Dynamic intravenous coronary arteriography by using synchrotion radiation and its application to measuring coronary blood flow

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We have developed dynamic intravenous coronary arteriography (CAG) by using a two-dimensional X-ray beam from synchrotron radiation. We investigated the ability of dynamic intravenous CAG images to visualize the coronary arteries and to estimate coronary blood flow in animals.We performed intravenous CAG in 10 dogs and one goat by using an intense, monochromatic (33.3KeV), two-dimensional X-ray beam, that was generated by asymmetrical reflection of synchrotron radiation from a silicon crystal. A contrast agent was injected through a catheter inserted into the inferior vena cava and the subject was irradiated with the X-ray beam. Images were obtained with a TV camera and were recorded on videotapes (33 images/sec).In the dogs, we estimated blood flow in the left anterior descending coronary artery (LAD) from the CAG images by applying a transit-time analysis. Six dogs underwent thoracotomy and their LAD flow was measured with an electromagnetic flow probe. In 4 dogs, a perivascular Dopp … More ler flow probe that had been implanted a few weeks before the intravenous CAG was used to measure LAD flow velocity. Estimated LAD flow was compared with LAD flow actually measured.The two-dimensional X-ray beam from synchrotron radiation permitted us to achieve dynamic intravenous CAG in the dogs and goat. Dynamic intravenous CAG images visualized clearly even an intentionally created coronary stenosis about 1 mm in length. In addition, coronary blood flow could be estimated from the dynamic CAG images with an acceptable degree of accuracy. LAD flow calculated from intravenous CAG was 14.7(]SY.+-.])5.1ml/min, whereas LAD flow measured with an electromagnetic flowmeter or ultrasound flowmeter was 16.6(]SY.+-.])4.8ml/min. There was a close correlation between the estimated and measured LAD flows (r=0.92, p<0.001).Thus, dynamic intravenous CAG using synchrotron radiation is minimally invasive and permits the simultaneous evaluation of coronary anatomy and coronary blood flow. Clinical application of this procedure seems to be feasible. Less