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Y Rolland

Publications and source records attributed to Y Rolland.

At least 37 records · Page 2Linked to original sources
PubMed2001

Fast detection and characterization of vessels in very large 3-D data sets using geometrical moments.

An improved and very fast algorithm dealing with the extraction of vessels in three-dimensional imaging is described. The approach is based on geometrical moments and a local cylindrical approximation. A robust estimation of vessel and background intensity levels, position, orientation, and diameter of the vessels with adaptive control of key parameters, is provided during vessel tracking. Experimental results are presented for lower limb arteries in multidetector computed tomography scanner.

Algorithms↗
PubMed2001

Spinal epidural angiolipoma.

Spinal epidural angiolipoma is a rare benign tumor predominantly located in the mid-thoracic region. The authors report a case of spinal epidural angiolipoma in a 36-year old woman who presented with subacute paraplegia. Clinico-pathological and MRI findings of this uncommon tumor are discussed.

Adult↗
PubMed2001

[Sport practice and cannabis consumption in a representative sample of French high school adolescents].

PURPOSE: - To assess the association between cannabis consumption and sport practice. METHODS: We randomised a representative sample of 1,506 girls and 1,420 boys from the third to the last year of school in the French Midi-Pyrénées region, excluding classes reserved for children practising high level sport. Information was collected by self-answer questionnaire. RESULTS: More than 90% of boys and 70% of girls declared they practised sport outside physical education at school (athletic students). Among boys, sport practice mainly concerned activities in clubs or competitions (respectively 66% and 60%, against 35% and 27% among girls; p<0.001). Twenty-eight percents of boys and 19% of girls declared they had consumed cannabis (at least occasionnally, during or outside sport). Among athletic students, such potential consumption concerned 28.6% of boys and 19.6% of girls (p<0.001). Moreover, 1.2% of athletic students (n=7) declared they had already consumed cannabis during the practice sport with clubs or competitions. Among boys, this potential consumption increased with age, was lower among non-athletic students and the most athletic students, but was highest among those practising an individual "X-treme" sport (50% in this group versus 26% among athletes practising collective or non- "X-treme" sport; p<0.001). Potential cannabis consumption was also highest among athletes who declared they practiced sport for seeking emotions, who did not practise sport for health benefits but who considered that sport could involve taking risks. CONCLUSION: It seems more important to consider how sport is practised rather than its intensity when assessing the association between sport and cannabis consumption. Indeed, sport appears to be more favourable for cannabis consumption when associated with ideas of emotion and risk and when practised outside of an organisation.

Adolescent↗
PubMed2000

[Prevention of falls and their consequences].

UNLABELLED: FREQUENCY AND SEVERITY: Approximately 30% of all elderly subjects experience a fall at least once a year. Hip fractures is the most severe consequence. PREVENTIVE MEASURES: The prevention of falls and hip fractures implies different strategies depending on the population concerned. For most all older subjects in good general health, one of the important risk factors is an abnormal single-leg stance which can reveal equilibrium disorders. For more frail subjects (20% of the elderly population), all factors must be considered, including, sarcopenia, nutritional status, and cognitive function. INSTITUTIONALIZED SUBJECTS: For institutionalized subjects, generally with multiple disease states, falls usually signal poor health, aggravated by multiple medications. One of the most frequent diseases observed in this population is Alzheimer type dementia. Adapted multidimensional management must be initiated within the framework of an overall gerontology policy to prevent falls and their consequences in institutionalized subjects.

Accidental Falls↗
PubMed2000

Radiology on Internet: advice in consulting websites and evaluating their quality.

Services offered by Internet are increasing continually and 15,000 medical websites covering all the specialties are available presently. Finding relevant information with a spider-web organization is difficult. We recommend starting with hierarchical lists which propose a selection of sites corresponding to medical specialties. We give our selection of important radiological websites dealing with image databases, case reports, radioanatomy and continuing medical education. While surfing the Web, an evaluation of the quality of websites is necessary. We used quality criteria proposed by Darmoni to rate the quality of ten websites. The global quality is good; help pages and external links are the main noticed shortcomings. All webmasters should pay attention to quality criteria and show visible marks of Darmoni criteria on their home page. To be able to foresee which Internet options should be developed, we evaluated our website and sent a questionnaire to our users. Clinical cases are the most requested facilities; they could be used for continuing medical education.

