Accuracy of multidetector row computed tomography for the diagnosis of acute bowel ischemia in a non-selected study population

The diagnostic accuracy of multidetector row computed tomography for the prospective diagnosis of acute bowel ischemia in the daily clinical routine was analyzed. Two hundred ninety-one consecutive patients with an acute or subacute abdomen, examined by MDCT over a time period of 5 months, were included in the study. All original CT diagnoses made during the daily routine by radiological generalists were compared to the final diagnoses made by using all available medical information from endoscopies, surgical interventions, autopsies and follow-up. Finally, all CT examinations of patients with an initial CT diagnosis or a final diagnosis of bowel ischemia were reread by a radiologist specialized in abdominal imaging in order to analyze the CT findings and the reasons for initially false negative or false positive CT readings. Twenty-four patients out of 291 (8.2%) had acute bowel ischemia. The age of affected patients ranged from 50 to 94 years (mean age: 75.7 years). Eleven patients were male, and 13 female. Reasons for acute bowel ischemia were: arterio-occlusive (n=11), non-occlusive (n=5), strangulation (n=2), over-distension (n=3) and radiation (n=3). The prospective sensitivity, specificity, PPV and NPV of MDCT for the diagnosis of acute bowel ischemia in the daily routine were 79.17, 98.51, 90.48 and 98.15%. MDCT reaches a similarly high sensitivity in diagnosing acute bowel as angiography. Furthermore, it has the advantage of being helpful in most of its clinical differential diagnoses and of being less invasive with the consecutive possibility of being used earlier in the diagnostic process with all the resulting positive effects on the patients prognosis. Therefore, nowadays MDCT should probably be used as the first step imaging modality of choice in patients with suspected acute bowel ischemi

Accuracy of chest radiographs in the emergency diagnosis of heart failure

The purpose of this study was to determine the diagnostic accuracy of chest radiographic findings of heart failure (HF) in current patients presenting with dyspnea in the emergency department. In a secondary analysis of the BASEL study, initial chest radiographs of 277 patients with acute dyspnea were evaluated by two radiologists blinded to the adjudicated diagnosis (56% had the final diagnosis of HF). Predefined radiographic criteria of HF were used. Statistical analysis included receiver-operating characteristic (ROC) analysis and calculation of a logistic regression model including B-type natriuretic peptide (BNP) levels. The reader's overall impression showed the highest area under the ROC curve for the diagnosis of HF in both supine and erect patient positions (0.855 and 0.857). Among individual radiographic findings, peribronchial cuffing in the supine position (0.829) showed the highest accuracies. The lowest accuracy was found for the vascular pedicle width in the supine position (0.461). Logistic regression analysis showed no significant differences between the reader's overall impression, the radiographic model, and BNP testing. In our study, the combination of radiographic features provided valuable information and was of comparable accuracy as BNP-testing for the diagnosis of H

Potential exposure of butterflies in protected habitats by Bt maize cultivation: a case study in Switzerland

Transgenic Bt maize can produce insecticidal Cry proteins toxic to butterflies and moths (Lepidoptera). In protected habitats near maize fields, Bt maize pollen containing the toxin can be drifted by wind onto host plants of Lepidoptera, and inadvertently harm lepidopteran larvae feeding on these host plants. For a heterogeneous, agricultural landscape in Switzerland, we investigated the butterfly community of protected habitats and their potential exposure to possible cultivation of Bt maize, recorded the densities of maize pollen deposited on a butterfly host plant, simulated the effect of different pollen dispersal ranges and Bt maize adoption rates on the exposure of protected habitats, and explored the consequences of different buffer zones around protected habitats. On average, the 49 recorded butterfly species showed a temporal overlap of larvae of 50.10% ± 30.09% with the maize pollen shedding period. Mean maize pollen density on nettles (Urtica dioica) was 6.49 ± 13.58 pollen/cm2 (range: 0–100). Most of the pollen was deposited close to maize fields less than 30 m distance, but pollen also drifted onto host plants as far as 500 m away. In simulations, protected habitats were highly exposed to Bt maize pollen deposition even at low adoption rates of Bt maize, given that maize pollen is distributed to larger distances. The conflict between species conservation and Bt maize cultivation could be minimised by establishing buffer zones around protected habitats, where non-Bt maize is grown. The results and the known sensitivities of lepidopteran larvae to Bt suggest at least 50 m–100 m broad buffer zones, and case-specific risk assessments for distances above 100 m