Computerized scar detection on renal cortical scintigraphy images

This paper compares renal scintigraphy (RS) with renal vein renin activity (RVRA), intravenous pyelography (IVP), and peripheral plasma renin activity (pPRA) in a population of hypertensive subjects with suspect renovascular hypertension (RVH), of whom 30 underwent surgery, in order to evaluate (a) screening ability of RS for RVH, and (b) surgical prognosis of RS for RVH. RS agreed with arteriographic findings of arterial stenosis in 91% of patients and proved more sensitive as a screening test than IVP and pPRA. The false-negative rate of RS was 9% and the false-positive rate was 10%. In the patients who underwent surgery RS was positive in 89% and RVRA in 85% of those who benefited from surgery. In this series false-negatives for RS occurred only in the presence of extensive collateral circulation, where RVRA also gave the same result. In patients who had been operated on, the sensitivity and specificity of RS, compared to RVRA, were very high. Our work supports the view that RS is a good screening test in RVH; moreover, it seems to be as accurate as RVRA as a surgical prognostic method for curable RVH.

Objectives: The purpose of this study was to find out incidence of renal cortical scintigraphy done with Technetium-99m (Tc-99m) dimercaptosuccinic acid III (DMSA-III), scan to diagnose cortical scarring in patients undergoing staged reconstruction of exstrophy bladder. Patients and Methods: We retrospectively reviewed 29 post operative patients who were referred to our department for Tc99m-DMSA scan to look for renal cortical scarring from January 2012 to April 2016. Tc-99m DMSA(III) scan was done in all 29 patients (58 kidneys). Tc-99m DTPA and Tc-99m L, L-EC scans were done in 9 (18 kidneys) and 2 (4 kidneys) patients respectively. Results: Out of 29 patients male comprised 69% of cases (n = 20) and female comprised 31% of cases (n = 09).The mean age of the presentation of patients with exstrophy bladder was 7.8 years. Tc-99m DMSA(III) scan was done in 29 patients (58 kidneys).Scarring was noted in 28/58 kidneys (48.27%) on Tc-99m DMSA(III) scan. Tc-99m DTPA scan was done in 9 patients (18 kidneys). In Tc-99m DTPA scan mean GFR (standardized Gates gamma camera method) was 71.91ml/min. Micturating cystouretherography(MCU) was done in 10 patients which revealed vesicoureteric reflux(VUR) in all the patients. DRCG was done in 1 patient which showed unilateral high grade VUR. Ultrasonography (USG) was done in 29 patients. Eighteen patients were found to have normal USG findings. Four patients had bilateral hydroureteronephrosis (HDUN) and one had unilateral HDUN. Three had mild hydronephrosis (HDN) and 3 had gross HDN. Conclusion: Preservation of renal function is one of the major goals of staged reconstruction of bladder exstrophy. Renal cortical scintigraphy with Tc-99m DMSA-III has become the “the gold standard” for renal cortical scarring imaging. Hence Tc-99m DMSA scan offers a significant diagnostic advantage over other diagnostic modalities to diagnose and follow up renal cortical scarring in patients with exstrophy bladder thus help in management.

In this study, an automated scheme for detecting pulmonary nodules in PET/CT images has been proposed using combined detection and hybrid false-positive (FP) reduction techniques. The initial nodule candidates were detected separately from CT and PET images. FPs were then eliminated in the initial candidates by using support vector machine with characteristic values obtained from CT and PET images. In the experiment, we evaluated proposed method using 105 cases of PET/CT images that were obtained in the cancer-screening program. We evaluated true positive fraction (TPF) and FP / case. As a result, TPFs of CT and PET detections were 0.76 and 0.44, respectively. However, by integrating the both results, TPF was reached to 0.82 with 5.14 FPs/case. These results indicate that our method may be of practical use for the detection of pulmonary nodules using PET/CT images.

The identification of encrypted Instant Messaging (IM) channels between users is made difficult by the presence of variable and high levels of uncorrelated background traffic. In this paper, we propose a novel Cross-correlation Outlier Detector (CCOD) to identify communicating end-users in a large group of users. Our technique uses traffic flow traces between individual users and IM service provider's data center. We evaluate the CCOD on a data set of Yahoo! IM traffic traces with an average SNR of −6.11dB (data set includes ground truth). Results show that our technique provides 88% true positives (TP) rate, 3% false positives (FP) rate and 96% ROC area. Performance of the previous correlation-based schemes on the same data set was limited to 63% TP rate, 4% FP rate and 85% ROC area.