Anatomy↗
PubMed2000

[Falls, frailty and osteoporosis in the elderly: a public health problem].

INTRODUCTION: Elderly people can be subdivided into three groups: healthy elderly persons (65-70% of the population), elderly subjects with diseases (about 5%) and frail old people. Frailty represents "age-related physiologic vulnerability resulting from impaired homeotasic stock and a reduced capacity of the organism to withstand stress". It could lead elderly subjects to pathological, barely reversible, ageing. CURRENT KNOWLEDGE AND KEY POINTS: One of the main objective of geriatricians is to develop useful screening tools to identify people at high risk, thus allowing them to benefit from preventive interventions as early as possible. It has been suggested that the decline in homeostatic stock involves numerous physiological systems. Those at the core of frailty would be neuromuscular changes resulting in sarcopenia, neuroendocrine dysregulation, and immune disorders. A recent study has shown that increased levels of interleukin 6 is a risk factor for frailty. FUTURE PROSPECTS AND PROJECTS: Work in progress aimed at identification of at-risk patients should: lead to early detection; draw attention on underestimated fields such as the nutritional status, sarcopenia, or gait disorders; promote the development of the standardized gerontological evaluation in order to identify the different components of frailty; and promote the development of non-pharmacological programmes including physical training, nutritional managing, and optimal social life.

Accidental Falls↗
PubMed2000

[Alzheimer's disease: from pathology to preventive methods?].

INTRODUCTION: Sporadic Alzheimer's disease is the most frequent form of dementia and appears to be associated with increasing age and certain genetic and environmental factors. Some studies have recently been published on potential protective factors. CURRENT KNOWLEDGE AND KEY POINTS: Several genes appear to be involved; one of the most common is the ApoE4 allele on chromosome 19. The physiopathology is not elucidated, but recent studies have shown a protective effect for NSAIDs, estrogen, nutritional factors (vitamins E, B6 and B12) as well as some biochemical amino acids (homocysteine). FUTURE PROSPECTS AND PROJECTS: Interventional studies are now in progress and some preventive approaches will soon be available.

Alzheimer Disease↗
PubMed2000

Quantification of carotid stenoses using 3D morphometer, CT angiography and conventional angiography.

BACKGROUND: The aim of this study is to compare the performances of 3D morphometer (M3D) regarding the quantification of extracranial carotid stenoses with selective 2D conventional angiography (reference technique) and spiral CT scan. METHODS: It is a prospective study, including 15 patients (mean age 75) presenting a symptomatic carotid lesion detected via duplex Doppler to be operated. Patients had to hold their breath for 20 seconds. Twenty-nine carotid bifurcations were studied by means of M3D and 2D conventional angiography (15 patients). Only 10 patients (19 bifurcations) underwent a CT scan. The measures were performed on a visual display unit by measuring the pixels as per the NASCET technique. Diameters (MIP technique) and surfaces (reformated axial slices) were measured. RESULTS: With MIP technique, a good correlation was found 20 times in 29 (69%) (overestimation: n=8/29) between M3D and angiography, but only in 9 of 19 cases (47%) between CT scan and angiography. Unlike with M3D, the slices re-oriented with CT scan gave better correlations: 15 times in 19 (79%). With the CT scan, the measures were impossible 8 times on MIP technique, and twice on reformated slices for calcified tight stenoses. Therefore, the quantification by means of spiral CT scan is easier by planimetry on slices. CONCLUSIONS: The reliability of these 3D explorations regarding quantification remains uncertain. The use of a morphometer, provided that technical adaptations are made, could replace selective sequences in multiple incidences that become accessible in the post-treatment period, with an acquisition field larger than the one of the CT scan.

