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Query: UMLS:C0034065 (pulmonary embolism)
 14,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine how pulmonary respiratory motion affects detection of pulmonary emboli, 11 dogs had routine lung scans and gated or cinematic perfusion images after undergoing autologous experimental pulmonary embolism. Six dogs had routine six-view perfusion studies, plus end-inspiratory and end-expiratory gated perfusion studies performed with a physiologic synchronizer set to 80% threshold. Five other dogs had three-view ungated and cinematic (post., LPO, RPO) perfusion images. Cinematic studies were acquired by synchronizing a camera-computer system to the Harvard respirator that ventilated the dog. Before death, all animals received i.v. India ink to outline pulmonary perfusion defects, and postmortem lung dissection verified sites of emboli. An ROC curve analysis of randomized perfusion studies showed that end-inspiratory gated images yielded true-positive rates 5--10% higher than ungated images at any given false-positive rate. Lesion detection by cinematic studies was comparable to detection by ungated images, but detection by end-expiratory images was worse. End-inspiratory gated imaging may be useful as an occasional adjunct to routine perfusion lung imaging.
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PMID:Gated and cinematic perfusion lung imaging in dogs with experimental pulmonary embolism. 54 97

The common strategy of combining clinical information, lung scintigraphy and pulmonary angiography in the diagnosis of acute pulmonary embolism (PE), has many limitations in clinical use. The major causes are that pulmonary angiography and lung scintigraphy are not universally available, and that pulmonary angiography is very expensive. The purpose of this thesis was to analyse different aspects of validity in regard to lung scintigraphy, pulmonary angiography, spiral CT, and ultrasound of the legs, with the subsequent intention of discussing new diagnostic strategies. Observer variations in lung scintigraphy interpretation when applying the PIOPED criteria were tested in 2 studies with 2 and 3 observers respectively and expressed as kappa values. The ability to improve agreement in lung scintigraphy interpretation was tested by training 2 observers from different hospitals. The impact of 3 observers' variations in lung scintigraphy interpretation when compared to pulmonary angiography, was tested by comparing the ROC areas of the observers. The value of combining subjectively derived numerical probabilities and the PIOPED categorical probabilities in lung scintigraphy reporting was compared to using the PIOPED categorization only, and this was tested by comparing ROC areas. The sensitivity and specificity of detecting an embolic source in the deep veins of the legs by ultrasound as a sign of PE when lung scintigraphy is inconclusive, was tested by comparison with pulmonary angiography. The sensitivity and specificity of spiral CT, compared to pulmonary angiography, was tested by comparison to pulmonary angiography. The inter- and intra-observer kappa values were in the range of moderate and fair. It was not possible to achieve better kappa values after training. Although observer variations were substantial, the accuracy did not differ significantly between the 3 observers. Incoorporating subjectively derived probabilities into lung scan reporting could not reduce the number of inconclusive investigations. Sensitivity and specificity of ultrasound in detecting PE was 0.70 and 0.97, respectively. However, 2 patients (of 9) had deep venous thrombosis and no pulmonary emboli at angiography. The sensitivity and specificity of spiral CT was 0.90 and 0.96, respectively. The observer variations at lung scintigraphy are substantial and may be difficult to improve between hospitals, even though the accuracy of observers in general is good. Although subjectively derived interpretation criteria did not show to be useful when added to categorical interpretation criteria, they may be useful when substituting established criteria. Despite recent progress in refining interpretation criteria, a substantial fraction of the patients still need pulmonary angiography to be performed. However, in many patients pulmonary angiography is not performed as prescribed. Spiral CT and ultrasound of the legs is a new favourable diagnostic strategy with a high validity in detecting venous thromboembolic disease, and a good availability and cost-effectiveness.
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PMID:Diagnostic imaging of acute pulmonary embolism. 910 83