Renal cortical scintigraphy with 99Tcm-dimercaptosuccinic acid is an excellent imaging modality for the detection of renal cortical defects in children presenting with vesicoureteric reflux and urinary tract infections. Single photon emission computed tomography (SPECT) has proven increased sensitivity over planar scintigraphy for lesion detection in the heart, liver and brain. However, its role in the evaluation of renal cortical defects compared to planar scintigraphy has not been fully assessed. We wished to determine whether SPECT increases the sensitivity for detecting renal cortical defects in children compared to high-resolution planar scintigraphy. Forty-one children (90 renal units) with underlying vesicoureteric reflux and/or recently treated urinary tract infection (UTI) were evaluated. There was no statistically significant difference in the number of defects detected between a single-head SPECT system and high-resolution planar scintigraphy, 24 and 20, respectively (P = 0.54). There were four defects detected by SPECT not reported by planar scintigraphy; two of these were only seen retrospectively on planar scintigraphy. There were two children with renal cortical defects detected by SPECT and not by planar scintigraphy. All defects defected by planar scintigraphy were detected by SPECT. It is concluded that although the risk of missing renal cortical defects is low when using high-resolution, three-view planar scintigraphy, SPECT should be employed whenever feasible. Single photon emission computed tomography detected renal cortical defects in children not diagnosed by planar scintigraphy and hence patient management may be altered.

Consensus on renal cortical scintigraphy in children with urinary tract infection

The comparison of radiation attenuation correction techniques for relative renal function in renal cortical scintigraphy

In the field of natural language processing (NLP), sentiment analysis is very important for comprehending user views and opinions. By using the Kaggle ChatGPT sentiment analysis dataset, this work investigates the use of sophisticated ensemble machine learning algorithms to enhance ChatGPT’s sentiment classification performance. Due to its skewed distribution, the dataset poses particular difficulties in reaching high performance metrics. For sentiment classification, we evaluate the performance of many boosting techniques such as AdaBoost, Gradient Boosting Machine (GBM), XGBoost, LightGBM (LGBM), and CatBoost. Moreover, ensemble techniques such as majority voting and stacking are used to improve classification results. While majority voting combines predictions for robust classification, stacking specifically uses many base learners in conjunction with a meta-model to maximize performance. With a classification accuracy of 88.57%, precision of 88.67%, recall of 88.57%, and an F-measure of 88.57%, our tests show that stacking performs better than any other technique. Its efficient mistake mitigation is further demonstrated by its False Positive Rate (FPR) of 0.09 and False Negative Rate (FNR) of 0.13. These findings highlight how ensemble methods — in particular, stacking — can be used to handle skewed data and enhance sentiment classification capabilities. In light of ChatGPT and related conversational artificial intelligence (AI) technologies, the results offer important new information for the creation of trustworthy sentiment analysis systems.

In this paper, a novel hyperspectral subspace clustering algorithm based on decision fusion strategy (SCDFS) is proposed. Because the different clusters are contained in different subspace of the same hyper-dimensional data, the clustering processing in different subspace is conducted by genetic K-means algorithm (KGA). The clustering results from different subspace can be combined into decision string. The proposed subspace clustering based on decision fusion strategy is conducted on decision string. Considering the selection of subspace, the decision results may be inaccurate. So by the majority voting processing for different subspace, the steady subspace combination can be determined. Finally, the weighted strategy is introduced into SCDFS algorithm to evaluate the distance of different decision string, and determine the fusion clustering result.

Multiple Neural Network Classification Scheme for Detection of Colonic Polyps in CT Colonography Data Sets

Pathology Working Groups (PWG) are a specialized form of review consisting of a panel of expert pathologists who provide an independent, unbiased assessment of specific questions concerning study results. PWGs may concentrate on pivotal studies with controversial end points, address questions that are of concern to a regulatory agency, or compare the results of multiple studies that may have been conducted and evaluated by different laboratories and/or pathologists. The PWG does not review the entire study but always includes a preliminary review by a peer review pathologist. The PWG chairperson needs to thoroughly understand the issue in question, reviews all relevant data and study results, and is responsible for the organization and conduct of the PWG. The members of the PWG examine coded slides without knowledge of treatment group or previous diagnosis and arrive at a consensus diagnosis by majority vote. Once the results are decoded, the PWG evaluates the results and provides discussion and conclusions that are reflected in the final PWG report. Specific examples of PWG issues are provided.

