Increase In Positive Predictive Value Research Articles

Interpretable diagnosis of breast lesions in ultrasound imaging using deep multi-stage reasoning

Objective.Ultrasound is the primary screening test for breast cancer. However, providing an interpretable auxiliary diagnosis of breast lesions is a challenging task. This study aims to develop an interpretable auxiliary diagnostic method to enhance usability in human-machine collaborative diagnosis.Approach.To address this issue, this study proposes the deep multi-stage reasoning method (DMSRM), which provides individual and overall breast imaging-reporting and data system (BI-RADS) assessment categories for breast lesions. In the first stage of the DMSRM, the individual BI-RADS assessment network (IBRANet) is designed to capture lesion features from breast ultrasound images. IBRANet performs individual BI-RADS assessments of breast lesions using ultrasound images, focusing on specific features such as margin, contour, echogenicity, calcification, and vascularity. In the second stage, evidence reasoning (ER) is employed to achieve uncertain information fusion and reach an overall BI-RADS assessment of the breast lesions.Main results.To evaluate the performance of DMSRM at each stage, two test sets are utilized: the first for individual BI-RADS assessment, containing 4322 ultrasound images; the second for overall BI-RADS assessment, containing 175 sets of ultrasound image pairs. In the individual BI-RADS assessment of margin, contour, echogenicity, calcification, and vascularity, IBRANet achieves accuracies of 0.9491, 0.9466, 0.9293, 0.9234, and 0.9625, respectively. In the overall BI-RADS assessment of lesions, the ER achieves an accuracy of 0.8502. Compared to independent diagnosis, the human-machine collaborative diagnosis results of three radiologists show increases in positive predictive value by 0.0158, 0.0427, and 0.0401, in sensitivity by 0.0400, 0.0600 and 0.0434, and in area under the curve by 0.0344, 0.0468, and 0.0255.Significance.This study proposes a DMSRM that enhances the transparency of the diagnostic reasoning process. Results indicate that DMSRM exhibits robust BI-RADS assessment capabilities and provides an interpretable reasoning process that better suits clinical needs.

The Impact of Intraoperative Glucagon on the Diagnostic Accuracy of Intraoperative Cholangiogram for the Diagnosis of Choledocholithiasis: Experience from a Large Tertiary Care Center.

A proportion of patients who undergo intraoperative cholangiogram (IOC) do not have bile duct stones at the time of endoscopic retrograde cholangiopancreatography (ERCP), either due to the spontaneous passage of stones or a false-positive IOC. Glucagon has been utilized as an inexpensive tool to allow the passage of micro-choledocholithiasis to the duodenum and resolve filling defects caused by stones or air bubbles. The purpose of our study is to understand the change in diagnostic accuracy of IOC to detect choledocholithiasis with intraoperative glucagon. We conducted a retrospective study at a tertiary care center on adult patients who underwent laparoscopic cholecystectomy with IOC. The diagnostic accuracy of IOC was assessed before and after the administration of intravenous glucagon. Of 1455 patients, 374 (25.7%) received intraoperative glucagon, and 103 of these 374 patients (27.5%) showed resolution of the filling defect with the passage of contrast to the duodenum. Pre- and post-glucagon administration comparison showed enhancement in specificity from 78% to 83%, an increase in positive predictive value from 67.3% to 72.4%, and an improvement in the diagnostic accuracy of IOC from 81.5% to 84.3%. Our findings suggest that intraoperative glucagon administration carries the potential to reduce the rate of false-positive IOCs, thereby reducing the performance of unnecessary ERCPs.

Prospective implementation of AI-assisted screen reading to improve early detection of breast cancer

Artificial intelligence (AI) has the potential to improve breast cancer screening; however, prospective evidence of the safe implementation of AI into real clinical practice is limited. A commercially available AI system was implemented as an additional reader to standard double reading to flag cases for further arbitration review among screened women. Performance was assessed prospectively in three phases: a single-center pilot rollout, a wider multicenter pilot rollout and a full live rollout. The results showed that, compared to double reading, implementing the AI-assisted additional-reader process could achieve 0.7–1.6 additional cancer detection per 1,000 cases, with 0.16–0.30% additional recalls, 0–0.23% unnecessary recalls and a 0.1–1.9% increase in positive predictive value (PPV) after 7–11% additional human reads of AI-flagged cases (equating to 4–6% additional overall reading workload). The majority of cancerous cases detected by the AI-assisted additional-reader process were invasive (83.3%) and small-sized (≤10 mm, 47.0%). This evaluation suggests that using AI as an additional reader can improve the early detection of breast cancer with relevant prognostic features, with minimal to no unnecessary recalls. Although the AI-assisted additional-reader workflow requires additional reads, the higher PPV suggests that it can increase screening effectiveness.

