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PubMed2001

Accuracy of biomarkers to diagnose acute cardiac ischemia in the emergency department: a meta-analysis.

STUDY OBJECTIVE: We sought to evaluate quantitatively the evidence on the diagnostic performance of presentation and serial biochemical markers for emergency department diagnosis of acute cardiac ischemia (ACI), including acute myocardial infarction (AMI) and unstable angina. METHODS: We conducted a systematic review and meta-analysis of the English-language literature published between 1966 and December 1998. We examined the diagnostic performance of creatine kinase, creatine kinase-MB, myoglobin, and troponin I and T testing. Diagnostic performance was assessed by using estimates of test sensitivity and specificity and was summarized by summary receiver-operating characteristic curves. RESULTS: Only 4 studies were found that evaluated all patients with ACI; 73 were found that focused only on a diagnosis of AMI. To diagnose ACI, presentation biomarker tests had sensitivities of 16% to 19% and specificities of 96% to 100%; serial biomarker tests had sensitivities of 31% to 45% and specificities of 95% to 98%. Considering only the diagnosis of AMI, presentation biomarker tests had summary sensitivities of 37% to 49% and summary specificities of 87% to 97%; serial biomarker tests had summary sensitivities of 79% to 93% and summary specificities of 85% to 96%. Variation of test sensitivity was best explained by test timing. Longer symptom duration or time between serial tests yielded higher sensitivity. CONCLUSION: The limited evidence available to evaluate the diagnostic accuracy of biomarkers for ACI suggests that biomarkers have very low sensitivity to diagnose ACI. Thus, biomarkers alone will greatly underdiagnose ACI and will be inadequate to make triage decisions. For AMI diagnosis alone, multiple testing of individual biomarkers over time substantially improves sensitivity, while retaining high specificity, at the expense of additional time. Further high-quality studies are needed on the clinical effect of using biomarkers for patients with ACI in the ED and on optimal timing of serial testing and in combination with other tests.

Acute Disease↗

PubMed2006

F-18 FDG-PET as a routine surveillance tool for the detection of recurrent head and neck squamous cell carcinoma.

In order to determine the efficacy and proper timing of routine PET scans for surveillance of recurrent head and neck squamous cell carcinoma (HNSCC), we evaluated the diagnostic performance of routine PET scans in relation to time interval from completion of treatment. Amongst 206 retrospectively evaluated post-treatment PET scans of 159 patients with HNSCC, 156 were performed for routine surveillance in subclinical cases. Diagnostic performance of PET scan and follow-up outcome were evaluated in relation to the time interval (2-6months, 6-12months, 12-24months, and >24months) of PET scan from the completion of treatment. Overall sensitivity and NPV of these PET scans for recurrence were 92.5% and 94.8%, compared with 55.0% and 76.9% for conventional evaluation methods. In the 156 routine scans, the diagnostic sensitivity, specificity, and NPV for locoregional recurrence were 90%, 91% and 97%, respectively, and the values for distant metastases and second primary cancers were 100%, 97% and 100%, respectively. The diagnostic accuracy of routine PET scans was not significantly altered by the time interval. Most (97%) of true negative cases on routine PET scans had no recurrence during a median 14months follow-up. PET scan may be a useful tool in routine surveillance for detection of recurrence in subclinical patients. For routine surveillance, the initial PET scan should be performed within 6months after completion of treatment and the proper timing of next routine PET scan for subclinical patient with initial negative PET result might be 1year after initial PET scan.

Adult↗

PubMed1999

Criteria, performance and diagnostic problems in diagnosing acute otitis media.

