Biomedical subjects

Anne Cotten

Publications and source records attributed to Anne Cotten.

27 records · Page 2Linked to original sources

PubMed2003

Trabecular bone structure of the calcaneus: preliminary in vivo MR imaging assessment in men with osteoporosis.

PURPOSE: To use magnetic resonance (MR) imaging to evaluate potential differences in bone structure between men with and men without osteoporosis. MATERIALS AND METHODS: Sagittal MR images of the calcaneus were obtained in 50 men (26 patients with osteoporosis and 24 age-matched healthy control subjects). Osteoporosis was defined as a low bone mineral density (at least 2.5 SDs below the normal value for young adults at either the lumbar spine or proximal femur) as measured with dual-energy x-ray absorptiometry. Seventeen patients had a history of osteoporotic fractures. For each participant, 10 consecutive sagittal three-dimensional gradient-echo MR sections were analyzed by using a rectangular region of interest. Twenty structural measurements were obtained from these images. Additionally, density measurements at the calcaneus were obtained in 46 participants. The significance of differences between the two groups was calculated by using the unpaired Student t test. The odds ratios for fracture per 1 SD decrease in the control group were calculated with logistic regression analysis. Adjustment for participant weight and height was performed if necessary. RESULTS: Thirteen of 20 structural parameters, especially connectivity parameters, showed significant differences between control subjects and patients (P <.05). Differences between the two groups were more significant (P <.001) for apparent bone marrow skeleton length, apparent node count, apparent node-to-node strut count, and apparent terminus-to-terminus strut count. Odds ratios for 11 of 13 structural parameters but not for calcaneus density were significant (P <.05). After adjustment for calcaneus density, these parameters were still significant predictors of osteoporotic fracture. CONCLUSION: Structural measurements derived from MR images of the calcaneus may be used in vivo to characterize trabecular bone architecture in men with osteoporosis.

Body Height↗

PubMed2003

Thoracic outlet: assessment with MR imaging in asymptomatic and symptomatic populations.

PURPOSE: To compare the dynamic modifications of the thoracic outlet in asymptomatic volunteers and symptomatic patients and assess the presence and location of vasculonervous compressions in these two populations. MATERIALS AND METHODS: Thirty-five healthy volunteers and 54 patients with clinical symptoms of thoracic outlet syndrome (TOS) underwent magnetic resonance (MR) imaging of the thoracic outlets with their arms alongside their bodies and after a postural maneuver. Measurements were obtained at the interscalene triangle (thickness of anterior scalene muscle, interscalene angle), at the costoclavicular space (minimum costoclavicular distance, distance between inferior border of subclavius muscle and the anterior chest wall, maximum thickness of subclavius muscle, angle between first rib shaft and horizontal), and at the retropectoralis minor space (distance between posterior border of pectoralis minor muscle and posterior lining of axilla at the passage of the axillary vessels, thickness of pectoralis minor muscle). The presence and location of vasculonervous compressions were also assessed. Group data were analyzed with the Student t test. RESULTS: Patients with TOS had a smaller costoclavicular distance after the postural maneuver (P <.001), a thicker subclavius muscle in both arm positions (P <.001), and a wider retropectoralis minor space after the postural maneuver (P <.001) than did volunteers. Venous compressions after the postural maneuver were observed in 47% of volunteers and 63% of patients at the prescalene space, in 54% of volunteers and 61% of patients at the costoclavicular space, and in 27% of volunteers and 30% of patients at the retropectoralis minor space. Arterial and nervous compressions, respectively, were seen in 72% and 7% of patients. No arterial or nervous compression was seen in volunteers. Except for venous thrombosis, vasculonervous compressions were demonstrated only with arm elevation. Only three thoracic outlet measurements differed significantly in both populations. CONCLUSION: MR imaging appeared helpful in demonstrating the location and cause of arterial or nervous compressions.

Adult↗

PubMed2003

Magnetic resonance imaging appearance of the hands and feet in patients with early rheumatoid arthritis.

OBJECTIVE: To describe the magnetic resonance (MRI) imaging findings of the feet in patients with early rheumatoid arthritis (RA), and to compare MRI appearance of the feet with that of the hands. METHODS: Thirty consecutive patients (18 women, 12 men; age range 19-64 yrs) with early RA underwent MRI of hands and feet. Axial fat suppressed gadolinium enhanced T1 weighted spin-echo and gadolinium enhanced 3-dimensional gradient-echo (FLASH) images were obtained. RESULTS: In the hands, MRI findings suggested active synovitis of the wrist and metacarpophalangeal (MCP) joints in 28 (93%) and 27 (90%) patients, respectively. In the feet, active synovitis was observed in 29 (97%) patients. Bone erosions were seen in the wrist joints in 24 (80%) patients. Observers found as many bony changes in the MCP as in the metatarsophalangeal joints [23 (77%) patients]. MRI detected tenosynovitis in 16 (53%) patients in the hands, and in 18 (60%) patients in the feet. Bursitis located between or beneath the metatarsal heads was a common MRI finding [19 (63%) patients]. CONCLUSION: Additional MRI of the feet may be useful when evaluation of the hands does not help identify early RA.

Adult↗

PubMed2003

Sonographic mapping of the normal brachial plexus.

