Type 2 diabetes mellitus and obesity in young adults: the extreme phenotype with early cardiovascular dysfunction.

AIM: A pilot study to phenotype young adults (< 40 years) with Type 2 diabetes mellitus. METHODS: Twenty people with Type 2 diabetes (aged 18-40 years), 10 lean and 10 obese control subjects underwent detailed assessment, including tagged cardiac magnetic resonance imaging, inflammatory proteins, lipids, vitamin D and maximal oxygen uptake. Outcomes were compared between the group with Type 2 diabetes and the control group. RESULTS: Mean (standard deviation) age, Type 2 diabetes duration and BMI in the group with Type 2 diabetes were 31.8 (6.6) years, 4.7 (4.0) years and 33.9 (5.8) kg/m(2) respectively. Compared with lean control subjects, those with Type 2 diabetes had more deleterious profiles of hyperlipidaemia, vitamin D deficiency, inflammation and maximal oxygen uptake relative to body mass. However, there was no difference between the group with Type 2 diabetes and the obese control group. The group with Type 2 diabetes had a higher left ventricular mass and a trend towards concentric remodelling compared with the lean control group (P = 0.002, P = 0.052) but not the obese control group (P > 0.05). Peak early diastolic strain rate was reduced in the group with Type 2 diabetes [1.51 (0.24)/s] compared with the lean control [1.97 (0.34)/s, P = 0.001] and obese control [1.78 (0.39)/s, P = 0.042] group. CONCLUSIONS: Young adults with Type 2 diabetes and those with obesity have similar adverse cardiovascular risk profiles, higher left ventricular mass and a trend towards left ventricular concentric remodelling. In addition, those with Type 2 diabetes demonstrate diastolic dysfunction, a known risk marker for future heart failure and mortality.

A new fully-digital anthropomorphic and dynamic thorax/heart model.

A numerical anthropomorphic model of the breathing thorax and the beating heart is presented. It includes the main thoracic/cardiac anatomical structures, the main vessel junctions as well as the structures' motion. Its main feature is that it is based on a Magnetic Resonance Imaging (MRI) examination performed on the same human subject within the same session from which both structural and motion information are retrieved. This confers to the model a very good consistency. This numerical model is virtually imaged by two simulators: a MRI simulator and a Positron Emission Tomography (PET) simulator. The overall resulting model (structure geometry & dynamics, images) is useful for the evaluation of cardiac image processing algorithms such as heart structure segmentation or multi-modality cardiac image registration.

Grid-enabling medical image analysis.

Grids have emerged as a promising technology to handle the data and compute intensive requirements of many application areas. Digital medical image processing is a promising application area for grids. Given the volume of data, the sensitivity of medical information, and the joint complexity of medical datasets and computations expected in clinical practice, the challenge is to fill the gap between the grid middleware and the requirements of clinical applications. The research project AGIR (Grid Analysis of Radiological Data) presented in this paper addresses this challenge through a combined approach: on one hand, leveraging the grid middleware through core grid medical services which target the requirements of medical data processing applications; on the other hand, grid-enabling a panel of applications ranging from algorithmic research to clinical applications.

Hemangiopericytoma of the parotid gland: CT and MR features.

Hemangiopericytomas are uncommon vascular neoplasms with rare occurrence in the head and neck region. They originate from the pericytes, which are small, oval cells encircling capillaries. Hemangiopericytomas traditionally appear in the retroperitoneum and in the capillaries of the extremities. A case of hemangiopericytoma of the parotid gland is presented. The clinical, surgical, histologic, and radiologic features are described and discussed.

Two-dimensional spatial and temporal displacement and deformation field fitting from cardiac magnetic resonance tagging.

Tagged magnetic resonance imaging is a specially developed technique to noninvasively assess contractile function of the heart. Several methods have been developed to estimate myocardial deformation from tagged image data. Most of these methods do not explicitly impose a continuity constraint through time although myocardial motion is a continuous physical phenomenon. In this paper, we propose to model the spatio-temporal myocardial displacement field by a cosine series model fitted to the entire tagged dataset. The method has been implemented in two dimensions (2D)+time. Its accuracy was successively evaluated on actual tagged data and on a simulated two-dimensional (2D) moving heart model. The simulations show that an overall theoretical mean accuracy of 0.1 mm can be attained with adequate model orders. The influence of the tagging pattern was evaluated and computing time is provided as a function of the model complexity and data size. This method provides an analytical and hierarchical model of the 2D+time deformation inside the myocardium. It was applied to actual tagged data from a healthy subject and from a patient with ischemia. The results demonstrate the adequacy of the proposed model for this evaluation.

Predictive value of regional left ventricular circumferential shortening in jeopardized myocardium. A two-dimensional SPAMM cine-MRI study in a canine model.

