PPV Values Research Articles

Performance Evaluation of IGRA-ELISA and T-SPOT.TB for Diagnosing Tuberculosis Infection.

To explore the application value of IGRA-ELISA in the diagnosis of tuberculosis. A total of 68 tuberculosis and 58 other pulmonary disease case samples were obtained. All the samples were tested by IGRA-ELISA and T-SPOT.TB assay in parallel. The consistency of IGRA-ELISA and T-SPOT.TB in the diagnosis of TB was analyzed. Five different methods for the diagnosis of TB were assayed: IGRA-ELISA, T-SPOT.TB, AFB staining, TB-Ab, and PPD. For the different PPD positive degrees, IGRA-ELISA and T-SPOT.TB positive rates were calculated. AFB staining positive and negative samples were analyzed by IGRA-ELISA, T-SPOT.TB, TB-Ab, and PPD. Positive rates, sensitivity, specificity, PPV, NPV and accuracy values of the five different detection methods were compared. There was good consistency between IGRA-ELISA and T-SPOT.TB in the diagnosis of TB and other pulmonary diseases. Compared with T-SPOT.TB, there was a significant correlation between the absorbance value of IGRA-ELISA and the number of ESAT-6 or CFP-10-specific SFCs (r = 0.902, p < 0.001; r = 0.901, p < 0.001). There was a significant difference in the positive rates among the above five different detection methods in the TB group and non-TB group (p < 0.001). For the different PPD positive degrees, there were highly significant differences in the positive rates of IGRA-ELISA and T-SPOT.TB in non-TB group; no similar trend was observed in the TB group. No significant differences in sensitivity, specificity, PPV, NPV, accuracy, LR+ and LR- were observed between IGRA-ELISA and T-SPOT.TB. The positive rates of IGRA-ELISA and T-SPOT.TB in the TB group were significantly higher than that of AFB staining, TB-Ab, and PPD (p < 0.05). IGRA-ELISA and T-SPOT.TB combined with AFB staining could further improve the sensitivity of tuberculosis detection without reducing its specificity. The AUC of IGRA-ELISA, ESAT-6, CFP-10, and T-SPOT.TB were 0.923, 0.893, 0.937, and 0.919, respectively. There was good correlation and consistency between the IGRA-ELISA and T-SPOT.TB in the diagnosis of TB. The sensitivity and accuracy of IGRA-ELISA were significantly better than those of AFB staining, TB-Ab, and PPD. IGRA-ELISA combined with AFB staining could further improve the diagnosis of tuberculosis.

Role of Bethesda system for reporting thyroid lesion and its correlation with histopathological diagnosis

Introduction: Interestingly enough, while TBS is forging ahead to bring about uniformity a thyroid FNA cytology reporting, a similar milestone has also been reported with an application of United Kingdom (UK-RC path system or BTA/RC Path) for reporting thyroid FNA cytology. It achieved practicing activism in 2003 and later got modified in the year 2009 & 2016. The TBS and RC path system being contemporary system of reporting thyroid cytopathology, uniform system of reporting cytopathology of nodular thyroid lesion still is not achieved but activated. Aim: To study the nodular thyroid lesions on FNAC by reporting system of TBSRTC and UK RC Path. Objectives: To compare the categories of the Bethesda system with contemporary categories of UK Royal college of pathologist for cytomorphological diagnosis and overlaps as well as with conventional reporting system and to compare with tissue diagnosis of surgically resected specimen of nodular thyroid lesions for its malignancy risk. Material and Methods: This study is hospital-based observational prospective and analytic study including 255 patients with nodular thyroid lesion. FNAC were carried out with or without under the guidance of sonography. The staining performed were conventional for smears of the aspirate. The smears were classified and categorized by two systems, TBSRTC and UK-RC path system of reporting thyroid lesion. The tissue diagnosis was done for the surgically resected specimens of nodular thyroid lesion in case of patient who underwent surgery. The values of comparative statistics were bought out. Observations: Females predominated over males. The distribution of cases for into the categories of TBSRTC and UK RC Path were as follow: category I/Thy1- 23, category II/Thy2-156, category III/Thy 3a-21/19, category IV/Thy3f-22/24, category V/Thy4-21, category VI/Thy5-16. There were 57 patients underwent surgical intervention in form of total or partial thyroidectomy or lobectomy and had available histopathological examination reports for cyto-histopathology co-relation. Values of comparative analysis show high NPV, PPV and high values of specificity, as compared to conventional. Conclusion: TBSRTC and UK RC path for reporting thyroid cytology are suitable for reporting thyroid nodular lesions on FNAC because of uniformity of nomenclature categories and implication at management with high correlation percentile with subsequent surgically resected specimen of thyroid.

