Cardiac CT angiography를 이용한 coronary artery plaque의 형태학적인 분류

Evaluation of coronary plaque morphology by coronary computed tomographic : after analysis through intravascular ultrasound results

Purpose In order to assess the plaque of the morphology in the coronary artery, the shape of the plaque needs to be analaysed through intravascular ultrasound(IVUS) techniques with cardiac CT angiography(CTA) Materials and methods 57 coronary plaque in 34 patients were included in this study. All patients underwent intravascular ultrasound (IVUS) after CT-CAG, for suspicious acute coronary syndrome. CT-CAG obtained by 64-slice multidetector computed tomography(CT) scanner (Sensation Cardiac 64, Siemens, Forchheim, Germany). IVUS obtained by 20MHz (Volcano Therapeutics Inc., Rancho Cordova, California, USA) or 40MHz (Boston Scientific, Maple Grove, Minnesota, USA) ultrasound catheter, under fluoroscopy guidance. Plaque morphology on IVUS was classified as (1) soft, (2) fibrous, (3) Mixed(fibrocalcific, fibrofatty), or (4) calcific, according to American College of Cardiology report on standards for IVUS acquisition, measurement and reporting, by experienced one cardiologist. And on CT, morphology was assessed by mean Hounsfield unit of coronary plaque by one radiologist. Results 57 coronary plaque were analyzed. Plaque morphology by IVUS were as follows; soft plaque (n=18), fibrous plaque (n=6), Mixed(fibrocalcific, fibrofatty) plaque (n=18) and calcific plaque (n=15). Hounsfield unit of coronary plaque obtained from CT angiography were quietly different for each plaque morphology, determined by IVUS. Mean Hounsfield unit for each plaque as follows: soft plaque is 51.0±52.8, fibrous plaque is 106.3±62.3, fibrocalcific plaque is 316.4±202.8, and calcific plaque is 520.8±185.6(p<0.01). To determine plaque morphology as calcified (calcific, fibrocalcific) versus noncalcified (soft, fibrous), CT angiography had sensitivity of 91% and specificity of 100%. Conclusion Because, the level of plaques is different in the degree of the risk it is important to classify plaques according to the form. If we classify the levels of plaques according to the Hounsfield Unit, which follows in the level of plaques, it will be useful for the following check up and interventional treatment.