Abstract 676: Quantitative Analysis of Myocardial Perfusion Imaging by Using 64 Channels Multi Detector-row Computed Tomography
Purpose The purpose of our study was to evaluate the accuracy of newly developed method in MDCT which measures myocardial blood flow in the cardiac CT perfusion imaging (CCTP).
Methods This study included 10 normal control subjects (chest pain syndrome with normal coronary arteries) and 19 patients with AMI who underwent emergency coronary arteriography. The acquisition of cardiac CT images was performed at chronic stage (14 days after) with standard manner as described elsewhere. Briefly, rotation time was 500 msec with non ECG gating cine mode and 40ml of contrast agent was intravenously injected. The obtained images were analyzed with deconvolution algorithm which had been formerly applied to the brain images for the measurement of cerebral blood flow. This technique produced 3 types of color images such as tissue blood flow (TBF), tissue blood volume (TBV) and mean transit time (MTT). We set a region of interest (ROI) on the images of TBV by visual inspection and measured regional TBV and TBF that were supplied by 3 major coronary arteries, separately. After the validation of these parameters to be physiologically normal values in normal control subjects, regional data were compared with various clinical parameters such as peak CK and QRS score, as well as scintigraphical parameters of Thallium defect score.
Results The TBF in normal control showed 128.4. ±20.7 ml/min/100g indicating closely similar value to the known physiological myocardial blood flow of 100 ml/min/100g. In patients with AMI, the defect area on TBV color map image showed significant proportional correlation with peak CK, QRS score and Thallium defect score (R=0.37, 0.30 and 0.39, respectively, all p<0.05). Furthermore, the ratio of TBF in outer layer of the myocardium to inner layer was significantly higher in AMI patients with good collateral circulation (1.48±0.40) compared with those with poor or no collateral circulation (0.87±0.23, P<0.01).
Conclusions Analysis using deconvolution algorithm on the perfusion images of MDCT may measure regional myocardial blood flow accurately. In practical clinical settings, utilization of MDCT should be useful not only for the understanding of coronary anatomy but also for the functional assessment of the myocardium and estimation of infraction size.