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PubMed2000

Endometrial sampling techniques in the diagnosis of abnormal uterine bleeding.

There have been many advances in sampling of the endometrium. Ideas and technologies have evolved, increasing our ability to gather adequate specimens that provide reliable information about uterine cavity pathologies. No technique surpasses the sensitivity and specificity of hysteroscopy with directed biopsy. Owing to its superior diagnostic potential, hysteroscopy, even when performed in the office with narrow scopes (not significantly larger in diameter than the Pipelle catheter), leads to precise diagnosis and appropriate management of intrauterine pathologic conditions. For physicians who are untrained or lacking the equipment to perform diagnostic hysteroscopy with directed biopsy, simple in-office endometrial sampling techniques with no visual control provide a means to obtain reasonably reliable samples with negligible patient discomfort.

Biopsy↗
PubMed2000

Diagnosing acute pulmonary embolism: effect of chronic obstructive pulmonary disease on the performance of D-dimer testing, ventilation/perfusion scintigraphy, spiral computed tomographic angiography, and conventional angiography. ANTELOPE Study Group. Advances in New Technologies Evaluating the Localization of Pulmonary Embolism.

In patients with chronic obstructive pulmonary disease (COPD), differentiating a pulmonary embolism (PE) from an exacerbation of COPD can be difficult, since clinical signs and symptoms of the two conditions overlap. Development of reliable noninvasive or minimally invasive techniques for the diagnosis of PE is, especially in these patients, necessary. In this study we assessed the effect of COPD on the accuracy of the clinical probability estimate (CPE), spiral computed tomographic angiography (SCTA), D-dimer analysis, ventilation perfusion (V/Q) scintigraphy, and pulmonary angiography for the diagnosis of PE. From May 1997 through March 1998, 627 consecutive patients with suspected PE were investigated in six teaching hospitals. In these patients, D-dimer testing, CPE, V/Q scintigraphy, and SCTA and/or pulmonary angiography were performed according to a strict diagnostic protocol. The patients were also independently categorized as having COPD or not. A diagnosis of COPD was established in 91 patients (15%). The prevalence of PE was similar in patients with and without COPD (29% and 31%, respectively), notwithstanding the larger proportion of nondiagnostic V/Q scan results in patients with COPD (46% versus 21%, p < 0.001). The distribution of CPEs, diagnostic value of the D-dimer assay and SCTA, and reproducibility of pulmonary angiography were comparable among patients with and without COPD. The presence of COPD does not affect the diagnostic performance of CPE, D-dimer testing, SCTA, or pulmonary angiography. Furthermore, although more nondiagnostic V/Q scan results can be expected in the presence of COPD, V/Q scintigraphy remains a valuable screening test in patients with COPD.

Acute Disease↗
PubMed1992

[Sepsis caused by Mycobacterium tuberculosis in patients with AIDS].

BACKGROUND: Techniques for detecting mycobacteria in blood can be a good alternative for diagnosing tuberculosis in acquired-immunodeficiency syndrome patients (AIDS). PATIENTS AND METHODS: Eleven patients with AIDS and pulmonary tuberculosis, and four controls with AIDS and without tuberculosis were studied. The diagnosis of mycobacteremia was made by the identification of the microorganisms in blood. The method used was a lysis-centrifugation with subsequent stain or culture identification in different media (agar Löwenstein-Jensen, M7H9, M7H11, brain-heart infusion and Sauton broth). RESULTS: In one case, direct staining of sample was positive. The culture results were positive in all 11 patients with tuberculosis and in none of the controls. M7H11 was the media that allows the fastest detection. CONCLUSIONS: This technique can be a good alternative method for tuberculosis diagnosis in AIDS patients. Is easy to perform, relatively fast an with diagnostic performance. It also could be of interest in extra-pulmonary tuberculosis.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Prognostic patch testing: the other kind of patch test.

Prognostic patch testing differs from diagnostic patch testing. Clinicians routinely perform diagnostic patch testing, but prognotic patch testing is the province of corporate research and development departments and, in the United States, contract laboratories. The three types of prognostic patch testing are described and referenced in the scientific and medical literature. A comparison among the three types of prognostic patch testing and diagnostic patch testing is provided. In addition, the variables in both prognostic and diagnostic patch testing are listed, as well as the types of ingredients and products routinely tested in prognostic patch testing.