OBJECTIVE: We aimed to assess criteria when diagnosing acute otitis media and related performance in general practice in Denmark. Furthermore, we aimed to identify the scale of and the reasons for diagnostic uncertainty. METHODS: We conducted: (i) a survey among GPs assessing criteria; and (ii) prospective registration of acute otitis-media-related consultations performed by GPs assessing performance. The survey was sent to all 790 GPs in Funen, North Jutland and Ringkøbing counties, Denmark. A total of 568 (72%) of all GPs in the three counties responded. A total of 368 children with acute otitis media or previous acute otitis media visiting 151 GPs were studied. The main outcome measures were: (i) criteria for symptoms and findings suggesting the diagnosis acute otitis media, criteria for use of equipment and reasons for diagnostic uncertainty; and (ii) prevalence of symptoms and findings in diagnosed cases, equipment used and multivariate analysis of factors predicting diagnostic certainty. RESULTS: The symptoms of earache, fever, reduced hearing, findings of bulging eardrum, red eardrum and purulent otorrhea were important criteria used during both diagnosis of acute otitis media by the GPs and assessment of performance. In the prospective study, diagnostic certainty of acute otitis media was 67% (95% CI 58-76) in children under 2 years and 75% (95% CI 69-81) in older children. Diagnostic certainty was statistically related (P < 0.05) to a good view of the eardrum and the findings of purulent otorrhea or a bulging eardrum. Logistic regression revealed that the two most important factors predicting diagnostic certainty were a satisfactory view of the eardrum, with an odds ratio (OR) 11.0 (95% CI 4.1-29.5), and purulent otorrhea OR 10.1 (95% CI 3.1-32.9). Main reasons for diagnostic uncertainty given by GPs were differential diagnostic doubts, insufficient view of the eardrum and lack of knowledge. CONCLUSION: Danish GPs' criteria for the diagnosis of acute otitis media were stricter than criteria used internationally. The discrepancy between diagnostic criteria and performance was small. Diagnostic accuracy and certainty could be substantially improved by cleaning the ear canal when needed and by widespread use of pneumatic otoscopy.

Acute Disease↗

PubMed2005

Comparison of eight different digital chest radiography systems: variation in detection of simulated chest disease.

OBJECTIVE: In a short period, a variety of technically different digital radiography chest systems have become available for clinical use. Our purpose was to assess the diagnostic performance of eight different digital radiography chest systems for detection of simulated chest disease under clinical conditions. MATERIALS AND METHODS: Assessed were four different flat-panel detector systems, two different charge-coupled device systems, one selenium-coated drum, and one storage phosphor system. For each system, 10 chest images of an anthropomorphic chest phantom were obtained. Each image contained one to 12 simulated chest lesions. Eight radiologists performed soft-copy interpretations. Entrance dose was measured and effective dose calculated. A semi-parametric logistic regression model was used for statistical analysis. RESULTS: Statistically significant differences were found in the diagnostic performance of the eight digital chest systems (p = 0.01). Best performance was observed with the charge-coupled device system with slot-scan technology, yielding a sensitivity of 46% (132 of 288) lesions detected. The performance of three flat-panel detectors and the selenium-drum system was not significantly different from the slot-scan charge-coupled device system. Fewer lesions were detected with the storage phosphor system than with all other digital technologies, with a sensitivity of 34% (99 of 288) lesions detected, slot-scan charge-coupled device system versus storage phosphor system, p < 0.001. The effective dose varied among the digital systems. CONCLUSION: We found differences in diagnostic performance among the eight different digital chest systems. Differences in detection rates are predominantly explained by detector design.

Diagnostic Errors↗

PubMed2005

Strategies for improving the diagnostic specificity of the frequency doubling perimeter.

PURPOSE: To evaluate various strategies designed to improve the specificity of the interpretation of results obtained with the frequency doubling technology perimeter (FDT) used in the full-threshold mode. METHODS: Three different strategies were compared using data from 452 glaucoma patients and 237 healthy subjects: combining several FDT parameters from a single test, combining the FDT test with a GDx test, and confirming an abnormal FDT test result with a repeat test. RESULTS: Confirming an abnormal FDT test result with a repeat test yielded a specificity increase of 0.10, from 0.80 to 0.90, at the expense of some loss of sensitivity for early but not for moderate or severe glaucoma. Combining several FDT parameters from a single test and combining FDT with GDx did not yield any noticeable increase in diagnostic performance. CONCLUSIONS: A modest increase in FDT diagnostic performance can be obtained by the confirmation of an abnormal test result with a repeat test.

