Quantitative 19F imaging using inductively coupled reference signal injection

This report describes recent efforts on our continuous development of a synthetic signal injection method for quantification of metabolite content in MR spectroscopy and MRI. Previous work showed that conversion of spectral peaks to quantitative units of metabolite content could be achieved with a calibrated synthetic free induction decay generated by an inductively coupled injection coil. This work demonstrates that calibrated synthetic voxels, injected in the same manner, can be used to quantify metabolite content in real ¹⁹F image voxels. Images of vials containing different concentrations of sodium fluoride (NaF) were converted to units of moles by reference to precalibrated synthetically injected voxels. Additional images of vials containing variable sodium chloride (NaCl) demonstrate that the quantification process is robust and immune to changes in coil loading conditions. Magn Reson Med 63:570–573, 2010. © 2010 Wiley‐Liss, Inc.     

Percutaneous Coronary Intervention Is More Beneficial Than Optimal Medical Therapy in Elderly Patients with Angina Pectoris

PurposeData comparing the clinical benefits of medical treatment with those of percutaneous coronary intervention (PCI) in an elderly population with angina pectoris are limited. Therefore, we evaluated the efficacy of elective PCI versus optimal medical treatment (OMT) in elderly patients (between 75 and 84 years old) with angina pectoris.ResultsMajor adverse events occurred in 5 patients (5.6%) of the PCI group and in 17 patents (19.5%) of the OMT group (p=0.015). There were no significant differences between the PCI group and the OMT group in cardiac death [hazard ratio (HR) for the PCI group 0.454; 95% confidence interval (CI) 0.041–5.019, p=0.520], myocardial infarction (HR 0.399; 95% CI 0.039–4.050, p=0.437), or stroke (HR 0.919; 95% CI 0.057–14.709, p=0.952). However, the PCI group showed a significant preventive effect of the composite of major adverse events (HR 0.288; 95% CI 0.106–0.785, p=0.015) and against the need for coronary revascularization (HR 0.157; 95% CI 0.035–0.703, p=0.016).ConclusionElective PCI reduced major adverse events and was found to be an effective treatment modality in elderly patients with angina pectoris and significant coronary artery stenosis, compared to OMT.     

A newly formed and ruptured atheromatous plaque within neointima after drug-eluting stent implantation: 2-year follow-up intravascular ultrasound and optical coherence tomography studies

Late stent thrombosis (LST) which is a life threatening complication has emerged as a serious problem of drug-eluting stents (DES). Several studies have suggested that incomplete neointimal coverage of stent struts contributes to LST. Progressive atherosclerosis within the neointima is an another possible cause of LST, but this phenomenon has seldom been reported in DES. We present a case of LST following DES implantation after a period of 28 months due to ruptured atheromatous plaque, despite complete neointimal coverage of stent struts proven by optical coherence tomography.     

Gender-based differences in the management and prognosis of acute coronary syndrome in Korea

Purpose

Gender-based differences exist in the characteristics, management, and prognosis of acute coronary syndrome (ACS). However, their impact on prognosis remains unclear. We aimed to identify factors causing these differences in Koreans.

Materials and Methods

We examined 6,636 ACS patients (66.2% males) visiting 72 Korean hospitals between April-2007 and December-2008. Gender-based differences in clinical demographics, therapy, and outcomes were analyzed over 6 months.

Results

Women were older than men [mean (standard deviation, SD) age, 67.6 (9.8) vs. 60.6 (11.2) years; p<0.001]; had higher rates of hypertension, diabetes mellitus, and lack of exercise (p<0.001 for all); and lower rates of obesity, familial history of cardiovascular disease (CVD), and smoking (p<0.05 for all). Atypical symptoms were more common in women (20.5% vs. 15.1% in men, p<0.001), whereas myocardial infarction with ST-segment elevation was less common (17.1% vs. 27.8%, p<0.001). Mean (SD) time lapse from symptom onset to arrival at hospital was longer in women [11.44 (18.19) vs. 8.26 (14.89) hours in men, p<0.001], as was the duration of hospitalization [7.58 (7.61) vs. 7.04 (7.72) days, p=0.007]. Fewer women underwent revascularization procedures, including thrombolytic therapy, balloon angioplasty, stent implantation, and coronary artery bypass grafting (79.4% vs. 83.3% men, p<0.001). No significant differences were observed in CVD-related death, recurrent ACS, stroke, refractory angina, or rehospitalization for angina.

Conclusion

Female ACS patients were older than male subjects and had more atypical presentation. They arrived at the hospital later than men and had longer hospital stays, but less often required revascularization therapy. However, no gender-based differences were noted in ACS-related mortality and morbidity.     

The comparison of the graft patency after coronary artery bypass grafting using coronary angiography and multi-slice computed tomography.

OBJECTIVE: Coronary angiography (CAG) is the gold standard method in evaluating graft patency following coronary artery bypass grafting (CABG), even though there are several kinds of non-invasive methods. Recently developed multi-slice CT (m-CT), having effective scan times up to 0.25 s and multi-row detector array systems, enable rapid imaging of cardiac structures, including coronary arteries during one breath-hold. We compared m-CT with CAG for the evaluation of graft patency following CABG. METHODS: Forty-two patients having undergone m-CT and CAG within 3 months of CABG were studied. Twenty-three patients underwent conventional CABG and 19 off-pump CABG. A total of 125 grafts were used, including 42 left internal mammary arteries (LIMA), 25 radial arteries (RA), 3 right internal mammary arteries (RIMA) and 55 vein grafts. RESULTS: CAG showed a 96% (120/125) patency rate (1 LIMA, 2 RA and 2 vein grafts were occluded). m-CT showed a 98% (122/125) correct positive ratio with a sensitivity and specificity of 98 and 100%, respectively. The sensitivity in LIMA, RA, RIMA and vein grafts was 98, 91, 100 and 100%, respectively, with 100% specificity for all. There was an equivocal result in the competitive grafts with native coronary artery that were patent in the CAG, but faint opacification with no significant flow in the m-CT. CONCLUSIONS: This study showed that m-CT was very simple, useful and accurate in evaluating graft patency during the early post-operative period following CABG, even though there was an equivocal result in the competitive grafts with a native coronary artery.