High-resolution intravascular magnetic resonance quantification of atherosclerotic plaque at 3T

<p>Abstract</p> <p>Background</p> <p>The thickness of fibrous caps (FCT) of atherosclerotic lesions is a critical factor affecting plaque vulnerability to rupture. This study tests whether 3 Tesla high-resolution intravascular cardiovascular magnetic resonance (CMR) employing tiny loopless detectors can identify lesions and accurately measure FCT in human arterial specimens, and whether such an approach is feasible <it>in vivo </it>using animal models.</p> <p>Methods</p> <p>Receive-only 2.2 mm and 0.8 mm diameter intravascular loopless CMR detectors were fabricated for a clinical 3 Tesla MR scanner, and the absolute signal-to-noise ratio determined. The detectors were applied in a two-step protocol comprised of CMR angiography to identify atherosclerotic lesions, followed by high-resolution CMR to characterize FCT, lesion size, and/or vessel wall thickness. The protocol was applied in fresh human iliac and carotid artery specimens in a human-equivalent saline bath. Mean FCT measured by 80 μm intravascular CMR was compared with histology of the same sections. <it>In vivo </it>studies compared aortic wall thickness and plaque size in healthy and hyperlipidemic rabbit models, with post-mortem histology.</p> <p>Results</p> <p>Histology confirmed plaques in human specimens, with calcifications appearing as signal voids. Mean FCT agreed with histological measurements within 13% on average (correlation coefficient, <it>R </it>= 0.98; Bland-Altman analysis, -1.3 ± 68.9 μm). <it>In vivo </it>aortic wall and plaque size measured by 80 μm intravascular CMR agreed with histology.</p> <p>Conclusion</p> <p>Intravascular 3T CMR with loopless detectors can both locate atherosclerotic lesions, and accurately measure FCT at high-resolution in a strategy that appears feasible <it>in vivo</it>. The approach shows promise for quantifying vulnerable plaque for evaluating experimental therapies.</p

Occupational Radiation Protection in Interventional Radiology: A Joint Guideline of the Cardiovascular and Interventional Radiology Society of Europe and the Society of Interventional Radiology

No Abstract

Emergence of vanA gene among vancomycin-resistant enterococci in a tertiary care hospital of North - East India

Background & objectives: Vancomycin-resistant enterococci (VRE) have become one of the most challenging nosocomial pathogens with the rapid spread of the multi-drug resistant strain with limited therapeutic options. It is a matter of concern due to its ability to transfer vancomycin resistant gene to other organisms. The present study was undertaken to determine the emergence of vancomycin-resistant enterococci and the vanA gene among the isolates in a tertiary care hospital of North-East India. Methods: A total of 67 consecutive enterococcal isolates from different clinical samples were collected and identified by using the standard methods. Antibiogram was done by disk diffusion method and VRE was screened by the disk diffusion and vancomycin supplement agar dilution method. The minimum inhibitory concentration (MIC) value for vancomycin was determined by E-test. The VRE isolates were analyzed by PCR for vanA gene. Results: A total of 54 (81%) Enterococcus faecalis and 13 (19%) E. faecium were detected among the clinical isolates and 16 (24%) were VRE. The VRE isolates were multidrug resistant and linezolid resistance was also found to be in three. MIC range to vancomycin was 16-32 µg/ml among the VRE. The vanA gene was found in nine of 16 VRE isolates. Interpretation & conclusions: Emergence of VRE and presence of vanA in a tertiary care hospital setting in North-East India indicate toward a need for implementing infection control policies and active surveillance

<span style="font-size:15.0pt;mso-bidi-font-size: 10.0pt;background:white;mso-bidi-font-weight:bold" lang="EN-GB">Prevalence and identification of extended spectrum β-lactamases (ESBL) in <i>Escherichia coli </i>isolated from a tertiary care hospital in North-East India </span>

108-114<span style="font-size:9.0pt;mso-bidi-font-size: 12.0pt" lang="EN-GB">Extended-spectrum β-lactamases (ESBLs) are rapidly evolving group of β-lactamase enzymes produced by the Gram negative bacteria. In this study, we determined the antimicrobial sensitivity pattern of <i style="mso-bidi-font-style: normal">Escherichia coli isolates and prevalence of TEM, SHV and CTX-M genes in ESBL positive E. coli isolated from the patients admitted to a tertiary care hospital in North-East India. A total of 85 multidrug-resistant isolates of E. coli obtained from clinical samples; urine (n=80), sputum (n=3), body fluid (n=1), vaginal discharge (n=1) were screened for resistance to third generation cephalosporins. ESBL production in resistant isolates was determined by double disk synergy test (DDST) and phenotypic confirmatory test (PCT). ESBL positive isolates were subjected to PCR for detection of TEM, SHV and CTX-M genes. Imipenem was found to be most effective against <i style="mso-bidi-font-style: normal">E. coli (susceptible isolates 96.47%) while ciprofloxacin was the least effective antibiotic (resistant isolates 60%). Among 33 ESBL positive isolates confirmed via PCT, preponderance in female population (60.6%) was noted. The most prevalent gene was blaSHV (63.04%) followed by blaTEM and blaCTX-M (60.86 and 54.34%, respectively) in ESBL positive E. coli. Most of the extensively used antibiotics, appear to be ineffective against the ever-mutating bacteria. This resistance urges cautious antimicrobial management on priority. Further, it helps in effectively designing the chemotherapeutic regimen for patients of a particular geographic area. </span

Safety of unprotected carotid artery stent placement in symptomatic and asymptomatic patients : a retrospective analysis of 30-day combined adverse outcomes

PURPOSE: To retrospectively evaluate the outcome of carotid artery stent placement (CAS) without the use of embolic protection devices (EPDs) in a large cohort of patients. MATERIALS AND METHODS: Institutional review board approval and informed consent from all patients were obtained. Preprocedure color Doppler ultrasonography (US), magnetic resonance (MR) imaging, or computed tomography (CT) were used to evaluate stenosis severity (70% or greater). Clinical findings and combined 30-day complication rates in 400 patients (289 men, 111 women; mean age, 73 years +/- 8 [standard deviation]) who underwent unprotected CAS for asymptomatic (n = 156; 39%) or symptomatic (n = 244, 61%) stenoses were analyzed. Follow-up at 30 days included neurologic evaluation and color Doppler US. RESULTS: Self-expanding stents were successfully deployed in 397 of 400 (99.25%) patients. Among the 397 patients, nine (2.27%) major complications (all in patients with prior symptoms) had occurred at 30 days, including three (0.76%) major (all in patients who had stopped antiplatelet prophylaxis) and six (1.5%) minor strokes--three intraprocedural and three delayed. Minor complications included 16 (4%) transient ischemic attacks, four in asymptomatic and 12 in symptomatic patients. The 30-day combined adverse outcomes (transient ischemic attack, ipsilateral stroke, death) were significantly correlated with prior presence of symptoms (symptomatic, 8.6%; asymptomatic, 2.6%; P < .03). CONCLUSION: Stent placement without EPD was performed with a high technical success rate. For asymptomatic patients, the combined 30-day adverse-outcomes rate was within the limits recommended by the American Heart Association for carotid endarterectomy and compared favorably with results reported for CAS with EPD. When a transient ischemic attack is excluded, the 30-day combined death and stroke rate among patients with prior symptoms also compared favorably with published results