Оценка местной распространенности (Т-стадии) рака предстательной железы по данным мультипараметрической магнитно-резонансной томографии: мультицентровое исследование

The study aimed to analyze the diagnostic performance of preoperative multiparametric magnetic resonance imaging (mp-MRI) in the staging of prostate cancer (PCa) versus postoperative histological examination and determine the most sensitive pulse sequence from the mp-MRI protocol in estimating the local extent of PCa. The study comprised 112 men aged 52 to 84 years with a morphologically verified diagnosis of prostate cancer. All patients underwent pelvic mp-MRI before radical prostatectomy (RPE) no earlier than six weeks after the prostate biopsy. Radical prostatectomy was performed within two weeks after mp-MRI. MP-MRI findings and the results of postoperative histology were compared using a binary logistic regression model. The sensitivity, specificity, diagnostic accuracy, positive (PPV) and negative (NPV) predictive values for predicting extracapsular extension were 87.5, 92.6, 91, 84 and 94.3%, respectively; for predicting seminal vesicles invasion, they were 85, 95, 90, 80.9 and 96.7%, respectively. When stratified by the presence or absence of the pseudocapsule invasion, the reliability of detecting the tumor spread for different types of images decreases in the following order: DWI - T2 + DWI - T2 VI - DCE-MRI. mp-MRI has high sensitivity, specificity, general diagnostic accuracy, high NPV, and PPV values in detecting an extracapsular extension of prostate cancer. According to the binary logistic regression model, the greatest contribution to the decision on the presence or absence of extracapsular extension is also made by the DWI.

Abstract 3308: Urine epigenetic biomarkers for NSCLC diagnosis

Abstract Purpose: The National Lung Cancer Screening Trial showed mortality reduction on patients with NSCLC by the use of Low-dose CT screening. The study exhibits an unreasonably high false positive rate of 96.6%, which can to lead to significant morbidity and mortality from unnecessary tests. This study aim to determine if methylated promoter regions of a panel of genes that are correlated with Non-Small Cell Lung Cancer can be detected in urine from patients with lung cancer versus those without. Materials and Methods: We conducted a prospective case-control study recruiting subjects from the Lung Cancer Spore Trial. Urine and pre-operative CT scans were obtained from all patients. We processed the urine using the Methylation on Beads assay to isolate and bisulfite treat circulating DNA and then employed Quantitative Methylation Specific Real-Time PCR to detect promoter methylation status of the genes: CDO1, TAC1, HOXA7, HOXA9, SOX17 and ZFP42. Sensitivity, specificity, PPV and NPV values were calculated for each gene methylation status. Results: 34 patients were studied, including 23 patients with NSCLC and 11 patients with benign non-cancerous lesions. The sensitivity, specificity, PPV and NPV values for lung cancer detection in urine are shown in Table 1. Sensitivities ranged 43-96%, Specificities 64-91%, PPV 71-100% and NPV 40-67%. Promoter methylation of the gene panel CDO1, TAC1, HOXA7, HOXA9, SOX17 and ZPF42 has a 78% sensitivity, 91% specificity, 95% PPV and 67% NPV for lung cancer detection. Conclusion: Our study suggests that urine can provide a highly sensitive and specific non-invasive route for lung cancer detection. These results are very promising and could potentially reduce unnecessary morbidity and mortality in people undergoing screening for NSCLC by use of a non-invasive method that could be more accessible on primary care centers. However, further studies and validation with larger sample sizes and different populations are necessary before its application to clinical practice. Patients with positive gene methylation from urine samples and its accuracy for NSCLC detection.Cancer (n=23)Cancer (n=23)Control (n=11)Control (n=11)nSensitivitynSpecificityPPVNPVCDO114611919353TAC11565010010058SOX1716704648050HOXA711483737940HOXA910431919143ZPF4222969187167Panel of genes18781919567 Citation Format: Lane Lerner, Lily Zheng, Anastasia Kottorou, Chen Chen, Tomoaki Ito, Kristen Rodgers, Beverly Lee, Robert Winn, Enrico Benedetti, Tza- Huei Wang, Malcolm V. Brock, James G. Herman, Alicia Hulbert. Urine epigenetic biomarkers for NSCLC diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3308.