Early NSE measurements at the ICU bear prognostic value in patients with and without CPR

Abstract Funding Acknowledgements Type of funding sources: None. Background Neuron-specific enolase (NSE) represents a diagnostic tool for identifying poor neurological outcomes in patients following CPR. As part of multimodal prognostication, NSE values above 60 µg/L after 48h and/or 72h were associated with a worse neurologic outcome (European Resuscitation Council Guidelines 2021). Despite the prognostic value of NSE 48h to 72h after CPR, measurements at admission to the ICU remain the topic of discussion as divergent findings are present in the literature (primarily in small collectives). Purpose Within the proposed study, we aimed to illuminate the prognostic value of NSE measurements on the day of admission to the ICU. Furthermore, we conducted a comparison of patients with and without CPR prior to ICU admission. Due to hemolysis sensitivity, we adjusted NSE values according to a previously published protocol to reveal potential changes in predictive potential through the occurrence of hemolysis. Methods This was a prospective, observational cohort study. 232 consecutive patients admitted to a cardiac ICU were screened over the course of one year. Patients with active malignancies or traumatic brain injuries were excluded. Furthermore, samples with hemolysis index >30 units were excluded to guarantee stable measurements. NSE values were measured on the day of admission to the ICU in a total of 202 patients (154 without previous CPR, 48 with CPR) using specific ELISA kits. According to an earlier publication, hemolysis was considered to account for an artificial increase of 0.29µg/L per unit (range 5-30 units) and was subsequently subtracted. Results Median age was 66.96 (IQR: 55.7-76.9), and 41.1% of the included patients were female. The total 30-day-mortality was calculated to be 27.2%, and 48 patients (23.8%) were admitted following CPR. Interestingly NSE at admission was not higher in patients after CPR (3.23 ± 3.88 µg/L vs 5.43 ± 5.78 µg/L, p = 0.072). However, NSE measurements on the day of admission were significantly elevated in 30-day none-survivors (3.23 ± 3.84 µg/L vs 6.91 ± 6.55 µg/L, p < 0.001). The same findings were made when excluding all patients after CPR (30-day survivors: 3.24 ± 3.99 µg/L vs 30-day none-survivors: 6.15 ± 6.17µg/L, p = 0.001). No statistically significant differences in survival were found when stratifying for the primary cause of admission. Comparing hemolysis-corrected NSE values to raw data showed a slight increase in positive predictive value for 30-day mortality in the total cohort (ROC-AUC: 0.732 vs 0.721) as well as in patients without prior CPR (ROC-AUC: 0.722 vs 0.703). Conclusion We provided evidence for the prognostic value of early NSE measurements at the ICU. In both the total cohort as well as a sub-cohort without patients admitted after CPR, 30-day none-survivors displayed markedly elevated levels of NSE. Moreover, the positive predictive value of these measurements was slightly increased when correcting for hemolysis >5 units.

Ultrasonographic evaluation of cervical length and amniotic fluid index as predictor of pregnancy outcome in cases of preterm premature rupture of membrane

