Cut-off values of Geriatric Nutritional Risk Index for cardiovascular events in Japanese patients with acute myocardial infarction.

The Geriatric Nutritional Risk Index (GNRI) is a straightforward nutritional risk assessment tool with an established relationship with poor prognosis in patients with heart failure. However, the utility of the GNRI in patients with acute myocardial infarction (AMI) remains unclear given the time-dependent changes in the pathophysiology of AMI and the selected endpoints. Accordingly, we aimed to evaluate the optimal cut-off values of the GNRI for cardiovascular events in patients with AMI. We used time-dependent receiver operating characteristic analysis to identify the optimal cut-off values for two endpoints, all-cause death and major adverse cardiac events (MACE: all-cause death, non-fatal myocardial infarction, hospitalization for heart failure, and stroke), over 4 years in 360 patients with AMI between 2012 and 2020. The cumulative incidence of MACE was 11.6%. The cut-off value of the GNRI for all-cause death was 82.7 (area under the curve [AUC], 0.834) at 3 months and 90.3 (AUC 0.854) at 4 years. The cut-off value of the GNRI for MACE was 83.0 (AUC 0.841) at 3 months and 95.3 (AUC 0.821) at 4 years. The GNRI demonstrated consistently high reliability relative to other indicators of AMI. Our findings indicated that the optimal cut-off value and reliability of the GNRI for cardiovascular events varied according to the endpoints and observation periods. GNRI emerges as a crucial predictor of prognosis for patients with AMI.

In-vivo Testing of Oral Mucosal Lesions with an In-house Developed Portable Imaging Device and Comparison with Spectroscopy Results.

Progression of oral mucosal lesions is generally marked by changes in the concentration of the intrinsic fluorophores such as collagen, nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD) and porphyrin present in the human oral tissue. In this study, we have probed the changes in FAD and porphyrin by exciting with 405 nm laser light on different sites (tongue, buccal mucosa, lip etc.) of the oral cavity. Testing has been done by an in-house developed fluorescence-based portable imaging device on oral squamous cell carcinoma (OSCC) patients, dysplastic patients and control (normal) group. Fluorescence images recorded from OSCC and dysplastic patients have displayed an enhancement in the red band (porphyrin) as compared to those from the normal volunteers. Porphyrin to FAD intensity ratio (IPorphyrin/IFAD), referred to red to green ratio (Ired/Igreen) has been taken as the diagnostic marker for classification among the groups. Receiver operating characteristic (ROC) analysis applied on IPorphyrin/IFAD is able to discriminate OSCC to normal, dysplasia to normal and OSCC to dysplasia with sensitivities of 100%, 81%, 92% and specificities of 100%, 93% and 92% respectively. Fluorescence imaging probe can capture a large area of oral lesions in a single scan and hence would be useful for initial scanning. On comparison with spectroscopy studies performed by our group, it is found that combining both spectroscopy and imaging as a device may be effective for the early detection of oral lesions. This clinical study was registered on the date 13/10/2017 in the clinical trials registry-India (CTRI) with registration number CTRI/2017/10/010102.

Usefulness of the autism spectrum quotient (AQ) in screening for autism spectrum disorder and social communication disorder.

BACKGROUND: In the Diagnostic and Statistical Manual and Mental Disorders, Fifth Edition (DSM-5), autism spectrum disorder (ASD) and social (pragmatic) communication disorder (SCD) were described as a new category of psychiatry nosography. SCD involves impairments in social communication and social interaction but not restricted, repetitive patterns of behavior, interests, or activities. The autism spectrum quotient (AQ) was developed to screen for autism tendencies in adults with normal intelligence. However, AQ cutoff scores for screening ASD and SCD in the DSM-5 have not been established. This study examined whether the Japanese version of the AQ (AQ-J) total scores could discriminate between an ASD group, an SCD group, and a neurotypical (NT) group. METHODS: Participants were 127 ASD patients, 52 SCD patients, and 49 NT individuals. Receiver operating characteristic (ROC) analyses were used to examine AQ-J total score cutoff values to distinguish between ASD and NT groups, SCD and NT groups, and ASD and SCD groups. RESULTS: In the ROC analysis for the ASD and NT groups, the area under the curve (AUC) was 0.96, and the optimum cutoff value was 23 points (sensitivity 92.9%, specificity 85.7%). The AUC for the SCD and NT groups was 0.89, and the optimum cutoff value was 22 points (sensitivity 84.6%, specificity 85.7%). The AUC for the ASD and SCD groups was 0.75; the optimum cutoff value was 32 points (sensitivity 67.7%, specificity 71.2%). CONCLUSION: Our findings suggest the usefulness of the AQ-J in screening for ASD and SCD.

