下肢周围动脉闭塞性疾病病人行心电图触发非对比增强MR血管成像(TRANCE)和数字减影血管造影(DSA)的对比研究

目的对心电触发非对比增强MR血管成像(TRANCE)和数字减影血管造影(DSA)诊断下肢(包括足部)周围动脉闭塞的诊断价值进行前瞻性对比研究。方法43例有症状的周围动脉闭塞疾病(PAOD)病人在DSA检查前进行TRANCE检查。将MR血管成像(MRA)显示下肢     

ECG-Triggered Non-Contrast-Enhanced MR Angiography (TRANCE) versus Digital Subtraction Angiography (DSA) in patients with peripheral arterial occlusive disease of the lower extremities

Objective

To prospectively determine the diagnostic value of electrocardiography-triggered non-contrast-enhanced magnetic resonance angiography (TRANCE) of the lower extremities including the feet versus DSA.

Methods

All 43 patients with symptomatic peripheral arterial occlusive disease (PAOD) underwent TRANCE before DSA. Quality of MRA vessel depiction was rated by two independent radiologists on a 3-point scale. Arterial segments were graded for stenoses using a 4-point scale (grade 1: no stenosis; grade 2: moderate stenosis; grade 3: severe stenosis; grade 4: occlusion). Findings were compared with those of DSA.

Results

In the 731 vessel segments analysed, intra-arterial DSA revealed 283 stenoses: 33.6% moderate, 16.6% severe and 49.8% occlusions. TRANCE yielded a mean sensitivity, specificity, positive and negative predictive value and diagnostic accuracy to detect severe stenoses or occlusions of 95.6%, 97.4%, 87.2%, 99.2%, 97.1% for the thigh segments and 95.2%, 87.5%, 83.2%, 96.6%, 90.5% for the calf segments. Excellent overall image quality was observed for TRANCE in 91.4% versus 95.7% (DSA) for the thigh and in 60.7% versus 91.0% for the calves, while diagnostic quality of the pedal arteries was rated as insufficient.

Conclusion

TRANCE achieves high diagnostic accuracy in the thigh and calf regions, whereas the pedal arteries showed limited quality.     

USPIO-enhanced magnetic resonance imaging of the knee in asymptomatic volunteers

The aim of this study was to compare signal characteristics of the synovium in knees of asymptomatic volunteers before and after intravenous administration of ultrasmall superparamagnetic iron oxide particles (USPIO). Ten knees of 10 asymptomatic volunteers were examined before and 36 h after intravenous administration of USPIO on a 1.5-T MR system using T1-weighted spin-echo, T2-weighted fast spin-echo, T2*-weighted gradient-echo (GRE), and short inversion time inversion-recovery sequences. In addition, synovial perfusion was measured using Gd-enhanced GRE imaging during the first imaging session. Images were analyzed qualitatively for any visual changes before and after USPIO administration. Signal-to-noise ratios (SNR) of the synovium were determined on unenhanced and USPIO-enhanced sequences. All MR images were reviewed for presence of any degenerative changes. Qualitative image analysis revealed no visually detectable changes of any knee joint before and after USPIO administration. The SNR values of the synovium on T1w, T2w, and T2*w images before and after USPIO administration showed no significant difference (T1, P = 0.86; T2, P = 0.95; T2*, P = 0.86). None of the volunteers showed any relevant degenerative changes of the knee and synovial perfusion was within normal limits. In knees of asymptomatic volunteers without any relevant degenerative changes and normal synovial perfusion neither visual changes nor changes of SNR values of the synovium can be depicted after USPIO administration. This means that USPIO-enhanced MRI may be used for assessment of knee disorders with increased macrophage activity.     

Neointimal Hyperplasia after Silverhawk Atherectomy versus Percutaneous Transluminal Angioplasty (PTA) in Femoropopliteal Stent Reobstructions: A Controlled, Randomized Pilot Trial

Background

Due to intimal hyperplasia instent reobstruction in the femoropopliteal arterial segment is still an unsolved problem. Different techniques have been discussed in case of reintervention to guarantee longlasting patency rate.

Methods

We conducted a randomized, controlled, pilot trial comparing Silverhawk atherectomy with percutaneous transluminal angioplasty (PTA) in patients with a first instent reobstruction in the femoropopliteal arterial segment, to evaluate intima media thickness (IMT) within the treated segment, as a parameter of recurrence of intimal hyperplasia.

