114 resultados para Positive predictive value
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Objective To evaluate the accuracy of computed tomography for local and lymph node staging of Wilms' tumor. Materials and Methods Each case of Wilms' tumor was evaluated for the presence of abdominal lymph nodes by a radiologist. Signs of capsule and adjacent organ invasion were analyzed. Surgical and histopathological results were taken as the gold standard. Results Sensitivity was 100% for both mesenteric and retroperitoneal lymph nodes detection, and specificity was, respectively, 12% and 33%, with positive predictive value of 8% and 11% and negative predictive value of 100%. Signs of capsular invasion presented sensitivity of 87%, specificity of 77%, positive predictive value of 63% and negative predictive value of 93%. Signs of adjacent organ invasion presented sensitivity of 100%, specificity of 78%, positive predictive value of 37% and negative predictive value of 100%. Conclusion Computed tomography tumor showed low specificity and low positive predictive value in the detection of lymph node dissemination. The absence of detectable lymph nodes makes their presence unlikely, and likewise regarding the evaluation of local behavior of tumors.
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Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemar's test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57%) patients. Such individuals presented with a total of 29 (41.43%) carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50) of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001) was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.
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Objective Undertaking of a complete audit of the service of mammography, as recommended by BI-RADS®, in a private reference institution for breast cancer diagnosis in the city of São Paulo, SP, Brazil, and comparison of results with those recommended by the literature. Materials and Methods Retrospective, analytical and cross-sectional study including 8,000 patients submitted to mammography in the period between April 2010 and March 2011, whose results were subjected to an internal audit. The patients were followed-up until December 2012. Results The radiological classification of 7,249 screening mammograms, according to BI-RADS, was the following: category 0 (1.43%), 1 (7.82%), 2 (80.76%), 3 (8.35%), 4 (1.46%), 5 (0.15%) and 6 (0.03%). The breast cancer detection ratio was 4.8 cases per 1,000 mammograms. Ductal carcinoma in situ was found in 22.8% of cases. Positive predictive values for categories 3, 4 and 5 were 1.3%, 41.3% and 100%, respectively. In the present study, the sensitivity of the method was 97.1% and specificity, 97.4%. Conclusion The complete internal audit of a service of mammography is essential to evaluate the quality of such service, which reflects on an early breast cancer detection and reduction of mortality rates.
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Objective: The present study was aimed at evaluating the contribution of transrectal prostate ultrasound in the screening for prostate neoplasias and in the guidance of prostate biopsies. Materials and Methods: Prospective study developed over a one-year period. All the patients with indication for prostate biopsy were evaluated. Regardless of PSA values, the patients underwent ultrasound in order to identify suspicious nodules (confirmed by two observers). Sextant biopsy was subsequently performed. In cases of finding suspicious nodules, an additional puncture directed to such nodules was done. Results: In a total of 155 cases the prevalence of malignancy was of 53%. Suspicious nodules were detected in 34 patients, and 25 where malignant (positive predictive value of 74%). The specificity and sensitivity for suspicious nodules were 88% and 31% respectively. Comparatively with the randomly obtained sextant specimens, the rate of findings of neoplasia was higher in the specimens obtained with puncture directed to the nodule (p = 0.032). No statistically significant difference was observed in the Gleason score for both types of specimens (p = 0.172). Conclusion: The high positive predictive value and the high rate of findings of neoplasia in specimens of suspicious nodules should be taken into consideration in the future. The authors suggest a biopsy technique similar to the one described in the present study (sextant biopsy plus puncture directed to the suspicious nodule).
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Abstract Objective: To propose an algorithm to determine the necessity for ultrasonography-guided fine-needle aspiration (US-FNA) in preoperative axillary lymph node staging of patients with invasive breast cancer. Materials and Methods: Prospective study developed at National Cancer Institute. The study sample included 100 female patients with breast cancer referred for axillary staging by US-FNA. Results: The overall US-FNA sensitivity was set at 79.4%. The positive predictive value was calculated to be 100%, and the negative predictive value, 69.5%. The US-FNA sensitivity for lymph nodes with normal sonographic features was 0%, while for indeterminate lymph nodes it was 80% and, for suspicious lymph nodes, 90.5%. In the assessment of invasive breast tumors stages T1, T2 and T3, the sensitivity was respectively 69.6%, 83.7% and 100%. US-FNA could avoid sentinel node biopsy in 54% of cases. Conclusion: Axillary ultrasonography should be included in the preoperative staging of all patients with invasive breast cancer. The addition of US-FNA in cases of lymph nodes suspicious for malignancy may prevent more than 50% of sentinel lymphadenectomies, significantly shortening the time interval to definitive therapy.