Time-dependent changes in P2Y12 reaction unit values for predicting the different types of cardiovascular events in patients with ischemic heart disease.

Several studies have investigated the association between P2Y12 reaction unit (PRU) value and major adverse cardiovascular events (MACEs) in patients with ischemic heart disease, but there is no well-established consensus on the utility of PRU value. Furthermore, the optimal PRU cut-off value varied with studies. One reason may be that the endpoints and observation periods differed, depending on the study. This study aimed to investigate the optimal cut-off and predictive ability of the PRU value for predicting cardiovascular events, while considering different endpoints and observation periods. We surveyed a total of 338 patients receiving P2Y12 inhibitors and measured PRU during cardiac catheterization. Using time-dependent receiver operating characteristic analysis, we evaluated the cut-off and area under curve (AUC) of the PRU value for two MACEs (MACE ①: composite of death, myocardial infarction, stent thrombosis, and cerebral infarction; MACE ②: composite of MACE ① and target vessel revascularization) at 6, 12, 24 and 36 months after cardiac catheterization. MACE ① occurred in 18 cases and MACE ② in 32 cases. The PRU cut-off values at 6, 12, 24, and 36 months were 257, 238, 217, and 216, respectively, for MACE ① and 250, 238, 209, and 204, respectively, for MACE ②. The AUCs at 6, 12, 24, and 36 months were 0.753, 0.832, 0.718, and 0.717, respectively, for MACE ① and 0.724, 0.722, 0.664, and 0.682, respectively, for MACE ②. The optimal cut-off and predictive ability of PRU values for cardiovascular events varied depending on different endpoints and duration of the observation periods. A relatively high PRU value is effective for short-term event suppression, but a low value is required for long-term event suppression.

Discrimination in the clinical diagnosis between patients with schizophrenia and healthy controls using eye movement and cognitive functions.

AIM: Eye movements and cognitive functions are significantly impaired in patients with schizophrenia. The authors aimed to develop promising clinical diagnostic markers that fit practical digital health applications in psychiatry using eye movement and cognitive function data from 1254 healthy individuals and 336 patients with schizophrenia. METHODS: Multivariate analyses using logistic regression were performed to confirm net performance of eye movements and cognitive functions scored using the Wechsler Adult Intelligence Scale, Third Edition, and Wechsler Memory Scale-Revised. The authors then examined the discrimination performance of pairs containing an eye movement and a cognitive function measure to search the pairs that would be effective in practical application for the discrimination according to the diagnostic criterion between the groups. RESULTS: Multivariate analyses confirmed that eye movements and cognitive functions were effective modalities for discriminating between patients with schizophrenia and healthy controls. The discriminant analyses of the pairs demonstrated that seven eye movement measures and seven scores from cognitive function tests showed high discrimination performance when paired with one measure from the other modality. Moreover, seven pairs of digit-symbol coding or symbol-search and eye movement measures had high and robust discrimination performance. CONCLUSION: Seven pairs of an eye movement and a cognitive function measure were effective, robust, and less time-consuming in assisting with clinical diagnosis by categorizing healthy individuals or patients with schizophrenia. These findings may help develop an objective auxiliary diagnosis method working even on portable devices, which facilitates the consistency of diagnosis, earlier intervention, and shared decision-making.

Approach to prediction and receiver operating characteristic analysis of a regression model for assessing the severity of the course Lyme borreliosis in children.