Cohort Studies↗

PubMed2003

Fundamental measures of diagnostic examination performance: usefulness for clinical decision making and research.

Measures of diagnostic accuracy, such as sensitivity, specificity, predictive values, and receiver operating characteristic curves, can often seem like abstract mathematic concepts that have a minimal relationship with clinical decision making or clinical research. The purpose of this article is to provide definitions and examples of these concepts that illustrate their usefulness in specific clinical decision-making tasks. In particular, nine principles are provided to guide the use of these concepts in daily radiology practice, in interpreting clinical literature, and in designing clinical research studies. An understanding of these principles and of the measures of diagnostic accuracy to which they apply is vital to the appropriate evaluation and use of diagnostic imaging examinations.

Decision Making↗

PubMed1992

Analytical and clinical evaluation of creatine kinase MB mass assay by IMx: comparison with MB isoenzyme activity and serum myoglobin for early diagnosis of myocardial infarction.

We analytically and clinically evaluated Abbott's IMx assay for creatine kinase (CK) isoenzyme MB (CK-MB) in serum. Over a 1-year period, the method was more specific but less precise than catalytic isoenzyme measurements by electrophoresis or immunoinhibition. Sera from different individuals without electrophoretic evidence of CK-MB but containing macro CK type 1 (n = 20), mitochondrial CK (n = 5), or CK-BB (n = 5) were scored as CK-MB negative by the IMx. Likewise, CK-MB-negative by the sera remained so after addition of purified human CK-MM (< or = 7600 U/L) or CK-BB (< or = 8100 U/L). For 39 patients admitted for suspicion of uncomplicated acute myocardial infarction (precordial pain for < or = 4 h), the diagnostic performance of the IMx CK-MB assay on admission and 4 h later was superior to that of total CK activity and compared well with that of CK-MB activity measured by electrophoresis or immunoinhibition. An admission, myoglobin showed a higher diagnostic sensitivity, specificity, and predictive value than did CK-MB and was the most informative test. Diagnostic performance on admission and 4 h later was further improved by considering positivity for myoglobin and for CK-MB by IMx and for the change in each over the first 4 h of hospitalization as criteria. Twelve hours after admission, diagnostic performance was further improved for all CK and CK-MB methods but began to decline for myoglobin.

Adult↗

PubMed2004

The positive predictive value of the breast imaging reporting and data system (BI-RADS) as a method of quality assessment in breast imaging in a hospital population.

Evaluation of the diagnostic performance of mammography and US in our hospital, based upon the positive predictive value (PPV) for breast cancer of the breast imaging reporting and data system (BI-RADS) final assessment categories, has been performed. A follow-up study of 2,762 mammograms was performed, along with 955 diagnostic exams and 1,807 screening exams. Additional US was performed in 655 patients (23.7%). The combined reports were assigned a BI-RADS category. Follow-up was obtained by pathologic examination, mammography at 12 months or from PALGA, a nationwide network and registry of histo- and cytopathology. Overall sensitivity was 85% (specificity 98.7%); sensitivity of the diagnostic examinations was 92.9% (specificity 97.7%) and of the screening examinations 69.2% (specificity 99.2%). The PPV of BI-RADS 1 was 5 of 1,542 (0.3%), and of BI-RADS 2, it was 6 of 935 (0.6%). BI-RADS 3 was 6 of 154 (3.9%), BI-RADS 4 was 39 of 74 (52.7%) and BI-RADS 5 was 57 of 57 (100%). The difference between BI-RADS 1 and 2 vs. BI-RADS 3 was statistically significant (P<0.01). Analysis of BI-RADS 3 cases revealed inconsistencies in its assignment. Evaluation of the BI-RADS final assessment categories enables a valid analysis of the diagnostic performance of mammography and US and reveals tools to improve future outcomes.

