Accurate Determination of Imaging Modality using an Ensemble of Text- and Image-Based Classifiers

Imaging modality can aid retrieval of medical images for clinical practice, research, and education. We evaluated whether an ensemble classifier could outperform its constituent individual classifiers in determining the modality of figures from radiology journals. Seventeen automated classifiers analyzed 77,495 images from two radiology journals. Each classifier assigned one of eight imaging modalities—computed tomography, graphic, magnetic resonance imaging, nuclear medicine, positron emission tomography, photograph, ultrasound, or radiograph—to each image based on visual and/or textual information. Three physicians determined the modality of 5,000 randomly selected images as a reference standard. A “Simple Vote” ensemble classifier assigned each image to the modality that received the greatest number of individual classifiers’ votes. A “Weighted Vote” classifier weighted each individual classifier’s vote based on performance over a training set. For each image, this classifier’s output was the imaging modality that received the greatest weighted vote score. We measured precision, recall, and F score (the harmonic mean of precision and recall) for each classifier. Individual classifiers’ F scores ranged from 0.184 to 0.892. The simple vote and weighted vote classifiers correctly assigned 4,565 images (F score, 0.913; 95% confidence interval, 0.905–0.921) and 4,672 images (F score, 0.934; 95% confidence interval, 0.927–0.941), respectively. The weighted vote classifier performed significantly better than all individual classifiers. An ensemble classifier correctly determined the imaging modality of 93% of figures in our sample. The imaging modality of figures published in radiology journals can be determined with high accuracy, which will improve systems for image retrieval.     

A Presentation System for Just-in-time Learning in Radiology

There is growing interest in bringing medical educational materials to the point of care. We sought to develop a system for just-in-time learning in radiology. A database of 34 learning modules was derived from previously published journal articles. Learning objectives were specified for each module, and multiple-choice test items were created. A web-based system—called TEMPO—was developed to allow radiologists to select and view the learning modules. Web services were used to exchange clinical context information between TEMPO and the simulated radiology work station. Preliminary evaluation was conducted using the System Usability Scale (SUS) questionnaire. TEMPO identified learning modules that were relevant to the age, sex, imaging modality, and body part or organ system of the patient being viewed by the radiologist on the simulated clinical work station. Users expressed a high degree of satisfaction with the system’s design and user interface. TEMPO enables just-in-time learning in radiology, and can be extended to create a fully functional learning management system for point-of-care learning in radiology.     

Dementia in Swedish Twins: Predicting Incident Cases

Thirty same-sex twin pairs were identified in which both members were assessed at baseline and one twin subsequently developed dementia, at least 3 years subsequent to the baseline measurement, while the partner remained cognitively intact for at least three additional years. Eighteen of the 30 cases were diagnosed with Alzheimer’s disease. Baseline assessments, conducted when twins’ average age was 70.6 (SD = 6.8), included a mailed questionnaire and in-person testing. Which twin would develop dementia was predicted by less favorable lipid values (higher apoB, ratio of apoB to apoA1, and total cholesterol), poorer grip strength, and—to a lesser extent—higher emotionality on the EAS Temperament Scale. Given the long preclinical period that characterizes Alzheimer’s disease, these findings may suggest late life risk factors for dementia, or may reflect changes that are part of preclinical disease.     

Proposing New RadLex Terms by Analyzing Free-Text Mammography Reports

After years of development, the RadLex terminology contains a large set of controlled terms for the radiology domain, but gaps still exist. We developed a data-driven approach to discover new terms for RadLex by mining a large corpus of radiology reports using natural language processing (NLP) methods. Our system, developed for mammography, discovers new candidate terms by analyzing noun phrases in free-text reports to extend the mammography part of RadLex. Our NLP system extracts noun phrases from free-text mammography reports and classifies these noun phrases as “Has Candidate RadLex Term” or “Does Not Have Candidate RadLex Term.” We tested the performance of our algorithm using 100 free-text mammography reports. An expert radiologist determined the true positive and true negative RadLex candidate terms. We calculated precision/positive predictive value and recall/sensitivity metrics to judge the system’s performance. Finally, to identify new candidate terms for enhancing RadLex, we applied our NLP method to 270,540 free-text mammography reports obtained from three academic institutions. Our method demonstrated precision/positive predictive value of 0.77 (159/206 terms) and a recall/sensitivity of 0.94 (159/170 terms). The overall accuracy of the system is 0.80 (235/293 terms). When we ran our system on the set of 270,540 reports, it found 31,800 unique noun phrases that are potential candidates for RadLex. Our data-driven approach to mining radiology reports can identify new candidate terms for expanding the breast imaging lexicon portion of RadLex and may be a useful approach for discovering new candidate terms from other radiology domains.     

