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[Diagnostic accuracy of the percutaneous spinal biopsy. Optimization of the technique].

Between 1992 and 1999, 210 percutaneous biopsies of the spine were performed in our department of neuroradiology. The purpose of this retrospective study was to determinate the diagnostic accuracy of the procedure and to discuss the technical points that might improve its accuracy. An accurate diagnosis was obtained in 72% of the spondylodiscitis and in 80% of the tumoral lesions (88% of metastatic lesions and 68% of primary tumors). These results have been compared with the other results of the literature. There was no significant difference of accuracy between CT and fluoroscopic guided biopsies. On the other hand, the type of needle and the multiplicity of samples for bacteriological and histologic studies improve the diagnostic accuracy.

Adolescent↗

[Diagnosis and treatment of "biliary" complications of laparoscopic cholecystectomy].

Optimal curative and diagnostic policy has been worked up in early "biliary" complications of laparoscopic cholecystectomy. 10 cases with such complications in the course of 1000 operations were analyzed, and the authors came to conclusion, that rational succession and optimal combination of noninvasive and minimally invasive diagnostic and curative measures contribute to upgrading diagnosis of the complications and in some cases to elimination of them by the use of minimally invasive endoscopical methods. The curative and diagnostic algorythm has been devised.

Adolescent↗

[Possibilities and limits of the diagnosis of aging in sports medicine].

The author orders by the presented survey publication the diagnostic of ageing into the sport medical diagnostic, thereby referring on the promising for the field of sport in future. The term of the so-called age is related to the categories adaptation, vitality and biological age(-ing). By a biography the reader gets informed on the current level of diagnostic of ageing within the national and international framework. Out of that the author draws conclusions for optimizing sports medical diagnostic.

Aged↗

Multicenter study to evaluate the OptiMAL test for rapid diagnosis of malaria in U.S. hospitals.

More than 1,000 cases of malaria are diagnosed each year in the United States. Reported numbers, however, may be artificially low because many clinicians fail to consider the diagnosis on presentation, U.S. hospital laboratory technologists have very limited experience in detecting and identifying malaria parasites, and reporting of malaria to state health departments is sporadic in many states. In this study, a rapid malaria diagnostic test, the OptiMAL test (DiaMed; under license from Flow Inc., Portland, Oreg.) was evaluated in six U.S. hospitals and compared with results of microscopy. The OptiMAL test is a 15-min rapid immunochromatographic test that both identifies and differentiates Plasmodium falciparum from non-P. falciparum malaria parasites on the basis of the detection of parasite lactate dehydrogenase in a drop of patient blood. A total of 216 specimens from patients suspected of having malaria were tested. Results indicated that 43 samples (20%) were positive for malaria parasites by microscopy (32 P. falciparum, 11 non-P. falciparum) while 42 (19%) were positive by OptiMAL (31 P. falciparum, 11 non-P. falciparum). The sensitivity of the OptiMAL test was 98%; its specificity was 100%, with positive and negative predictive values of 100 and 99%, respectively. Participating hospital physicians and laboratory directors independently reported that the OptiMAL rapid malaria test was accurate, easy to use, and well accepted by those working in their diagnostic laboratories. The overall conclusion was that integration of the OptiMAL rapid malaria test into the U.S. health care infrastructure would provide an important and easy-to-use tool for the timely diagnosis of malaria.

Animals↗

Sequential test selection in the analysis of abdominal pain.

Numerous decision-making tools exist to assist physicians in diagnosis management. However, the accuracy of available clinical information is often ambiguous or unknown and current analytical models do not explicitly incorporate judgementally defined information. A model encompassing both physician judgment and probability analysis was developed to accommodate such data. A problem requiring sequential diagnostic testing was structured utilizing the analytic hierarchy process (AHP). The case presented involved a patient complaining of upper abdominal pain who, after initial evaluation, did not need immediate surgery. Physicians were faced with identifying the optimal sequence of diagnostic testing. The criteria used for test selection included minimizing risk, patient discomfort, and cost of testing and maximizing diagnostic capability. Although at the onset the "best" test choice was unknown, the clinical picture indicated four test alternatives: upper gastrointestinal series (GI), abdominal ultrasonography (US), abdominal computed tomography (CT), and upper gastrointestinal endoscopy (END). Based upon the relative preferences of the criteria utilized, the AHP analysis indicated that upper GI series was the optimal first test. Given a negative test, posterior probabilities were calculated using Bayes' theorem, resulting in a new estimate of diagnostic capability. The AHP analysis was reiterated, identifying abdominal ultrasonography as the optimal second test. This analysis may be repeated as many times as necessary. Sensitivity analysis demonstrated that changing criteria preferences may alter the choice of tests and/or their sequence.

