Clinical Study Of Assessment Of Coronary Artery Stenosis Degree By Multi-slice Spiral CT

ObjectiveEarly diagnosis of coronary artery disease has important clinical significance. As a kind of noninvasive and expenseless coronary angiography examine ,multi -slice spiral CT coronary angiography gets more and more attention. The purpose of the study is to evaluate the clinical application value of multi - slice spiral CT coronary angiography with retrospectively ECG - gated.Methods101 consecutive patients (68 male, 33 female, aged 33 -78,average 57.9 years) who were in hospital in our hospital from 2003.11 to 2005.12 with coronary disease or suspected coronary disease were studied. Criteria for exclusion included allergy to iodine contrast media, pacemaker implanted, renal insufficiency , cardiac dysfunction, irregular heart rate and so on. All Patients were referred for catheterization coronary angiography ( CAG) and multi - slice spiral CT coronary angiography to detect coronary disease. Coronary arteries were classified as evaluable or unevaluable. In evaluable arteries, left main artery (LM) , left anterior ( LAD) , left circumflex artery (LCX) , right coronary artery (RCA) were analyzed and side branches were included in the analysis of the respective main coronary artery ( LAD, LCX, RCA). CAG pictorial evaluation selected most lumina stenosis one in each body position projection. If several stenoses were found, the most severe stenosis was analyzed. The results of theCAG and multi — slice spiral CT coronary angiography were compared. According to results of CAG, the stenosis grade of coronary artery was classified as mild, medium and high - grade.ResultsIn 31 arteries of 404 coronary arteries could not be evaluated (7. 67% ). The main reason that could not be evaluated were motion artifacts (17 arteries) , vessel wall severe calcification (9 arteries) and coronary artery caliber tiny. 373 coronary arteries (left main, left anterior descending, left circumflex and right coronary artery, including their respective side branches) could be evaluated. Of 183 arteries whose lumens were normal in CAG, 149 arteries were correctly diagnosed, 24 arteries were misdiagnosed mild stenoses, 5 arteries were overestimated for medium stenoses, 5 arteries were overestimated for high stenoses.Of 55 arteries whose lumens showed mild stenoses in CAG, 24 arteries were correctly diagnosed, 18 arteries were missed diagnosed, 5 arteries were overestimated for medium stenoses, 8 arteries were overestimated for high stenoses. Of 52 arteries whose lumens showed medium stenoses in CAG, 41 arteries were correctly diagnosed, 8 arteries were missed diagnosed, 3 arteries were overestimated for high stenoses. Of 83 arteries whose lumens showed medium stenoses in CAG, 75 arteries were correctly diagnosed, 8 arteries were missed diagnosed. The sensitivity, specificity, positive and negative predictive value to identify mild, medium and high - grade stenosis of coronary artery with multi - slice MSCT were 67. 3% X81. 4% %52. 1% %89. 2%;84. 6% ^90. 3% ,65. 7% N96. 4%;90.4% ^4. 5% ^82.4% X97. 2% respectively.DisgussUsually stenosis degree of coronary artery more than 50% can be diagnosed as coronary artery disease and stenosis degree more than 75% is the evidence of invasive detection. The study results showed that the diagnosis value of MSCT was increasing with the increase of stenosis digree of coronary artery. Especial-ly, medium and high stenoses had better negative predictive value. These study results exposed that MSCT had the clinical applicable value to suspect coronary artery disease and for pre - coronary intervention operative examination.In arteries whose lumens presented medium and high stenoses, motion artifacts, vessel wall severe calcificationand coronary artery caliber tiny were the main reason of misdiagnosis.ConclusionsMSCT with retrospective ECG gating is a non - invasive method to permit the detection of coronary artery stenoses, especially medium and high stenoses that have important clinical significance.