Biomedical subjects

Frédéric Lecouvet

Publications and source records attributed to Frédéric Lecouvet.

4 recordsLinked to original sources

PubMed2006

Correlation between baseline femoral neck marrow status and the development of femoral head osteonecrosis in corticosteroid-treated patients: a longitudinal study by MR imaging.

OBJECTIVE: To test the hypothesis that the development of corticosteroid (CS)-associated femoral head osteonecrosis (ON) is influenced by baseline femoral neck marrow status. PATIENTS AND METHODS: The population consisted of 20 untreated patients with a newly diagnosed rheumatic disease in whom a standardized CS regimen was planned. Before CS treatment, baseline femoral neck marrow status was determined by magnetic resonance (MR) imaging on T1-weighted images (proportion of surface area of femoral neck and intertrochanteric area occupied by fatty marrow; index of marrow conversion [IMC]) and on a quantitative MR sequence (bulk T1 values of femoral head and neck). The presence of ON was assessed by coronal T1-weighted MR images of the hips at 6 and 12 months. RESULTS: None of the patients suffered from ON at baseline. Four patients (20%) developed bilateral femoral head ON at 6 months. The mean percentage of fat marrow in the femoral neck before treatment was significantly higher in ON-positive than in ON-negative patients (p=0.0025). The mean baseline femoral neck IMC value, which parallels the degree of red to yellow marrow conversion, was higher in ON-positive than in ON-negative patients (p=0.089). The mean baseline bulk T1 value of the femoral neck (but not of the femoral head), which inversely correlates with the amount of fat marrow, was significantly shorter in ON-positive than in ON-negative patients (p=0.0298). CONCLUSION: The development of CS-associated femoral head ON is correlated with a high fat content in the proximal femur before CS therapy.

Adipose Tissue↗

PubMed2005

Primary chronic sclerosing osteomyelitis--a case-report.

A case of primary chronic sclerosing osteomyelitis of the fibula in a 14-year-old is described. This rare condition can be difficult to differentiate from a bone tumor. Its pathogenesis is controversial, although the prevalent hypothesis involves chronic osteomyelitis developing after an unrecognized phase of acute infection. The existence of primary chronic sclerosing osteomyelitis as a disease in its own right has been challenged. Recently, primary chronic sclerosing osteomyelitis has been interpreted as a localized or monofocal variant of multifocal recurrent chronic osteitis or of the bone abnormalities associated with seronegative spondyloarthropathies (SAPHO syndrome).

Adolescent↗

PubMed2004

The etiologic diagnosis of infectious discitis is improved by amplification-based DNA analysis.

OBJECTIVE: Blood cultures and cultures of disc material are required to identify and treat bacterial agents responsible for septic spondylodiscitis, but these methods have limited sensitivities. We undertook this study to compare nonculture amplification-based DNA analysis with conventional culture of disc aspirate. METHODS: Nineteen patients with spondylodiscitis, including 11 with a history of spinal surgery, presented with negative blood cultures and underwent percutaneous disc or epidural abscess puncture for bacterial diagnosis. Amplification by polymerase chain reaction was performed on 16S ribosomal DNA universal target genes and femA staphylococci-specific target genes in all patients, and on the upstream p34 mycobacterial gene in 1 patient. Species identification relied on amplicon sequencing and comparison with templates from GenBank. Amplification of the femA gene led to subsequent testing for methicillin resistance by amplification of the mecA gene. Further assessment using a staphylococci- and methicillin resistance-specific DNA array was performed on 3 samples. RESULTS: Microbiologic and molecular assays identified the causative organism in 14 of 19 patients (74%) and 19 of 19 patients (100%), respectively. In culture-positive patients, DNA-based and microbiologic results were highly correlated. Five agents (Staphylococcus simulans, Staphylococcus sciuri, Brucella species, Actinomyces israelii, and Mycobacterium tuberculosis complex) were identified only by DNA-based methods. In 1 sample, Corynebacterium jeikeium and coagulase-negative Staphylococcus were both cultured, whereas DNA analysis identified only Staphylococcus hominis. CONCLUSION: DNA-based methods are highly sensitive and specific. They can usefully complement standard microbiologic methods for identifying the cause of infectious spondylodiscitis and contribute to species-specific therapeutic orientation in patients with negative blood and disc aspirate cultures.

Adult↗

PubMed2004

Imaging study findings in elastofibroma dorsi.

Elastofibroma dorsi is a tumor or pseudotumor typically located under the tip of the scapula. It is far from uncommon in older individuals. The mass contains both fibrous tissue and fatty tissue. Imaging studies can provide the definite diagnosis in many cases. Computed tomography (CT) and magnetic resonance imaging (MRI) are particularly effective, as they visualize the characteristic layered pattern of fatty tissue (low-density by CT, high-signal on T1 images and intermediate signal on T2 images by MRI) and fibrous tissue (similar to muscle in terms of density by CT and signal intensity by MRI). To a lesser extent, plain radiographs and ultrasonography identify a number of suggestive features (location and layered structure). When the lesion exhibits typical imaging features and produces no symptoms, as is usually the case, further investigations are probably unnecessary.

Fibroma↗