Age Differences in Genetic and Environmental Variations in Stress-Coping During Adulthood: A Study of Female Twins

The way people cope with stressors of day to day living has an important influence on health. The aim of the present study was to explore whether genetic and environmental variations in stress-coping differ over time during adulthood. The brief COPE was mailed to a large sample of the UK female twins (N = 4,736) having a wide range of age (20–87 years). Factor analyses of the items of the brief COPE yielded three coping scales: ‘Problem-Solving’, ‘Support Seeking’, and ‘Avoidance’. Monozygotic and dizygotic twin correlations tended to become lower with age for all three scales, suggesting that unique environmental factors may become more important with age during adulthood. Model-fitting results showed that relative influences of unique environmental factors increased from 60 % at age 20 years to 74% at age 87 years for ‘Problem-Solving’ and 56 % at age 20 years to 76% at age 87 years for ‘Avoidance’. During the same age period, genetic factors decreased from 40 to 26 % for ‘Problem-Solving’ and from 44 to 24 % for ‘Avoidance’. For ‘Seeking Support’, the magnitude of genetic and unique environmental factors was not significantly different across the adulthood. For all three scales, shared environmental effects were negligible. Overall, our findings implicate that the effects of environment that stem from idiosyncratic experience of stressful life events accumulate and become increasingly important in adulthood.     

The epidemiology of extraintestinal non-typhoid Salmonella in Israel: the effects of patients’ age and sex

Extraintestinal disease occurs in 5–8% of non-typhoid Salmonella enterica (NTS) infections and is more likely to be associated with hospitalization and death. The study examined the epidemiology of extraintestinal NTS infections in Israel and the possible effects of patients’ age and sex. NTS isolates passively submitted to the National Salmonella Reference Center during 1996–2006 were the source for the study cohort. Poisson regression models were used to assess incidence trends over the study years and to evaluate the effects of patients’ age and sex on the incidence of extraintestinal NTS manifestations. A total of 36,822 stool and 1,415 (3.7%) patient-unique NTS isolates from blood (74.1%), urine (18.3%), and other sources (3.7%) were studied. Serotypes Enteritidis, Virchow, and Typhimurium accounted for 66.3% of the isolates. Analysis showed a highly significant quadratic (U-shaped) relationship between patients’ age and the incidence of extraintestinal isolation (p < 0.001), with increasing risk in the two extremes of age. Differences between the incidence of blood and urine sources were significant in patients <10 and ≥60 years old (relative risk [RR] = 5.88, 95% confidence interval [CI] 3.36–10.30, p < 0.001 and RR = 1.66, 95% CI 1.09–2.53, p = 0.017, respectively). Males ≥60 years of age were more likely than females of the same age to have bacteremia (RR = 1.90, 95% CI 1.39–2.61, p > 0.001) and less likely to have urinary NTS isolation (RR = 0.50, 95% CI 0.28–0.89, p = 0.018). Serotype Virchow had the highest incidence in patients <10 years of age, while serotype Enteritidis had the highest incidence in patients ≥60 years old. The study revealed a complex effect of patients’ age and sex on the epidemiology of extraintestinal NTS manifestations.     

Taking into account the observers’ uncertainty: a graduated approach to the credibility of the patient’s pain evaluation

This article presents two experiments aiming to investigate the adoption of a graduated measure to describe credibility attribution by observers who evaluate patients’ pain accounts. A total of 160 medical students were required to express a credibility judgment on the pain intensity level of hypothetical patients. We used 16 vignettes based on a factorial mixed-design. Within-participants factors were the reported pain, the presence of a physical sign, the patient’s facial expression and the patient’s gender, and between-groups factors were the patient’s age and the geographical distribution of the patient’s name. Results confirm the well-established tendency not to believe patients’ self-reports and provide information regarding the evaluators’ uncertainty. The findings suggest that a graduated measure is useful for assessing the degree of uncertainty of the observers and subtle effects of different factors upon the judgment of patient’s pain.     

