| Objective: To compare anatomic structure and left ventricular myocardial perfusion at rest between normal adults and the patients with uncomplicated type 2 diabetes and with negative finding on coronary CT angiography(CCTA) by 320 slice dynamic volume CT;To probe the change of myocardial perfusion at rest and to study the relationship between the transmural perfusion ratio(TPR) of left ventricular myocardium and Hgb A1 c, and to provide theoretical basis and reference for the prevention and treatment of diabetes and cardiovascular complications.Materials and Methods: The total 23 subjects were collected from August 2015 to January 2016 in our hospital, including 11 normal cases as control group, and 12 uncomplicated type 2 diabetes patients with negative finding on coronary CT angiography as experimental group. Toshiba 320-row dynamic volumetric CT(Aquilion One, Japan Toshiba medical device company) was used for full cardiac cycle scan in this study. According to patients' body mass index(BMI), a double-head high-pressure injector was used to inject a volume of 40-60 m L non-ionic contrast medium(370mg I/ml) into the median vein of forearm which preset 20 G intravenous catheter at injection rate of 4.0~6.0 ml/s, and followed by 30 ml normal saline at the same rate. Scan range were from the level of trachea bifurcation to the position of 1.5cm under diaphragm. According to patients' BMI, the tube voltage was between 100 and 120 k V, and with automatic tube current. Used retrospective electrocardiogram(ECG)-gated, the exposure scope were determined automatically depending on cardiac cycle of the patients' heart rate in 1~2 cardiac cycle. The scan was intelligent triggered or manual triggered by Sure Start software, configured the descending aorta as region of interest(ROI), and with the threshold of 240 Hu. And then, the diameter of left atrium, left ventricle cavity, left ventricular wall were measured and other data on the obtained image were acquired. The original data is reconstructed for 10 phases with 10% of the interval, and then transferred into a cardiac function analysis software, and the end-systolic volume(ESV), end-diastolic volume(EDV), stroke volume(SV), ejection fraction(EF), cardiac output(CO), LV Myocardial Mass(LVMM), left ventricular mass index(LVMI),posterior wall thickness(PWT),and so on were obtained. Myocardial transmural perfusion rate(TPR) at resting state were calculated by using Myocardial perfusion software(Vitrea FX processing station) to analyze cardiac images at 75% R-R interphase. Statistical analysis between the two groups was performed by using independent sample t test, scatterplot analysis, and consistency test.Result: 1. The CCTA image quality consistency of Kappa in 2 Groups is 0.744, 0.750, respectively, that means the consistency of image quality are good in normal group and experimental group. The fasting plasma glucose and glycosylated hemoglobin(Hgb A1c) had significant statistical difference(P<0.05) between normal control group and experimental group. The rest of the clinical data had no significant statistical difference. The total radiation dose of every subject was about 5.64±2.07 m Sv in this study. 2. The end-systolic ventricular septal thickness(ISTsys)is1.40±0.25 cm in experimental group, and 1.22±0.13 cm in the normal group,which had significant statistical difference(t=-2.14,P<0.05). The end-diastolic ventricular septal thickness(ISTdia)is 0.98±0.17 cm in experimental group, and 0.84±0.08 cm in the normal group,which also had significant statistical difference(t=-2.38,P<0.05). The EF, ESV, EDV, SV, CO, LVMM, LADsys, LVIDsys, PWTsys, LVIDdia, PWTdia in experimental group is higher than that in the normal group, but there was no significant statistical difference. 3. The TPR values in S3?S7?S9?S11?S12?S13 in experimental group was lower than that in the normal one, which had significant statistical difference(P<0.05). Other segments in experimental group also were lower than that in normal one, but there had no significant statistical difference. 4. The TPR values in the territories of left anterior descending branch(LAD), left circumflex branch(LCX), right coronary artery(RCA) in experimental group were 1.12±0.13,1.07±0.12,1.07±0.12, respectively, while they were 1.20±0.15,1.16±0.13 and 1.11±0.11 in the normal group, respectively. There was significant statistical difference among them(t=3.34, P<0.05; t=3.81, P<0.05; t=3.47, P<0.05). 5. The TPR values in basal segment, middle segment, apical segment of left ventricular in experimental group were 1.10±0.13,1.02±0.10,1.12±0.13, respectively, while they were 1.16±0.11,1.12±0.12,1.21±0.18 in the normal group,respectively. There also was significant statistical difference among them(t= 2.88,P<0.05;t= 5.12,P<0.05;t= 2.79,P<0.05). 6. There was weak negative correlation between Hgb A1 c and the average TPR values of left ventricular, had no significant statistical difference between them(r=-0.374,P=0.086). 7. There was weak negative linear correlation between ventricular septum thickness and the average TPR values of ventricular septum at systolic phase, and had no significant statistical difference between them(r=-0.388,P=0.068). There was moderate negative linear correlation between ventricular septum thickness and the average TPR values of ventricular septum at diastolic phase, and had significant statistical difference between them(r=-0.599,P=0.003).Conclusion: 1. Utilizing single-scan technique of myocardial perfusion at rest, choosing personalized scanning methods and parameters, the whole cardiac cycle phase of CCTA scan can be completed at a lower dose by using Toshiba 320-slice CT, and a good-quality image, anatomic information of heart, and resting myocardial perfusion can be obtained. 2. With the increase of ventricular septum thickness, a negative linear correlation was observed between the average TPR of ventricular septum and LV ventricular septum thickness, which provides useful information on early diagnosis of DCM for clinic. 3. The TPR values in experimental group was lower than that in the normal one, either in the territories of LAD, LCX, RCA or basal segment, middle segment, apical segment of left ventricular, which reflect the uncomplicated type 2 diabetes with early change(decrease) of myocardial perfusion of left ventricular when no finding on CCTA imaging. The decrease of TPR in S3, S7, S9, S11, S12, S13 in experimental group, which those segments mainly in the middle segment and in anterior, lateral wall and ventricular septum of left ventricular, suggesting that these regions may be the first place of myocardial damage with type 2 diabetes. 4. With the level of the Hgb A1 c increasing, there is weak negative correlation between Hgb A1 c and the average TPR values of left ventricular, which suggests that controlling the level of the Hgb A1 c may be helpful to improve the myocardial perfusion. 5. 320-row coronary CTA resting image combined with myocardial perfusion technology is a more practical and convenience semi-quantitative method for detecting myocardial perfusion abnormalities in type 2 diabetes patients. It can provide useful information to prevention diabetes patients with cardiac complications early. |
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