Aged↗
PubMed2000

Feasibility [corrected] of regular physical exercise for patients with moderate to severe Alzheimer disease.

BACKGROUND: Physical activity delays loss of autonomy in the elderly. In patients with Alzheimer disease (AD), physical activity could be a useful strategy in therapeutic management by delaying loss of functional independence and the usual complications of the disease. OBJECTIVE: To determine, using standardized tools, the effects on autonomy (ADL, IADL), cognitive function (MMS), nutritional status (MNA), behavioral problems (NPI) and risk of falls (Tinetti test) of a physical exercise program in patients with AD. DESIGN: Twenty-three subjects (13 men and 10 women, aged 71-92 years, mean 78 years) with AD (mean MMS 16, range 1-23) carried out for a mean of 7 weeks (5-12 weeks) a program of endurance exercise (walking, exercise bicycle) adapted to their individual capacities. Standardized gerontological evaluation was performed before and after the study. RESULTS: No significant change in autonomy (ADL, IADL) was observed. There was an improvement in the MNA (p<0.001) and the MMS (p<0.001). Risk of falls (p<0.01) and behavioral problems (p<0.05) decreased. These results were obtained without increasing family workload. CONCLUSION: We suggest that physical activity is a therapeutic option which can reduce nutritional and behavioral complications and risk of falls in subjects with AD.

Accidental Falls↗
PubMed2000

Determination of appendicular muscle mass by dual energy X-ray absorptiometry method in women with sarcopenia and Alzheimer's disease.

OBJECTIVES: To study appendicular muscle mass in women with Alzheimer's disease (AD) to investigate the association between sarcopenia and AD. To examine the AD associated changes in body fat distribution. DESIGN: a cross-sectional study of 32 women with AD and 32 healthy age and bone mineral density matched women. SETTING: Toulouse, France. RESULTS: No differences were noted in fat free soft tissue mass or Appendicular Skeletal Muscle (ASM) mass between AD women and control women. The difference of ASM (kg) /height2 (m)2, used as an index of relative skeletal muscle mass, was not statistically significative between the two groups. The prevalence of sarcopenia increased from 21.9 % in healthy elderly women to 40.6 % in AD women but the difference was not statistically significant. No statistically significant relationship emerged between sarcopenia and AD (OR= 0.41, CI 0.12-1.4). Moreover, total body fat mass was significantly lower in women with AD than in the age -, sex - and bone mineral density - matched controls. CONCLUSION: AD are not necessary linked to sarcopenia. The decrease in adipose tissue in women with AD could be one more factor involving estrogen deficiency in the etiology of the disease.

Absorptiometry, Photon↗
PubMed2000

[Value of pulsed color Doppler before transverse rectus abdominis musculocutaneous flap breast reconstruction. 45 cases].

The transverse rectus abdominis musculocutaneous TRAM flap is an interesting alternative for breast reconstruction after mastectomy for cancer disease in patients who refuse mammary prosthesis and when the clinical situation allows it. There is however a risk of unpredictable partial necrosis even after rigorous surgical procedure. Some authors have proposed a Doppler evaluation before reconstruction surgery to better identify the vascular network and optimize patient selection. We performed a preliminary study in 45 patients between January 1996 and December 1999. An echo-Doppler Ultramark 9 HDI (Advanced Technology Laboratories) equipped with a high frequency (10 MHz) linear probe was used to compare blood flow and vessel caliber in the superior epigastric artery and the perforating vessels (number, localization, peak flow). The results obtained in this series could be used to determine indications for TRAM flap with or without delay procedure.

Female↗
PubMed1999

Flavonoid-related modulators of multidrug resistance: synthesis, pharmacological activity, and structure-activity relationships.