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OBJECTIVE: to evaluate the accuracy of frozen section histopathology from fragments of tissue obtained by percutaneous core needle biopsy of palpable tumors in the diagnosis of breast cancer. METHODS: a cohort study was performed on 57 patients with palpable tumors and suspected breast cancer undergoing percutaneous thick needle core biopsy. The fragments were analyzed by the same pathologist. RESULTS: frozen section diagnosed 16 benign cases (28.6%) and 40 malignant (71.4%), whereas paraffin showed that 15 were benign (26.8%) and 41 malignant (73.2%). Histopathological examinations were concordant in 55 cases and there was one false-negative (6.2%). Statistics rates were: negative predictive value of 93.8%, positive predictive value of 100%, no false-positive (0%), one false negative (6.2%), specificity of 100%, sensitivity of 97 6%; observed agreement = 98.2%; expected agreement = 59.9%, Kappa = 0.955 [ 95% CI = 0.925-0.974, p < 0.01 ]. CONCLUSIONS: frozen section histopathological findings showed excellent correlation with the findings by the technique in paraffin in the fragments of palpable breast tumors obtained by thick needle percutaneous core biopsy (98.2% accuracy). Therefore, in these patients, it was possible to anticipate the diagnosis, staging and the breast cancer treatment planning.
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ABSTRACTObjective:to evaluate effectiveness of using chest X-ray (CXR), pelvis X-ray (RXP) and FAST (Focused Abdominal Sonography on Trauma) to exclude significant lesions of the body in blunt trauma.Methods:a prospective study involving 74 patients whom made the three tests (CXR, RXP and FAST) during the initial evaluation between October 2013 and February 2014. The results were compared to the tomography of the same patients or clinical outcome. If the patient did not have alterations on the CT scans or during the observation time, the initial workup was considered safe. All patients were evaluated at the Hospital João XXIII, Belo Horizonte, Brazil.Results:of the 74 patients studied the average age was 33 years, RTS: 6.98, ECG: 12. From 44 (59.45%) patients with exams (radiographs and FAST) unchanged, three had significant injuries (two splenic injuries and one liver injury) diagnosed by clinical monitoring. The remaining patients - 30 (40.55%) - had at least one alteration in conventional tests. Of these group 27 (90%) had significant injuries and three (10%) minor injuries. The sensitivity of all three tests for screening considerable lesions was 90% and the specificity was 93%. The negative predictive value was 93% and the positive predictive value 89%.Conclusion:this research showed that all the three exams - chest X-ray, pelvis and FAST - are safe to lead with the blunt trauma if well used and associated with clinical examination.
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Objective: Io evaluate the expression of p16INK4a and p53 biomarkers in conization specimens from patients with high grade cervical intraepithelial neoplasia (HG-CIN), correlating them with the ability to predict the recurrence. Methods : we conducted a retrospective study of patients with HG-CIN in cervical biopsy treated with conization between January 1999 and January 2006 who had a minimum follow-up of 18 months. The expression of the p16 and p53 was assessed by tissue microarrays and correlated with disease recurrence. For analysis, we used the test of proportions (chi-square), considering value p<0.05, 95% CI and calculations of sensitivity, specificity and accuracy of these immunomarkers in predicting recurrence. Results : the series comprised 83 patients aged between 16 and 86 years (35±11.7), divided into two groups: 30 with HG-CIN recurrence (study group) and 53 without recurrence (control group). Mean age, parity, smoking and conization technique were similar in both groups. The p53 expression was present in 43% of the study group and 57% of the control group, and the p16 was present in 43% of the study group and in 57% of the control group (p>0.05). p53 had a positive predictive value (PPV) of 42% and negative predictive value (NPV) of 73%, sensitivity 70%, specificity of 47% and accuracy of 59%. The p16, PPV 42%, NPV 72%, sensitivity 66%, specificity of 49% and accuracy of 56%. Conclusion : immunohistochemistry expression of p53 and p16 showed low sensitivity and low specificity as predictors of HG-CIN recurrence after conization treatment.
