VISUALIZATION OF SINUS NODE ARTERIES BY MULTISLICE SPIRAL COMPUTED TOMOGRAPHY CORONARY ANGIOGRAPHY

Objective: to assess the capabilities of multislice spiral computed tomography coronary angiography (MSCT-CA) to visualize the anatomy of the sinus node artery (SNA). Material and methods. The retrospective analysis of coronary artery examinations covered 46 patients with the referral diagnosis of coronary heart disease. MSCT-CA showed no evidence of coronary artery stenosis. This sample included 23 (50%) men and 23 (50%) women; the mean age of the patients was 52.4±9.1 years; the mean height was 170±6.67 cm; the mean weight was 80.7±12.1 kg. X-ray computed tomography was carried out using a SOMATOM Definition AS+ 128-slice computed tomography scanner with retrospective ECG synchronization, reconstructed slice thicknesses of 1 and 3-mm. The Spearman correlation test was used for statistical data analysis. Results. The SNA was visualized in 83% of the patients. It originated from the right coronary artery (RCA) and the circumflex branch of the left coronary artery in 84 and 16% of cases, respectively. No significant association was found between the type of heart blood supply and that of sinus node one (r = 0.06). In 18% of cases, the SNA was visualized only at the level of the ostium, allowing the assessment of the origin of the artery, and at the level of its mid-third in 32%; the distal SNA bed was visualized up to its division; in 10% of them the artery could be visualized all the way, including the division (the dissipation site). Unclear visualization of the proximal SNA was observed among 17% of the patients in whom the SNA could not be visualized with a heart rate (HR) of more than 80 beats/min in 62.5% of the patients, less than 41 beats/min in 12.5%, and 60–61 beats/min in 25%. HR was not found to be associated with the quality of SNA visualization (r = 0.09). Conclusion. MSCT can assess the anatomy of SNA up to the distal bed and dissipation site. In the overwhelming majority of the patients, the SNA  originated from the RCA (84%) regardless of the type of heart blood supply. The best SNA visualization was noted with a HR of 50 to 80 beats per minute. There was no statistical relationship of the quality of visualization to HR

CORRELATION BETWEEN LEFT VENTRICULAR CONTRACTILITY AND MYOCARDIAL T1-RELAXATION TIME DURING MAPPING IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY BY MAGNETIC RESONANCE IMAGING

Objective. To determine a correlation of myocardial deformation with myocardial T1-relaxation time during extracellular volume (ECV) fraction mapping and the degree of focal fibrosis in each left ventricular (LV) segment in patients with hypertrophic cardiomyopathy (HCM). Material and methods. A diagnostic test was carried out in 30 patients diagnosed with HCM and in a control group of 10 patients without LV pathology. Cardiac magnetic resonance imaging was performed on a 3.0 T Philips Achieva TX MRI scanner (Philips, Best, the Netherlands) in accordance of the specialized protocol using a 32-channel cardiac coil with heart rate synchronization and the use of gadolinium-based contrast agents at a dose of 0.3 ml/kg. LV T1 mapping was done using the Modified Look-Locker Inversion Recovery (MOLLI) sequences. Postprocessing was performed on Philips and CVI42 workstations. When the data were processed, T1-relaxation time was estimated before and after contrast enhancement.Results. In all cases, myocardial thickness, extent of myocardial fibrosis, myocardial T1-relaxation time parameters, and ECV could be estimated according to the American Heart Association 16-segment coronary artery model. Before injection of contrast agent, the average LV T1 relaxation time in patients with HCM was 1317±94 msec which was significantly higher than that in the control group (1093±23.7 msec). ECV in the control group was lower (24.8±1.9%) than that in the HCM group (29.8±4.5%). In the univariable group, each index was related to myocardial deformation indicators (radial (Err-FT) and circular (Ecc-FT)) at the segment level. There was a moderate positive correlation between LV thickness and Ecc-FT (r=0.52; p<0.0001), a moderate negative correlation between Err-FT and LV hypertrophy (r=–0.5; p<0.0001), and between Err-FT and myocardial T1relaxation time prior to contrast enhancement (r=–0.5; p<0.0001).Conclusion. Myocardial T1 time relaxation mapping before contrast enhancement has detected that ECV in patients with HCM is much higher than in those with the intact myocardium. LV deformation in patients with HCM correlates with changes in myocardial T1 time and the magnitude of myocardial hypertrophy and to a lesser extent with focal LV fibrosis