Ontology-based classification of radiological procedures for consistent sharing in Clinical Data Warehouses

International audienceClinical data warehouses (CDW) allow the reuse of care data in a research context. Designing and operating CDWs require addressing interoperability, data enrichment and data modeling problems, among others. This work concerns the management of medical imaging data in CDWs. It proposes a data-driven approach for classifying radiological procedures using an ontology-based approach. This approach relies on the RadLex ontology and an imaging procedures terminology called RadLex Playbook, both developed by RSNA. We first created an ontology of the radiological procedures by merging the Playbook with the relevant extract of the RadLex ontology and enriched it with French terms using the UMLS meta thesaurus. Then, we developed a proof of concept of a radiological procedures data classifier that exploits the richness of RadLex ontology and the ontological reasoning and we assessed it using medical imaging data retrieved from two different facilities. Our results demonstrate feasibility and relevance of the approach. They also highlight differences in the methods of filling imaging procedure data in the two institutions, as well as some problems in the RadLex ontology. Based on this experience, this proof of concept will be refined to evolve towards a routinely usable classification tool supporting medical imaging data management in CDWs

Automatic Detector of Abnormal EEG for Preterm Infants

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Does subthalamic nucleus stimulation affect the frontal limbic areas? A single-photon emission computed tomography study using a manual anatomical segmentation method.

International audienceAmong the basal ganglia nuclei, the subthalamic nucleus (STN) is considered to play a major role in output modulation. The STN represents a relay of the motor cortico-basal ganglia-thalamo-cortical circuit and has become the standard surgical target for treating Parkinson's patients with long-term motor fluctuations and dyskinesia. But chronic bilateral stimulation of the STN produces cognitive effects. According to animal and clinical studies, the STN also appears to have direct or indirect connections with the frontal associative and limbic areas. This prospective study was conducted to analyse regional cerebral blood flow changes in single-photon emission computed tomography imaging of six Parkinson's patients before and after STN stimulation. We particularly focused on the dorsolateral prefrontal cortex and the frontal limbic areas using a manual anatomical MRI segmentation method. We defined nine regions of interest, segmenting each MR slice to quantify the regional cerebral blood flow on pre- and postoperative SPECT images. We normalised the region-of-interest-based measurements to the entire brain volume. The patients showed increased activation during STN stimulation in the dorsolateral prefrontal cortex bilaterally and no change in the anterior cingulate and orbito-frontal cortices. In our study, STN stimulation induced activation of premotor and associative frontal areas. Further studies are needed to underline involvement of the STN with the so-called limbic system

Automatic Selection of Clinical Trials Based on A Semantic Web Approach

International audienceRecruitment of patients in clinical trials is nowadays preoccupying, as the inclusion rate is particularly low. The main identified factors are the multiplicity of open clinical trials, the high number and complexity of eligibility criteria, and the additional workload that a systematic search of the clinical trials a patient could be enrolled in for a physician. The principal objective of the ASTEC project is to automate the prescreening phase during multidisciplinary meetings (MDM). This paper presents the evaluation of a computerized recruitment support systems (CRSS) based on semantic web approach. The evaluation of the system was based on data collected retrospectively from a 6 month period of MDM in Urology and on 4 clinical trials of prostate cancer. The classification performance of the ASTEC system had a precision of 21%, recall of 93%, and an error rate equal to 37%. Missing data was the main issue encountered. The system was designed to be both scalable to other clinical domains and usable during MDM proces

SPECT and PET analysis of subthalamic stimulation in Parkinson's disease: analysis using a manual segmentation.

International audienceThe subthalamic nucleus (STN) has become an effective target of deep-brain stimulation (DBS) in severely disabled patients with advanced Parkinson's disease (PD). Clinical studies have reported DBS-induced adverse effects on cognitive functions, mood, emotion and behavior. STN DBS seems to interfere with the limbic functions of the basal ganglia, but the limbic effects of STN DBS are controversial. We measured prospectively resting regional cerebral metabolism (rCMb) with 18-fluorodeoxyglucose and PET, and resting regional cerebral blood flow (rCBF) with HMPAO and SPECT in six patients with Parkinson's disease. We compared PET and SPECT 1 month before and 3 months after STN DBS. On cerebral MRI, 13 regions of interest (ROI) were manually delineated slice by slice in frontal and limbic lobes. We obtained mean rCBF and rCMb values for each ROI and the whole brain. We normalized rCBF and rCMB values to ones for the whole brain volume, which we compared before and following STN DBS. No significant difference emerged in the SPECT analysis. PET analysis revealed a significant decrease in rCMb following STN DBS in the superior frontal gyri and left and right dorsolateral prefrontal cortex (p < 0.05). A non-significant decrease in rCMb in the left anterior cingulate gyrus appeared following STN DBS (p = 0.075). Our prospective SPECT and PET study revealed significantly decreased glucose metabolism of the two superior frontal gyri without any attendant perfusion changes following STN DBS. These results suggest that STN DBS may change medial prefrontal function and therefore the integration of limbic information, either by disrupting emotional processes within the STN, or by hampering the normal function of a limbic circuit

How to Optimize Connection Between PACS and Clinical Data Warehouse: A Web Service Approach Based on Full Metadata Integration

International audienceClinical image data analysis is an active area of research. Integrating such data in a Clinical Data Warehouse (CDW) implies to unlock the PACS and RIS and to address interoperability and semantics issues. Based on specific functional and technical requirements, our goal was to propose a web service (I4DW) that allows users to query and access pixel data from a CDW by fully integrating and indexing imaging metadata. Here, we present the technical implementation of this workflow as well as the evaluation we carried out using a prostate cancer cohort use case. The query mechanism relies on a Dicom metadata hierarchy dynamically generated during the ETL Process. We evaluated the Dicom data transfer performance of I4DW, and found mean retrieval times of 5.94 seconds and 0.9 seconds to retrieve a complete DICOM series from the PACS and all metadata of a series. We could retrieve all patients and imaging tests of the prostate cancer cohort with a precision of 0.95 and a recall of 1. By leveraging the CMOVE method, our approach based on the Dicom protocol is scalable and domain-neutral. Future improvement will focus on performance optimization and de identification

KCNT1 epilepsy with migrating focal seizures shows a temporal sequence with poor outcome, high mortality and SUDEP

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High Mobility Indium Zinc Oxide Thin Film Field-Effect Transistors by Semiconductor Layer Engineering

Indium zinc oxide thin-film transistors are fabricated via a precursor in solution route on silicon substrates with silicon dioxide gate dielectric. It is found that the extracted mobility rises, peaks, and then decreases with increasing precursor concentration instead of rising and saturating. Investigation with scanning probe techniques reveals full thickness variations within the film which are assumed to adversely affect charge transport. Additional layers are coated, and the extracted mobility is observed to increase up to 19.7 cm2 V–1 s–1. The reasons for this are examined in detail by direct imaging with scanning tunneling microscopy and extracting electron density profiles from X-ray reflection measurements. It is found that the optimal concentration for single layer films is suboptimal when coating multiple layers and in fact using many layers of very low concentrations of precursor in the solution, leading to a dense, defect and void free film, affording the highest mobilities. A consistent qualitative model of layer formation is developed explaining how the morphology of the film develops as the concentration of precursor in the initial solution is varied