Background: Amniotic fluid index (AFI) and cervical length (CL) can be used to predict delivery latency, maternal, and neonatal outcome in cases of preterm premature rupture of membrane (PPROM). Aims and Objectives: The aims of this study were to study the AFI and CL as a predictor of pregnancy outcome in cases presenting with PPROM, to determine the AFI in cases presenting with PPROM, to determine CL ultrasonographically in cases presenting with PPROM, and to measure the efficacy of these parameters as a predictor of pregnancy outcome in cases presenting with PPROM. Materials and Methods: This was an ambispective observational study conducted from November 2019 to July 2021 in the Department of Obstetrics and Gynecology in S. N. Medical College, Agra. A total of 100 women with singleton pregnancy and vertex presentation who presented to hospital within 12 h of spontaneous rupture of membrane (PPROM) from period of gestation 28–34+6 weeks were enrolled in this study. Results: Delivery latency was inversely related to period of gestation at pprom (P<0.0001). Mean AFI in Group 1 was 5.15 cm and in Group 2 was 7.12 cm and the difference between both group was statistically significant (P<0.0001). Thus, our study shows positive correlation between AFI and delivery latency. Mean transvaginal CL (TVCL) in Group 1 was 2.47 cm and in Group 2 was 2.99 cm. Difference in terms of TVCL between both the groups was found to be statistically significant (P=0.00005). Need for neonatal intensive care unit admission was higher in Group 1 than Group 2 and this difference was statistically significant (P=0.020). Conclusion: Our study shows that there was an increase in positive predictive value when we combine AFI and TVCL in prediction of delivery latency, so women with AFI ≤5 and TVCL ≤2.5 cm had 85.6% risk of delivery within 7 days after PPROM. A long CL (TVCL >2.5 cm) and AFI >5 correlated with increased delivery latency and increased risk of maternal morbidity (chorioamnionitis, abruption, and cord prolapse).

Causal determinants of complex PTSD in Syrian refugee children living in informal settlements in Lebanon

IntroductionDisplaced refugee children with a history of war exposure are at risk of developing complex and severe forms of post-traumatic stress disorder (PTSD).ObjectivesSearch for the most relevant causal predictors of complex PTSD in a prospective cohort of Syrian refugee children living in informal settlements in Lebanon (N=1007).Methods A latent class unsupervised analysis was carried out to determine clusters with complex PTSD presentation at the follow-up assessment. A new exploratory causal discovering modelling approach was applied using 97 multilevel psychosocial variables as predictors (Biazoli et al., 2021). Associations between discovered candidate causal factors assessed at baseline with a presumed diagnosis of complex PTSD one year later were calculated using a multiple logistic regression model.Results Several putative causal factors emerged: perceived social coherence of the neighbourhood (Positive Predictive Value increase: 1.22); impulsivity (1.25), self-efficacy (1.23) and depressive symptoms (1.15) at the parental level; positive home experiences (1.16) at the family level; and child-level factors such as being forced to work (1.22), being a victim of verbal or physical bullying (1.19), loneliness (1.17) and well-being (1.18). In further confirmatory multiple logistic regression analysis and after correction for multiple comparisons, verbal or physical bullying victimization (p=.005) and caregiver depressive symptoms (p=.0004) at baseline were associated with complex PTSD presentations one year later.Conclusions Our results support the need for a multi-level psychosocial care model to prevent psychological distress and promote mental health in refugee children. Specifically, our results suggest that programs tackling caregiver’s mental health and children’s exposure to violence might effectively prevent complex PTSD.DisclosureNo significant relationships.

Abstract A33: High-throughput prediction of MHC Class I and Class II neoantigens with MHCnuggets

Abstract Computational prediction of binding between neoantigen peptides and major histocompatibility complex (MHC) proteins is an emerging biomarker for predicting patient response to cancer immunotherapy. Current neoantigen predictors focus on in silico estimation of MHC binding affinity and are limited by low positive predictive value for actual peptide presentation, inadequate support for rare MHC alleles, and poor scalability to high-throughput data sets. To address these limitations, we developed MHCnuggets, a deep neural network method to predict peptide-MHC binding. MHCnuggets is the only method to handle binding prediction for common or rare alleles of MHC Class I or II, with a single neural network architecture. Using a long short-term memory network (LSTM), MHCnuggets accepts peptides of variable length and is capable of faster performance than other methods. When compared to methods that integrate binding affinity and HLAp data from mass spectrometry, MHCnuggets yields a fourfold increase in positive predictive value on independent MHC-bound peptide (HLAp) data. We applied MHCnuggets to 26 cancer types in TCGA, processing 52.6 million allele-peptide comparisons in under 2.3 hours, yielding 103,587 candidate immunogenic missense mutations (IMMs). IMM hotspots occurred in 36 genes, including 22 driver genes. Predicted IMM load was significantly associated with increased immune cell infiltration (p<2e-16), including CD8+ T cells. Notably, only 0.15% of predicted immunogenic missense mutations were observed in >2 patients, with 65% of these derived from driver mutations. Our results provide a new method for neoantigen prediction with high performance characteristics and demonstrate its utility in large data sets across human cancers. Citation Format: Xiaoshan M. Shao, Rohit Bhattacharya, Justin Huang, Ashok Sivakumar, Collin Tokheim, Lily Zheng, Dylan Hirsch, Ben Kaminow, Ashton Omdahl, Maria Bonsack, Angelika B. Riemer, Victor E. Velculescu, Valsamo Anagnostou, Kymberleigh Pagel, Rachel Karchin. High-throughput prediction of MHC Class I and Class II neoantigens with MHCnuggets [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A33.