Abstract 11: Development and Comparison of Two Natural Language Processing Methods for Identifying Bleeding Events in Clinical Text

Background: Learning healthcare systems need techniques that can accurately and automatically identify health outcomes in large populations. Outcomes are often described in clinical narration in the electronic medical record. Objective: To develop and compare two natural language processing (NLP) approaches, rules-based (RB) and machine-learning (ML), for identifying bleeding events in clinical notes. Methods: We used de-identified notes from the Medical Information Mart for Intensive Care. We randomly selected 990 notes for a training set and 660 notes for a test set. Physicians classified each note as present or absent for a clinically relevant bleeding event during the hospitalization. We developed a dictionary of target and modifier words for the RB approach. In RB, the computer “reads” the text and tags bleeding targets as present or absent based on the modifier words; the mentions are aggregated to arrive at a classification for the note. For the ML approach, each note was represented as a high-dimensional vector where each dimension corresponds to the frequency of a certain word. Similar notes (e.g. bleeding present notes) have similar vectors; the computer learns these patterns to predict the class for an unseen note. One RB and three ML models (support vector machine (SVM), extra trees (ET), convolutional neural network (CNN)) were trained using the full 990-note training set. Another instance of each ML model was also trained on a down-sampled (DS) set of 450 notes, with equal positive and negative notes. We ran the trained models on the 660-note test set and compared classification performance using McNemar’s test. Results: The 660 note test set represented 527 unique patients, 40% female. Bleeding events were present in 21% of the notes. The ET-DS model was the most sensitive, followed by the RB approach (93.8% versus 91.1%, p=0.44). The PPV value for the ET-DS model, however, was &lt;50%. The RB had the best performance overall, with 84.6% specificity, 62.7% positive predictive value, and 97.1% negative predictive value (NPV) for identifying clinically relevant bleeding. Discussion: A RB NLP approach, compared to ML, has the best overall performance in independently identifying bleeding events among critically ill patients. The current models have high NPV, so could be used to reduce the chart review burden.

Multi-field-of-view SPECT is superior to whole-body scanning for assessing metastatic bone disease in patients with prostate cancer.

The aim of this study was to compare the diagnostic performance of whole-body bone scintigraphy (WBS) and multi-field-of-view single photon emission tomography (multi-FOV SPECT) with 99mTc-oxidronate (99mTc-HDP) in patients with prostate cancer (PCa). In a prospective study, WBS and SPECT acquisitions were performed in 194 patients with histologically confirmed PCa and serum prostate-specific antigen (PSA) levels above 10 ng/mL. Scans obtained using the two modalities were interpreted separately. Clinical and biochemical follow-up, radiological studies and biopsies served as benchmarks for the assessments. The impact of PSA level on WBS and SPECT results was also evaluated. The patient-based sensitivity, specificity, accuracy, PPV and NPV values of SPECT examinations were higher than those of WBS, especially in patients with serum PSA levels <40 ng/mL. Multi-FOV SPECT proved to be more sensitive and specific than WBS in detecting bone metastases in PCa patients.

Mediastinal node staging by positron emission tomography-computed tomography and selective endoscopic ultrasound with fine needle aspiration for patients with upper gastrointestinal cancer: Results from a regional centre.