Introduction: Lyme borreliosis (LB) is a multisystemic zoonotic disease transmitted by the bite of infected tick vectors.The aim of the study is to develop a mathematical model for predicting the risk of severity of Lyme disease by the risk factor of the disseminated form of LB in children who have had a tick attack. To test the effectiveness of the formula for predicting the development of the disseminated stage of LB, we built a receiver operating characteristic (ROC) curve and determined the specificity and sensitivity of our model. The results of the examination of 122 patients with the confirmed local and disseminated stages of LB were taken as a basis. Material and methods: To build a prognostic model for prediction of the risk of the developing of the stage in LB predicting the risk of severity of course in Lyme borreliosis (PRSCLB), 122 children (aged 13 ±3 years) with LB were examined using multivariate regression analysis, including 52 boys and 70 girls. Groups of patients: 79 children with erythema migrans, 16 with Lyme arthritis, and 27 with nervous system involvement by LB. The quality of the prognostic model was checked by the Nagelkerke R Square (Nagelkerke R2) and the acceptability of this model was assessed using ROC analysis. Results: The method of multivariate regression analysis for predicting severe course and organ and system damage in LB in children, taking into account the factors and variants of the disease itself, makes it possible to develop a mathematical model for predicting the relative response factors (RRF) of severe forms of Lyme disease and will improve the effectiveness of treatment. This will create all the prerequisites for high-quality preventive measures and reduce the relative response factors rate.The initial data for predicting the severity of LB were 28 factors. According to the results of regression analysis, 24 factors were included in the model for predicting the severity of LB. Conclusions: The results of the study showed that the multifactorial model predicts the severity and organ and system damage in LB in children with an accuracy of 95%. The ROC curve, which was built on the basis of the results, has an area under the curve of 0.94, which indicates the high efficiency of the model.

The value of combining the simple anthropometric obesity parameters, Body Mass Index (BMI) and a Body Shape Index (ABSI), to assess the risk of non-alcoholic fatty liver disease.

BACKGROUND: Body mass index (BMI) and A Body Shape Index (ABSI) are current independent risk factors for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to explore the value of combining these two most common obesity indexes in identifying NAFLD. METHODS: The subjects in this study were 14,251 individuals from the NAfld in the Gifu Area, Longitudinal Analysis (NAGALA) cohort who underwent routine health examination. We integrated BMI with WC and with ABSI to construct 6 combined obesity indicators-obesity phenotypes, the combined anthropometric risk index (ARI) for BMI and ABSI, optimal proportional combination OBMI+WC and OBMI+ABSI, and multiplicative combination BMI*WC and BMI*ABSI. Several multivariable logistic regression models were established to evaluate the relationship between BMI, WC, ABSI, and the above six combined indicators and NAFLD; receiver operating characteristic (ROC) curves were drawn to compare the ability of each obesity indicator to identify NAFLD. RESULTS: A total of 2,507 (17.59%) subjects were diagnosed with NAFLD. BMI, WC, ABSI, and all other combined obesity indicators were significantly and positively associated with NAFLD in the current study, with BMI*WC having the strongest correlation with NAFLD in female subjects (OR per SD increase: 3.13) and BMI*ABSI having the strongest correlation in male subjects (OR per SD increase: 2.97). ROC analysis showed that ARI and OBMI+ABSI had the best diagnostic performance in both sexes, followed by BMI*WC (area under the curve: female 0.8912; male 0.8270). After further age stratification, it was found that ARI and multiplicative indicators (BMI*WC, BMI*ABSI) and optimal proportional combination indicators (OBMI+WC, OBMI+ABSI) significantly improved the NAFLD risk identification ability of the basic anthropometric parameters in middle-aged females and young and middle-aged males. CONCLUSION: In the general population, BMI combined with ABSI best identified obesity-related NAFLD risk and was significantly better than BMI or WC, or ABSI. We find that ARI and the multiplicative combined indicators BMI*WC and BMI*ABSI further improved risk prediction and may be proposed for possible use in clinical practice.

Detection of inaccessible head and neck lesions using human saliva and fluorescence spectroscopy.

