Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

Background Ultrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy. Methods We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance. Results We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography. Conclusion Combined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data

Extra-Visual Functional and Structural Connection Abnormalities in Leber's Hereditary Optic Neuropathy

We assessed abnormalities within the principal brain resting state networks (RSNs) in patients with Leber's hereditary optic neuropathy (LHON) to define whether functional abnormalities in this disease are limited to the visual system or, conversely, tend to be more diffuse. We also defined the structural substrates of fMRI changes using a connectivity-based analysis of diffusion tensor (DT) MRI data. Neuro-ophthalmologic assessment, DT MRI and RS fMRI data were acquired from 13 LHON patients and 13 healthy controls. RS fMRI data were analyzed using independent component analysis and SPM5. A DT MRI connectivity-based parcellation analysis was performed using the primary visual and auditory cortices, bilaterally, as seed regions. Compared to controls, LHON patients had a significant increase of RS fluctuations in the primary visual and auditory cortices, bilaterally. They also showed decreased RS fluctuations in the right lateral occipital cortex and right temporal occipital fusiform cortex. Abnormalities of RS fluctuations were correlated significantly with retinal damage and disease duration. The DT MRI connectivity-based parcellation identified a higher number of clusters in the right auditory cortex in LHON vs. controls. Differences of cluster-centroid profiles were found between the two groups for all the four seeds analyzed. For three of these areas, a correspondence was found between abnormalities of functional and structural connectivities. These results suggest that functional and structural abnormalities extend beyond the visual network in LHON patients. Such abnormalities also involve the auditory network, thus corroborating the notion of a cross-modal plasticity between these sensory modalities in patients with severe visual deficits

Surgical management of vesicoureteral reflux in children

Vesicoureteral reflux (VUR) is the most common uropathy affecting children. Compared to children without VUR, those with VUR have a higher rate of pyelonephritis and renal scarring following urinary tract infection (UTI). Options for treatment include observation with or without antibiotic prophylaxis and surgical repair. Surgical intervention may be necessary in patients with persistent reflux, renal scarring, and recurrent or breakthrough febrile UTI. Both open and endoscopic approaches to reflux correction are successful and reduce the occurrence of febrile UTI. Estimated success rates of open and endoscopic reflux correction are 98.1% (95% CI 95.1, 99.1) and 83.0% (95% CI 69.1, 91.4), respectively. Factors that affect the success of endoscopic injection include pre-operative reflux grade and presence of functional or anatomic bladder abnormalities including voiding dysfunction and duplicated collecting systems. Few studies have evaluated the long-term outcomes of endoscopic injection, and with variable results. In patients treated endoscopically, recurrent febrile UTI occurred in 0–21%, new renal damage in 9–12%, and recurrent reflux in 17–47.6% of treated ureters with at least 1 year follow-up. These studies highlight the need for standardized outcome reporting and longer follow-up after endoscopic treatment

T2-weighted MR imaging of the liver : optimization of hybrid-rare sequences

The objectives of this study were to optimize T2-weighted hybrid-RARE pulse sequences for clinical MR imaging of the liver, and to compare them to the conventional spin-echo (CSE) sequence. Specifically, the ranges of the echo train length (ETL) and the effective echo time (TEeff) were investigated to optimize image quality and liver-spleen contrast, in healthy volunteers, A total of thirteen volunteers were scanned at 1.5 Tesla with an extensive array of hybrid-RARE scans, The images were analyzed quantitatively with respect to CNR (contrast-to-noise ratio of spleen vs, liver), SNR (signal to noise ratio of the spleen), SIR (signal intensity ratio of liver and spleen) and CDR (contrast difference ratio between the spleen and liver), The images were also analyzed qualitatively with respect to image sharpness, vascular artifacts, ghosting, chemical shift, and truncations, Results of quantitative analysis indicated that CDR and SIR of hybrid-RARE at higher ETL (> 13) were consistently better than both the reference CSE and the lower ETL sequences (p 13 proved to be consistently better than that for the CSE (TE = 90 ms) with respect to imaging sharpness, vascular artifacts and ghosting artifacts (p < 0.05), In conclusion, the optimized hybrid-RARE sequences with ETL greater than or equal to 13 are capable of producing sharp and relatively artifact free images with the advantage of a much greater acquisition time efficiency. (C) 1997 Elsevier Science Inc

Results of the Leeds Assessment of Neuropathic Symptoms and Signs pain scale in Turkey: A validation study

Classification of pain and identification of the specific pain mechanisms through utilization of clinical data are helpful to the physician in choosing the appropriate treatment model. For discrimination between different pain types, various tests could be used. The Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) Pain Scale is a scale based on the analysis of data obtained during bedside examination. The LANSS Pain Scale, as first used by Bennett, is a very useful tool that provides immediate information in the clinical setting and helps distinguish nociceptive pain from neuropathic pain. In this study we targeted validation of the LANSS Pain Scale in the Turkish population. A total of 104 patients who consulted the Algology Department of Istanbul Faculty of Medicine Outpatient Clinic were enrolled in our validation study. The sensitivity and specificity of the scale were found to be 89.9% and 94.2%, respectively. These results suggest a high validity level for the Turkish version of the LANSS Pain Scale. We believe that this scale is a useful tool for the differential diagnosis of neuropathic pain and can be used in future pharmacologic studies