Adult↗

PubMed2001

Comparison of adenosine and exercise stress test for quantitative perfusion imaging in patients on beta-blocker therapy.

UNLABELLED: Beta-blocker therapy is used to decrease myocardial ischemia during exercise but may cause suboptimal diagnostic performance in exercise stress testing. The aim of the present study was to compare results of quantitative technetium-99-sestamibi single photon emission tomography (SPECT), following exercise stress test or pharmacological stress test with adenosine. We chose adenosine as comparison, since betablockers may not interfere with adenosine induced vasodilatation and therefore possibly may not interfere with its diagnostic performance. Sixteen patients with angiographically documented coronary disease (5 single-vessel, 6 two-vessel and 5 three-vessel disease), who were chronically treated with beta-blockers, performed SPECT imaging at rest, following bicycle exercise and following adenosine infusion in random order. The SPECT data were analyzed visually and quantitatively, using dedicated computer software (CEqual). According to both visual and quantitative SPECT analysis, adenosine was superior to show reversibility. Higher reversibility extent (50 +/- 15 vs. 26 +/- 12 pixels, p < 0.01) and more intense reversibility severity (110 +/- 29 vs. 49 +/- 23 sum of SDs, p < 0.05) were observed during adenosine than exercise. CONCLUSIONS: Less myocardial perfusion abnormalities during exercise than during adenosine stress in patients treated with beta-blockers may indicate less ischemia but also an impaired diagnostic performance. Thus adenosine stress test should be preferred to optimize the diagnostic sensitivity in patients during beta-blocker treatment.

Adenosine↗

PubMed2006

Diagnostic value of curved multiplanar reformatted images in multislice CT for the detection of resectable pancreatic ductal adenocarcinoma.

The purpose of this study was to assess the usefulness of curved multiplanar reformatted (MPR) images obtained by multislice CT for the depiction of the main pancreatic duct (MPD) and detection of resectable pancreatic ductal adenocarcinoma. This study included 28 patients with pancreatic carcinoma (size range 12-40 mm) and 22 without. Curved MPR images with 0.5-mm continuous slices were generated along the long axis of the pancreas from pancreatic-phase images with a 0.5- or 1-mm slice thickness. Seven blinded readers independently interpreted three sets of images (axial images, curved MPR images, and both axial and curved MPR images) in scrolling mode. The depiction of the MPD and the diagnostic performance for the detection of carcinoma were statistically compared among these images. MPR images were significantly superior to axial images in depicting the MPD, and the use of both axial and MPR images resulted in further significant improvements. For the detection of carcinoma, MPR images were equivalent to axial images, and the diagnostic performance was significantly improved by the use of both axial and MPR images. High-resolution curved MPR images can improve the depiction of the MPD and the diagnostic performance for the detection of carcinoma compared with axial images alone.

Adult↗

PubMed2001

Diagnostic value of radiological breast imaging in a non-screening population.

The aim of this study was to assess the diagnostic performance of breast imaging in the diagnosis of breast cancer in a non-screening population. In a consecutive set of patients referred for mammography in one year, the results of palpation and radiological breast imaging were scored on a 5-point grading scale and linked to pathology as gold standard after a follow up period of one year. The diagnostic performance was studied by logistic regression analysis and ROC-curves. There were 1,944 breast examinations in 1,890 patients and 3,816 breasts. Pathology results reported 118 malignancies in 115 women. With a cut-off point between benign and uncertain benign a sensitivity of 89% and a specificity of 98% was found for radiological imaging. ROC-curves showed a significant increase in diagnostic performance when radiology was added to results of palpation and age (p = 0.007). Radiological imaging tests have a large diagnostic value in the detection of breast cancer in addition to palpation and age. A sensitivity close to 100% could be reached.

Adolescent↗

PubMedDate not supplied

Clinical validation of SPECT attenuation correction using x-ray computed tomography-derived attenuation maps: multicenter clinical trial with angiographic correlation.