Head and neck cancer detection using fluorescence spectroscopy from human saliva is reported here. This study has been conducted on squamous cell carcinoma (SCC), and dysplastic (precancer) and control (normal) groups using an in-house developed compact set-up. Fluorescence set-up consists of a 375-nm laser diode and optical components. Spectral bands of flavin adenine dinucleotide (FAD), porphyrins, and Raman are observed in the spectral range of 400 to 800 nm. Presence of FAD and porphyrin bands in human saliva is confirmed by the liquid phantoms of FAD and porphyrin. Significant differences in fluorescence intensities among all the three groups are observed. Three spectral ranges from 455 to 600, 605 to 770, and 400 to 800 nm are selected for each group and area values under each spectral range are computed. To differentiate among the groups, receiver operating characteristic (ROC) analysis is employed on the area values. ROC differentiates among the groups with accuracies of 98%, 92.85%, and 81.13% respectively in the spectral ranges of 400 to 800 nm. However, in other two spectral ranges (455 to 600 and 605 to 770 nm), low accuracy values are found. Obtained accuracy values indicate that selection of human saliva for head and neck cancer detection may be a good alternative.

Comprehensive Targeted Metabolomic Study in the Lung, Plasma, and Urine of PPE/LPS-Induced COPD Mice Model.

(1) Background: Progression of chronic obstructive pulmonary disease (COPD) leads to irreversible lung damage and inflammatory responses; however, biomarker discovery for monitoring of COPD progression remains challenging. (2) Methods: This study evaluated the metabolic mechanisms and potential biomarkers of COPD through the integrated analysis and receiver operating characteristic (ROC) analysis of metabolic changes in lung, plasma, and urine, and changes in morphological characteristics and pulmonary function in a model of PPE/LPS-induced COPD exacerbation. (3) Results: Metabolic changes in the lungs were evaluated as metabolic reprogramming to counteract the changes caused by the onset of COPD. In plasma, several combinations of phenylalanine, 3-methylhistidine, and polyunsaturated fatty acids have been proposed as potential biomarkers; the α-aminobutyric acid/histidine ratio has also been reported, which is a novel candidate biomarker for COPD. In urine, a combination of succinic acid, isocitric acid, and pyruvic acid has been proposed as a potential biomarker. (4) Conclusions: This study proposed potential biomarkers in plasma and urine that reflect altered lung metabolism in COPD, concurrently with the evaluation of the COPD exacerbation model induced by PPE plus LPS administration. Therefore, understanding these integrative mechanisms provides new insights into the diagnosis, treatment, and severity assessment of COPD.

The Usefulness of Auditory Perceptual Assessment and Acoustic Analysis as a Screening Test for Voice Problems.

BACKGROUND/AIMS: The aims of study were (1) to determine the cut-off values of parameters related to auditory perceptual assessment (visual analog scale [VAS]) and acoustic analysis (cepstral peak prominence [CPP], low-frequency/high-frequency [L/H] ratio, CPP SD, L/H ratio SD, acoustic voice quality index [AVQI], and cepstral spectral index of dysphonia [CSID]) for predicting voice problems within a Korean population, and (2) to verify the discriminative power of these cut-off values. METHODS: 1,113 voice samples were analyzed in this study. Perceptual assessments (VAS) were performed by 5 speech-language pathologists. For the acoustic analysis, cepstral parameters, CSID, and AVQI were calculated. The cut-off values of parameters predicting voice problems were obtained using receiver operating characteristic (ROC) analysis. Additionally, the sensitivity, specificity, and area under the ROC curve (AUC) were measured. RESULTS: High reliabilities were observed for the perceptual assessments. The cut-off values of parameters had a high sensitivity, specificity, and AUC. Of these, CSID was the parameter with the highest AUC values. CONCLUSION: Each parameter demonstrated a high discriminative power for classifying the presence or absence of voice problems. The results of this study could be used as an objective criterion for screening voice problems.

Validation and clinical usefulness of pre- and postoperative systemic inflammatory parameters as prognostic markers in patients with potentially resectable pancreatic cancer.