The diagnostic value of transthoracic echocardiography in acute pulmonary embolism is not well established. Although many parameters are abnormal, the thresholds used vary according to the authors, limiting the contribution of the investigation to the diagnosis. In a prospective study of 70 patients with suspected acute pulmonary embolism without previous cardio-respiratory disease, the authors tried to determine the diagnostic thresholds using discriminating linear analysis and ROC curves. Parameters easily recorded in an emergency were analysed: end diastolic ventricular dimensions, ratio of these diameters and maximal velocity of tricuspid regurgitant flow. Thirty-one patients had pulmonary embolism quantified by the Miller index (average: 16 +/- 7, range 2 to 28). Measurements of left ventricular dimension were disappointing (sensitivity: 0.52, specificity: 0.73 for a threshold value of 45 mm). The right ventricular dimension was a better predictive parameter (sensitivity: 0.70, specificity: 0.86 for a threshold value of 25 mm). However, the ratio of right to left ventricular dimension had a better diagnostic value (sensitivity: 0.85, specificity: 0.78 for a threshold value of 0.5). The best diagnostic parameter was the maximal velocity of tricuspid regurgitation (sensitivity: 0.93, specificity: 0.82 for a threshold value of 2.5 m/s). The authors conclude that the maximal velocity of tricuspid regurgitation with a threshold of 2.5 m/s and the ratio of the ventricular dimensions with a threshold value of 0.5 are valuable diagnostic indicators for acute pulmonary embolism.
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PMID:[Transthoracic echocardiography and diagnosis of acute pulmonary embolism. Change in the diagnostic valve with respect to thresholds of classification]. 923 63

Our objective was to investigate possible factors implicated in either early death from or scintigraphic resolution of pulmonary embolism. To that end we conducted a retrospective study of 116 patients with either a high likelihood of pulmonary thromboembolism (PTE) diagnosed by scintiscan or with a fair probability of PTE by scintiscan accompanied by a positive phlebograph. The images were taken upon admission, at 7 days, 10 days and 6 months. The factors analyzed were age, sex, trauma, immobility, surgery, obesity, hemiplegia, venous insufficiency, cardiopulmonary disease, neoplasia, chest X-ray and ECG alterations, D(A-a)O2 and size of perfusion defects upon admission and 7 to 10 days later. We performed single-variable analyses and multiple logical regression analyses using perfusion defect at 6 months as the dependent variable. The early mortality rate (13%) was higher in patients with neoplasms, a larger alveolar-arterial index and greater perfusion defects upon admission. Scintiscans became normal in 28%. Multivariate analysis to predict total or partial resolution at 6 months showed that size of perfusion defects at 7 to 10 days was the best predictive factor. A cutoff point was calculated by analyzing the ROC for this factor. Thus, when the defect at 7 to 10 days was equal to or greater than 1 segment, the probability of residual defects remaining after 6 months was twice as great (sensitivity 83%, specificity 57%). In conclusion, early death was more likely in PTE patients with neoplasms, larger defects upon admission and greater alveolar-arterial difference. Scintigrams showed resolution 6 months after admission in 28%. The size of perfusion defects 7 to 10 days after admission was the factor that best predicted total of partial resolution at 6 months.
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PMID:[The prognostic factors for early mortality and for total or partial gammagraphic resolution in venous thromboembolic disease]. 925 67

Twenty-one physicians examined records of 43 patients who had attended the hospital because of chest pain. Of these patients, 20 had had coronary heart disease (CHD), 15 had had nonspecific pain, and eight had had pulmonary embolism. The physicians indicated the probability of CHD in each case on the basis of 18 clinical findings, not including ECG, x-ray, or biochemical studies. The trial was repeated five years later, using the same records, by 16 of the same physicians. Diagnostic accuracy was evaluated by ROC curves, and the weight ascribed to each cue was inferred by multiple regression with estimated probability of CHD as the dependent variable. No significant change of areas under the ROC curves with increasing length of clinical experience was observed. Multiple regression was significant in 30 of 37 analyses. The distributions of most physicians' estimates of probabilities had similar shapes five years apart. It is concluded that "experience" does not have a clear role in diagnostic performance based on recorded data and that personal calibration and preferences in estimating probabilities often persist for years.
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PMID:The role of clinical "experience" in diagnostic performance. 956 49