AIMTo investigate the impact of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and positron emission tomography-computed tomography (PET-CT) in the nodal staging of upper gastrointestinal (GI) cancer in a tertiary referral centre.METHODSWe performed a retrospective review of prospectively recorded data held on all patients with a diagnosis of upper GI cancer made between January 2009 and December 2015. Only those patients who had both a PET-CT and EUS with FNA sampling of a mediastinal node distant from the primary tumour were included. Using a positive EUS-FNA result as the gold standard for lymph node involvement, the sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy of PET-CT in the staging of mediastinal lymph nodes were calculated. The impact on therapeutic strategy of adding EUS-FNA to PET-CT was assessed.RESULTSOne hundred and twenty one patients were included. Sixty nine patients had a diagnosis of oesophageal adenocarcinoma (Thirty one of whom were junctional), forty eight had oesophageal squamous cell carcinoma and four had gastric adenocarcinoma. The FNA results were inadequate in eleven cases and the PET-CT findings were indeterminate in two cases, therefore thirteen patients (10.7%) were excluded from further analysis. There was concordance between PET-CT and EUS-FNA findings in seventy one of the remaining one hundred and eight patients (65.7%). The sensitivity, specificity, PPV and NPV values of PET-CT were 92.5%, 50%, 52.1% and 91.9% respectively. There was discordance between PET-CT and EUS-FNA findings in thirty seven out of one hundred and eight patients (34.3%). MDT discussion led to a radical treatment pathway in twenty seven of these cases, after the final tumour stage was altered as a direct consequence of the EUS-FNA findings. Of these patients, fourteen (51.9%) experienced clinical remission of a median of nine months (range three to forty two months).CONCLUSIONEUS-FNA leads to altered staging of upper GI cancer, resulting in more patients receiving radical treatment that would have been the case using PET-CT staging alone.

Repeat multiparametric MRI in prostate cancer patients on active surveillance.

IntroductionThis study was conducted to describe the changes in repeat multiparametric MRI (mpMRI) occurring in prostate cancer (PCa) patients during active surveillance (AS), and to study possible associations between mpMRI-related parameters in predicting prostate biopsy (Bx) Gleason score (GS) upgrading >3+3 and protocol-based treatment change (TC).Materials and methodsThe study cohort consisted of 76 AS patients with GS 3+3 PCa and at least two consecutive mpMRIs of the prostate performed between 2006–2015. Patients were followed according to the Prostate Cancer Research International Active Surveillance (PRIAS) protocol and an additional mpMRI. The primary end points were GS upgrading (GU) (>3+3) in protocol-based Bxs and protocol-based TC.ResultsOut of 76 patients, 53 (69%) had progression (PIRADS upgrade, size increase or new lesion[s]), while 18 (24%) had radiologically stable disease, and 5 (7%) had regression (PIRADS or size decrease, disappearance of lesion[s]) in repeat mpMRIs during AS. PIRADS scores of 4–5 in the initial mpMRI were associated with GU (p = 0.008) and protocol-based TC (p = 0.009). Tumour progression on repeat mpMRIs was associated with TC (p = 0.045) but not with GU (p = 1.00). PIRADS scores of 4–5 predict GU (sensitivity 0.80 [95% confidence interval (CI); 0.51–0.95, specificity 0.62 [95% CI; 0.52–0.77]) with PPV and NPV values of 0.34 (95% CI; 0.21–0.55) and 0.93 (95% CI; 0.80–0.98), respectively.ConclusionmpMRI is a useful tool not only to select but also to monitor PCa patients on AS.

Role of dynamic contrast-enhanced and diffusion weighted MRI in evaluation of hepatocellular carcinoma after chemoembolization

PurposeTo assess the role of dynamic contrast- enhanced and diffusion-weighted (DWI) MRI in the evaluation of the response of hepatocellular carcinoma (HCC) after chemoembolization. Patient & method30 patients having 40 HCC lesions underwent transcatheter arterial chemoembolization (TACE). Ages ranged between 41 and 76 years. All examinations were performed using Philips 1.5 Tesla MRI (Achieva). Precontrast T1, T2, Dynamic contrast enhanced and respiratory triggered DWI MR images with (b = 50, 400, 800 mm/s). DWI MRI images and Contrast-enhanced MRI images after TACE are assessed to evaluate post treatment response. DWI was used to create ADC maps and ADC values were calculated looking for a cut off value using the ROC curve. ResultsDynamic MRI had a sensitivity of 94.1%, a specificity of 95.6%, PPV value of 94.1%, NPV of 95.6% and an overall agreement of 95% compared to 82%, 73.9%, 70%, 85% and 77.5% respectively of DWI MRI. The difference between the malignant residual and well ablated groups' ADC variables was statistically significant P value 0.009. ConclusionDynamic and diffusion MRI complete each other in assessment of HCC response to therapy, especially in those who cannot properly hold their breath that cause degradation of the dynamic MR quality.