Histologically confirmed intracranial germ cell tumors; an analysis of 62 patients in a single institute

This study was undertaken to document the clinicopathologic characteristics of histologically verified, primary intracranial germ cell tumors (GCTs), determine treatment outcomes, and to identify prognostic factors. The records of 62 patients (45 males and 17 females) with a primary intracranial GCT were retrospectively analyzed. Mean patient age was 18 years, and median follow-up was 41 months. The most common histological subtypes were germinoma (48.4%), followed by mixed GCT (27.4%), and teratoma (19.4%). In 23 patients (37.1%), disease onset occurred between 16 and 20 years. Germinomas and malignant non-germinomatous germ cell tumors were most prevalent in the pineal gland, suprasellar region, and basal ganglia, whereas teratomas dominated at other sites. Synchronous bifocal GCTs were found in six patients. Five-year overall survival (OS) rates according to a therapeutic classification proposed by Sawamura were 82.93%, 83.08%, and 64.71% in the good, intermediate, and poor prognosis groups, respectively (P = 0.2839). Five-year OSs in patients with normal tumor marker (αFP or βHCG) and patients with elevated marker were 85.26% and 66.96%, respectively (P = 0.0568). Five of six patients with alpha-fetoprotein (α-FP) of >1,000 ng/ml succumbed to disease, whereas all five patients with a beta-human chorionic gonadotropin of >1,000 mIU/ml survived. Mixed GCTs are more common in Korea than in the West. Sawamura’s classification of intracranial GCT may be a fine tool for stratifying patients’ survival. Patients with elevated tumor marker levels may appear to have poorer OS independent of histology. In particular, high titers of α-FP seem to impact prognosis.     

Magnetocardiography Based Spatiotemporal Correlation Analysis is Superior to Conventional ECG Analysis for Identifying Myocardial Injury

Electrocardiogram (ECG) particular from tiny, non Q-wave myocardial infarction may lack striking infarct pattern. Spatiotemporal correlation analysis (SCA) of multichannel magnetocardiogram (MCG) is a high-resolution “magnifying glass” to analyze homogeneity of repolarization. SCA involves full 4D spatiotemporal information to identify abnormalities as empirically done by eye in conventional ECG—but on an advanced level of analysis. We compared the discriminatory performance of SCA to ECG analysis in identifying myocardial infarction. Eleven SCA parameters were taken from signal averaged 31-channel MCG and compared to infarct indicators of ECG’s in 178 subjects: 108 patients (76 males, mean age 62 years) after myocardial infarction (16–64 d) and 70 controls (36 males, mean age 46 years). SCA improves the detection of myocardial injury: in 72.5% ECG (sensitivity 68.6%, specificity 56%) and in 80.2% SCA parameters (sensitivity 72.6%, specificity 64%) separated patients from controls. SCA is applicable for the analysis of de- and repolarization of cardiac mapping data.     

Content Analysis of Reporting Templates and Free-Text Radiology Reports

The Radiological Society of North America (RSNA) has developed a set of templates for structured reporting of radiology results. To measure how much of the content of conventional narrative (“free-text”) reports is covered by the concepts included in the RSNA reporting templates, we selected five reporting templates that represented a variety of imaging modalities and organ systems. From a sample of 8,275 consecutive, de-identified radiology reports from an academic medical center, we identified one corresponding imaging procedure code for each reporting template. The reports were annotated with RadLex and SNOMED CT terms using the BioPortal Annotator web service. The reporting templates we examined accounted for 17 to 49 % of the concepts that actually appeared in a sample of corresponding radiology reports. The findings suggest that the concepts that appear in the reporting templates occur frequently within free-text clinical reports; thus, the templates provide useful coverage of the “domain of discourse” in radiology reports. The techniques used in this study may be helpful to guide the development of reporting templates by identifying concepts that occur frequently in radiology reports, to evaluate the coverage of existing templates, and to establish global benchmarks for reporting templates.     

Development of postural adjustments during reaching in typically developing infants from 4 to 18 months

Knowledge on the development of postural adjustments during infancy, in particular on the development of postural muscle coordination, is limited. This study aimed at the evaluation of the development of postural control during reaching in a supported sitting condition. Eleven typically developing infants participated in the study and were assessed at the ages of 4, 6, 10 and 18 months. We elicited reaching movements by presenting small toys at an arm’s length distance, whilst activity of multiple arm, neck and trunk muscles was recorded using surface EMG. A model-based computer algorithm was used to detect the onset of phasic muscle activity. The results indicated that postural muscle activity during reaching whilst sitting supported is highly variable. Direction-specific postural activity was inconsistently present from early age onwards and increased between 10 and 18 months without reaching a 100 % consistency. The dominant pattern of activation at all ages was the ‘complete pattern’, in which all direction-specific muscles were recruited. At 4 months, a slight preference for top-down recruitment existed, which was gradually replaced by a preference for bottom-up recruitment. We conclude that postural control during the ecological task of reaching during supported sitting between 4 and 18 months of age is primarily characterized by variation. Already from 4 months onwards, infants are—within the variation—sometimes able to select muscle recruitment strategies that are optimal to the task at hand.     