Consumer Product Safety↗
PubMed1996

The development of diagnostic competence: comparison of a problem-based, an integrated, and a conventional medical curriculum.

PURPOSE: To compare the diagnostic performances of students in five curriculum years educated at schools with problem-based, integrative, or conventional medical curricula. METHOD: Data were analyzed in 1994 for 612 students in their second, third, or fourth (preclinical) or fifth or sixth (clinical) years at three Dutch medical schools with problem-based, integrative, or conventional curricula. The students gave differential diagnoses for 30 case histories that were epidemiologically representative of Dutch society and covered all organ systems. The numbers of accurate diagnostic hypotheses were tallied for each of the groups involved. The data were analyzed using analysis of variance and post-hoc Newman-Keuls tests. RESULTS: Overall, the students trained within the problem-based framework and the students trained within the integrated curriculum made more accurate diagnoses than the students trained within the conventional curriculum. No overall differences were found between the students in the problem-based and integrated curricula, although the second- and third-year students from the latter performed better than the second- and third-year students from both other schools. CONCLUSION: Integration between basic and clinical sciences and an emphasis on patient problems may be the critical factors that determine superior diagnostic performance rather than whether a curriculum is self- or teacher-directed. Problem-based learning seems to live up to its expectations, but so does the integrated approach to medical education. In addition, the procedure for measuring diagnostic performance appears to be valid and to provide a simple means of measuring curriculum effects. It remains to be seen whether the findings would be replicated when students are allowed to freely gather data in open interaction with patients rather than respond to written presentations of cases.

Aged↗
PubMed2002

Comparing the accuracy of Dutch dentists and dental students in the radiographic diagnosis of dentinal caries.

OBJECTIVES: To compare the diagnostic accuracy of dental students using bitewing radiographs for the diagnosis of dentinal caries with that of general dental practitioners and to establish a bench mark for testing for improvement in diagnostic performance. METHODS: Fourth year dental students (n=259) viewed bitewing radiographs of 105 proximal tooth surfaces. According to a micro-radiography "gold standard" 45 surfaces had dentine caries. The students were asked to diagnose presence and absence of dentine caries from which, under supervision, they calculated their sensitivity (TPR) and false positive rate (FPR). The students binary diagnostic data was compared with the historical data from a random sample of Dutch dentists (n=273). The Summary Receiver Operating Characteristic (SROC) curve method was used to analyse the data. The two groups were tested for differences in (a) diagnostic odds ratio and (b) the area under the SROC curve. RESULTS: The students mean TPR for dentine caries diagnosis was 67.2% (s.d. 11.8%) and the FPR was 8.3% (s.d. 8.4%). The corresponding values for dentists were: TPR 54.0% (s.d. 14.1%) and FPR 3.1% (s.d. 4.5%). Significantly more dentists (85%) than students (72%, P<0.001) had a diagnostic odds ratio > or =21. The area under the SROC curve (Az) was 0.8194 for students and 0.8140 for dentists (P=0.70). CONCLUSIONS: In our study (i) the students had a higher TPR but also a higher FPR than the dental practitioners, (ii) their overall performance (Az) was similar but (iii) for a clinically relevant population the dental practitioners would out-perform the students in diagnostic performance.

Benchmarking↗
PubMed2003

Utility of laparoscopy in chronic abdominal pain.

