Impact of Head-Down Position on Cerebral Blood Flow in Healthy Subjects: An Arterial Spin-Labeling MR Perfusion Study.

Background: A head-down (HD) position is used in some stroke centers to maintain cerebral perfusion (CP) in stroke patients.

Purpose: To assess CP in healthy volunteers in the supine and HD (-15°) positions.

Study Type: Prospective.

[Contribution of C.S. Peirce thought to the representation knowledge and medical reasoning].

Modelling knowledge and medical reasoning can be an epistemological project especially now, as medicine seems to reach a scientific status. Through his work on semiotics, abductive reasoning and pragmatism, CS Peirce (1839-1914) offers a series of original solutions. These solutions can give an account of (be considered as a theorical ground for) most of the medical activity in various fields such as the evaluation of the students, the knowledge bases and expert systems, the formal descriptions languages (ontologies), and the evidence-based medicine.

Measuring Cerebral Hypoperfusion Induced by Hyperventilation Challenge With Intravoxel Incoherent Motion Magnetic Resonance Imaging in Healthy Volunteers.

Objectives: The aim of this study was to demonstrate the feasibility to assess cerebral hypoperfusion with a hyperventilation (HV) challenge protocol using intravoxel incoherent motion (IVIM) magnetic resonance imaging.

Materials And Methods: Magnetic resonance imaging experiments were performed on 10 healthy volunteers at 1.5 T, with a diffusion IVIM magnetic resonance imaging protocol using a set of b-values optimized by Cramer-Rao Lower Bound analysis.

Diffusional kurtosis imaging (DKI) incorporation into an intravoxel incoherent motion (IVIM) MR model to measure cerebral hypoperfusion induced by hyperventilation challenge in healthy subjects.

Objectives: The objectives were to investigate the diffusional kurtosis imaging (DKI) incorporation into the intravoxel incoherent motion (IVIM) model for measurements of cerebral hypoperfusion in healthy subjects.

Materials And Methods: Eight healthy subjects underwent a hyperventilation challenge with a 4-min diffusion weighted imaging protocol, using 8 b values chosen with the Cramer-Rao Lower Bound optimization approach. Four regions of interest in gray matter (GM) were analyzed with the DKI-IVIM model and the bi-exponential IVIM model, for normoventilation and hyperventilation conditions.

An ontological analysis of medical Bayesian indicators of performance.

Background: Biomedical ontologies aim at providing the most exhaustive and rigorous representation of reality as described by biomedical sciences. A large part of medical reasoning deals with diagnosis and is essentially probabilistic. It would be an asset for biomedical ontologies to be able to support such a probabilistic reasoning and formalize Bayesian indicators of performance: sensitivity, specificity, positive predictive value and negative predictive value.

What type of imaging work-up will help to confirm the diagnosis of gossypiboma in the limb? Review of literature.

Unlabelled: Gossypiboma imaging features are not well known and are often confused with soft tissue tumours. Publications on this topic mainly consist of case reports and small cohorts. Its appearance on various imaging modalities is not well defined.

MRI investigation of radiating pain in the lower limbs: value of an additional sequence dedicated to the lumbosacral plexus and pelvic girdle.

Objective: In some cases, sciatica-like symptoms radiating through the buttock, anterior thigh, or leg result from spinal root compression in an extraspinal location or from injury to the pelvic girdle. It has been suggested that adding a coronal STIR sequence dedicated to the lumbosacral plexus and pelvis to the routine MRI protocol can provide a good depiction of disorders of this type.

Materials And Methods: Two hundred nine patients with sciatica-like symptoms of suspected lumbar origin were included in the study.

MRI quantification of diffusion and perfusion in bone marrow by intravoxel incoherent motion (IVIM) and non-negative least square (NNLS) analysis.

Object: To assess the feasibility of measuring diffusion and perfusion fraction in vertebral bone marrow using the intravoxel incoherent motion (IVIM) approach and to compare two fitting methods, i.e., the non-negative least squares (NNLS) algorithm and the more commonly used Levenberg-Marquardt (LM) non-linear least squares algorithm, for the analysis of IVIM data.

Current role of CT and whole body MRI in multiple myeloma.

Radiology of bone lacunae can help differentiate between smouldering and symptomatic myeloma. CT seems to be more apt for this purpose than a standard X-ray but appropriate principles must be applied when performing and reading it. Lesions visible in an MRI above all allow myelomas to be monitored during treatment.

Is a breast MRI possible and indicated in case of suspicion of breast cancer during lactation?

The paper tries to answer two questions: the safety of the injection of gadolinium during breastfeeding; the value of a breast MRI in the nursing mother if breast cancer is suspected. Recent Anglo-Saxon publications are in favour of continued breastfeeding following the injection of gadolinium. In fact, only a minute quantity of contrast product passes into the mother's milk, much less than the threshold recommended in paediatrics in the infant.

Texture analysis software: integration with a radiological workstation.

Image analysis is the daily task of radiologists. The texture of a structure or imaging finding can be more difficult to describe than other parameters. Image processing can help the radiologist in completing this difficult task.

Ontology driven decision support systems for medical diagnosis - an interactive form for consultation in patients with plasma cell disease.

