Computerized DICOM Echocardiographic Analysis System And Its Application For Quantitative Assessment Of Regional Wall Motion

Part-1 Design and development of the computerized DICOM echocardiographic analysis systemObjectives1. To develop the computerized DICOM echocardiographic analysis system (DICOM-ECHOAS) with the capabilities for processing high frame rate echocardiographic images with DICOM formatted raw data.2. To design the software for the quantitative assessment of regional left ventricular wall motion (RLVWM) with four methods alone and simultaneously.MethodsHard and soft environment General computer with Intel Core 2 CPU, 2G RAM, 250G hard disc, DVD-RW and independent display card was used. Based on Windows operator system, the software for RLVWM was developed by using Visual C++ and Visual Basic.Sorts of images and data The sorts of images and data acquired in the study included: (1) Dicom Raw data echo images with high frame rate. (2) The Dicom image and other type images produced by the medical instruments. (3) The images stored in other formats. (4) The quantitative data.General image processing DICOM-ECHOAS was capable of encoding DICOM data and then switching to common controls.Software for RLVWM The RLVWM software of DICOM-ECHOAS was designed and developed for semi-automatical generation of a modified LV centre and RLVWM analytic coordinate system, semi-automatical detection of the LV contours, automatical definition of LV wall segments, automatical measurement of LV endocrinal motion and LV wall thickness, automatical assessment of wall thickening (ΔTH), endocardium displacement (EndoD), systolic tissue velocity (VS) and time to systolic peak (TS) separately, and display 4 RLVWM curves synchronically with simultaneous integrated multi-curve analysis (SIMCA).ResultsThe DICOM-ECHOAS in combination with the RLVWM software provided capabilities as follows: (1) acquisition and processing of the high frame rate raw DICOM images with the original spatial and temporal resolution. (2) semi-automatical generation of the modified LV centre and RLVWM analytic coordinate system through identification of the reference points of the intra-cardiac anatomic markers such as mitral valve and papillary muscles. (3) semi-automatical detection and acquisition of LV contours by computerized image processing techniques. (4) automatical definition of LV wall as 6 segments by using ASE recommendation as reference. (5) automatical assessment of LV endocardial motion by mesaureing the length of the radial axes based on the RLVWM analytic coordinate system. (6) automatical assessment of LV wall thickness by the modified center-line method. (7) automatical quantitation of RLVWM including wall thickening (ΔTH), endocardial displacement (EndoD), systolic tissue velocity (VS) and time to systolic peak (TS) separately in the same modified fixed-axis coordinate system. (8) SIMCA for RLVWM simultaneously, facilitating head-to-head comparison between four analytic methods.Conclusions1. DICOM-ECHOAS is capable of acquisition and processing of the original raw DICOM images except for general image processing functions.2. DICOM-ECHOAS is able to quantitatively analysis of 4 sorts of RLVWM parameters separatively, or simultaneously with SIMCA. Part-2 Application of DICOM-ECHOAS in quantification of RLVWM and its clinical significance: Usefulness of SIMCAObjectives1. To apply the DICOM-ECHOAS in the quantitative assessment of regional wall motion by single parameter analysis (SPA) and simultaneous integrated multi-curve analysis( SIMCA) .2. To compare the accuracy and reproducibility of the quantitative parameters of RLVWM derived from SPA and SIMCA.MethodsPatients and clinical data250 cases were divided to 3 groups according to patients'clinical characteristics:Control-group There were 60 cases, 46 male, 14 female, aged at 54±18 years, who were ortherwise healthy by clinical assessment and coronary artery angiography (CAG).MI-group There were 90 cases, 73 male, 17 female, aged at 56±17years, in whom myocardial infarction (MI) was comfirmed by clinical assessment and CAG.CAD-group There were 100 cases, 65 male, 35 female, aged at 57±19years, in whom coronary artery stenosis and myocardial ischemia was comfirmed by clinical assessment and CAG, with diameter stenosis of (86.6±9.4)%.RLVWM analysisTwo-dimensional echocardiography(2DE) was performed in all subjects by commencialy available medical diagnostic systems (GE Vivid7 dimension, Siemens Sequira 512). The high frame rate images were recorded from the LV short-axis views at the levels of the mitral valve,the papillary muscle and the apex. LV wall was divided to 18 sections according to ASE recommendation i.e., anteseptum, anterior wall, lateral wall, posterior wall, inferior wall and inferior septum. Coronary artery perfusion teritory was decided according to Segar'S method.Single Parameter Analysis (SPA) All echocardiographic images stored were imported to DICOM-ECHOAS and ECHO PAC workstation, and were analysised off-line. The radial strain (RS) and time to peak radial strain (TPRS) was assessed by ECHO PAC workstation.Wall thickening (ΔTH), endocardial displacement (EndoD), systolic tissue velocity (VS) and time to systolic peak (TS) were assessed by DICOM-ECHOAS.Simultaneous integrated multi-curve analysis (SIMCA) SIMCA was performed by using DICOM-ECHOAS, The curves derived from four RLVWM parameters, i.e., endocardium displacement, ecdocardium velocity, wall thickening, radial strain were realigned using ECG as refenrence and displayed in one screen synchronically.Sensitivity and specificity Sensitivity and specificity of each parameter to detect RLVWMA were obtained using receiver operating characteristic analysis(ROC). All parameters were compared between MI-group, CAD-group and control-group, and their accuracy and reproducibility in the detection of RLVWMA and in the diagnosis of coronary heart disease (CHD) were evaluated.Results1. The measurements of RS,ΔTH, EndoD, VS in MI- and CAD-group were remarkable lower than those in control group(p<0.01-0.001), respectively; the measurements of TS and TPRS in MI- and CAD-group were remarkable longer than those in control group (p<0.01-0.001), respectively.2. The accuracy of RS,ΔTH, EndoD, VS, TS, TPRS and SIMCA in detection of RLVWMA in MI-group were 89.3%, 89.3%, 81.3%, 80.7%, 62.0%, 62.0% and 94.0%, respectively; and in CAD-group were 68.1%, 70.0%, 61.9%, 60.0%, 55.6%, 55.0% and 74.4%, respectively.3. The ROC area of RS,ΔTH, EndoD,VS,TS and TPRS in detection of RLVWMA in MI-group were 0.868, 0.863, 0.833, 0.859, 0.593 and 0.71, respectively; and in CAD-group were 0.724, 0.705, 0.689, 0.663, 0.581 and 0.625, respectively.4. The parameters of TS and TPRS were not identical, TPRS was much longer than TS.5. For the quantification of RLVWM, the intra-obsever's Coefficients of Variability (CV) of RS,ΔTH, EndoD,VS,TS and TPRS were 7.6%, 5.3%, 6.9%, 14.2%, 24.6% and 14.3%, respectively; and inter-obsever's Coefficients of Variability (CV) of RS,ΔTH, EndoD, VS, TS and TPRS were 9.1%, 6.0%, 8.1%, 19.6%, 30.4 and 16.9%, respectivelyConclusions1. DICOM-ECHOAS has capability of quantitative detection of RLVWMA either by using single parameter analysis (SPA) or simultaneous integrated multi-curve analysis (SIMCA).2.ΔTH and RS by SPA were similar and the most accurate in the detection of RLVWMA, and SIMCA further increases the accuracy by facilitating head-to-head comparison between deferent methods.