Abdominal Pain↗

Technical report: evidence for the diagnosis and treatment of acute uncomplicated sinusitis in children: a systematic overview.

OBJECTIVE: To evaluate and analyze the existing evidence for the diagnosis and treatment of acute uncomplicated sinusitis in children. DESIGN: A systematic overview and meta-analysis considered all pertinent studies with at least 10 children younger than 18 years with acute symptoms of <30 days and without serious complications. OUTCOMES: Clinical improvement rates for intervention studies of antibiotics or ancillary measures; concordance of diagnostic tests (expressed as likelihood ratios). RESULTS: Of 1857 citations originally reviewed, we identified 21 qualifying studies, compared with 450 reports on complications of acute sinusitis and 233 nonsystematic reviews of the subject. The qualifying studies included 5 randomized, controlled trials and 8 case series on antibiotic therapy, 3 randomized, controlled trials on ancillary treatments, and 8 studies with information on diagnostic tests (including 3 therapeutic trials). Definitions and inclusion criteria were heterogeneous across studies. The pooled clinical improvement rate with antibiotics was 88% (177/202) in randomized, controlled trials and 92% (318/345) in nonrandomized studies; the improvement rates on no antibiotics were 60% and 80%, respectively. Improvement rates were significantly higher in nonrandomized studies (Mantel-Haenszel odds ratio: 1.79; 95% CI: 1.05-3.04, stratified for use of antibiotics). Data on ancillary measures were sparse and heterogeneous. In studies comparing clinical findings with plain film radiography, the pooled rate of abnormal radiographic findings against a clinical diagnosis of sinusitis was 73% (596/814; range: 55% to 96% between studies). There was poor concordance between clinical criteria, plain radiographs, ultrasonography, computed tomography, and fluid on aspiration in all available paired assessments (all positive likelihood ratios were </=4 and all negative likelihood ratios were >/=0.2). CONCLUSIONS: Good, high-quality evidence for acute uncomplicated sinusitis in children is limited. Diagnostic modalities show poor concordance, and treatment options are based on inadequate data. More evidence is needed for defining the optimal treatment and diagnostic methods for this common condition.

Acute Disease↗

Small bronchiectases and bronchiolectases in high resolution computed tomography (HRCT).

Large bronchiectases form characteristic patterns, and are visible even on plain chest radiograms. Small bronchiectases and bronchiolectases may not be visible even in conventional CT. HRCT is a diagnostic method, which optimizes the spatial resolution and achieves the best quality of lung images, and therefore in diagnosis of bronchiectases HRCT is a diagnostic method of choice. In diagnosis of small bronchiectases and bronchiolectases the knowledge of typical HRCT patterns is essential. They include "signet-ring sign", "tram track", lack of normal tapering, visibility of bronchi in peripheral lung areas, within 2 cm from the parietal pleura. In varicose bronchiectases the "string of pearls" and in cystic "cluster of grapes" are typical appearances.

Adult↗

[Sensitivity and specificity in AIDS screening system].

The interest in the optimal combination of the diagnostic tests is growing in terms of reasoning rationale and cost-effectiveness of the diagnostic system. As an example of the two-stage test system, we investigated the sensitivity, specificity, and posterior probabilities of the HIV screening system with incomplete information of the conditional independency between the enzyme immunoassay and the Western Blot. The theoretical analysis of the probabilistic reasoning of the HIV screening system could provide us with the upper and lower limits of the predictive positive value, given the prior probability of HIV infection. Consequently, we could show that the lower and the upper boundaries of the predictive positive value are, respectively, 4.07% and 100% for the low risk group (prevalence of HIV: 0.01%), while 99.86% and 100% for the high risk group (prevalence of HIV: 62%). These analyses imply that clinicians must be very careful in the interpretation of the positive test result in the HIV screening system, depending on how the risk of HIV infection of the patient is estimated in advance. In addition to the probabilistic analyses of the test parameters, the approach by use of the utility theory is favorable for the issue of optimizing the diagnostic test sequences. It remains for future investigation.

