plaques possible. Methods and Results—IB-IVUS was performed in coronary arteries (total 18 segments) of 9 patients at autopsy, and the findings were compared with the histology. RF signals, which were digitized at 2 GHz in 8-bit resolution, were obtained with an IVUS system with a 40-MHz catheter. IB values of the RF signal from the region of interest (ROI) (100-µm depth, 1.4° per line) were calculated by use of a personal computer. IB values on the ROIs were divided into 5 categories, compared with each of the plaque histologies: category 1 (thrombus), -88 < IB Conclusions—IB-IVUS represents a new and useful tool for evaluating the tissue structure of human coronary arterial plaques.
Revised on March 22, 2002
Accepted on March 22, 2002
In Vivo Quantitative Tissue Characterization of
Human Coronary Arterial Plaques by Use of
Integrated Backscatter Intravascular Ultrasound and Comparison With
Angioscopic Findings
Masanori Kawasaki MD,
-80; category 2 (intimal hyperplasia or lipid core), -73 < IB -63; category 3 (fibrous tissue), -63 < IB -55; category 4 (mixed lesions), -55 < IB -30; and category 5 (calcification), -30 < IB -23. On the basis of these categories, we analyzed 5120 ROIs per segment in each ring-like arterial specimen. Color-coded maps of plaques were constructed by use of these IB data and conventional IVUS data, which reflected the plaque histology of autopsied coronary arteries well. Then, the same method was undertaken in 24 segments with plaque from 12 patients in vivo with angina pectoris. Comparisons between coronary angioscopy and IB-IVUS revealed that the surface color of plaques in angioscopy reflected the thickness of the fibrous cap rather than the size of the lipid core.
Key words: ultrasonics • plaque • tissue