Dynamic “Inline” Images: Context-Sensitive Retrieval and Integration of Images into Web Documents

Integrating relevant images into web-based information resources adds value for research and education. This work sought to evaluate the feasibility of using “Web 2.0” technologies to dynamically retrieve and integrate pertinent images into a radiology web site. An online radiology reference of 1,178 textual web documents was selected as the set of target documents. The ARRS GoldMiner™ image search engine, which incorporated 176,386 images from 228 peer-reviewed journals, retrieved images on demand and integrated them into the documents. At least one image was retrieved in real-time for display as an “inline” image gallery for 87% of the web documents. Each thumbnail image was linked to the full-size image at its original web site. Review of 20 randomly selected Collaborative Hypertext of Radiology documents found that 69 of 72 displayed images (96%) were relevant to the target document. Users could click on the “More” link to search the image collection more comprehensively and, from there, link to the full text of the article. A gallery of relevant radiology images can be inserted easily into web pages on any web server. Indexing by concepts and keywords allows context-aware image retrieval, and searching by document title and subject metadata yields excellent results. These techniques allow web developers to incorporate easily a context-sensitive image gallery into their documents.     

Life meaning: an important correlate of health in the hungarian population

One of the 5 coping scales in Rahe’s Brief Stress and Coping Inventory, entitled Life Meaning, was examined in relation to demographic characteristics, other coping measures, and health status in a sample of 12,640 Hungarian participants. Participants were selected to represent the country’s population according to sex, age, and place of residence. The study also explored the contribution of life meaning to the explanation of variations of middle-aged (45—64 years) male and female mortality rates across 150 subregions in Hungary. On an ecological level life meaning proved to be inversely related to male and female oncological, female cardiovascular, and total premature mortality rates in the 150 subregions of Hungary and on an individual level to participants’reported health status. In the total sample of individuals after controlling for gender, age, and education, life meaning scores showed strong correlations with the World Health Organization well-being scale, with self-rated absence of depression, with self-rated health, and with self-rated absence of disability. Although relatively unrelated to age, gender, and education, life meaning was positively related to self-efficacy, importance of religion, problem-oriented coping, and social support.     

Genetic and Environmental Causes of Variation in Trait Resilience in Young People

The aim of this multi-informant twin study was to determine the relative role of genetic and environmental factors in explaining variation in trait resilience in adolescents. Participants were consenting families (N = 2,638 twins in 1,394 families), from seven national cohorts (age 12–18 years, both sexes) of monozygotic and dizygotic twins reared together. Questionnaire data on the adolescents’ Ego-resilience (ER89) was collected from mothers, fathers and twins, and analysed by means of multivariate genetic modelling. Variance in trait resilience was best represented in an ADE common pathways model with sex limitation. Variance in the latent psychometric resilience factor was largely explained by additive genetic factors (77% in boys, 70% in girls), with the remaining variance (23 and 30%) attributable to non-shared environmental factors. Additive genetic sources explained more than 50% of the informant specific variation in mothers and fathers scores. In twins, additive and non-additive genetic factors together explained 40% and non-shared environmental factor the remaining 60% of variation. In the mothers’ scores, the additive genetic effect was larger for boys than for girls. The non-additive genetic factor found in the twins’ self ratings was larger in boys than in girls. The remaining sex differences in the specific factors were small. Trait resilience is largely genetically determined. Estimates based on several informants rather than single informants approaches are recommended.     

Significant decline in pneumonia admission rate after the introduction of routine 2+1 dose schedule heptavalent pneumococcal conjugate vaccine (PCV7) in children under 5 years of age in Kielce, Poland

This study was performed to estimate the effect of heptavalent pneumococcal conjugate vaccine (PCV7) on the pneumonia admission rate in children younger than 5 years of age, after the introduction of routine 2+1 dose schedule immunization. We compared the pneumonia admission rate (number of cases per 1,000 population) 2 years before and 2 years after the introduction of PCV7 in 2006. Only children with radiologically confirmed pneumonia were analyzed. The vaccination rate in the analyzed periods was around 99%. In the period preceding the implementation of PCV7, the average pneumonia admission rate was 41.48/1,000 and 6.15/1,000 for 1-year-old and 2–4-year-old children, respectively. Statistical analysis showed a significant fall in this rate in two consecutive years after PCV7 implementation (p < 0.0000001 for 1-year-old and p = 0.011 for 2–4-year-old children, respectively). In the first year of vaccination, the admission number decreased in these two groups by about 65 and 23%, respectively. In the second year, only a few percent fall in the admission rate was noted. In children younger than 2 years of age, the age group targeted for vaccination, pneumonia-related healthcare utilization declined substantially following PCV7 introduction. These results suggest that PCV7 may play an important role in reducing the burden of pneumonia in Poland.     