BACKGROUND: Several preoperative systemic inflammatory parameters, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), prognostic nutritional index (PNI), and Glasgow prognostic score, have been reported to be associated with the prognosis of solid tumors. In this study, we compared pre- and postoperative hematological inflammatory parameters and validated their prognostic significance in pancreatic cancer patients who underwent surgical resection. METHODS: Clinical records from 211 consecutive pancreatic cancer patients who underwent surgical resection at our institution were retrospectively analyzed. The optimal cutoff values of hematological inflammatory parameters, including lymphocyte count, NLR, PLR, LMR, and PNI, were determined by time-dependent receiver-operating characteristic analysis. RESULTS: The postoperative neutrophil count and serum albumin level were significantly decreased in patients who underwent pancreatoduodenectomy (PD group) and in those who underwent distal pancreatectomy (DP group) compared to the levels at baseline. The postoperative lymphocyte count, monocyte count, and platelet count were significantly increased in the DP group compared to those at baseline. As a result, the postoperative NLR and PNI significantly decreased in both groups. The multivariate analysis identified intraoperative peritoneal washing cytology, administration of adjuvant therapy, tumor size, extrapancreatic nerve plexus invasion, and preoperative PLR as independent prognostic factors for overall survival. CONCLUSIONS: Systemic inflammatory responses were altered after pancreatic resection in pancreatic cancer patients. Preoperative PLR may be a useful prognostic marker in pancreatic cancer patients undergoing surgical resection.

Nonparametric confidence regions for the symmetry point-based optimal cutpoint and associated sensitivity of a continuous-scale diagnostic test.

In medical research, diagnostic tests with continuous values are widely employed to attempt to distinguish between diseased and non-diseased subjects. The diagnostic accuracy of a test (or a biomarker) can be assessed by using the receiver operating characteristic (ROC) curve of the test. To summarize the ROC curve and primarily to determine an "optimal" threshold for test results to use in practice, several approaches may be considered, such as those based on the Youden index, on the so-called close-to-(0,1) point, on the concordance probability and on the symmetry point. In this paper, we focus on the symmetry point-based approach, that simultaneously controls the probabilities of the two types of correct classifications (healthy as healthy and diseased as diseased), and show how to get joint nonparametric confidence regions for the corresponding optimal cutpoint and the associated sensitivity (= specificity) value. Extensive simulation experiments are conducted to evaluate the finite sample performances of the proposed method. Real datasets are also used to illustrate its application.

A Diagnostic Biomarker for Pediatric Generalized Anxiety Disorder Using the Error-Related Negativity.

The error-related negativity (ERN) is a negative deflection in the event-related potential following a mistake that is a putative biomarker of anxiety. The study assessed the ERN as a diagnostic biomarker using receiver operating characteristic (ROC) analyses in 96 cases with anxiety disorders (AD) and 96 matched healthy controls (HC) ages 8 to 18 years. Forty-one cases had generalized anxiety disorder (GAD); 55 cases had other anxiety disorders (OAD) without GAD. ERN amplitude was significantly increased in AD cases compared to HC. The area under the curve (AUC) in the ROC analysis was 0.64, indicating the ERN is an inadequate diagnostic test for AD altogether. The ERN was significantly increased in cases with either GAD or OAD compared to HC. The AUC in ROC analyses with GAD and OAD was 0.75 and 0.56, respectively, suggesting the ERN provides an adequate diagnostic test for GAD but not for OAD.

[Comparison of Detectability for the New Image Processing and Conventional Image Processing by ROC Analysis: A Phantom Study of Chest Radiography].

The purpose of this study is to compare the detectability of diseases the new image processing and the conventional image processing by receiver operating characteristic (ROC) analysis and to show the usefulness of the new image processing. Radiographs with and without nodular cancer models in the chest phantom were used for observation samples. Totally 200 radiographs were evaluated by 10 radiological technologists (each readers had over 20 years or under 4 years of experience). The mean area under the curve (AUC) calculated from the over 20 years group was 0.754 for the new processing and 0.771 for the conventional processing (p value=0.651, 95% confidence interval=-0.084/0.049 (lower bound/upper bound)). On the other hand, the average AUC calculated from under 4 years group was 0.819 for the new processing and 0.678 for the conventional processing (p value= 0.041, 95% confidence interval=0.019/0.262 (lower bound/upper bound)). New image processing provides high detectability in less than 4 years group compared to conventional processing.

Association of Preoperative Platelet-to-Lymphocyte Ratio with Poor Outcome in Patients with Distal Cholangiocarcinoma.