BACKGROUND: Patients with chronic abdominal pain can undergo numerous diagnostic tests with little change in their pain. This study was undertaken to assess the utility of performing diagnostic and therapeutic laparoscopy in patients with chronic abdominal pain for longer than 12 weeks. METHODS: All patients undergoing laparoscopy by the primary author were prospectively entered into a database for the 3-year period July 1, 1997 through June 30, 2000. The patients' demographic data, length of time with pain, number of diagnostic studies performed before surgery, intraoperative findings, interventions, pathology, and long-term follow-up were determined. RESULTS: A total of 70 patients (61 women and 9 men) with an average age of 42 years, underwent diagnostic laparoscopy only for the evaluation and treatment of chronic abdominal pain. The average length of time with pain was 74 weeks (range 12-260) and the average number of studies performed prior to surgical referral was 3.3. Fifty-three (76%) patients had their procedures performed as outpatients, with the remainder admitted for observation status. The average length of operative time was 70 minutes; no cases required conversion to an open procedure and no complications occurred. Findings included adhesions in 39, a hernia in 13, adhesions from the appendix to adjacent structures in 6, appendiceal pathology in 5, endometriosis in 3, and gallbladder pathology in 2. Ten patients had no obvious pathology. At the time of their initial postoperative visit, 90% reported their pain to be gone or improved. After an average follow-up of 129 weeks, 71.4% had long-term pain relief. All patients with recurrence of pain had it within the first 6 months. No patient experienced any long-term complications and all reported satisfaction with their procedure. CONCLUSIONS: Laparoscopy has a significant diagnostic and therapeutic role in patients with chronic pain. Therapeutic laparoscopy studies have to follow-up with patients at least 6 months. With aggressive indicated therapeutic laparoscopy, including adhesiolysis, appendectomy, cholecystectomy, or hernia repairs, more than 70% of patients can have improvement in their pain.

Abdominal Pain↗
PubMed2000

Measuring performance in chest radiography.

PURPOSE: To use a standardized set of chest radiographs to quantify interobserver differences and to provide a basis for comparing the diagnostic performance of physicians. MATERIALS AND METHODS: A standardized set of 60 chest radiographs was presented to 162 study participants. Each participant reviewed the radiographs and recorded his or her diagnostic impression by using a fixed five-point scale. These response data were used to generate receiver operating characteristic curves and to establish performance benchmarks. The variations in performance were tested for statistical significance. RESULTS: Significant interobserver variability was identified during these assessments. The composite group of board-certified radiologists demonstrated performance superior to that of the radiology residents and nonradiologist physicians. CONCLUSION: By using a receiver operating characteristic approach and a standardized set of chest radiographs, observer accuracy and variability are easily quantified. This approach provides a basis for comparing the diagnostic performance of physicians. When value is measured as a diminution in uncertainty, board-certified radiologists contribute substantial value to the diagnostic imaging system.

Certification↗
PubMed2001

Multicenter evaluation of strategies for serodiagnosis of primary infection with Toxoplasma gondii.

The diagnostic performance of single-serum assays for toxoplasma-specific immunoglobulin (Ig)M. IgA. IgG, and IgE antibodies and of different combinations of such antibody assays in 20 European reference centers was assessed. A panel of 276 sera, of which 73 came from patients who seroconverted within 3 months (acute infection), 49 from patients who had seroconverted 3-12 months earlier (convalescence), and 154 from subjects who had two IgG-positive samples obtained 12 months apart (past infection), was tested with 20 toxoplasma-antibody assays and 195 combinations. In general, every assay with high diagnostic sensitivity showed low diagnostic specificity, i.e. no assay performed alone could reliably distinguish acute from past infection. Furthermore, no single assay (or combination) could separate convalescence from the other stages of toxoplasma infection. However, excellent diagnostic performances were reached by sequential use of highly sensitive IgM assays and methods examining IgG avidity or stage specificity. IgA or IgM assays were less suitable for confirmation of toxoplasma-IgM positivity. This study documents the strength of test combinations in assessing the stage of toxoplasma infection.

Acute Disease↗
PubMed2006

LEAD: a methodology for learning efficient approaches to medical diagnosis.