Postnatal changes in the styloid process,vagina processus styloidei,and stylomastoid foramen in relation to the function of muscles originating from the styloid process

We investigated age-related changes in the styloid process in 88 skulls, aged from 5 months to 85 years of age. The osseous styloid process was not well developed in children. Its length increased significantly with age (from 2.3 mm in 11–20 age group to 16.3 mm in 61–85 group). In adolescent specimens (11–20 years of age), the median distance from the styloid process to the stylomastoid foramen was 0.7–0.8 mm, whereas in adult and old age specimens the two structures were completely adjacent or very close, usually less than 0.2 mm. The process was missing in 5% of the adult specimens. There was a statistically significant positive association between the length of the styloid process with age (r = 0.3210, 95% CI 0.0817–0.5254; P = 0.0097), whereas the distance from the styloid process to the stylomastoid foramen significantly decreased with age (r = −0.4518, 95% CI −0.6167 to −0.2490; P = 0.0001). Changes in the length and shape of the styloid process reflected altered function of the three muscles originating from the styloid process—m. stylopharyngeus, m. stylohyoideus and m. styloglossus. They have a common function of lifting the aerodigestive elements upward and backward, after the descent of the aerodigestive tract and final morphological differentiation of the vocal system during puberty. Relationship between altered muscle function and the morphology of the styloid process are important for understanding the clinical syndromes related to the styloid process, such as Eagle’s syndrome. Presented as a poster at the 78 Jahresversammlung 2007 der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V., Munich, 17–20 May 2007.     

The incidence of myocardial infarction

I studied 183 patients with myocardial infarction including sudden deaths related to ischaemic heart disease occurring in general practice during a period of four years.

The figures are examined by age, sex, history of event, and place of treatment. The ratio of male to female infarctions was 2:1, males having a mean age of 63 years and females 71 years.

The total death rate for all myocardial infarctions was 46 per cent, but if sudden deaths are excluded, the rate becomes 24 per cent.

The annual incidence of myocardial infarction per 1,000 in the practice population of 11,195 was 4.1 and the total annual death rate per 1,000 was 1.9.

     

New Cardiac MRI Gating Method Using Event-Synchronous Adaptive Digital Filter

When imaging the heart using MRI, an artefact-free electrocardiograph (ECG) signal is not only important for monitoring the patient’s heart activity but also essential for cardiac gating to reduce noise in MR images induced by moving organs. The fundamental problem in conventional ECG is the distortion induced by electromagnetic interference. Here, we propose an adaptive algorithm for the suppression of MR gradient artefacts (MRGAs) in ECG leads of a cardiac MRI gating system. We have modeled MRGAs by assuming a source of strong pulses used for dephasing the MR signal. The modeled MRGAs are rectangular pulse-like signals. We used an event-synchronous adaptive digital filter whose reference signal is synchronous to the gradient peaks of MRI. The event detection processor for the event-synchronous adaptive digital filter was implemented using the phase space method—a sort of topology mapping method—and least-squares acceleration filter. For evaluating the efficiency of the proposed method, the filter was tested using simulation and actual data. The proposed method requires a simple experimental setup that does not require extra hardware connections to obtain the reference signals of adaptive digital filter. The proposed algorithm was more effective than the multichannel approach.     

Endocrine Cell Replacement of Oxyntic Glands in Zollinger-Ellison Syndrome: A Role for Female Sex Hormones?

A 48-year-old woman with Zollinger-Ellison syndrome (ZES), but no evidence of multiple endocrine neoplasia (MEN)-1 syndrome, developed an unusually florid evolution of enterochromaffin-like (ECL) cell hyperplasia, which led to extensive replacement of oxyntic glands by endocrine tissue and resulted in the disappearance of the patient’s gastric acid hypersecretion with antisecretory treatment no longer required. The patient’s previous history included breast cancer, treated with surgery and 5 years of antiestrogen therapy, and bilateral granulosa-thecal cell tumor of the ovary. In addition, increased circulating levels of 17 β-estradiol (17βE) and progesterone, possibly depending on concomitant development of liver cirrhosis, were also found. On the basis of these associations, it is suggested that abnormalities in the domain of female sex hormones, with a potential synergistic role of liver dysfunction, may be involved in the florid evolution of hypergastrinemia-driven proliferation of ECL cells observed in the present case.