OBJECTIVE: To determine whether myocardial circumferential shortening assessed in the different myocardial layers by SPAMM cine-MRI may help to discriminate between various degrees of myocardial injury in reperfused myocardium. METHODS: Dogs underwent 90 minutes of coronary occlusion and 24 hours of reperfusion. Using a 1.5 T whole-body MR scanner, SPAMM cine-MRI images were acquired before and 24 hours after surgery on the short axis plan of the left ventricle and analyzed to evaluate the mean myocardial circumferential shortening (% MCS) in the different layers. Based on the residual blood flow, animals were assigned to group I (residual flow < 22.5%) or group II (residual flow > 22.5%). RESULTS: Dogs in group I developed larger infarctions (25.3% +/- 14.6 of the area at risk, n = 5) compared with those in group II (5.81% +/- 1.1, n = 7, P < 0.05). In the jeopardized zone, the % MCS of the subendocardium decreased more significantly in group I (-0.03% +/- 3.7 to 2.2% +/- 5.2) compared with group II (14.7% +/- 1.5 to 18.4% +/- 1.4). CONCLUSIONS: SPAMM cine-MRI is a fast and noninvasive means of measuring % MCS. The MR measurement of this parameter in the subendocardial layer appears quite accurate in describing the degree of damage in reperfused myocardium.

Tracking geometrical descriptors on 3-D deformable surfaces: application to the left-ventricular surface of the heart.

Motion and deformation analysis of the myocardium are of utmost interest in cardiac imaging. Part of the, research is devoted to the estimation of the heart function by analysis of the shape changes of the left-ventricular endocardial surface. However, most clinically used shape-based approaches are often two-dimensional (2-D) and based on the analysis of the shape at only two cardiac instants. Three-dimensional (3-D) approaches generally make restrictive hypothesis about the actual endocardium motion to be able to recover a point-to-point correspondence between two surfaces. The present work is a first step toward the automatic spatio-temporal analysis and recognition of deformable surfaces. A curvature-based and easily interpretable description of the surfaces is derived. Based on this description, shape dynamics is first globally estimated through the temporal shape spectra. Second, a regional curvature-based tracking approach is proposed assuming a smooth deformation. It combines geometrical and spatial information in order to analyze a specific endocardial region. These methods are applied both on true 3-D X-ray data and on simulated normal and abnormal left ventricles. The results are coherent and easily interpretable. Shape dynamics estimations and comparisons between deformable object sequences are now possible through these techniques. This promising framework is a suitable tool for a complete regional description of deformable surfaces.

Validation of a new method for stereotactic localization using MR imaging.

Magnetic resonance is recognized as potentially the best imaging procedure for localization in stereotactic neurosurgery. However, special difficulties necessitate specific adaptation to localize targets in the stereotactic frame. We developed a new method for stereotactic localization. The MR studies were performed using a 0.5 T imager. Four small boxes filled with CuSO4 solution were inserted into the intracranial holders of a Talairach frame. Using fast sequences, thirty 7-mm thick contiguous sagittal slices and twenty 5-mm thick axial slices enabled us to image the entire brain. The image data were transferred for analysis to an image processing station, including special software to handle stereotactic calculations. The accuracy of the origin of the trihedron and systematic geometrical errors were carefully evaluated using a cubic phantom, and corrective algorithms were applied when needed. Moreover, checks have been designed to detect geometrical distortion due to ferromagnetic artifacts, alterations in gradient calibration, or movements made by the patient. This localization method does not necessitate the use of stereotactic frames and appears to be precise enough for clinical use. Duration of MR examination is not a restricting factor, mainly because the patient can be positioned easily.

A computer-assisted system for 3-D frameless localization in stereotaxic MRI.

A low-cost PC-based system for 3-D localization of brain targets in stereotaxic imaging is presented. It relies on a method, using MR images, in which four markers are inserted in the fastenings of a Talairach stereotaxic frame during MRI examination. By locating these markers on the images with this system, the transformation matrixes can be computed to obtain the 3-D coordinates of the center of a tumour in the stereotaxic space or in the MRI space. The system calculates the frame and arc setting parameters of a probe trajectory to the target, either for an orthogonal or a double oblique approach if needed. Simulated probe trajectory intersections with consecutive slices can be viewed in order to validate the trajectory before and during the surgical procedure. The method presents no major constraints in routine examinations. Mathematical details on the calculation of the transformation matrices are given.

[Mesenchymal chondrosarcoma]. / Mesenchymaal chondrosarcoma.

A case is presented of mesenchymal chondrosarcoma. This extremely rare tumor has a characteristic histology. The prognosis is poor. Radical surgery is essential. A lifelong follow-up is recommended.

[Ototopic agents]. / Ototopica.

In treating ear disease every otolaryngologist is familiar with topical medications. The choice of the ideal agent for a given clinical situation may be difficult. In order to make this decision more easy, we overlook the composition of ear-drops. The most important disadvantages are ototoxicity, allergy and pain. The place of ototopical agents in otitis externa, otitis media and otomycosis is discussed.