Correlation between Acute Coronary Syndrome Classification and Multi-detector CT Characterization of Plaque

Objective To determine if multi-detector CT （MDCT） characterization of plaque is correlated with the classification of acute coronary syndrome （ACS）. Methods Altogether 1900 patients were examined by MDCT from December 2007 to May 2009, of whom 95 patients fulfilled the criteria of ACS. Those patients were divided into the discrete plaque group （n=61） and diffuse plaque group （n=34） based on the findings in MDCT. The clinical diagnosis of ACS and CT results were analyzed, including segment stenosis score, segment involvement score, 3-vessel plaque score, left main score, calcification score, and remodeling index. The incidences of major adverse cardiac events in follow-up period were also recorded. Results The patients of the diffuse plaque group were older than those of the discrete plaque group （P〈0.0001）. The diffuse plaque group presented more cases of hypertension, peripheral artery disease, diabetes, and heart failure than discrete plaque group （all P〈0.05）. All the 5 patients with ST-segment elevation myocardial infarction were found in discrete plaque group. The segment stenosis score of the discrete plaque group was lower than that of the diffuse plaque group （5.15±3.55 vs. 14.91±5.37, P〈0.001）. The other four scores demonstrated signiflcant inter-group difference as well （all P〈0.05）. The remodeling index of the discrete plaque group was higher （1. 12±0.16 vs. 0.97±0.20, P〈0.05）. Follow-up data showed that major adverse cardiac events occurred more frequently in diffuse plaque group than in discrete group （29.41% vs. 11.48%, P=0.0288）. Conclusions Characteristics of discrete and diffuse plaques may be significantly different among different classes of ACS. The diffuse plaque may present higher risk, correlated to higher mortality. The diagnosis of discrete and diffuse plaques by MDCT would provide a new insight into the prognosis and treatment of ACS.

A pilot study on diagnosis of coronary artery disease using computed tomography first-pass myocardial perfusion imaging at rest

Background:Although computed tomography coronary angiography (CTCA) can identify coronary stenosis,little data exists on the ability of multislice computed tomography (MSCT) to detect myocardial perfusion defects at rest.Methods:In 33 patients with diagnosed or suspected coronary artery disease (CAD),CTCA using retrospective electrocardiography (ECG) gating at rest and invasive coronary angiography (ICA) was performed.The 2D myocardial images were reconstructed in diastolic and systolic phases using the same raw data for CTCA.CT values of the myocardium were used as an estimate of myocardial enhancement,which were shown by color mapping.Myocardial ischemia was defined as a pattern of transient endocardial hypo-enhancement at systole and normal enhancement at diastole.The results of ICA were taken as the reference standard.Results:When a diameter reduction of more than 50% in ICA was used as diagnostic criteria of CAD,the sensitivity,specificity,positive predictive value (PPV),and negative predictive value (NPV) of CT first-pass myocardial perfusion imaging (MPI) at rest were 0.85,0.67,0.92,and 0.50 per patient,respectively,and 0.58,0.93,0.85,and 0.76 per vessel,respectively.Conclusions:CT first-pass MPI at rest could detect CAD patients,which could become a practical and convenient way to detect ischemia,consequently offering the ability for MSCT to act as a "one stop shop" for the diagnosis of CAD.

Coexistence of primary hepatic myopericytoma and mediastinal Castleman disease in one patient:an interesting;^(18)F-FDG PET/CT imaging case

To the Editor:Primary hepatic myopericytoma(MPC)is a rare soft tumor,and the concept of myopericyte was first proposed by Dictor in 1992.[1]In 1998,Granter adopted the name myopericytoma for this form of tumor.[2]Most MPCs arise from the skin and superficial soft tissues of distal extremities,[3]but rarely described in the liver.[4]MPC observed by^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)has rarely been reported.Surgical resection of myopericytomas has a good curative effect,and occasionally there is recurrence or metastasis.[5]Castleman disease(CD)was first described in 1954.[6]About 70%of CD cases are in the chest,and it can also occur in other areas such as the pelvis,neck,retroperitoneum,and muscles.18F-FDG PET/CT is effective diagnostic imaging for the diagnosis of CD.Here we report a rare case of coexistence of MPC and mediastinal CD on^(18)F-FDG PET/CT.