Use of Hysteroscopy in Abnormal Uterine Bleeding: An Edge Over Histopathological Examination.

To assess the efficacy of hysteroscopy in diagnosis of AUB. A total of 56 women in reproductive and peri-menopausal age group (20-50years) with complaints of abnormal uterine bleeding were enrolled in the study. All the patients underwent hysteroscopic examination followed by biopsy/histopathological evaluation. Hysteroscopic findings were compared against histopathological findings. Sensitivity, specificity, PPV, NPV and accuracy of hysteroscopy were calculated. Mean age of patients was 36.4±7.6. Majority (60.7%) presented within 6months of complaints. Clinically, 66.1% were diagnosed as menorrhagia, 30.4% polymenorrhoea and 3.6% intermenstrual bleeding. Hysteroscopically 53.6% presented with abnormal pathology, it diagnosed polyps in 16.1%, calcification in 12.5%, submucous fibroma in 10.7%, necrotic mass in 7.1%, adhesion and forgotten IUCD in 5.4% cases each. However, on histopathology, 33 (58.9%) cases had normal/proliferative/atrophic endometrium, 12 (21.4%) had hyperplasia, 7 (12.5%) had calcified endometrium, and 12 (21.4%) had polyp. No significant difference between two modalities was observed with respect to number of normal/proliferative/atrophic endometrium (p=0.185). Histopathology diagnosed hyperplasia in significantly higher proportion of patients as compared to hysteroscopy (p=0.042). Hysteroscopy diagnosed significantly higher proportion of patients with submucous myoma (p=0.012) and necrotic mass (p=0.042). Statistically, no significant difference between two modalities was observed with respect to other pathologies (p>0.05). Overall agreement between two modalities was 62.5%. For pathological abnormalities in general, hysteroscopy had sensitivity, specificity, PPV, NPV and accuracy values of 78.3, 63.6, 60, 80.8 and 69.6%, respectively. Hysteroscopy provided additional information for some of the pathologies, otherwise remaining undiagnosed by HPE.

P 129 Quantitative EEG and neuropsychological tests to differentiate between Parkinson’s disease patients and healthy controls with Random Forest algorithm

Background and bbjectives studies have shown that quantitative EEG (QEEG) and neuropsychological parameters are associated with Parkinson’s disease (PD). We investigated the differences between PD patients and healthy controls (HC) in high-resolution QEEG measures, and analyzed the prediction accuracy. We also wanted to see if a combination of QEEG and neuropsychological factors could increase the prediction accuracy of the model in comparison with QEEG parameters alone. Methods high-resolution 256-channel EEG were recorded in 66 PD patients and 59 HC. Neuropsychological assessment of the patients covered five cognitive domains: attention, working memory, executive functions, memory and visuo-spatial functions (18 cognitive tests). An average score for each domain was calculated along with an overall cognitive score, resulting in 6 additional scores. EEG data were processed to calculate the relative power in alpha, theta, delta, beta frequency bands across 10 regions of the brain. Alpha1/theta ratios were also calculated, resulting in a total of 77 QEEG frequency measures. Random Forest algorithm was applied to the data to check for change in prediction accuracy. Results using the QEEG measures alone for classification, Area-under-the-Curve (AUC) value of 0.819 was obtained along with Positive and Negative predictive values (PPV, NPV) of 0.736 and 0.754, respectively. The 6 neuropsychological domain scores, when used alone, resulted in an AUC of 0.82, PPV of 0.71 and NPV of 0.8. On combining the QEEG measures and the 6 neuropsychological scores, an AUC value of 0.859 was obtained along with a PPV of 0.729 and NPV of 0.76. A slight increase in the AUC was observed on combining the QEEG and 6 neuropsychological measures, in comparison to using them alone while the PPV and NPV values did not have much difference. However, on combining the QEEG measures with all 24 available neuropsychological scores instead of using the average domain scores and overall cognitive scores alone, the AUC value increased to 0.88 while the PPV and NPV values increased to 0.785 and 0.8. Conclusion QEEG measures can be useful in distinguishing Parkinson’s disease patients from healthy controls with a considerable accuracy. This accuracy can be significantly improved by combining the QEEG measures with distinct neuropsychological test scores.