Determining the most efficient use of diagnostic tests is one of the complex issues facing medical practitioners. With the soaring cost of healthcare, particularly in the US, there is a critical need for cutting costs of diagnostic tests, while achieving a higher level of diagnostic accuracy. This paper develops a learning based methodology that, based on patient information, recommends test(s) that optimize a suitable measure of diagnostic performance. A comprehensive performance measure is developed that accounts for the costs of testing, morbidity, and mortality associated with the tests, and time taken to reach diagnosis. The performance measure also accounts for the diagnostic ability of the tests. The methodology combines tools from the fields of data mining (rough set theory, in particular), utility theory, Markov decision processes (MDP), and reinforcement learning (RL). The rough set theory is used in extracting diagnostic information in the form of rules from the medical databases. Utility theory is used in bringing various nonhomogenous performance measures into one cost based measure. An MDP model together with an RL algorithm facilitates obtaining efficient testing strategies. The methodology is implemented on a sample problem of diagnosing solitary pulmonary nodule (SPN). The results obtained are compared with those from four alternative testing strategies. Our methodology holds significant promise to improve the process of medical diagnosis.

Algorithms↗
PubMed1979

Images, image quality and observer performance: new horizons in radiology lecture.

Technical and diagnostic image quality are distinguished and the limitations of three methods currently used for assessing diagnostic image quality are discussed. They are evaluations based on individual clinical experience, measurement of diagnostic performance, and physical measurements made on images or imaging systems. Finally, a psychophysical approach to image quality evaluation is presented and its potential value discussed.

Humans↗
PubMed1992

One-step, labeled-antibody assay for measuring free thyroxin. II. Performance in a multicenter trial.

The technical and diagnostic performance of a labeled antibody radioassay for free thyroxin (Amerlex-MAB* FT4) was examined in a multicenter trial. The overall mean within-assay precision (CV) in eight centers was 6.2% at 30 pmol/L and 3.6% at 13 pmol/L concentrations of FT4. Between-assay precision was 5.4% at 18 pmol/L and 6.8% at 50 pmol/L. The euthyroid central 95% reference range for FT4 was 11.3 to 24.3 pmol/L. Results of the method correlated well with those of an analog radioimmunoassay: [Amerlex-MAB* FT4] = 1.09 [Amerlex-M FT4] + 1.50 pmol/L (r = 0.96, n = 732). Clinical performance of the assay was better than that of first-generation analog tracer assays for sera from patients with nonthyroidal illness or binding-protein abnormalities.

Autoantibodies↗
PubMed2005

[Results of diagnostic hysteroscopy in a 7-year period in the gynecological clinic of "UMBAL-Pleven"].

The aim of the authors is to show the data for the reception diagnosis, age, histological results and the conduct after the performed diagnostic hysteroscopies in Gynecological clinic of UMBAL-Pleven. For the fulfillment of this aim was made a prospective study for 7 years' period: from 01/01/1997 to 31/01/2003. The objects of observation were 74 women of age from 16 to 65 years, with performed hysteroscopies for gynecologic complaints. There were performed 74 diagnostic hysteroscopies for the studied period. The hysteroscopic findings were 20 cases with endometrial polyposis, 14--submucosal myoamatic nodes, deforming the uterine cavity, 4--cervical polyp, 19--increased endometrium, 9--Asherman syndrome, 1--bicomous uterus, 1--a suspected section for endometrial carcinoma and 6 cases without pathologic findings. There were performed 59 trial abrasions and the removed materials were sent for histological examination The performed comparative analysis between the hysteroscopic presentation and histological findings showed a coincidence of the diagnosis. It was made the conclusion, that the hysteroscopy is an easy, accessible and inexpensive diagnostic method, which must take its place as one of the basic contemporary diagnostic methods in gynecology.

Adolescent↗
PubMed1991

Comparison of rubidium-82 positron emission tomography and thallium-201 SPECT imaging for detection of coronary artery disease.