High-Throughput Prediction of MHC Class I and II Neoantigens with MHCnuggets.

Computational prediction of binding between neoantigen peptides and major histocompatibility complex (MHC) proteins can be used to predict patient response to cancer immunotherapy. Current neoantigen predictors focus on in silico estimation of MHC binding affinity and are limited by low predictive value for actual peptide presentation, inadequate support for rare MHC alleles, and poor scalability to high-throughput data sets. To address these limitations, we developed MHCnuggets, a deep neural network method that predicts peptide-MHC binding. MHCnuggets can predict binding for common or rare alleles of MHC class I or II with a single neural network architecture. Using a long short-term memory network (LSTM), MHCnuggets accepts peptides of variable length and is faster than other methods. When compared with methods that integrate binding affinity and MHC-bound peptide (HLAp) data from mass spectrometry, MHCnuggets yields a 4-fold increase in positive predictive value on independent HLAp data. We applied MHCnuggets to 26 cancer types in The Cancer Genome Atlas, processing 26.3 million allele-peptide comparisons in under 2.3 hours, yielding 101,326 unique predicted immunogenic missense mutations (IMM). Predicted IMM hotspots occurred in 38 genes, including 24 driver genes. Predicted IMM load was significantly associated with increased immune cell infiltration (P < 2 × 10-16), including CD8+ T cells. Only 0.16% of predicted IMMs were observed in more than 2 patients, with 61.7% of these derived from driver mutations. Thus, we describe a method for neoantigen prediction and its performance characteristics and demonstrate its utility in data sets representing multiple human cancers.

Boosted trees to predict pneumonia, growth, and meat percentage of growing-finishing pigs1.

In pig production, efficiency is benefiting from uniform growth in pens resulting in single deliveries from a pen of possibly all animals in the targeted weight range. Abnormalities, like pneumonia or aberrant growth, reduce production efficiency as it reduces the uniformity and might cause multiple deliveries per batch and pigs delivered with a low meat yield or outside the targeted weight range. Early identification of pigs prone to develop these abnormalities, for example, at the onset of the growing-finishing phase, would help to prevent heterogeneous pens through management interventions. Data about previous production cycles at the farm combined with data from the piglet’s own history may help in identifying these abnormalities. The aim of this study, therefore, was to predict at the onset of the growing-finishing phase, that is, at 3 mo in advance, deviant pigs at slaughter with a machine-learning technique called boosted trees. The dataset used was extracted from the farm management system of a research center. It contained over 70,000 records of individual pigs born between 2004 and 2016, including information on, for example, offspring, litter size, transfer dates between production stages, their respective locations within the barns, and individual live-weights at several production stages. Results obtained on an independent test set showed that at a 90% specificity rate, the sensitivity was 16% for low meat percentage, 20% for pneumonia and 36% for low lifetime growth rate. For low lifetime growth rate, this meant an almost three times increase in positive predictive value compared to the current situation. From these results, it was concluded that routine performance information available at the onset of the growing-finishing phase combined with data about previous production cycles formed a moderate base to identify pigs prone to develop pneumonia (AUC > 0.60) and a good base to identify pigs prone to develop growth aberrations (AUC > 0.70) during the growing-finishing phase. The mentioned information, however, was not a sufficient base to identify pigs prone to develop low meat percentage (AUC < 0.60). The shown ability to identify growth aberrations and pneumonia can be considered a good first step towards the development of an early warning system for pigs in the growing-finishing phase.