BACKGROUND: Several preoperative systemic inflammatory parameters, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and Glasgow Prognostic Score, have been reported to be associated with the prognosis of solid tumors. However, there are conflicting survival data regarding these parameters in cholangiocarcinoma. OBJECTIVES: In this study, we performed a retrospective cohort analysis of patients with distal cholangiocarcinoma (DCC) who underwent surgical resection to evaluate the prognostic value of a cluster of preoperative hematological inflammatory parameters for survival. METHOD: Fifty-three patients with DCC who underwent pancreaticoduodenectomy with curative intent were enrolled. The optimal cutoff values of hematological inflammatory parameters, including the absolute lym-phocyte count, NLR, PLR, and LMR, were determined by time-dependent receiver operating characteristic analysis. -Results: The univariate analysis for overall survival (OS) of conventional factors and hematological inflammatory parameters identified that portal vein invasion and PLR had p values of ≤0.1. The univariate analysis for disease-free survival (DFS) identified that lymph node metastasis, PLR, lymphocyte count, and number of positive lymph nodes (≥3) had p values of ≤0.1. These factors were incorporated into the full model and variables were selected using the backward stepwise method. The multivariate analysis identified portal vein invasion and high PLR as independent prognostic factors for OS (p = 0.033 and 0.039, respectively) and high PLR and number of positive lymph nodes (≥3) as independent prognostic factors for DFS (p = 0.016 and 0.004, respectively). CONCLUSIONS: Preoperative PLR assessment may be useful for detecting high-risk DCC patients undergoing surgical resection for aggressive adjuvant therapy.

A grading system that predicts the risk of dialysis induction in IgA nephropathy patients based on the combination of the clinical and histological severity.

Histological classification is essential in the clinical management of immunoglobulin A nephropathy (IgAN). However, there are limitations in predicting the prognosis of IgAN based on histological information alone, which suggests the need for better prognostic models. Therefore, we defined a prognostic model by combining the grade of clinical severity with the histological grading system by the following processes. We included 270 patients and explored the clinical variables associated with progression to end-stage renal disease (ESRD). Then, we created a predictive clinical grading system and defined the risk grades for dialysis induction by a combination of the clinical grade (CG) and the histological grade (HG). A logistic regression analysis revealed that the 24-h urinary protein excretion (UPE) and the estimated glomerular filtration rate (eGFR) were significant independent variables. We selected UPE of 0.5 g/day and eGFR of 60 ml/min/1.73 m2 as the threshold values for the classification of CG. The risk of progression to ESRD of patients with CG II and III was significantly higher than that of patients with CG I. The patients were then re-classified into nine compartments based on the combination of CG and HG. Furthermore, the nine compartments were grouped into four risk groups. The risk of ESRD in the moderate, high, and super-high-risk groups was significantly higher than that in the low-risk group. Herein, we are giving a detailed description of our grading system for IgA nephropathy that predicted the risk of dialysis based on the combination of CG and HG.

In vivo detection of oral precancer using a fluorescence-based, in-house-fabricated device: a Mahalanobis distance-based classification.

In vivo detection of oral precancer has been carried out by a fluorescence-based, in-house-developed handheld probe on three groups: oral squamous cell carcinoma (OSCC), dysplastic (precancer), and control (normal). Measurements have been performed on a total of 141 patients and volunteers of different age groups. Excitation wavelength of 405 nm was used and fluorescence emission spectra were recorded in the scan range of 450.14 to 763.41 nm at very low incident power (122 µW) from different oral sites buccal mucosa (BM), lateral boarder of tongue (LBT), and dorsal surface of tongue (DST). Spectral profiles are found to vary among the three groups as well as among the different oral sites. Major and minor bands of flavin adenine dinucleotide (FAD) and porphyrins near 500, 634, 676, 689, and 703 nm have been obtained. Porphyrin contribution is found to be more dominant than the FAD in OSCC and dysplastic groups as compared to the control group. A better classification has been observed using the entire spectral range rather than restricting to individual bands, by application of principal component analysis (PCA), Mahalanobis distance model, and receiver operating characteristic analysis (ROC). ROC on Mahalanobis distance differentiates OSCC to normal, dysplastic to normal, and OSCC to dysplastic with sensitivities from 71% to 98%, 92% to 94% and 81% to 93% and specificities 91% to 100%, 86% to 100% and 79% to 97% for oral sites BM, LBT and DST. LBT and DST appear to be more sensitive to dysplasia detection as compared to BM.