BACKGROUND: Nonuniform attenuation artifacts cause suboptimal specificity of stress single photon emission computed tomography (SPECT) myocardial perfusion images. In phantoms, normal subjects, and patients suspected of having coronary artery disease (CAD), we evaluated a new hybrid attenuation correction (AC) system that combines x-ray computed tomography (CT) with conventional stress SPECT imaging. METHODS AND RESULTS: The effect of CT-based AC was evaluated in phantoms by assessing homogeneity of normal cardiac inserts. AC improved homogeneity of normal cardiac phantoms from 11% +/- 2% to 5% +/- 1% (P < .001). Attenuation-corrected normal patient files were created from 37 normal subjects with a low likelihood (<3%) of CAD. The diagnostic performance of AC for detection of CAD was evaluated in 118 patients who had stress technetium 99m sestamibi or tetrofosmin stress SPECT imaging and coronary angiography. SPECT images with and without AC were interpreted by 4 blinded readers with different interpretative attitudes. Overall, AC improved the diagnostic performance of all readers, particularly the normalcy rate. The degree of improvement depended on interpretative attitude. Readers prone to high sensitivity or with less experience had the greatest gain in the normalcy rate, whereas a reader prone to higher specificity had improvements in sensitivity and specificity but not the normalcy rate. Importantly, improvement of one diagnostic variable was not associated with worsening of other variables. CONCLUSION: CT-based AC of SPECT images consistently improved overall diagnostic performance of readers with different interpretive attitudes and experience. CT-based AC is well suited for routine use in clinical practice.

Angiography↗

PubMed2026

Endoscopic Ultrasound-Guided Franseen Fine-Needle Biopsy for Solid Pancreatic Lesions: A Systematic Review and Meta-Analysis.

INTRODUCTION: Accurate tissue acquisition (TA) of solid pancreatic lesions is essential for guiding treatment with endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) being the preferred method. Among FNB designs, the three-pronged Franseen-tip needle demonstrates strong diagnostic performance, though direct head-to-head comparisons with other FNB designs remain limited. METHODOLOGY: This meta-analysis was conducted in accordance with PRISMA guidelines (PROSPERO: CRD420251123856). Eligible studies enrolled patients with solid pancreatic lesions who underwent EUS-guided FNB, directly compared the Franseen-tip with other FNB needles. Six databases were systematically searched through July 2025, and study selection, data extraction, and risk of bias assessment (QUADAS-2 tool) were performed independently by two reviewers. Pooled estimates were generated using random-effects and bivariate hierarchical models. RESULTS: Sixteen studies (2,010 Franseen vs. 2,811 comparator) were included. Bivariate analysis showed that sensitivity and specificity of the Franseen needle were comparable to newer-generation comparator needles (sensitivity 91.3% vs. 94.0%; specificity 99.99% vs. 99.15%), whereas older-generation needles demonstrated lower sensitivity (80.8%) and inferior discriminatory performance (Negative Likelihood Ratio [LR⁻] 0.19 vs. 0.09). Diagnostic accuracy was higher with the Franseen needle (RR 1.07, 95% CI 1.01-1.14; I2 = 69%). Sample adequacy was similar overall (RR 1.04, 95% CI 0.95-1.14) but superior to older-generation needles (RR 1.19, 95% CI 1.02-1.41) and in lesions > 30 mm (RR 1.14, 95% CI 1.02-1.28, I2 = 81.2%). The Franseen needle achieved nominally strong diagnostic performance (DOR 116.6), although small-study effects were observed. Primary procedural outcomes were comparable between Franseen and comparator needles, including technical success (RR 1.00, 95% CI 0.98-1.02) and histological core procurement (RR 1.04, 95% CI 0.92-1.17). The Franseen needle had fewer low-cellularity samples (RR 0.56, 95% CI 0.45-0.69) and lower specimen bloodiness (RR 0.48, 95% CI 0.25-0.90) but a slightly higher overall adverse event rate (RR 1.29, 95% CI 1.06-1.57). CONCLUSION: The Franseen needle provides superior diagnostic accuracy and sample adequacy compared to older-generation FNB needles with comparable performance to newer-generation designs. It reduces low-cellularity samples and specimen bloodiness, although adverse events are slightly increased, with other primary procedural outcomes remaining comparable. TRIAL REGISTRATION: PROSPERO (Registration No. CRD420251123856).