Is it possible to achieve more accurate mediastinal nodal radiotherapy planning for NSCLC with PET/CT?

To assess whether more accurate mediastinal lymph nodes radiotherapy can be performed with fluorode oxyglu cosepositron emission tomogaphy/computed tomography. The retrospective study was conducted at Inonu University Medical Faculty, Malatya, Turkey, and Afyon Kocatepe University Medical Faculty, Afyon, Turkey, and comprised record of patients histopathologically diagnosed with non-small cell lung carcinoma and who underwent fluorodeoxyglucose positron emission tomography / computed tomography between January 2013 and December 2016. Surgery and pathology reports of the patients were reviewed. Histopathologically proven malignant and benign lymph nodes were re-identified with fluorodeoxyglucose positron emission tomography / computed tomography imaging. Anatomical and metabolic parameters of lymph nodes were re-assessed by specialists and compared with histopathology reports. Maximum standardised uptake values were used to assess sensitivity, specificity, positive predictive value, and negative predictive values. SPSS 22 was used for data analysis. The study included 144 mediastinal lymph nodes related to 42 patients who had a mean age of 62.4±9.8 years (range: 41-79 years). In terms of subtypes of the primary squamous cell carcinoma was found in 24(57.2%) patients, adenocarcinoma in 12(27.5%), and other subtypes in 6(15.3%) patients. Of the 144 lymph nodes, 48(33.3%) were metastatic. Sensitivity, specificity, positive predictive value, and negative predictive value were 92.8%, 64.3%, 56.9%, and 94.7%, respectively when maximum standardised uptake value >2.5 was used as the malignancy criterion. When lymph node maximum standardised uptake value / liver standardised uptake value-mean>1.69 was used as the criterion, the sensitivity, specificity, positive predictive value, and negative predictive value were 95.83%, 91.67%, 85.2%, and 97.8%, respectively. When the same values with lymph node >8mm was used as the criterion, the four resultant values were 89.6%, 93.8%, 87.8%, and 94.7%, respectively. When lymph node was replaced with mean attenuation >35 as the criterion, the consequent values were 79.2%, 93.8%, 86.4%, and 90.0%, respectively. Lymph node maximum standardised uptake value / liver standardised uptake valuemean> 1.69 was associated with higher negative predictive value and more useful positive predictive value compared to maximum standardised uptake value >2.5. When this parameter was used along with short axis or mean attenuation value, there were no significant increase in positive predictive value, but there was a decrease in negative predictive value.

Do Deauville Scores Improve the Clinical Utility of End-of-Therapy FDG PET Scans for Pediatric Hodgkin Lymphoma?

The purpose of this study was to evaluate the clinical utility of Deauville scores in interpretation of end-of-chemotherapy FDG PET scans. Deauville scores improve the clinical utility of end-of-chemotherapy PET, as evidenced by an increase in positive predictive value to 72.7% from 44.4% on the basis of report alone. The negative predictive value remains greater than 95%.

Utility of a time frame in assessing psychological pain and suicide ideation.

BackgroundAssessing psychological pain has been recommended as an integral part of a comprehensive suicide risk assessment. The Psychache Scale, an established measure of psychological pain, does not specify a time frame for when pain is experienced, which may inadvertently increase the likelihood of identifying individuals as being at elevated suicide risk when they complete the Psychache Scale based on psychological pain experienced at some undefined time in the past.MethodsWe conducted a national general population survey among United States adults to determine whether addition of a time frame to the instructions of the Psychache Scale would more accurately reflect current psychological pain and more effectively identify people with current suicide ideation. A between-subjects design was used where respondents were randomized to complete the original Psychache scale or a modified scale with time frame. Data were collected online from September 2015 to June 2016. A total of 242 respondents had complete psychological pain data: 133 completed the original Psychache Scale and 109 completed the Psychache Scale with time frame.ResultsAddition of a time frame did not result in differences in psychological pain scores. However, when screening for participants with current suicide ideation, 13% fewer false positives were observed with the modified scale at higher cut-off values than previously reported (38 vs. 24). The substantial increase in positive predictive value suggests that a time frame is a worthwhile addition to the Psychache Scale.DiscussionWe recommend using the Psychache Scale with a time frame and testing the cut-off score for suicide ideation in population samples that reflect the general population more accurately. Psychological pain cut-off scores in clinical samples have yet to be established.