Acquired Immunodeficiency Syndrome↗

Fasting plasma glucose diagnostic criterion, proposed by the American Diabetes Association, has low sensitivity for diagnoses of diabetes in Mexican population.

To determine the best cutoff value of fasting plasma glucose (FPG) for diagnosis of diabetes, using the 2-h postglucose load (2-h PG) as the gold standard, in Mexican population and compare it to the 7.0 mmol/l limit proposed by the American Diabetes Association (ADA). 712 apparently healthy Mexican individuals were included in a cross-sectional randomized population survey. Sensitivity of FPG criterion for diagnoses of type 2 diabetes was calculated from a fourfold table. Glycemia value 2-h PG of >or=11.1 mmol/l was the "gold standard" diagnostic test. The optimal FPG value for diagnoses of diabetes was established on a receiver operating characteristic (ROC) scatter plot. On the basis of the "gold standard" diagnostic test, diagnosis of type 2 diabetes was established in 65 (9.12%) subjects, whereas the ADA FPG diagnostic criterion only identified 39 (5.47%) subjects; that is a sensitivity of 60% (CI(95%) 47.1-72.0). The ROC scatter plot showed the best cutoff value of FPG for diagnoses of diabetes that corresponds to 6.1 mmol/l, which has the highest sensitivity (0.985). FPG diagnostic criterion proposed by the ADA Expert Committee for diagnosis of type 2 diabetes has low sensitivity in Mexican population. For epidemiological purposes, estimates of diabetes prevalence in Mexico based on a FPG value of >or=6.1 mmol/l will improve the success of the screening.

Adult↗

PCR and in vitro cultivation for detection of Leishmania spp. in diagnostic samples from humans and dogs.

A PCR assay for the diagnosis of leishmaniosis was developed by using primers that were selected from the sequence of the small-subunit rRNA gene. The assay was optimized for routine diagnostic use. Processing of the clinical samples is rapid and simple (lysis of erythrocytes in Tris-EDTA buffer, digestion with proteinase K directly in PCR buffer, and no further purification steps). Furthermore, an internal control is included in every specimen in order to detect the presence of PCR inhibitors. The PCR was compared with diagnostic in vitro cultivation of promastigote stages for the detection of Leishmania spp. in clinical specimens from humans and dogs with a tentative diagnosis of leishmaniosis. PCR and cultivation gave identical results with all but 1 of the 95 specimens from humans. The PCR result in this case was false negative, possibly because of unequal apportionment of this sample. With 10 skin biopsies from six patients with cutaneous leishmaniosis, the sensitivity was 60%. For six human immunodeficiency virus-positive patients with visceral leishmaniosis, all bone marrow biopsies and 7 of 11 whole blood samples (after isolation of leukocytes by Ficoll-Paque) were positive in both tests. PCR detected one more case with the use of 500 microliters of whole blood with direct lysis of the erythrocytes in Tris-EDTA buffer. With dog lymph node aspirates, the sensitivity was 100% (16 of 16 samples) for both methods; furthermore, PCR was positive for 5 of 13 whole blood samples from dogs with leishmaniosis. The specificity of the PCR was 100% (70 specimens from patients without leishmaniosis). This PCR assay proved to be feasible as a routine diagnostic test, being reliable and faster than in vitro cultivation.

Animals↗

Sentinel lymph nodes in malignant melanoma: extended histopathologic evaluation improves diagnostic precision.