Objective: Overlapping anatomy in projection mammography can degrade the detection of mammographic lesions and further create mass-like features that can confound computer-aided detection (CADe) systems and degrade their performance. Tri-plane correlation imaging (TCI) aims to reduce this impact by incorporating three projection images into CADe using a geometric correlation scheme. This study aimed to assess the efficacy of TCI for breast cancer detection. Materials and Methods: An image set of 198 human subjects was used from a breast tomosynthesis database. Each case included 25 projections acquired within a 45 degree angular span at an approximate total glandular dose equal to that of two-view mammography. Triplet images were derived from each case (the central projection along with two symmetrical images) and analyzed by two independent CADe programs. The CADe results from the three projections from each program were combined using two TCI correlation rules based on unanimous vote and majority vote. The findings were analyzed in terms of true positives (TP), sensitivity, false positives per breast volume (FP), and a positive predictive index combining the two figures (i.e., TP/(TP+FP)). Results: For the first CADe program, the TCI scheme using the majority voting rule improved sensitivity by 40% while maintaining specificity, leading to a 40% improvement in the PPI performance. For the second, a higher-sensitivity/lower-specificity CADe program, the TCI using the majority voting rule improved sensitivity by 10% while increasing false positives per breast volume by 3%, leading to an improvement of 8% in the PPI performance. The unanimous voting rule led to notably lower performance for both programs. For both CADe programs, an angular separation of six degrees (± 3 degrees) proved optimal. Conclusions: TCI was able to improve sensitivity over single projection imaging while maintaining specificity for both CADe programs, which suggests its potential as a supplement to standard mammography and as a complementary module to existing CADe algorithms.

Introduction: DMSA scan is superior to ultrasonography in detecting cortical scars, although the later identifies dilatation of the collecting systems and renal swelling. This study was conducted to know the role of 99m- Tc Dimercaptosuccinic acids (DMSA) scan in children with UTI, its role in the early detection of renal scar. Materials and Methods: A study was conducted among 125 children at Dr. B.R. Ambedkar Medical College, Bangalore from August 2015- October 2017. The study group included both inpatient and outpatient children with urinary tract infection. The patients with culture positive urinary tract infections during first and recurrent attacks were studied and followed from 3 months to 2 years. On follow- up 99m -Tc DMSA scan was conducted, if needed USG abdomen and MCU scan were conducted. Results: 44% of the children showed abnormal features both by DMSA scan and USGand 21.6% of the children had normal scan but found to have abnormality in DMSA scan. On follow- up of the children, it was noticed that in 56% of the DMSA scan was normal, in 6% of children who initially had renal scar, on follow up did not have renal scar. 24% of the children persisted to have renal scar on follow up and 12% who initially had normal DMSA scan, on follow up had scar. In that 12 children with renal scar, all the children had VUR grade 4-5. Conclusion: 99m-Tc DMSA scintigraphy is the gold standard for early identification and evaluation of acute renal inflammation and subsequent renal scarring. This study recommends both renal ultrasound scanning and 99m-Tc DMSA scintigraphy to be routinely performed in infants and children with a first febrile UTI because ultrasonography alone as low sensitivity for the detection of renal cortical abnormalities.

Die Nierenszintigrafie gehört zu den häufigsten nuklearmedizinischen Verfahren, die insbesondere im Kindesalter durchgeführt werden. Dieser Übersichtsartikel erläutert ausführlich die Indikationen, die Untersuchungsvorbereitung, die Datenakquisition, die Auswertung und die Interpretation der Nierenfunktionsszintigrafie mit 99mTc-MAG3, einschl. der indirekten Refluxprüfung (Radionuklidzystografie) und der statischen Nierenszintigrafie mit 99mTc-DMSA. Die aktuellen Kontroversen in der Beurteilung werden berücksichtigt, insbesondere im Hinblick auf die Interpretation des verminderten bzw. verzögerten Abflusses. Potenzielle Fehlerquellen und deren Vermeidung bei der Durchführung und Auswertung werden ausführlich dargestellt. Die Nierenfunktionsszintigrafie ist eine einfach durchzuführende, robuste Routinemethode und dient der visuellen und quantitativen Beurteilung verschiedener Teilaspekte der Nierenfunktion.

Ultrasonography is one of the most important methods for breast cancer screening in Japan. Several mechanical whole breast ultrasound (US) scanners have been developed for mass screening. We have reported a computer-aided detection (CAD) scheme for the detection of masses in whole breast US images. In this study, the method of detecting mass candidates and the method of reducing false positives (FPs) were improved in order to enhance the performance of this scheme. A 3D difference (3DD) filter was newly developed to extract low-intensity regions. The 3DD filter is defined as the difference of pixel values between the current pixel value and the mean pixel value of 17 neighboring pixels. Low-intensity regions were efficiently extracted by use of 3DD filter values, and FPs were reduced using a FP reduction method employing the rule-based technique and quadratic discriminant analysis with the filter values. The performance of our previous and improved CAD schemes indicated a sensitivity of 80.0% with 16.8 FPs and 9.5 FPs per breast, respectively. The FPs of the improved scheme were reduced by 44% as compared to the previous scheme. The 3DD filter was useful for the detection of masses in whole breast US images.