Combination Of Tomography Ultrasound Imaging And Quantitative Gray-scale In Evaluating The Vulnerable Plaques

Tomography Ultrasound Imaging (TUI) can completely capture the echo of carotid plaque (CP). Combination with gray-scale quantitative analysis (GSQA) of image helps assess the characteristic and stability of plaque more objectively.Objective1. Utilize TUI to detect the carotid plaque and capture the tomographic image, combining with the measurement of gray-scale median (GSM), percentage of lower gray-scale (PLGS) and gray-scale quartile interval (GSQ) by Adobe Photoshop. Then, use these to analyze the characteristic of plaque and to investigate the diagnostic value of GSM for vulnerable plaques (VP).2. Compare the GSM of CP between acute cardiac and cerebrovascular events (ACCE group) and non-ACCE group, identifying whether TUI combined with GSQA could find the VP and thus be an effective method for screening the patients at high risk for acute cardiac and cerebrovascular events.Methods1. A total of 88 type 2 diabetic patients with CP were analyzed. The sex, age, smoking history, diabetes history, coronary heart disease history, hypertension history, related treatments and C-reactive protein (CRP) were recorded.2. At first, the size, the location and the maximum sectional area of CP were measured by two-dimensional ultrasound. TUI was used to capture the multi-section echograms. Then, the echograms were standardized by Adobe Photoshop (the GSM of lumen represents as 0 and the GSM of adventitia represented as 190). After standardization, the GSM and PLGS were read.3.32 patients with increased CRP and initial acute cardiac and cerebrovascular events within two weeks were assigned to ACCE group.56 patients with normal CRP and identified have no acute cardiac and cerebrovascular events within two weeks were assigned to non-ACCE group. The three-dimensional quantitative gray-scale parameters of plaques between the two groups were studied.4. Binary logistic regression analysis was used to analyze the risk factors for acute cardiac and cerebrovascular events. The fitting effects of regression models were determined by ROC curve.5. We used ROC curve to study the efficacy of three-dimensional gray-scale parameters for predicting acute cardiac and cerebrovascular events and to determine the diagnostic nodes.Results1. The thickness of plaque was different between the two groups (P<0.01), the plaques in ACCE group were thicker than non-ACCE group.2. The GSM of ACCE group was different from non-ACCE group (P<0.01), GSM of ACCE group was lower than non-ACCE group.3. As well as PLGS was different between the two groups (P<0.01). PLGS of ACCE group was higher than non-ACCE.4. Binary logistic regression analysis showed that thickness of plaque, GSM and PLGS were the risk factors for ACCE. ROC curve showed that the regression equation was effective in predicting ACCE (AUC=0.877,95%CI 0.792-0.963, P<0.01).5. The ROC curve of three-dimensional gray-scale parameters showed that the AUC of plaque thickness, GSM and PLGS were 0.758,0.885 and 0.897, respectively. When GSM<43 or PLGS>58%, GSM and PLGS might be associated with ACCE.Conclusion1. Great thickness, low GSM and high PLGS might be the characteristic of VP, which could be served as the predictors.2. Three-dimensional gray-scale parameters of plaques were associated with ACCE, of which plaques with GSM<43 or PLGS>58% were likely to be vulnerable. TUI combined with GSQA could be an effective method for predicting ACCE, which provides an early warning via quantitative diagnosis of plaque echograms.