The diagnostic performance of rubidium-82 (Rb-82) positron emission tomography (PET) and thallium-201 (Tl-201) single-photon emission-computed tomography (SPECT) for detecting coronary artery disease was investigated in 81 patients (52 men, 29 women). PET studies using 60 mCi of Rb-82 were performed at baseline and after intravenous infusion of 0.56 mg/kg dipyridamole in conjunction with handgrip stress. Tl-201 SPECT was performed after dipyridamole-handgrip stress and, in a subset of patients, after treadmill exercise. Sensitivity, specificity and overall diagnostic accuracy were assessed using both visually and quantitatively interpreted coronary angiograms. The overall sensitivity, specificity and accuracy of PET for detection of coronary artery disease (greater than 50% diameter stenosis) were 84, 88 and 85%, respectively. In comparison, the performance of SPECT revealed a sensitivity of 84%, specificity of 53% (p less than 0.05 vs PET) and accuracy of 79%. Similar results were obtained using either visual or quantitative angiographic criteria for severity of coronary artery disease. In 43 patients without prior myocardial infarction, the sensitivity for detection of disease was 71 and 73%, respectively, similar for both PET and SPECT. There was no significant difference in diagnostic performance between imaging modalities when 2 different modes of stress (exercise treadmill vs intravenous dipyridamole plus handgrip) were used with SPECT imaging. Thus, Rb-82 PET provides improved specificity compared with Tl-201 SPECT for identifying coronary artery disease, most likely due to the higher photon energy of Rb-82 and attenuation correction provided by PET. However, post-test referral cannot be entirely excluded as a potential explanation for the lower specificity of Tl-201 SPECT.

Adult↗
PubMed2000

Neuropsychological function in subjects with psychotic and affective disorders. Relationship to diagnostic category and duration of illness.

OBJECTIVE: To explore the links between neuropsychological performance, diagnostic category and duration of illness in subjects with psychotic and affective disorders. METHODS: Memory and executive abilities were tested in consecutively admitted patients with schizophrenia (N = 20), other non-schizophrenic psychotic disorders (N = 29), bipolar disorder (N = 33) and major depression (N = 19). RESULTS: Subjects with schizophrenia had poorer global memory performances than subjects with major depression, and poorer delayed verbal memory abilities than those from the other three diagnostic groups. Executive abilities explored by the Stroop test and the Wisconsin Card Sorting Test did not differ between diagnostic groups. Neuropsychological performances were not influenced by previous duration of illness. CONCLUSION: Memory deficits are the most discriminatory cognitive features between subjects with schizophrenia and those with other psychotic or mood disorders. The fact that cognitive deficits are static whatever the diagnostic group indirectly suggests that they may have a neurodevelopmental origin in subjects with schizophrenia, but perhaps also in subjects with other psychotic and mood disorders.

Adolescent↗
PubMed2026

Evaluation of three Aspergillus antibody assays for screening of chronic pulmonary aspergillosis: prospective diagnostic accuracy study.

OBJECTIVES: Chronic pulmonary aspergillosis (CPA) is a frequent complication of pulmonary tuberculosis (PTB), particularly in high-burden settings where access to reliable serological diagnostics remains limited. We evaluated the diagnostic performance of two immunochromatographic technology (ICT) lateral flow assays (LFAs) and an ELISA for CPA screening among patients with active or previously treated PTB. METHODS: In this two-year prospective multicentre diagnostic evaluation, serum from adults with prior or active PTB was tested using the Era Biology Aspergillus IgG ICT LFA, LDBio Aspergillus IgG/IgM ICT LFA, and Bordier Aspergillus fumigatus IgG ELISA. CPA diagnosis was established using a consensus composite reference standard incorporating clinical, immunological, radiological, and microbiological criteria. The Bordier ELISA was used as part of the immunological component of the consensus CPA diagnosis, with a cutoff optical density of &#x2265;1.0. Diagnostic accuracy, agreement statistics, receiver operating characteristic analysis, and latent class analysis (LCA) were performed. RESULTS: Among 340 participants, 24 (7.06%) had CPA. Proportion of participants with positive antibody tests among all tested individuals were 6.76% for LDBio ICT LFA, 20.0% for Era Biology ICT LFA, and 11.47% for Bordier ELISA. Against consensus CPA diagnosis, Bordier ELISA showed 87.50% sensitivity and 94.30% specificity, LDBio ICT LFA 58.33% sensitivity and 97.15% specificity, and Era Biology LFA 66.67% sensitivity and 83.54% specificity. LCA estimated CPA prevalence at 7.72%. LCA-derived sensitivities and specificities were 86.58% and 99.92% for LDBio ICT LFA, 83.39% and 85.31% for Era Biology LFA, and 79.10% and 94.19% for Bordier ELISA. CONCLUSIONS: The Bordier ELISA showed high sensitivity and specificity, while the LDBio ICT LFA demonstrated very high specificity with strong LCA-derived performance. These findings support the use of ELISA for laboratory diagnosis and ICT as a point-of-care screening tool for CPA in resource-limited settings. Era Biology Aspergillus IgG LFA demonstrated moderate sensitivity and acceptable diagnostic performance, indicating its potential utility as a supplementary screening assay for CPA in settings where rapid, point-of-care testing is required.