BACKGROUND: The optimal technique for sentinel lymph node (SN) assessment in patients with melanoma is controversial. Molecular analysis (reverse transcriptase-polymerase chain reaction) detects significantly greater numbers of SNs with suspected micrometastases (up to 71%) than does routine histopathology (approximately 20%). The authors sought to identify possible reasons for this discrepancy and to determine whether using an extended histopathologic protocol could improve diagnostic precision. METHODS: Two hundred thirty-one SNs from 100 consecutive patients with cutaneous melanomas that measured 1-4 mm in thickness were bisected, and half of the lymph node was examined according to an extensive histopathologic protocol involving serial sectioning and immunohistochemical analysis of 3 melanocyte-associated markers (S-100, HMB-45, and Melan-A). RESULTS: Lymph node melanocytic lesions were frequent, with micrometastases and benign nevus inclusions (BNI) found in SNs in 28% and 28% of patients, respectively (4 SNs contained both). Melan-A was the most sensitive immunohistochemical marker and was positive in all BNI-positive SNs and 97% of micrometastasis-positive SNs. Although HMB-45 showed differential labeling in micrometastases compared with BNI (82% vs. 16%), immunohistochemistry could not distinguish between those lesions. Micrometastases were already identified on the first central level in 49% of positive SNs, whereas only 23% of SNs with BNI were diagnosed on the first level. CONCLUSIONS: Extensive serial sectioning with immunohistochemical analysis substantially increased the histopathologic detection of micrometastases and BNI in melanoma SNs to a level approaching the level reported for molecular techniques. The large number of BNIs represents an important potential source of imprecision (false positivity) in SN assays based on nonmorphologic methods.

Adult↗

Malignancy-related pericardial effusion. 127 cases from the Roswell Park Cancer Institute.

BACKGROUND: Malignancy-related pericardial effusions may represent a terminal event in patients with therapeutically unresponsive disease. However, select patients with malignancies sensitive to available therapies may achieve significant improvement in palliation and long term survival with prompt recognition and appropriate intervention. METHODS: From 1968 to 1994, 150 invasive procedures were performed for the treatment or diagnosis of pericardial effusion in 127 patients with underlying malignancies. These cases were reviewed retrospectively to best identify the clinical features, appropriate diagnostic workup, and optimal therapy for this complication of malignancy. RESULTS: Dyspnea (81%) and an abnormal pulsus paradoxus (32%) were the most common symptoms. Echocardiography had a 96% diagnostic accuracy. Cytology and pericardial biopsy had sensitivities of 90% and 56%, respectively. Fifty-five percent of all effusions were malignant comprising 71% of adenocarcinomas of the lung, breast, esophagus, and unknown primary site. In 57 patients, a malignant effusion could not be determined, and no definitive etiology could be established for 74% of these effusions. Radiation-induced, infectious, and hemorrhagic pericarditis each were identified in fewer than 5% of cases. CONCLUSIONS: Subxyphoid pericardiotomy proved to be a safe and effective intervention that successfully relieved pericardial effusions in 99% of cases with recurrence and reoperation rates of 9% and 7%, respectively. Survival most closely was related to the extent of disease and its inherent chemo-/radiosensitivity, with 72% of the patients who survived longer than 1 year having breast cancer, leukemia, or lymphoma.

Adolescent↗

[Ultrasound diagnostics of upper urinary tract calculi].

The review is dedicated to ultrasonography of the upper urinary tract in patients with nephrolithiasis. Ultrasonographic semiotics of urolithiasis, the ability of unlrasonography to detect nephrolithiasis, and methods of the optimization of these diagnostic techniques in patients with upper urinary tract calculi are covered. The author discusses difficulties that may be faced while differentiating between nephrolithiasis and such conditions as spongious kidney, nephrocalcinosis, calcification of renal papillae, cysts, tumors, and vascular walls, as well as other kinds of renal calcification, associated with ultrasonographic acoustic path phenomenon. The advantages and disadvantages of ultrasonography in cases of X-ray urolithiasis are evaluated in the paper. The article describes hardships in ultrasound visualization of ureteral calculi causing acute upper urinary tract obstruction, and the ways of getting over them.

Diagnosis, Differential↗

Evaluation of rapid methods for the detection of bacteriuria (screening) in primary health care.

The diagnostic performance of six methods for bacteriuria testing has been studied in 781 urine specimens obtained in primary health care, using conventional culture as reference method. The cut-off limits for classification of test results into positive and negative have been optimized with respect to diagnostic performance in primary health care. With optimized tests the following diagnostic efficiencies were obtained: Bacterial ATP, 0.94; Bacterial count in sediment, 0.93; Nitrite test, 0.92; Dipslide test, 0.92; White cell count in sediment; 0.87; Goffulocyte esterase test; 0.83. The diagnostic performance was also studied for all combinations of two tests. The highest diagnostic efficiency (0.96) was obtained by combining the ATP and dipslide tests. High diagnostic efficiencies can be obtained by a rapid primary test, using other tests for follow-up testing of specimens with intermediate or uninterpretable primary results. The most promising results were obtained by using ATP as the primary test, with follow-up testing of specimens with 3-25 nmol/l of ATP (12 per cent of the specimens). Follow-up testing by conventional culture resulted in overall diagnostic efficiency of 0.98. By performing the nitrite test on specimens with intermediary ATP-results, 81 per cent of the patients with UTI can be classified without culture. Only patients with intermediary ATP and negative nitrite results (10 per cent of the total number) will have to wait for final diagnosis based on conventional culture. Some alternative strategies to combine available methods are discussed in detail. Major advantages of the ATP test are that the test can be performed while the patients are waiting; it provides a numerical and objective result, and, in contrast to culture, it is not influenced by adhesion of bacteria to somatic cells.