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PURPOSE: To evaluate the accuracy of sonographic endometrial thickness and hysteroscopic characteristics in predicting malignancy in postmenopausal women undergoing surgical resection of endometrial polyps. METHODS: Five hundred twenty-one (521) postmenopausal women undergoing hysteroscopic resection of endometrial polyps between January 1998 and December 2008 were studied. For each value of sonographic endometrial thickness and polyp size on hysteroscopy, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated in relation to the histologic diagnosis of malignancy. The best values of sensitivity and specificity for the diagnosis of malignancy were determined by the Receiver Operating Characteristic (ROC) curve. RESULTS: Histologic diagnosis identified the presence of premalignancy or malignancy in 4.1% of cases. Sonographic measurement revealed a greater endometrial thickness in cases of malignant polyps when compared to benign and premalignant polyps. On surgical hysteroscopy, malignant endometrial polyps were also larger. An endometrial thickness of 13 mm showed a sensitivity of 69.6%, specificity of 68.5%, PPV of 9.3%, and NPV of 98% in predicting malignancy in endometrial polyps. Polyp measurement by hysteroscopy showed that for polyps 30 mm in size, the sensitivity was 47.8%, specificity was 66.1%, PPV was 6.1%, and NPV was 96.5% for predicting cancer. CONCLUSIONS: Sonographic endometrial thickness showed a higher level of accuracy than hysteroscopic measurement in predicting malignancy in endometrial polyps. Despite this, both techniques showed low accuracy for predicting malignancy in endometrial polyps in postmenopausal women. In suspected cases, histologic evaluation is necessary to exclude malignancy.
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PURPOSE: The aim of this longitudinal study was to investigate the value of uterine artery Doppler sonography during the second and third trimesters in the prediction of adverse pregnancy outcome in low-risk women. METHODS: From July 2011 to August 2012, a total of 205 singleton pregnant women presenting at our antenatal clinic were enrolled in this prospective study and were assessed for baseline demographic and obstetric data. They underwent ultrasound evaluation at the time of second and third trimesters, both included Doppler assessment of bilateral uterine arteries to determine the values of the pulsatility index (PI) and resistance index (RI) and presence of early diastolic notch. The endpoint of this study was assessing the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Doppler ultrasonography of the uterine artery, for the prediction of adverse pregnancy outcomes including preeclampsia, stillbirth, placental abruption and preterm labor. RESULTS: The mean age of cases was 26.4±5.11. The uterine artery PI and RI values for both second (PI: 1.1±0.42 versus 1.53±0.59, p=0.002; RI: 0.55±0.09 versus 0.72±0.13, p=0.000 respectively) and third-trimester (PI: 0.77±0.31 versus 1.09±0.46, p=0.000; RI: 0.46±0.10 versus 0.60±0.14, p=0.010 respectively) evaluations were significantly higher in patients with adverse pregnancy outcome than in normal women. Combination of PI and RI >95th percentile and presence of bilateral notch in second trimester get sensitivity and specificity of 36.1 and 97% respectively, while these measures were 57.5 and 98.2% in third trimester. CONCLUSIONS: According to our study, it seems that uterine artery Doppler may be a valuable tool for the prediction of a variety of adverse outcomes in second and third trimesters.
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An indirect enzyme linked immunoassay (ELISA-I) was developed and standardized for the serological diagnosis of classical swine fever (CSF). For the comparison, nine hundred and thirty-seven swine serum samples were tested by serum neutralization followed by immunoperoxidase staining (NPLA), considered as the standard. Of these, 223 were positive and 714 negative for neutralizing antibodies to classical swine fever virus (CSFV). In relation to the NPLA, the ELISA-I presented a 98.2% sensitivity; 92.86% specificity, 81.11% positive predictive value, 99.4% negative predictive value and a 94.1% precision. Statistical analysis showed a very strong correlation (r=0,94) between both tests. When compared to a commercially available ELISA kit, the performance of both, in relation to the NPLA, was similar. It was concluded that the ELISA-I is suitable for large scale screening of antibodies to classical swine fever virus, although it does not distinguish antibodies to classical swine fever virus from those induced by other pestiviruses.
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An indirect hemagglutination test for a seroepidemiological survey of Streptococcus pyogenes infection was standardized. This is an improved modification of the indirect hemagglutination test which utilizes an unstable reagent prepared with fresh blood cells. Two types of bacterial antigens represented by extracellular products and purified streptolysin O were assayed, but only the former antigen gave good results. Pretreatment of the bacterial antigen with 0.15 M NaOH and neutralization to pH 5.5, as well as postfixation of sensitized red cells with 0.1% glutaraldehyde at 56oC for 30 min were found to be essential to give long stability to the reagent in liquid suspension, at least 9 months at 4oC. A total of 564 serum samples with high, moderate and low anti-streptolysin O antibodies as determined by the neutralization assay were studied by the indirect hemagglutination test using the new reagent. The sensitivity, specificity, efficiency, positive predictive value and negative predictive value of the test in relation to the neutralization assay were 0.950, 0.975, 0.963, 0.973, and 0.955, respectively. The kappa agreement index between the two techniques was high (0.926) and ranked as "almost perfect". Antibody levels detected by both techniques also presented a high positive correlation (rs = 0.726). Five reagent batches successively produced proved to be reproducible. Thus, the improved indirect hemagglutination test seems to be useful for public health laboratories.