Sequential Objective Structured Clinical Examination based on item response theory in Iran.

PurposeIn a sequential objective structured clinical examination (OSCE), all students initially take a short screening OSCE. Examinees who pass are excused from further testing, but an additional OSCE is administered to the remaining examinees. Previous investigations of sequential OSCE were based on classical test theory. We aimed to design and evaluate screening OSCEs based on item response theory (IRT).MethodsWe carried out a retrospective observational study. At each station of a 10-station OSCE, the students’ performance was graded on a Likert-type scale. Since the data were polytomous, the difficulty parameters, discrimination parameters, and students’ ability were calculated using a graded response model. To design several screening OSCEs, we identified the 5 most difficult stations and the 5 most discriminative ones. For each test, 5, 4, or 3 stations were selected. Normal and stringent cut-scores were defined for each test. We compared the results of each of the 12 screening OSCEs to the main OSCE and calculated the positive and negative predictive values (PPV and NPV), as well as the exam cost.ResultsA total of 253 students (95.1%) passed the main OSCE, while 72.6% to 94.4% of examinees passed the screening tests. The PPV values ranged from 0.98 to 1.00, and the NPV values ranged from 0.18 to 0.59. Two tests effectively predicted the results of the main exam, resulting in financial savings of 34% to 40%.ConclusionIf stations with the highest IRT-based discrimination values and stringent cut-scores are utilized in the screening test, sequential OSCE can be an efficient and convenient way to conduct an OSCE.

The diagnostic accuracy of biomarkers for diagnosis of primary biliary cholangitis (PBC) in anti-mitochondrial antibody (AMA)-negative PBC patients: a review of literature.

Primary biliary cholangitis (PBC), also known as primary biliary cirrhosis, is an autoimmune disease of the liver characterized by anti-mitochondrial antibodies (AMA) in 90%-95% of patients. The aim of this study was to evaluate the diagnostic value of several serum biomarkers in patients with PBC but negative for AMA. Some antinuclear antibodies (ANA) pattern, detected by indirect immunofluorescence (IIF), such as multiple nuclear dot (MND) and rim-like patterns are well-known to be specific for PBC. The corresponding nuclear antigens are the components of the nuclear pore complex (Gp210 for rim-like pattern) and Sp100, PML proteins (for MND pattern) detectable by immunoblotting and ELISA methods. More recently, new biomarkers have been evaluated in order to improve the diagnostic sensitivity, such as kelch-like 12 (KLHL12) and hexokinase-1. Considering these different serum biomarkers, studies evaluating their diagnostic role in AMA-negative PBC patients compared to AMA-positive ones and controls were included in this review. Pooled sensitivity and specificity were 37% and 85%, respectively. The overall PPV and NPV mean values were 45% and 83%. Even if all biomarkers are very specific for PBC, the overall sensitivity was poor and therefore is necessary to identify a marker with a greater sensitivity for PBC in AMA-negative patients.

Contribution of temporal data to predictive performance in 30-day readmission of morbidly obese patients.

BackgroundReduction of readmissions after discharge represents an important challenge for many hospitals and has attracted the interest of many researchers in the past few years. Most of the studies in this field focus on building cross-sectional predictive models that aim to predict the occurrence of readmission within 30-days based on information from the current hospitalization. The aim of this study is demonstration of predictive performance gain obtained by inclusion of information from historical hospitalization records among morbidly obese patients.MethodsThe California Statewide inpatient database was used to build regularized logistic regression models for prediction of readmission in morbidly obese patients (n = 18,881). Temporal features were extracted from historical patient hospitalization records in a one-year timeframe. Five different datasets of patients were prepared based on the number of available hospitalizations per patient. Sample size of the five datasets ranged from 4,787 patients with more than five hospitalizations to 20,521 patients with at least two hospitalization records in one year. A 10-fold cross validation was repeted 100 times to assess the variability of the results. Additionally, random forest and extreme gradient boosting were used to confirm the results.ResultsArea under the ROC curve increased significantly when including information from up to three historical records on all datasets. The inclusion of more than three historical records was not efficient. Similar results can be observed for Brier score and PPV value. The number of selected predictors corresponded to the complexity of the dataset ranging from an average of 29.50 selected features on the smallest dataset to 184.96 on the largest dataset based on 100 repetitions of 10-fold cross-validation.DiscussionThe results show positive influence of adding information from historical hospitalization records on predictive performance using all predictive modeling techniques used in this study. We can conclude that it is advantageous to build separate readmission prediction models in subgroups of patients with more hospital admissions by aggregating information from up to three previous hospitalizations.