[Image Evaluation with Paired Comparison Method Using Automatic Analysis Software: Comparison of CT Images with Simulated Levels of Exposure Dose].

To simplify a procedure of the observer study with Ura's method of Scheffé's paired comparison and to improve experimental accuracy, we developed a software package to automatically analyze observer study data obtained by using a computer interface developed specially for the ROC observer study. Simulated low-dose CT images were used to demonstrate practical utility of this proposed method with a software package, in terms of a statistical analysis of the change of noise property due to the change of exposure dose. Six radiological technologists were participated in this observer study and compared each of six sample images selected at lower lung and liver slices with dose levels of 100, 80, 60, 40, 20, 10% per case. In the statistical analysis, the average psychological measures were highly correlated with the dose levels (lower lungs: R=0.95, liver: R=0.99). In addition, there were statistically significant differences in all combination of dose levels in liver slices. In conclusion, we demonstrated practical utility of this proposed method in terms of simplification of experimental procedure and the consistency of the analytic results.

Receiver operating characteristic analysis of prediction for gastric cancer development using serum pepsinogen and Helicobacter pylori antibody tests.

BACKGROUND: Chronic Helicobacter pylori infection plays a central role in the development of gastric cancer as shown by biological and epidemiological studies. The H. pylori antibody and serum pepsinogen (PG) tests have been anticipated to predict gastric cancer development. METHODS: We determined the predictive sensitivity and specificity of gastric cancer development using these tests. Receiver operating characteristic analysis was performed, and areas under the curve were estimated. The predictive sensitivity and specificity of gastric cancer development were compared among single tests and combined methods using serum pepsinogen and H. pylori antibody tests. RESULTS: From a large-scale population-based cohort of over 100,000 subjects followed between 1990 and 2004, 497 gastric cancer subjects and 497 matched healthy controls were chosen. The predictive sensitivity and specificity were low in all single tests and combination methods. The highest predictive sensitivity and specificity were obtained for the serum PG I/II ratio. The optimal PG I/II cut-off values were 2.5 and 3.0. At a PG I/II cut-off value of 3.0, the sensitivity was 86.9% and the specificity was 39.8%. Even if three biomarkers were combined, the sensitivity was 97.2% and the specificity was 21.1% when the cut-off values were 3.0 for PG I/II, 70 ng/mL for PG I, and 10.0 U/mL for H. pylori antibody. CONCLUSIONS: The predictive accuracy of gastric cancer development was low with the serum pepsinogen and H. pylori antibody tests even if these tests were combined. To adopt these biomarkers for gastric cancer screening, a high specificity is required. When these tests are adopted for gastric cancer screening, they should be carefully interpreted with a clear understanding of their limitations.

Evaluation of endolymphatic hydrops using 3-T MRI after intravenous gadolinium injection.

Aim of this work is to establish evaluation criteria for identifying endolymphatic hydrops in the vestibule and cochlea using a magnetic resonance imaging (MRI) scanner. This is a retrospective diagnostic study. We evaluated 70 ears of 35 unilateral Ménière's disease patients. We performed 3-T MRI 4 h after intravenous gadolinium injection. Otologists manually traced the outline of vestibule, cochlea, and endolymphatic space of the vestibule and cochlea on two-dimensional fluid-attenuated inversion-recovery (2D-FLAIR) images. The traced area was measured, and rates of endolymphatic space to the vestibule and cochlea were calculated. The same otologists judged whether the low signal intensity area of the cochlea was at the edge of the cochlea. For measuring the rate of endolymphatic space to the vestibule, when the cut-off value was 30%, the presence of endolymphatic hydrops was determined with sensitivity of 87.1% and specificity of 94.3%. In contrast, the rate of endolymphatic space to the cochlea produced low accuracy. Therefore, when the presence of endolymphatic hydrops in the cochlea was judged by whether the low signal intensity area in the cochlea was at the edge of cochlea, endolymphatic hydrops could be detected with sensitivity of 91.4% and specificity of 94.3%. We were able to identify endolymphatic hydrops in the vestibule when the rate of endolymphatic space to the vestibule was greater than 30%, and could detect endolymphatic hydrops in the cochlea when a low signal intensity area was located at the edge of the cochlea in 2D-FLAIR images. Level of evidence 4.