Humans↗

PubMed2001

Comparison of 'pattern recognition' and logistic regression models for discrimination between benign and malignant pelvic masses: a prospective cross validation.

OBJECTIVES: To test prospectively the diagnostic performance of two logistic regression models for calculation of individual risk of malignancy in adnexal tumors (the 'Tailor model' and the 'Timmerman model'), and to compare them to that of 'pattern recognition' (subjective evaluation of the gray-scale ultrasound image and color Doppler ultrasound examination). DESIGN: Consecutive women with a pelvic mass judged clinically to be of adnexal origin underwent preoperative ultrasound examination including color and spectral Doppler examination. The same examination techniques and definitions as those used in the studies in which the logistic regression models had been created were used. The Tailor model was tested in 133 women (35 of whom hada malignancy) and the Timmerman model in 82 women (29 of whom had a malignancy). A subset of 79 women (28 of whom had a malignancy) was used to compare the performance of the Tailor model and the Timmerman model by calculating and comparing the areas under the receiver operating characteristics curves of the two models. Sensitivity and specificity with regard to malignancy were calculated for all three methods. RESULTS: Pattern recognition performed better than the two logistic regression models (sensitivity around 85%, specificity around 90%). Using a risk of malignancy of > 50% to indicate malignancy (as suggested in the original publications), the sensitivity of the Tailor model was 69% and the specificity 88% (n = 133). The corresponding values for the Timmerman model were 62% and 79% (n = 82). The receiver operating characteristics curves showed the two logistic regression models to have similar diagnostic properties (area under the curve, 0.87 vs. 0.84; P = 0.25; n = 79). The diagnostic performance of the mathematical models was much poorer in this study than in those in which the models had been created. CONCLUSION: The poor diagnostic performance of the mathematical models can probably be explained by subtle differences in definitions and examination technique and by differences between the original tumor populations and the study population. For mathematical models to be generally useful, they probably need to be created on the basis of a very large number of tumors, and the variables in the model must be unequivocally defined and the examination technique meticulously standardized.

Adenofibroma↗

PubMed2004

Detection of liver metastases: gadobenate dimeglumine-enhanced three-dimensional dynamic phases and one-hour delayed phase MR imaging versus superparamagnetic iron oxide-enhanced MR imaging.

The aim of this study was to compare the diagnostic performance of gadobenate dimeglumine (Gd-BOPTA)-enhanced MR imaging, including dynamic phases and one-hour delayed phase, versus superparamagnetic iron oxide (SPIO)-enhanced imaging for detection of liver metastases. Twenty-three patients with 59 liver metastases underwent Gd-BOPTA-enhanced MR imaging (unenhanced, arterial, portal, equilibrium and one-hour delayed phase) using three-dimensional volumetric interpolated imaging and SPIO-enhanced T2-weighted turbo spin-echo and T2*-weighted gradient-echo sequences on a 1.5-T unit. Three observers independently interpreted the three sets of images, i.e. Gd-BOPTA-enhanced dynamic MRI (set 1), delayed phase imaging (set 2) and SPIO-enhanced MRI (set 3). Diagnostic accuracy was evaluated using the alternative-free response receiver operating chracteristic (ROC) analysis. Sensitivity and positive predictive value were also evaluated. The mean accuracy (Az values) and sensitivity of Gd-BOPTA-enhanced delayed phase imaging (0.982, 95.5%) were comparable to those of SPIO-enhanced imaging (0.984, 97.2%). In addition, Az values and sensitivities of both imaging sets were significantly higher than those of Gd-BOPTA-enhanced dynamic images (0.826, 77.4%: p<0.05). There was no significant difference in the positive predictive value among the three image sets. Gd-BOPTA-enhanced delayed phase imaging showed comparable diagnostic performance to SPIO-enhanced imaging for the detection of liver metastases, and had a better diagnostic performance than Gd-BOPTA-enhanced dynamic images.