A series of 28 flavonoid derivatives containing a N-benzylpiperazine chain have been synthesized and tested for their ability to modulate multidrug resistance (MDR) in vitro. At 5 microM, most compounds potentiated doxorubicin cytotoxicity on resistant K562/DOX cells. They were also able to increase the intracellular accumulation of JC-1, a fluorescent molecule recently described as a probe of P-glycoprotein-mediated MDR. This suggests that these compounds act, at least in part, by inhibiting P-glycoprotein activity. As in other studies, lipophilicity was shown to influence MDR-modulating activity but was not the only determinant. Diverse di- and trimethoxy substitutions on N-benzyl were examined and found to affect the activity differently. The most active compounds had a 2,3, 4-trimethoxybenzylpiperazine chain attached to either a flavone or a flavanone moiety (13, 19, 33, and 37) and were found to be more potent than verapamil.

Antibiotics, Antineoplastic↗
PubMed1999

Comparison of automated and visual texture analysis in MRI: characterization of normal and diseased skeletal muscle.

Automated magnetic resonance imaging (MRI) texture analysis was compared with visual MRI analysis for the diagnosis of skeletal muscle dystrophy in 14 healthy and 17 diseased subjects. MRI texture analysis was performed on 8 muscle regions of interest (ROI) using four statistical methods (histogram, co-occurrence matrix, gradient matrix, runlength matrix) and one structural (mathematical morphology) method. Nine senior radiologists assessed full leg transverse slice images and proposed a diagnosis. The 59 extracted texture parameters for each ROI were statistically analyzed by Correspondence Factorial Analysis. Non-parametric tests were used to compare diagnoses based on automated texture analysis and visual analysis. Texture analysis methods discriminated between healthy volunteers and patients with a sensitivity of 70%, and a specificity of 86%. Comparison with visual analysis of MR images suggests that texture analysis can provide useful information contributing to the diagnosis of skeletal muscle disease.

Adolescent↗
PubMed1999

Modeling of the parenchymous vascularization and perfusion.

RATIONALE AND OBJECTIVES: The authors sought to create a realistic model of the parenchymous vascularization and perfusion. METHODS: A three-dimensional vascular model has been developed that reproduces the growth process of a vascular tree (angiogenesis). This model follows physical laws related to blood flow in vessels (Poiseuille's law), takes into account anatomic constraints, and optimizes a cost function related to the blood volume. RESULTS: Vascular trees, the ramifications of which go from main arteries to small arterioles, were simulated. Vascular structures corresponding to either a normal tissue perfusion or an abnormal perfusion (for example, a local hypervascularization) were presented in three dimensions (volume rendering). Geometric and hemodynamic characteristics computed on these trees were consistent with those of real data found in the literature. The vascular model is also a good tool for studying the propagation of the contrast product in normal and abnormal vessels. CONCLUSIONS: The three-dimensional vascular model presented in this article provides insight into the simulation and the understanding of anatomic or physiologic vascular modifications.

Blood Vessels↗
PubMed1999

Slice simulation from a model of the parenchymous vascularization to evaluate texture features: work in progress.

RATIONALE AND OBJECTIVES: To demonstrate the usefulness of a model of the parenchymous vascularization to evaluate texture analysis methods. METHODS: Slices with thickness varying from 1 to 4 mm were reformatted from a 3D vascular model corresponding to either normal tissue perfusion or local hypervascularization. Parameters of statistical methods were measured on 16128x128 regions of interest, and mean values and standard deviation were calculated. For each parameter, the performances (discrimination power and stability) were evaluated. RESULTS: Among 11 calculated statistical parameters, three (homogeneity, entropy, mean of gradients) were found to have a good discriminating power to differentiate normal perfusion from hypervascularization, but only the gradient mean was found to have a good stability with respect to the thickness. Five parameters (run percentage, run length distribution, long run emphasis, contrast, and gray level distribution) were found to have intermediate results. In the remaining three, curtosis and correlation was found to have little discrimination power, skewness none. CONCLUSION: This 3D vascular model, which allows the generation of various examples of vascular textures, is a powerful tool to assess the performance of texture analysis methods. This improves our knowledge of the methods and should contribute to their a priori choice when designing clinical studies.

Blood Vessels↗