Predictors of Good Long-Term Renal Outcomes in Lupus Nephritis: Results from a Single Lupus Cohort.

This study aims to elucidate the predictive capabilities of proteinuria, serum creatinine (Cr), and urine RBCs (uRBCs) with respect to long-term renal outcomes in lupus nephritis (LN) in patients followed in clinic. Methods. A retrospective analysis was performed on patients with LN. We evaluated the ability of proteinuria, serum Cr, and uRBCs at 12 months to predict good long-term renal outcomes defined as serum Cr ≤ 100 mmol/L and kidney transplant/dialysis-free at the 7th year. Receiver operator characteristic curves were generated for proteinuria, serum Cr, and uRBCs to study their ability to predict good long-term outcomes and to identify their best cut-off. Descriptive statistics studied the pattern of change of proteinuria and serum Cr. Results. Proteinuria of 0.6 g/d and Cr of 83 mmol/L performed independently moderately well in predicting good long-term renal outcomes while uRBC was less accurate. Combining serum Cr to proteinuria gave a small increase in positive predictive value with a trade-off in sensitivity. Proteinuria changed within the first year whereas serum Cr changed until the 7th year. Conclusions. Both proteinuria and Cr predict good long-term renal outcomes in LN. Proteinuria's ability to change faster at 12 months makes it a favorable endpoint for clinical trials and research studies.

Significantly Improved Performance of a Multitarget Assay Over a Commercial SCCmec-Based Assay for Methicillin-Resistant Staphylococcus aureus Screening: Applicability for Clinical Laboratories

Detection of the SCCmec gene is a common strategy for methicillin-resistant Staphylococcus aureus (MRSA) screening assays. However, if SCCmec is used alone, it may not be specific for detecting MRSA. Herein, we describe an in-house MSRA PCR-based screening assay involving detection of three targets (nuc, coa, and mecA). The assay is suitable for a wide range of real-time PCR platforms used in clinical microbiological laboratories. Performance characteristics of the in-house assay were significantly improved compared with the commercial assay, leading to an increase of positive predictive value by 40%. Compared with the bacterial culture, the sensitivity, specificity, and positive and negative predictive values of the in-house PCR assay were 100% (95% CI>83.2%), 99.2% (95% CI = 98.2% to 99.8%), 80% (95% CI = 59.3% to 93.2%), and 100% (95% CI >99.2%), respectively.

Customer Behavior Analysis Using Rough Set Approach

The customer relationship management (CRM) is a business methodology used to build long term profitable customers by analyzing customer needs and behaviors. The customer behavior is analyzed by choosing important attributes in the customer database. The customers are then segmented into groups according to their attribute values. The rules are generated using rule induction algorithms to describe the customers in each group. These rules can be used by the entrepreneur to predict the behavior of their new customers and to vary the attraction process for existing customers. In this paper a new rule algorithm has been proposed based on the concepts of rough set theory. Its performance has been compared with LEM2 (Learning from Examples Module, version 2) algorithm, an existing rough set based rule induction algorithm. Real data set of the customer transaction is used for analysis. Recency(R), Frequency (F), Monetary (M) and Payment (P) are the attributes chosen for analyzing customer data. The proposed algorithm on average achieves 0.439% increase in sensitivity, 0.007% increase in specificity, 0.151% increase in accuracy, 0.014% increase in positive predictive value, 0.218% increase in negative predictive value and 0.228% increase in F-measure when compared to LEM2 algorithm.

