ABSTRACT
Objective To evaluate the cause of ischemia related to myocardial bridge (MB) by using SPECT/CT MPI and CTCA.Methods A total of 294 patients with chest pain,tightness or palpitation undergoing both CTCA and MPI were retrospectively enrolled in this study from March 2008 to March 2013.Among them,49 patients (26 males,23 females,age:32-85 (55.4± 16.6) years) had MB.Locations of MB and myocardial ischemia were recorded.Fused MPI/CTCA was analyzed.If there was no mural atherosclerotic plaque-related stenosis on CAG at the same location of coronary artery where ischemic myocardium was found,then MB was considered as the ischemic cause.Myocardial ischemia rates of different MB locations were compared by x2 test.Results Among 49 patients with MB,3 cases had MB in proximal segment of LAD,34 in mid LAD,4 in distal LAD,3 in septal branch,2 in distal LCX,1 in intermedius,and 2 in mid RCA.There were 41 cases with myocardial ischemia.Myocardial ischemia in 32 cases was caused by MB,including 23 caused by MB in mid LAD.The myocardial ischemia rates of the most common MB location (mid LAD,n =34) and other locations (n =15) were not significantly different (67.6％ (23/34) vs 60.0％ (9/15),x2 =0.27,P＞0.05).Conclusions MB is commonly found in the mid LAD.The myocardial ischemia rates caused by MB is not related the MB location.Hybrid MPI/CTCA could evaluate the sites of coronary MB and myocardial ischemia simultaneously and therefore may be useful to evaluate the relationship between MB and myocardial ischemia.
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Objective To compare the nephrotoxicity of the iso-osmolar contrast media (iodixanol) to low-osmolar contrast media (LOCM) in intravenous contrast-enhanced CT.Methods Randomized controlled trials (RCTs) of iodixanol or low-osmolar contrast media in intravenous contrastenhanced CT were searched in the database of VIP,CBM,CNKI,Wanfang,PubMed,EMBASE,Web of Science,Cochrane Library from their start year to July 2012.Screening and information extracted were did by two researchers independently.The quality of the included documents was evaluated by the criterion of Cochrane handbook.Revman software (version 5.0) of the Cochrane collaboration was used in data analysis.Results There was no significant difference in the incidence of contrast-induced nephropathy (CIN) among 6 trials recruited 907 patients between the iodixanol group and the LOCM group [RR =0.64,95％CI (0.31-1.32),P=0.22] by using serum creatinine increased by more than 44 μmol/L (0.5 mg/dl) as the diagnostic criteria.No considerable difference was existed by using serum creatinine increased by more than 25％ as the diagnostic criteria between the two groups [RR =0.79,95％CI (0.48-1.30),P =0.35].Subgroup analysis showed there was no obvious difference [RR =0.57,95％CI (0.30-1.10),P =0.09] between the two groups in patients with increased baseline of serum creatinine.No obvious difference were gained in normal baseline group [RR =1.28,95％CI (0.57-2.86),P =0.55].Conclusion Compared with low-osmolar contrast media,iodixanol is not associated with less CIN in intravenous contrast-enhanced CT.
ABSTRACT
Recently non-invasive diagnostic imaging replaced the invasive catheter angiography in the diagnosis of vascular disease. Catheter methods are now almost confined to the purpose of intervention. Coronary artery or coronary artery bypass graft still needs catheter technique because of small diameter and the cardiac motion. The last challenge for radiologists in this domain is to obtain a non-invasive imaging. Electron beam tomography(EBT) for high temporal resolution is able to obtain a coronary arteriogram or coronary artery bypass graft (CABG), of which CABG imaging is quite useful for the evaluation of patency. In our experience as well as others, the accuracy of EBT angiogram in evaluating CABG patency revealed that the accuracy of patency of saphenous vein grafts(SVG) is high due to relatively wide lumen, short and straight course and less influence from cardiac motion. The sensitivity and specificity of patency of SVGs were 92%, 97% respectively in the prospective evaluat on and 100% each in the retrospective evaluation. A false positive and a false negative case are rudimentary errors in the initial learing period. In contrast the analysis of left internal mammary artery(LIMA) graft was difficult due to the inherent small size and the adjacent surgical clips provoking beam-hardening artifact; therefore, the method of combining 3 dimensional reconstruction and flow mode study was important in improving the accuracy of LIMA patency. The sensitivity and specificity of LIMA patency were 100% and 80% in both prospective and retrospective evaluation. Therefore, EBT angiography is an accurate non-invasive diagnostic modality for evaluating the patency of CABG, particularly in SVGs. The accuracy can be improved with the improvement of the EBT and the development of the image reconstruction software.