Multiple myeloma (MM) is a malignant disorder characterized by the monoclonal proliferation of B cell derived plasma cells in the bone marrow. The diagnosis depends on the identification of abnormal monoclonal marrow plasma cells, monoclonal protein in the serum or urine, evidence of end-organ damage, and a clinical picture consistent with MM. The distinction between MM stages- monoclonal gammopathy of undetermined significance or indolent myeloma-is critical in guiding therapy.

MRI image artifact ontology: a proposed method for improved recognition.

Unlabelled: Magnetic Resonance Imaging is an essential diagnostic imaging technique. The complexity of interpreting MRI images is often compounded by the presence of a wide range of artifacts which are often challenging to identify and eliminate. Ontology permits the construction of a knowledge database with which users can interact given an appropriate interface.

Imaging of snapping phenomena.

Snapping phenomena result from the sudden impingement between anatomical and/or heterotopical structures with subsequent abrupt movement and noise. Snaps are variously perceived by patients, from mild discomfort to significant pain requiring surgical management. Identifying the precise cause of snaps may be challenging when no abnormality is encountered on routinely performed static examinations.

Snapping knee: imaging findings with an emphasis on dynamic sonography.

Objective: The purpose of this article is to illustrate the causes of snapping knee. The value of imaging techniques is discussed with an emphasis on dynamic sonography in light of the available surgical and radiologic literature.

Conclusion: Because of its dynamic capabilities, dynamic sonography provides real-time visualization of snapping knee syndrome and may be used as a first-line modality.

Ontology and medical diagnosis.

Ontology and associated generic tools are appropriate for knowledge modeling and reasoning, but most of the time, disease definitions in existing description logic (DL) ontology are not sufficient to classify patient's characteristics under a particular disease because they do not formalize operational definitions of diseases (association of signs and symptoms=diagnostic criteria). The main objective of this study is to propose an ontological representation which takes into account the diagnostic criteria on which specific patient conditions may be classified under a specific disease. This method needs as a prerequisite a clear list of necessary and sufficient diagnostic criteria as defined for lots of diseases by learned societies.

Creating a magnetic resonance imaging ontology.

The goal of this work is to build an ontology of Magnetic Resonance Imaging. The MRI domain has been analysed regarding MRI simulators and the DICOM standard. Tow MRI simulators have been analysed: JEMRIS, which is developed in XML and C++, has a hierarchical organisation and SIMRI, which is developed in C, has a good representation of MRI physical processes.

Creating an ontology driven rules base for an expert system for medical diagnosis.

Expert systems of the 1980s have failed on the difficulties of maintaining large rule bases. The current work proposes a method to achieve and maintain rule bases grounded on ontologies (like NCIT). The process described here for an expert system on plasma cell disorder encompasses extraction of a sub-ontology and automatic and comprehensive generation of production rules.

Roogle: an information retrieval engine for clinical data warehouse.

High amount of relevant information is contained in reports stored in the electronic patient records and associated metadata. R-oogle is a project aiming at developing information retrieval engines adapted to these reports and designed for clinicians. The system consists in a data warehouse (full-text reports and structured data) imported from two different hospital information systems.

Automatic definition of the oncologic EHR data elements from NCIT in OWL.

Unlabelled: Semantic interoperability based on ontologies allows systems to combine their information and process them automatically. The ability to extract meaningful fragments from ontology is a key for the ontology re-use and the construction of a subset will help to structure clinical data entries. The aim of this work is to provide a method for extracting a set of concepts for a specific domain, in order to help to define data elements of an oncologic EHR.

Snapping biceps femoris tendon: a dynamic real-time sonographic evaluation.

Snapping of the distal arms of the biceps femoris tendon may explain pain and discomfort at the lateral aspect of the knee. We report two cases in which dynamic sonography was able to confirm the diagnosis and document which of the main arms was involved in the process.

Is MRI useful to assess labral reduction following acute anterior shoulder dislocation?

Introduction: Better knowledge of the anatomical lesions following primary anterior dislocation of the shoulder could help to resolve the issue of the recommended position of immobilization. The aim of this study was to describe such early lesions and to evaluate labral reducibility in both external and internal rotation of the arm.

Patients And Methods: Fifteen shoulders were investigated by MRI without intra-articular injection.

Comparing the APGAR score representation in HL7 and OpenEHR formalisms.

Semantic interoperability, a prerequisite to eHealth projects, relies on sharing both information and knowledge models between information systems. Two of the standards of information models are HL7 v3 and the European norm, EN13606/OpenEHR. The paper compares both standards on a fragment of the prenatal medical record, the APGAR score.

["Méta-analyse": a web-based tool for research and analysis of radiology papers].

Finding articles providing answers to specific clinical questions is greatly facilitated by the availability of indexed Medline abstracts using the Pubmed search engine. Nonetheless, the large number of references sometimes requires a time-consuming review of multiple abstracts. In order to streamline the search process, we have created a tool facilitating the search and review of these abstracts.

[Evaluation of CT guided cervical epidural injections in patients with mechanical cervicobrachial neuralgia].

Purpose: Prospective study evaluating the efficacy and tolerability of CT guided cervical epidural injections for mechanical cervicobrachial neuralgia.

Materials And Methods: Between July 2003 and August 2004, 34 patients (16 females, 18 males) with mean age of 44.5 years were enrolled.