Results

In a total 19 patients were included: 9 patients in the atherectomy device and 10 patients in the PTA arm. IMT within the treated segment was statistically significantly elevated in all patients treated with the Silverhawk device versus the patients treated with PTA. The obvious differentiation in elevation of IMT in nonfavor for patients treated with the Silverhawk device started at month 2 (max IMT SH 0.178 mm vs. IMT PTA 0.1 mm, p = 0.001) with a spike at month 5 (max IMT SH 0.206 mm vs. IMT PTA 0.145 mm, p = 0.003) and a decline once again at month 6 (max IMT SH 0.177 mm vs. IMT PTA 0.121 mm, p = 0.02). The values for mean IMT performed the same way.

Conclusions

Although Silverhawk atherectomy provides good results at first sight, in the midterm follow-up of treatment of first instent restenosis it did not perform better than PTA as it showed elevated reoccurrence of intimal media hyperplasia.     

Analysis of heritability of hormonal responses to alcohol in twins: beta-endorphin as a potential biomarker of genetic risk for alcoholism

BACKGROUND: Hormonal responses to alcohol have been reported to differ in subjects with and without a family history of alcoholism which suggests that alcohol-induced hormonal changes might be used to identify individuals who are at elevated genetic risk for developing alcoholism. However, before a biological response can be used as a marker of genetic risk for disease, it must first be demonstrated that the response is, in fact, heritable. The present study was designed to determine whether hormonal responses to alcohol are heritable. METHODS: The adrenocorticotropic hormone (ACTH), beta-endorphin (beta-E), cortisol (CORT), and prolactin (PRL) responses to alcohol were examined in male and female identical (monozygotic or MZ) and fraternal (dizygotic or DZ) twin pairs. Male subjects consumed 0.35 g ethanol/kg body weight (BW) and females consumed 0.325 g ethanol/kg BW in each of two alcohol drinking sessions administered 1 hr apart (total dose of 0.7 g/kg BW in males and 0.65 g/kg BW in females). Plasma hormone content was analyzed in samples collected before (resting conditions) and at 15, 60, 75, 120, 180, and 240 min after onset of drinking. Hormonal responses to alcohol were examined with twin analyses using the TWINAN90 program. A separate analysis was performed for each of the four hormones. A subset of subjects from each zygosity was seen on two separate occasions to establish retest reliability. Heritability of hormonal responses to alcohol was estimated using the intraclass correlation approach before and after removing the contribution of covariates that have the potential of influencing the plasma levels of these hormones. RESULTS: Resting plasma levels of all four hormones were within the expected range, and the beta-E, ACTH, and PRL responses to the alcohol challenge evidenced good test-retest reliability. Of the four hormones examined, the only one that showed significant heritability after alcohol drinking was beta-E. Heritability estimates were not altered for any of the four hormones after removal of the variance contributed by covariates, such as gender and age. CONCLUSIONS: Taken together with other recent findings, the results suggest that the beta-E response to alcohol may represent a new biomarker that can be used to identify individuals who are at elevated genetic risk for developing alcoholism.     

Appropriateness of colorectal cancer screening: appraisal of evidence by experts.

OBJECTIVE: . To evaluate how the level of evidence perceived by an international panel of experts was concordant with the level of evidence found in the literature, to compare experts perceived level of evidence to their appropriateness scores, and to compare appropriateness criteria for colonoscopy between experts and an evidence-based approach. DESIGN: Comparison of expert panel opinions and systematic literature review regarding the level of evidence and appropriateness of colonoscopy indications. PARTICIPANTS: European Panel on the Appropriateness of Gastrointestinal Endoscopy multidisciplinary experts from 14 European countries. MAIN OUTCOME MEASURES: Concordance and weighted kappa coefficient between level of evidence as perceived by the experts' and that found in the literature, and between panel- and literature-based appropriateness categories. RESULTS: Experts overestimated the level of published evidence of 57 indications. Concordance between the level of evidence perceived by the experts and the actual level of evidence found in the literature was 36% (weighted kappa 0.18). Indications for colonoscopy were reported to be appropriate, uncertain, and inappropriate by the experts in 54, 19, and 27% of the cases, and by the literature in 37, 46, and 17% of the cases. A 46% agreement (weighted kappa 0.29) was found between literature-based and experts' appropriateness criteria. CONCLUSIONS: Experts often overestimated the level of evidence on which they based their decisions. However, rarely did the experts' judgement completely disagree with the literature, although concordance between panel- and literature-based appropriateness was only fair. A more explicit discussion of existing evidence should be undertaken with the experts before they evaluate appropriateness criteria.