Role of Multidetector Computed Tomography in Evaluation of Ovarian Lesions in Women Clinically Suspected of Malignancy

Objective:To determine the diagnostic accuracy of multidetector computed tomography (MDCT) in the evaluation of ovarian carcinoma using histopathology as the gold standard.Methods:This prospective cross-sectional study was conducted at Department of Radiology, Dow international medical college, DUHS, Karachi from December 2015 to April 2016. All patients of 30-60 years of age who were referred for CT a scan of the abdomen and pelvis with clinical suspicion of malignant ovarian cancer were included. A total of 158 cases were assessed with signs and symptoms of weight loss and an abdominal or pelvic mass detected on examination by a physician.Results:The mean age was 42.7 ±10.3 years (range 30-60). The largest group (46, 29.1%) presented with Stage 0 disease. The mean duration of symptoms was 4.06 ±1.39 months (range 1-6). Taking histopathology as the gold standard the sensitivity, specificity, NPV, PPV and overall diagnostic accuracy values for MDCT were 95.6%, 97.3%, 93.5%, 97.3% and 96.8%, respectively.Conclusion:MDCT showed high accuracy in differentiating benign and malignant lesions and as well as staging of malignant cases which should be very helpful in management of ovarian disease.

Evaluation of blast-induced ground vibrations in open-pit mines by using adaptive neuro-fuzzy inference systems

This study addresses the effects of rock characteristics and blasting design parameters on blast-induced vibrations in the Kangal open-pit coal mine, the Tulu open-pit boron mine, the Kirka open-pit boron mine, and the TKI Can coal mine fields. Distance (m, R) and maximum charge per delay (kg, W), stemming (m, SB), burden (m, B), and S-wave velocities (m/s, Vs) obtained from in situ field measurements have been chosen as input parameters for the adaptive neuro-fuzzy inference system (ANFIS)-based model in order to predict the peak particle velocity values. In the ANFIS model, 521 blasting data sets obtained from four fields have been used (r 2 = 0.57–0.81). The coefficient of ANFIS model is higher than those of the empirical equation (r 2 = 1). These results show that the ANFIS model to predict PPV values has a considerable advantage when compared with the other prediction models.

Comparison of clinical performance of antigen basedenzyme immunoassay (EIA) and major outer membrane protein (MOMP)-PCR for detection of genital Chlamydia trachomatis infection

Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen worldwide. Early detection and treatment of C.trachomatis genital infection prevent serious reproductive complications. Performances of enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-polymerase chain reaction (PCR) for diagnosis of genital C.trachomatis infection in women were compared. In this cross sectional study a total of 518 women volunteers were included (33.67±8.3 yrs) who had been referred to Gynecology clinics of Qom province, Iran, were included. Endocervical swab specimens were collected to detect lipopolysaccharide (LPS) antigen in EIA and to amplify MOMP gene of C.trachomatis in PCR. Results were confirmed using ompI nested-PCR. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated for performance of the tests. Odds ratios were determined using binary logistic regression analysis. In total, 37 (7.14%) cases were positive by EIA and/or MOMP-PCR. All discrepant results were confirmed by nested-PCR. Sensitivity, specificity, PPV and NPV values of EIA were 59.46%, 100%, 100% and 96.98%, and those of MOMP-PCR were 97.30%, 100%, 100%, 99.79%, respectively. Reproductive complications including 2.7% ectopic pregnancy, 5.4% stillbirth, 5.4% infertility, and 10.8% PROM were recorded. The risk of developing chlamydiosis was increased 4.8-fold in volunteers with cervicitis (p<0.05; OR 4.80; 95% CI 1.25-18.48). C.trachomatis infection should be regarded in women of reproductive ages especially those with cervicitis. Primary screening of women by using the low cost antigen-EIA is recommended; however, due to the low sensitivity of Ag-EIA, verification of the negative results by a DNA amplification method is needed.