The role of PET/CT in detection of gastric cancer recurrence

BackgroundIn the course of surveillance of gastric cancer recurrence after curative resection, contrast CT scan is used in general. However, new findings from CT scan are not always confirmatory for the recurrence. In this case, we usually use short-term follow up strategy or therapeutic intervention with clinical decision. Recently, the use of fusion Positron Emission Tomography/Computed Tomography (PET/CT) is increasing. The purpose of this study is to evaluate the efficacy and usefulness of PET/CT for detecting recurrence of gastric cancer after curative resection.MethodsFifty two patients who received curative resection of gastric cancer and had undergone PET/CT and contrast CT for surveillance of recurrence until Dec 2006 in Seoul National University Hospital were analyzed retrospectively. Recurrence of gastric cancer was validated by histologic confirmation (n = 17) or serial contrast CT follow up with at least 5 month interval (n = 35). McNemar's test and Fisher's exact test were used to evaluate sensitivity and specificity of PET/CT and contrast CT.ResultsOf 52 patients, 38 patients were confirmed as recurrence. The sensitivity was 68.4% (26/38) for PET/CT and 89.4% (34/38) for contrast CT (p = 0.057). The specificity was 71.4% (10/14) and 64.2% (9/14), respectively (p = 1.0). In terms of the recurred sites, the sensitivity and specificity of PET/CT were similar to those of contrast CT in all sites except peritoneum. Contrast CT was more sensitive than PET/CT (p = 0.039) for detecting peritoneal seeding. Additional PET/CT on contrast CT showed no further increase of positive predictive value regardless of sites. Among 13 patients whose image findings between two methods were discordant and tissue confirmation was difficult, the treatment decision was made in 7 patients based on PET/CT, showing the final diagnostic accuracy of 42.8% (3/7).ConclusionPET/CT was as sensitive and specific as contrast CT in detection of recurred gastric cancer except peritoneal seeding. However, additional PET/CT on contrast CT did not increase diagnostic accuracy in detection of recurred gastric cancer. Further studies are warranted to validate the role of PET/CT in detection of gastric cancer recurrence.

Blunt bowel and mesenteric injuries in children: Do nonspecific computed tomography findings reliably identify these injuries?

Abdominal computed tomography has proven accurate for the detection of pediatric solid organ injuries following blunt abdominal trauma but is less reliable in detecting blunt bowel and mesenteric injuries (BBMI). The purpose of this study was to determine the significance of nonspecific findings on abdominal computed tomography (CT) scan in children at risk for BBMI. Retrospective chart review. Regional pediatric trauma center. All patients who received an abdominal CT scan as part of their evaluation following blunt abdominal trauma over a 10-yr period (September 1991 to September 2001). None. Individual records were reviewed by one of the authors and analyzed for age, gender, mechanism of injury, diagnostic studies and procedures, results of initial CT scan, treatment, surgical procedures, complications, and outcome. Patients were excluded if they suffered penetrating trauma, had an abdominal CT scan performed at another institution, had a surgical procedure before CT scan, or had incomplete records. A total of 2,114 patients met inclusion criteria. Sixty-five percent were male and ages ranged from 3 wks to 18 yrs. There were 178 patients who had at least one nonspecific finding on abdominal CT scan suggestive of BBMI; 151 patients had one finding, 24 patients had two findings, and three had three findings. The risk of BBMI increased with the number of nonspecific findings (positive predictive value = 11% with at least one finding and 44% with two or more findings). This increase in positive predictive value, however, was accompanied by a reduction in sensitivity (62% and 37%, respectively). A total of 32 patients had surgically proven BBMI. Of these, eight had a single nonspecific finding on CT scan, ten had two findings, and two had three findings (12 patients had no CT findings suggestive of BBMI). There were complications in four of the 32 patients with BBMI and one death (due to laceration of the superior mesenteric artery). The complications appeared to occur independent of the time to surgical intervention. The presence of multiple nonspecific findings on abdominal CT scan does not reliably predict BBMI in children. Children also appear to suffer complications from BBMI less frequently than adults, regardless of the time to surgery. Therefore, nonspecific findings alone do not warrant surgical exploration. The decision to operate should instead be based on clinical data that include serial physical examinations.