Adult↗

PubMed1995

Artificial neural network for diagnosis of acute pulmonary embolism: effect of case and observer selection.

PURPOSE: To compare the diagnostic performance of an artificial neural network (ANN) with that of physicians in patients with suspected pulmonary embolism (PE). MATERIALS AND METHODS: An ANN was developed to predict PE by using findings from ventilation-perfusion lung scans and chest radiographs. First, the network was evaluated on 1,064 cases from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study that had a definitive angiographic outcome. An upper and lower bound of its diagnostic performance was provided depending on case difficulty. Then, the network was tested on 104 patients with suspected PE in whom pulmonary angiography was essential for diagnosis. The diagnostic performance of the ANN was compared with that of (a) two nuclear medicine physicians who read the scans for the needs of this study and (b) the nuclear medicine physicians who originally read the scans. The effects of case and observer selection on performance were addressed. RESULTS: The ANN outperformed the physicians when they used the PIOPED criteria for categoric assessment, and it performed as well as the two study physicians on the basis of their probability assessments. CONCLUSION: The ANN can detect or exclude PE in a highly selected group of difficult cases with a consistency equivalent to that of very experienced physicians.

Algorithms↗

PubMed2006

Stepwise combination algorithms of non-invasive markers to diagnose significant fibrosis in chronic hepatitis C.

BACKGROUND/AIMS: In chronic hepatitis C, biopsy is the gold standard for assessment of liver fibrosis. Non-invasive markers have been proposed but their use is limited by diagnostic accuracy. Our aim was to increase the diagnostic performance of non-invasive markers of liver fibrosis by combining them in sequential algorithms. METHODS: One hundred and ninety patients with chronic hepatitis C were evaluated for AST to platelets ratio (APRI), Forns' index and Fibrotest at the time of liver biopsy and stepwise combination algorithms were developed and validated prospectively in 100 additional patients. RESULTS: Three algorithms were developed: (1) significant fibrosis (F>or=2 by METAVIR) was identified with high diagnostic performance (>94% accuracy) using APRI as screening test, followed by Fibrotest in APRI non-classified cases and restricting liver biopsy to patients classified F0-F1 by non-invasive tests. (2) A slightly modified algorithm had similar performance when applied to hepatitis C carriers with normal ALT. (3) Identification of cirrhosis (95% accuracy) was achieved using a dedicated algorithm with different cut-off, reducing by 60-70% the liver biopsies needed. CONCLUSIONS: Stepwise combination of non-invasive markers of liver fibrosis improves the diagnostic performance in chronic hepatitis C. Need for liver biopsy is reduced by 50-70% but cannot be completely avoided.

Adult↗

PubMed1994

[Effect of ambient lighting on the diagnostic efficiency of display screen workplaces].

The aim of our study was to determine the influence of ambient lighting conditions on the diagnostic performance when using digital reporting work-stations. We acquired 15 normal and 30 fractured porcine femurs using a storage phosphor system. All images were demonstrated on a high-quality image display under optimised (128 lx) and non-optimised (450 lx) ambient lighting conditions and on a conventional viewing-box under non-optimised conditions (450 lx). Results were analysed using ROC-statistics. The area under the ROC-curve was 0.895 for optimised conditions and 0.684 for non-optimised conditions using digital displays and 0.849 for the conventional viewing-box. The difference in diagnostic performance between optimised and non-optimised conditions using a digital display was highly significant (p < 0.001). Our results emphasise the importance of adequate surrounding lighting conditions for radiologic diagnostic performance, particularly for the use of digital reporting consoles.

Animals↗