We prospectively evaluated the diagnostic performance of a new soluble fibrin assay in 303 consecutive patients with suspected pulmonary embolism and examined potentially useful cut-off levels at which this disease can be safely excluded. In addition, the diagnostic accuracy was calculated in the subgroups of in- and outpatients. The ROC curve of the assay in the total study cohort had an area under the curve of 0.69. The cut-off level associated with a sensitivity and negative predictive value of 100% was 20 ng/ml, but the specificity was only 4%. The cut-off level with a sensitivity of 90% was 30 ng/ml, which corresponded with a specificity and negative predictive value of 27% and 86%. respectively. The diagnostic performance was comparable in the subgroups of in- and outpatients. We conclude that the soluble fibrin assay has a low diagnostic accuracy and seems unsuitable as a screening test for the exclusion of pulmonary embolism.
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PMID:Use of a new monoclonal antibody-based enzyme immunoassay for soluble fibrin to exclude pulmonary embolism. ANTELOPE-Study Group. 1101 74

Certain clinical findings raise the suspicion of pulmonary embolism (PE) and may be useful in selecting patients for further diagnostic testing. Three prediction rules for PE have been described recently: Wells' rule (WR), Geneva rule (GR) and Miniati' rule (MR). The aim of present study is to compare the predictive accuracy of the three methods on the basis of our patients' results. Eighty-five patients admitted to our department with suspicion of PE were included into the study. Sixty-three patients were discharged with the diagnosis of PE, whereas in 22 patients, the initial PE diagnosis was ruled out. The three methods for assessing the clinical probability of PE classified similar proportions of patients into the low, intermediate and high clinical probability categories. The frequencies of PE in each method (WR, GR and MR) were 5%, 64% and 14% in the low category, 90%, 80% and 75% in the intermediate category and 100%, 100% and 94% in the high category (p = 0.001, 0.064, 0.001) respectively. When we compared the performances of WR and GR, including all possible total score values, the area under the ROC curve (AUC) was 0.99 for the WR (p= 0.001) and 0.74 for the GR (p= 0.001). When we used only the three probability categories (low, intermediate, high), AUC was 0.96 for the WR (p= 0.001), 0.64 for the GR (p= 0.04), and 0.7 for the MR (p= 0.005). In conclusion, the present study indicates that clinical assessment is a fundamental step in the diagnostic work-up of PE. The Wells' method performs better than other two methods.
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PMID:[Comparison of three clinical prediction rules among patients with suspected pulmonary embolism]. 1625 84

Type B natriuretic peptide (BNP) versus n-terminal type B natriuretic propeptide in the diagnosis of cardiac failure in the elderly over 75 population The value of BNP is well established in the diagnosis of cardiac failure in cases of dyspnoea in the emergency room in young and, more and more, in elderly subjects. However, there are few studies comparing the diagnostic value of BNP and of the n-terminal pro-BNP in patients over 75 years of age. The aim of this study was to compare the diagnostic value of BNP and NT-pro BNP in dyspnoea of the elderly patient. One hundred and three consecutive patients over 75 years of age admitted to the emergency unit for dyspnoea were included. A blood sample for measuring the BNP (Biosite) and the NT-proBNP (Roche Diagnostic) was taken in the admission unit in addition to the standard blood workup. The final reference diagnosis was established by two independent cardiologists. Of the 103 patients, 61 were women and the average age was 84.9 +/- 6.2 years. The final diagnosis was cardiac failure in 49 patients (48%), pulmonary embolism in 6 patients, an acute exacerbation of chronic obstructive airways disease in 36 patients and an acute bronchitis in 30 patients. In 9 cases, the dyspnoea was considered to result from mixed cardiac and pulmonary disease. Renal function was assessed by calculating the creatinine clearance by Cockcroft and Gault's formula. The average value of the creatinine clearance was 41.7 +/- 16.4 ml/min indicating that mild renal failure was relatively common. The diagnostic value, assessed by the area under the ROC curve, was similar for the BNP (0.79; CI: 0.70-0.88) and NT-proBNP (0.80; CI: 0.71-0.89). A BNP value of 300 pg/ml had the same sensitivity and specificity as an NT-proBNP of less than 1 500 pg/ml. A BNP of less than 200 pg/ml and an NT-proBNP of less than 1 000 pg/ml had excellent negative predictive values for excluding the diagnosis of cardiac failure. The authors conclude that the BNP and NT-proBNP are useful for the diagnosis of cardiac failure in acute dyspnoea of the elderly and seem to have a comparable diagnostic value.
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PMID:[Type B natriuretic peptide (BNP) versus n-terminal type B natriuretic propeptide in the diagnosis of cardiac failure in the elderly over 75 population]. 1661 22