Adenosine Triphosphate↗

Counter current line deflection immunoelectrophoresis. A technique for the quantification of antibodies.

Combining the electrophoretic principles of counter current immunoelectrophoresis and deflection of line precipitates in line immunoelectrophoresis provides a new technique for quantitative determination of antibodies against specific antigens (CCLD electrophoresis), even if no purified antigen or monospecific antibodies are available for construction of the detection system. We have used the method for quantitative determination of antibodies against the flagellum of Treponema phagedenis biotype Reiter and compared the diagnostic potential of this method in the diagnosis of syphilis with an ELISA method for the quantification of IgG antibodies against the flagellum. The CCLD electrophoresis could be optimized to a diagnostic performance very similar to that achieved using the ELISA method.

Animals↗

Human parvovirus B19 infections: routine diagnosis by a new nested polymerase chain reaction assay.

A nested primer PCR assay was developed to detect human parvovirus B19 in various clinical specimens in a routine diagnostic laboratory. Under optimized conditions the highly specific assay had a sensitivity of less than 10 genome units. For practical reasons, however, this sensitivity was adjusted to 10-100 virus genomes in diagnostic applications. Using clinical specimens from 200 patients with suspected B19 infection, nested PCR was shown to have important diagnostic advantages over the detection of B19 specific antibodies. The data suggest that on the basis of serological data as obtained with currently available test systems a considerable proportion of B19 infections would be misdiagnosed. Examples for the usefulness of the PCR assay in routine diagnosis are given.

Adolescent↗

[Rational diagnosis of urinary tract infections].

The basis for a rational diagnostic work-up of urinary tract infections is a detailed history and a maximally standardised examination of the urine, with test strips measuring, measurement of specific density, microscopic examination of the sediment, and determination of the bacterial count in the urine employing dipstick procedures are recommended for use in the doctor's office. Isolation and identification of pathogens and the preparation of an antibiogram require a special knowledge of microbiological techniques. A requirement for the evaluation of the urine and its constituents is a knowledge of how the urine was collected; we recommend spontaneously passed urine in men and young children, and catheter urine in the case of women. Chronic inflammation of the male adnexa and chronic recurrent urinary tract infections requires radiological studies by the urologist, including a urogram, a urethrocystogram, a miction cystogram, urethropyelography and ultrasonography. Occasionally, nuclear-medical investigations and angiography or computed tomography may be necessary to obtain further clarification. In the case of outflow obstructions in the region of the lower urinary tract or urge or stress incontinence, uroflowmetry and cystometry should be performed. With the aid of this "stepwise diagnostic evaluation", both optimal clarification of the urinary tract infection and a saving of costs are possible.

Bacteriuria↗

Cascade effects of medical technology.

Cascade effect refers to a process that proceeds in stepwise fashion from an initiating event to a seemingly inevitable conclusion. With regard to medical technology, the term refers to a chain of events initiated by an unnecessary test, an unexpected result, or patient or physician anxiety, which results in ill-advised tests or treatments that may cause avoidable adverse effects and/or morbidity. Examples include discovery of endocrine incidentalomas on head and body scans; irrelevant abnormalities on spinal imaging; tampering with random fluctuations in clinical measures; and unwanted aggressive care at the end of life. Common triggers include failing to understand the likelihood of false-positive results; errors in data interpretation; overestimating benefits or underestimating risks; and low tolerance of ambiguity. Excess capacity and perverse financial incentives may contribute to cascade effects as well. Preventing cascade effects may require better education of physicians and patients; research on the natural history of mild diagnostic abnormalities; achieving optimal capacity in health care systems; and awareness that more is not the same as better.

Biomedical Technology↗