Continuing Medical Education Questions

Objective: Abdominal computed tomography has proven accurate for the detection of pediatric solid organ injuries following blunt abdominal trauma but is less reliable in detecting blunt bowel and mesenteric injuries (BBMI). The purpose of this study was to determine the significance of nonspecific findings on abdominal computed tomography (CT) scan in children at risk for BBMI. Design: Retrospective chart review. Setting: Regional pediatric trauma center. Patients: All patients who received an abdominal CT scan as part of their evaluation following blunt abdominal trauma over a 10-yr period (September 1991 to September 2001). Interventions: None. Measurements and Main Results: Individual records were reviewed by one of the authors and analyzed for age, gender, mechanism of injury, diagnostic studies and procedures, results of initial CT scan, treatment, surgical procedures, complications, and outcome. Patients were excluded if they suffered penetrating trauma, had an abdominal CT scan performed at another institution, had a surgical procedure before CT scan, or had incomplete records. A total of 2,114 patients met inclusion criteria. Sixty-five percent were male and ages ranged from 3 wks to 18 yrs. There were 178 patients who had at least one nonspecific finding on abdominal CT scan suggestive of BBMI; 151 patients had one finding, 24 patients had two findings, and three had three findings. The risk of BBMI increased with the number of nonspecific findings (positive predictive value = 11% with at least one finding and 44% with two or more findings). This increase in positive predictive value, however, was accompanied by a reduction in sensitivity (62% and 37%, respectively). A total of 32 patients had surgically proven BBMI. Of these, eight had a single nonspecific finding on CT scan, ten had two findings, and two had three findings (12 patients had no CT findings suggestive of BBMI). There were complications in four of the 32 patients with BBMI and one death (due to laceration of the superior mesenteric artery). The complications appeared to occur independent of the time to surgical intervention. Conclusions: The presence of multiple nonspecific findings on abdominal CT scan does not reliably predict BBMI in children. Children also appear to suffer complications from BBMI less frequently than adults, regardless of the time to surgery. Therefore, nonspecific findings alone do not warrant surgical exploration. The decision to operate should instead be based on clinical data that include serial physical examinations.

Liquid‐based cytology and conventional smears compared over two 12‐month periods

Liquid based cytology (LBC) was introduced across the Scottish Cervical Screening Programme in 2003-2004. The objective of this study was to compare in a large cytopathology laboratory the results of cervical samples over two twelve-month periods, 2001-2002, when the great majority of smears were conventional, with 2003-2004, when all were LBC. The results of smears in both periods were analysed to give overall reporting profiles, and correlated with results of cervical biopsies. The numbers of patients referred for colposcopy were compared. The percentage of unsatisfactory smears fell from 13.6% to 1.9%. Colposcopic referrals for repeated unsatisfactory smears fell from almost 25% to 0.5%. There was a decrease in overall smear numbers, but despite this there was an increase in the number of smears reported as showing dyskaryosis of any grade. There was an increase in positive predictive value for moderate dyskaryosis and above, from 79.5% to 86.1%. The outcome of biopsies from patients referred with mild dyskaryosis showed no decrease in accuracy of predicting a low grade histological lesion. Workload in the laboratory decreased, due to fewer smears received overall, more rapid primary screening times and fewer multi-slide cases. Primary screening backlogs all but disappeared, and reporting times greatly improved. Introduction of liquid based cytology led to improvements in unsatisfactory smear rates, with significant benefits to colposcopic referrals and laboratory turnaround times. Pick-up rates of dyskaryosis were maintained, and the positive predictive value of a dyskaryotic smear report was improved.

Predicting gadolinium enhancement status in MS patients eligible for randomized clinical trials

Gadolinium enhancement is often used in randomized clinical trials to evaluate the efficacy of new drugs in multiple sclerosis (MS). Knowledge about predictors of enhancement status is important for the selection of patients for MRI monitored trials. Data from 17 trials were available in anonymized format through the Sylvia Lawry Centre for MS Research. In an open part containing 1,328 (non primary progressive) patients, two logistic regression analyses were explored, including demographic, clinical, and MRI predictors. The authors examined the area under the curve (AUC) and the increase in positive predictive value (PPV). The final selection of models was validated in a closed part of 848 comparable patients. Age at onset, disease duration, and disease course (CIS/RR/SP) were important predictors from the multivariate models. Further, a multivariate model including T2 burden of disease was more predictive than one with only clinical predictors (AUC 0.719 vs 0.625, p < 0.001). For the model with T2 burden of disease, the PPV was 66.8%, compared to 58.5% for the model without (a priori chance 46.4%). These findings were unequivocally confirmed in the closed part of the database. Gadolinium status can be predicted by a set of baseline variables, certainly when T2 burden of disease is included. These findings may benefit the design and statistical power of future randomized clinical trials.