Pulmonary embolism (PE) is a major health problem associated with a significant morbidity and mortality. Immediate recognition of submassive and massive cases is extremely important in order to commencement of early and appropriate therapy that could be life saving. The aim of this study was to assess the ability of two scoring systems, electrocardiography (ECG) and simplified Wells (sWells) clinical scorings in predicting anatomic severity of PE. Hence, ECG and sWells scorings were combined in order to test the hypothesis if this new scoring does enhance the prediction of severity. Fifty six patients with proven PE with high (50 patients) and moderate (six patients)-probability of ventilation/perfusion (V/Q) scan were retrospectively studied. Baseline ECGs were analysed by two independent observers in order to constitute ECG scorings. Baseline sWells scores were also calculated. Anatomic severity of PE was calculated by scintigraphically and categorized into mild (<50% perfusion defect) (group 1), and severe (50% perfusion defect) (group 2) diseases. The mean of ECG scores, sWells scores and the combined scores were 5.23+/-3.42 and 5.85+/-3.82; 6.60+/-1.88 and 7.03+/-2.40; and 10.73+/-3.60 and 11.60+/-4.32 in groups 1 and 2, respectively (p>0.05). An ECG score of 6.5 predicted severe disease (perfusion defect 50%) with a sensitivity of 41.7% and a specificity of 82%). sWells and combined scores did not provide better sensitivity or specificity values based on ROC curve analysis. Our results indicated that ECG scoring could be valuable test in predicting anatomic severity of PE, adding sWells scoring to ECG scoring did not provide any beneficial effect.
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PMID:Electrocardiography and Wells scoring in predicting the anatomic severity of pulmonary embolism. 1722 26

The value of a computer-aided detection tool (CAD) as second reader in combination with experienced and inexperienced radiologists for the diagnosis of acute pulmonary embolism (PE) was assessed prospectively. Computed tomographic angiography (CTA) scans (64 x 0.6 mm collimation; 61.4 mm/rot table feed) of 56 patients (31 women, 34-89 years, mean = 66 years) with suspected PE were analysed by two experienced (R1, R2) and two inexperienced (R3, R4) radiologists for the presence and distribution of emboli using a five-point confidence rating, and by CAD. Informed consent was obtained from all patients. Results were compared with an independent reference standard. Inter-observer agreement was calculated by kappa, confidence assessed by ROC analysis. A total of 1,116 emboli [within mediastinal (n = 72), lobar (n = 133), segmental (n = 465) and subsegmental arteries (n = 455)] were included. CAD detected 343 emboli (sensitivity = 30.74%, correct-positive rate = 6.13/patient; false-positive rate = 4.1/patient). Inter-observer agreement was good (R1, R2: kappa = 0.84, 95% CI = 0.81-0.87; R3, R4: kappa = 0.79, 95% CI = 0.76-0.81). Extended inter-observer agreement was higher in mediastinal and lobar than in segmental and subsegmental arteries (kappa = 0.84-0.86 and kappa = 0.51-0.58 for mediastinal/lobar and segmental/subsegmental arteries, respectively P < 0.05). Agreement between experienced and inexperienced readers was improved by CAD (kappa = 0.60-0.62 and kappa = 0.69-0.72 before and after CAD consensus, respectively P < 0.05). The experienced outperformed the inexperienced readers (Az = 0.95, 0.93, 0.89 and 0.86 for R1-4, respectively, P < 0.05). CAD significantly improved overall performances of readers 3 and 4 (Az = 0.86 for R3, R4 and Az = 0.89 for R3, R4 with CAD, P < 0.05), by enhancing sensitivities in segmental/subsegmental arteries. CAD improved experienced readers' sensitivities in segmental/subsegmental arteries (sens. = 0.93 and 0.90 for R1, R2 before and 0.97 and 0.94 for R1, R2 after CAD consensus, P < 0.05), without significant improvement of their overall performances (P > 0.05). Particularly inexperienced readers benefit from consensus with CAD data, greatly improving detection of segmental and subsegmental emboli. This system is advocated as a second reader.
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PMID:Computer-assisted detection of pulmonary embolism: performance evaluation in consensus with experienced and inexperienced chest radiologists. 1790 58


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