Atsuko Suzuki's scientific contributions

Objective: Although coronary arterial lesions due to Kawasaki disease (KD) should be evaluated as early as possible after the acute phase, conventional X-ray coronary angiography poses high risks for young children with the disease. The use of noninvasive MR coronary angiography is desirable, although it is difficult to produce clear images in young children. We developed a method to improve the quality of MR coronary angiography in young children. MR coronary angiography with vector electrocardiogram gating, real-time navigator-echo, 3D, steady-state free precession was performed in 35 children with KD. Many parameters (i.e., field of view, acquisition delay, turbo-field echo-factor, navigator window, and resolution) were optimized for each patient. Conclusion: Optimization resulted in the acquisition of high-resolution and highsignal images of the coronary arteries. It remarkably improved not only the quality of the images, but also the detection rate of coronary artery segments. MR coronary angiography is a useful method for evaluating coronary aneurysms from the early stages of KD, even in infants and small children.

We evaluated the efficiency of non-invasive magnetic resonance coronary angiography in detecting coronary arterial lesions in 106 patients, aged from 4 months to 37 years, with a median of 13 years, with Kawasaki disease. Non-contrast enhanced, free-breathing magnetic resonance coronary angiographic studies using both the steady-state free precession technique, namely bright blood imaging, and navigator-echo proton density weighted black blood imaging, so-called black blood imaging, were performed in all the patients. Conventional X-ray coronary angiography was performed in 70 patients with coronary arterial lesions. We observed 97 aneurysms, 17 dilatations, 17 occlusions, 18 localized stenoses and 10 recanalized vessels, and we clarified their unique pattern of images on magnetic resonance coronary angiography. The differences in size of the aneurysms as seen on X-ray coronary angiography and bright blood imaging was mean 0.0, and the 95% confidence interval was from −1.4 to 1.5 on the Bland-Altman plots. With bright blood imaging, the sensitivity of occlusion and localized stenosis based on X-ray angiography was 94.2% and 97.2%, specificity was 99.5% and 97.2%, and negative-predictive value was 99.5% and 97.2%, respectively. Black blood imaging provided remarkable visualization of the thickened intima of aneurysms, and/or thrombus, in 38 lesions. We conclude that magnetic resonance coronary angiography can visualize all types of lesions due to Kawasaki disease in patients of all ages, and that it is useful to reduce the number of times X-ray angiography needs to be performed in patients with Kawasaki disease.

{Background and Objective} Coronary angiography (CAG) has been validated as the standard method for the follow-up of the coronary arterial lesions (CAL) due to Kawasaki disease, which start with aneurysms and progress to stenotic lesions frequently. However, patients with CAL need to be studied repeatedly throughout the life, and CAG is associated with substantial amount of risk, especially in small infants. This study examined the validity of magnetic resonance coronary angiography (MRCA) in evaluation of the morphology of CAL due to Kawasaki disease. {Patients and Method} Seventeen patients of Kawasaki disease (age;12288;4 months-24 years; mean:9 years) underwent MRCA examinations. Methods used to visualize CAL; induced 3D true FISP in 10 patients, 3D-FLASH in 9, and 3D FLASH-IR in 2, and MRCA under free respiration using navigator echo 3D-FLASH was done in 6 children who could not hold their breath. Three infants were sedated with Tricloril (1mg/Kg) during the examination. MRCA findings were compared with those of 2D echocardiography in 9 patients and with CAG findings in 8 patients. {Results} Twelve of 13 aneurysms (92%) were demonstrated by MRCA, however it failed to detect a slightly dilated lesion. Four stenotic lesions of more than 50% were all clearly visualized, and CABG patency in 2 patients (100%) and 34 out of 36 of normal coronary arterial branches (94%) (seg.1-4, 5-7 & 11) were also documented. An aneurysm which could not be shown by 2D echo was readily demonstrated by MRCA. {Conclusion} Feasibility of noninvasive demonstration of CAL of Kawasaki disease was confirmed including in young infants. It was suggested that MRCA could reduce the number of CAG in follow-up of Kawasaki disease patients. Its potential to screen premature arteriosclerotic changes in Kawasaki disease patients was also suggested.