Humans↗
PubMed2004

The dopamine D2 receptor ligand 18F-desmethoxyfallypride: an appropriate fluorinated PET tracer for the differential diagnosis of parkinsonism.

For therapeutic and prognostic reasons it is important to differentiate between idiopathic parkinsonian syndrome (IPS, Parkinson's disease) and atypical parkinsonian syndromes (APS) like multiple system atrophy or progressive supranuclear palsy. Whereas IPS patients usually show a normal or upregulated postsynaptic dopamine D2 receptor profile, APS patients present decreased postsynaptic tracer binding. The aim of this prospective study was to evaluate the D2 receptor antagonist fluorine-18 desmethoxyfallypride (18F-DMFP), a recently developed positron emission tomography (PET) tracer with better clinical availability than carbon-11 raclopride, for the differential diagnosis of IPS versus APS. The study included 16 healthy control subjects and 35 patients with clinically diagnosed parkinsonism (16 IPS patients, 19 APS patients). All patients underwent PET imaging after injection of 180-200 MBq 18F-DMFP. Receiver operating characteristic (ROC) analyses were performed in order to assess the diagnostic performance of 18F-DMFP PET. We found the striatal 18F-DMFP uptake ratio to be significantly (P<0.01) reduced in the APS patients (2.44+/-0.42) compared with the healthy control subjects (3.61+/-0.43) and the IPS patients (3.21+/-0.78), whereas the uptake ratios of the IPS patients and the control subjects did not differ significantly. For the differential diagnosis of APS versus IPS, the ROC analysis of caudate 18F-DMFP binding showed a specificity, sensitivity and accuracy of 100%, 74% and 86%, respectively, as well as positive and negative predictive values of 100% and 76%, respectively. Based on these first clinical results, we consider 18F-DMFP to be an appropriate PET tracer for the differential diagnosis of parkinsonian syndromes, with the advantage of better clinical availability than 11C-labelled D2 radioligands.

Adult↗
PubMed2005

The negative predictive value of electrical impedance scanning in BI-RADS category IV breast lesions.

OBJECTIVES: We sought to prospectively assess the value of electrical impedance scanning (EIS) in discriminating benign from malignant lesions classified as BI-RADS category IV in mammography in comparison with ultrasound (US), with a special focus on negative prediction. MATERIALS AND METHODS: EIS was performed on 128 BI-RADS category IV lesions in 121 women (mean, 51.8 years). The newly developed EIS software 2.67 calculates a BI-RADS-like level of suspicion (LOS) on a 5-grade scale. LOS 1, 2, and 3 were considered negative; LOS 4 and 5 were considered positive. Histopathologic results were obtained in all lesions. RESULTS: Histology proved 37 lesions malignant, 91 benign. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of EIS compared with US were 94.6%, 74.7%, 80.5%, 60.3%, 97.1% versus 90.5%, 33.8%, 47.2%, 29.7%, 92.0%, respectively. In 43 lesions sized < or = 10 mm, EIS demonstrated better sensitivity, specificity, accuracy, PPV, and NPV of 100%, 83.3%, 90.7%, 82.6%, and 100%, respectively. Although NPV was also high, US showed no sufficient results in 39 (30.5%) lesions because of microcalcifications. Receiver operating curve analysis revealed best results for a combined use of US and EIS. CONCLUSIONS: With a NPV of 97.1% of EIS in BI-RADS category IV breast lesions, a negative result in these lesions could be firm indication to manage them as BI-RADS-category III and refer patients for a 6-month short-interval follow-up rather than performing a biopsy. The best adjunctive diagnostic performance can be achieved by a combination of US and EIS. Costs and patient morbidity could be minimized.

Breast↗