Early detection and classification of powdery mildew-infected rose leaves using ANFIS based on extracted features of thermal images

Spatial and temporal changes in surface temperature of infected and non-infected rose plant (Rosa hybrida cv. ‘Angelina’) leaves were visualized using digital infrared thermography. Infected areas exhibited a presymptomatic decrease in leaf temperature up to 2.3°C.In this study, two experiments were conducted: one in the greenhouse (semi-controlled ambient conditions) and the other, in a growth chamber (controlled ambient conditions). Effect of drought stress and darkness on the thermal images were also studied in this research. It was found that thermal histograms of the infected leaves closely follow a standard normal distribution. They have a skewness near zero, kurtosis under 3, standard deviation larger than 0.6, and a Maximum Temperature Difference (MTD) more than 4. For each thermal histogram, central tendency, variability, and parameters of the best fitted Standard Normal and Laplace distributions were estimated. To classify healthy and infected leaves, feature selection was conducted and the best extracted thermal features with the largest linguistic hedge values were chosen. Among those features independent of absolute temperature measurement, MTD, SD, skewness, R2l, kurtosis and bn were selected. Then, a neuro-fuzzy classifier was trained to recognize the healthy leaves from the infected ones. The k-means clustering method was utilized to obtain the initial parameters and the fuzzy “if-then” rules. Best estimation rates of 92.55% and 92.3% were achieved in training and testing the classifier with 8 clusters. Results showed that drought stress had an adverse effect on the classification of healthy leaves. More healthy leaves under drought stress condition were classified as infected causing PPV and Specificity index values to decrease, accordingly. Image acquisition in the dark had no significant effect on the classification performance.

Ground Vibrations and Air Blast Effects Induced by Blasting in Open Pit Mines: Case of Metlaoui Mining Basin, Southwestern Tunisia

Blasting is widely used in quarries and mining production processes. It is the beneficial industrial technology which provides achievement of expected results in a short period of time with relatively low cost. Never one less, blasts produce undesirablevibrations and sounds. This current investigation reports the ground motion and airblast over pressure measurements around the open pit mine nearby Metlaoui village (south-western Tunisia). An empirical relation proposed by USBM was utilized to calculate K (site constant) and n (slope of the PPV vs scaled distance) and verifies whether the recorded shots overcame the thresholds indicated by DIN and USBM. The site parameters obtained provide us with the propagation equation of the blast induced seismic waves in the study site. Also, an overview of frequency for the study area revealed the dominance of low frequencies (>40 Hz). Such values can cause damage to the nearby structures when a specific PPV value is reached by blasting. Moreover, it has been demonstrated in this study that all over pressure magnitudes are less than 134 dB, which is the safe limit of air blast level.

Diagnostic performance of CT colonography with limited cathartic preparation in colorectal cancer screening; comparison with conventional colonoscopy

PurposeTo prospectively evaluate the diagnostic performance of computed tomographic colonography with limited bowel preparation for the depiction of colorectal polyps, by using conventional colonoscopy as the gold standard technique. Material and MethodsThe study included forty five consecutively registered patients referred for conventional colonoscopy for colorectal cancer screening or for evaluation of colorectal symptoms, and they were scheduled to undergo MDCT examination on the same day at Radiology Department in our institution, before the conventional colonoscopy examination. All patients undergo limited preparation main outcome measures: sensitivity, specificity, positive and negative predictive value of CTC versus CC in each group and overall. ResultsA total of 60 polypoid lesions were detected with colonoscopy in 45 patients; overall sensitivity of CTC in polyp detection was 85.71%, specificity 71.24, PPV 96.77 and NPV 33.33, as regarding CTC performance in each group. ConclusionThis study proved that CTC with limited cathartic bowel preparation and iodinated agents for fecal tagging can obtain high sensitivity and PPV values results for <5mm polyps comparable to those obtained with conventional preparation with laxatives. Furthermore, this method could really improve the acceptance of CTC for colorectal cancer screening.