The Application Of ASMA-FAM And MSCT In Patients With Coronary Heart Disease

Background:Conventional coronary angiography, which currently remains as the reference and gold standard of the diagnosis of coronary disease, is invasive, expensive and time consumptive. In current clinical practice, there is a need for a less-invasive modality that can help to assess the cardiovascular system of patients. Owing to ongoing technical refinements and intense scientific and clinical evaluations, multi-slice spiral computed tomography (MSCT) and automated segmental motion analysis and free angel mode (ASMA-FAM) of the heart have matured into a clinical application that is about to fulfill its promise to replace invasive cardiac catheterization in selected patient populations.The development of electrocardiographically(ECG) synchronized multi-slice spiral CT scanning and reconstruction techniques has yielded fast volume coverage and high spatial and temporal resolution as prerequisites for successful cardiac imaging; and ASMA-FAM can show the regional wall motion abnormality sensitively ,which can reflect the situation of heart. But CT coronary angiography is technically more challenging than other CT applications owing to the continuously moving heart, many factors can affect the quality of the images, and the cardiac rhythm is the key one of them.The study is about the application of ASMA-FAM and MSCT in patients with coronary heart disease.OBJECTIVE:To compare ASMA-FAM, MSCT with CAG in patients with coronary heart disease;and to evaluate the accuracy for the assessment of coronary heart disease with the two noninvasive diagnosis.To analyze cardiac rhythm during the scanning and its influence on image quality in coronary angiography with 64-slice spiral CT;and to study the ECG-editor enhancing the image qulity of MSCT. MEHODS:This study was divided into 2 parts; PartⅠwas about the comparative study of ASMA-FAM and MSCT to CAG, and partⅡwas about the influence of cardiac rhythm on image quality of 64-slice spiral CT in coronary angiography and the solution.In partⅠ,A retrospective study was undertaken in 48 cases(male 39 cases, female 9 cases, and mean age of 54.1±2.3) which were performed with ASMA-FAM,MSCT and CAG within 7 days. The regional wall motion (RWM)and the fraction of area changing(FAC) were measured with ASMA-FAM ;Images from MSCT were retrospectively reconstructed under different reformations: multi-planner reconstruction(MPR),maximum intensity projection(MIP) and volume rendering (VR);All the post-process images were reviewed by two observers with 2 years working experience. Both the results from ASMA-FAM and MSCT are compared with the values of CAG, which served as the reference and gold standard. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated.In partⅡ, A retrospective study was undertaken in 112 cases (male 70 cases, female 42 cases, and mean age of 63.4±2.8)which had retrospectively ECG-gated 64-slice spiral CT scan in coronary angiography, and fluctuation of heart rate during the scanning was recorded. Maximum intensity projection (MIP), multi-planar reconstruction (MPR) and volume rendering (VR) were reconstructed .The 112 cases are divided into 4 groups according to the heart rate's fluctuation. Group A 0～4bpm,Group B 5～9bpm,Group C 10～19bpm,Group D≥20bpm .The image qualities of brands or segments of coronary arteries (total 1118) were compared between different groups.RESULTS:In partⅠ, 768,523 and 573 segments among the 48 patients are shown with ASMA-FAM ,MSCT and CAG respectively, and 372(48.4%) are regional wall motion abnormality reflected by ASMA-FAM ; 523 coronary arteries were evaluated with 189(36.1%) lesions found by MSCT. Of them, 174 lesions were consisted with CAG, 15 lesions were falsely positive and 13 lesions were found by CAG not picked up by MSCT;And 196/573(34.2%) segments are stenoses shown by CAG. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of ASMA-FAM in diagnosis of coronary heart disease were 83.3%,75.1%, 78.8%, 73.7%, 84.2%;and those of MSCT were 93.0%,95.5%, 94.6%,92.1%, 96.1% respectively.In partⅡ,There is no significant difference between group A,B and C(P>0.001), but the difference between group D and A,B,C is very obvious(P<0.001), and the image quality in group D was significantly lower than those in group A,B and C in the display of RCA1,RCA3,PDA,LM,LAD1,LAD2,LAD3,LCX1 and LCX2.The image quality of RCA2 was significant different among different groups (P<0.001).CONCLUSION:ASMA-FAM and MSCT are available in the diagnosis of coronary heart disease as noninvasive methods; they have excellent sensitivity and specificity in detecting CHD, and also can give fairly accurate assessment of stenoses severity in most patients as compared to CAG. As alternative methods, they can be used for screening patients with coronary heart disease.The cardiac rhythm is an important factor on image quality of 64-slice spiral CT in coronary angiography. The image quality of coronary artery begins to be poor when the fluctuation of heart rate is greater than 15bpm,especially in RCA2.The ECG-editor can enhance the image qulity of MSCT.