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To assess the clinical relevance of a semi-quantitative measurement of human cytomegalovirus (HCMV) DNA in renal transplant recipients within the typical clinical context of a developing country where virtually 100% of both receptors and donors are seropositive for this virus, we have undertaken HCMV DNA quantification using a simple, semi-quantitative, limiting dilution polymerase chain reaction (PCR). We evaluated this assay prospectively in 52 renal transplant patients from whom a total of 495 serial blood samples were collected. The samples scored HCMV positive by qualitative PCR had the levels of HCMV DNA determined by end-point dilution-PCR. All patients were HCMV DNA positive during the monitoring period and a diagnosis of symptomatic infection was made for 4 of 52 patients. In symptomatic patients the geometric mean of the highest level of HCMV DNAemia was 152,000 copies per 106 leukocytes, while for the asymptomatic group this value was 12,050. Symptomatic patients showed high, protracted HCMV DNA levels, whereas asymptomatic patients demonstrated intermittent low or moderate levels. Using a cut-off value of 100,000 copies per 106 leukocytes, the limiting dilution assay had sensitivity of 100%, specificity of 92%, a positive predictive value of 43% and a negative predictive value of 100% for HCMV disease. In this patient group, there was universal HCMV infection but relatively infrequent symptomatic HCMV disease. The two patient groups were readily distinguished by monitoring with the limiting dilution assay, an extremely simple technology immediately applicable in any clinical laboratory with PCR capability.
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The purpose of the present study was to validate the quantitative culture and cellularity of bronchoalveolar lavage (BAL) for the diagnosis of ventilator-associated pneumonia (VAP). A prospective validation test trial was carried out between 1992 and 1997 in a general adult intensive care unit of a teaching hospital. Thirty-seven patients on mechanical ventilation with suspected VAP who died at most three days after a BAL diagnostic procedure were submitted to a postmortem lung biopsy. BAL effluent was submitted to Gram staining, quantitative culture and cellularity count. Postmortem lung tissue quantitative culture and histopathological findings were considered to be the gold standard exams for VAP diagnosis. According to these criteria, 20 patients (54%) were diagnosed as having VAP and 17 (46%) as not having the condition. Quantitative culture of BAL effluent showed 90% sensitivity (18/20), 94.1% specificity (16/17), 94.7% positive predictive value and 88.8% negative predictive value. Fever and leukocytosis were useless for VAP diagnosis. Gram staining of BAL effluent was negative in 94.1% of the patients without VAP (16/17). Regarding the total cellularity of BAL, a cut-off point of 400,000 cells/ml showed a specificity of 94.1% (16/17), and a cut-off point of 50% of BAL neutrophils showed a sensitivity of 90% (19/20). In conclusion, BAL quantitative culture, Gram staining and cellularity might be useful in the diagnostic investigation of VAP.
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The objective of the present study was to determine the efficacy of detection of antigliadin immunoglobulins G and A (IgG and IgA) for the diagnosis of celiac disease in a developing country, since other enteropathies might alter the levels of these antibodies. Three groups were studied: 22 patients with celiac disease (mean age: 30.6 months), 61 patients with other enteropathies (mean age: 43.3 months), and 46 patients without enteropathies (mean age: 96.9 months). Antigliadin IgG and IgA ELISA showed sensitivity of 90.9 and 95.5%, respectively. With the hypothetical values of prevalence ranging from 1:500 to 1:2000 liveborns, the positive predictive value varied from 8.5 to 2.3% for IgG and from 4.8 to 1.1% for IgA. Considering the patients without enteropathies, specificity was 97.8 and 95.7% for IgG and IgA, respectively. In patients with other enteropathies, specificity was 82.0 and 84.1%, respectively. When patients with and without other enteropathies were considered as a whole, specificity was 88.8 and 91.6%, respectively. The specificity of positive IgG or IgA was 93.5% in children without enteropathies and 78.7% in the presence of other enteropathies. The negative predictive value for hypothetical prevalences varying from 1:500 to 1:2000 liveborns was 99.9%. Thus, even in developing countries where the prevalence of non-celiac enteropathies is high, the determination of serum antigliadin antibody levels is a useful screening test prior to the jejunal biopsy in the investigation of intestinal malabsorption.