BACKGROUND AND PURPOSE: Mapping of the brachial plexus with MR imaging has been reported and may have potential clinical applications (eg, precise localization of traumatic or tumoral nerve lesions, selective anesthesia of the brachial plexus). We sought to demonstrate that mapping of the brachial plexus may be performed by means of sonography. METHODS: Twelve healthy adult volunteers (seven women and five men; age range, 24-38 years; mean, 31 years) underwent bilateral sonographic examination for the assessment of the nerve structures of the brachial plexus from the extraforaminal part to the axillary part. Four formolated cadavers (two male and two female; age range, 66-84 years; mean, 77.5 years) were frozen and sawed into 3-mm-thick contiguous sections in the same plane as that used for the sonographic exploration. RESULTS: A satisfactory sonographic examination was performed in 10 of 12 volunteers, leading to a good association with anatomic sections. Two volunteers were excluded from the study because a clear depiction of the brachial plexus was difficult owing to a short neck and low echogenicity at examination. The association between sonographic images and anatomic sections allowed us to map the brachial plexus. The subclavian and deep cervical arteries were useful landmarks for this mapping. The eighth cervical nerve root and the first thoracic nerve root were the most difficult part of the brachial plexus to depict because of their deep location. CONCLUSION: The brachial plexus can be mapped with sonography. However, this technique requires a good grounding in anatomy and may be impossible in short-necked individuals.

Adult↗

PubMed2002

Rapidly destructive osteoarthritis of the hip: MR imaging findings.

OBJECTIVE: The aim of our study was to describe the MR imaging findings in patients with rapidly destructive osteoarthritis of the hip. CONCLUSION: The key MR imaging features of rapidly destructive hip osteoarthritis include joint effusion (100%), bone marrow edemalike pattern in the femoral head and neck (100%) or acetabulum (83%) or both, femoral head flattening (92%), and cystlike subchondral defects (83%). Additional findings are low-signal-intensity lines (33%) in the femoral epiphysis, bandlike areas of low signal intensity in the upper pole of the femoral head (8%), and focal signal abnormalities in the adjacent soft tissues (33%) on short tau inversion recovery MR images, fat-suppressed T2-weighted MR images, and fat-suppressed gadolinium-enhanced T1-weighted MR images.

Acetabulum↗

PubMed1998

Normal Anatomy of the Elbow on Conventional MR Imaging and MR Arthrography.

Conventional MR imaging allows clear depiction of the muscles, tendons, nerves, vessels, ligaments, bones, and cartilage that compose the elbow. MR arthrography can be a valuable supplementary technique for optimizing evaluation of intraarticular structures, including the undersurfaces of the collateral ligaments. Regardless of the imaging technique utilized, knowledge of normal anatomy-and normal anatomic variants-is fundamental for accurate assessment of normal and diseased states.

Journal Article↗

PubMed1997

Percutaneous Acetabular Osteoplasty.

The diagnostic value of ultrasound for musculoskeletal pathology is well recognized. Ultrasound offers a low-cost, nonionizing, readily available imaging technique for the evaluation of tendons, muscles, soft-tissue masses, cysts, and other fluid collections. These advantages also make ultrasound a valuable tool for guiding a variety of musculoskeletal interventions. Its real-time capabilities permit continuous monitoring of the needle position relative to the target lesion and to surrounding structures such as vessels. Ultrasound can be regarded as the ÒfluoroscopyÓ for soft tissues. Ultrasound therefore can be used to localize and characterize the lesion, monitor the needle position during the procedure, document the efficacy of the drainage or the technique, and be used for follow-up imaging. Procedures that can be performed under ultrasound guidance include aspiration of fluid for analysis, injection of medication (steroids), decompression of cyst, bursitis or joint, abscess and hematoma drainage, treatment of calcific tendinitis, biopsy, and foreign body retrieval.

Journal Article↗

PubMedDate not supplied

Imaging of foot and ankle nerve entrapment syndromes: from well-demonstrated to unfamiliar sites.

Nerve entrapment at the foot and ankle involves thin and complex anatomic structures and is underdiagnosed because clinical symptoms and electrophysiologic findings may not contribute to the diagnosis. Nerve entrapment can be secondary to acute trauma or repetitive microtrauma. The latter often results from intensive sports-related activity, inappropriate footwear, or internal foot derangement. Various lesions that occur in fibro-osseous tunnels can cause nerve compression (eg, ganglion cysts, varicosities, bone and joint abnormalities, tumors, tenosynovitis, supernumerary or hypertrophic muscles). Accurate nerve examination must be performed, particularly in patients with atypical ankle pain, to detect focal tenderness or paresthesia. Ultrasonography is useful in this setting because it yields both clinical and morphologic findings. High-resolution magnetic resonance imaging provides accurate delineation of the nervous system anatomy. Furthermore, technologic developments in the field of radiology are making it possible to obtain clearer, more accurate images. Radiologists must be aware of the main nerve entrapment syndromes at the foot and ankle and be able to perform accurate nerve examinations with different imaging modalities in patients with foot and ankle pain.

Ankle↗

PubMedDate not supplied

Imaging assessment of thoracic outlet syndrome.

The thoracic outlet includes three compartments (the interscalene triangle, costoclavicular space, and retropectoralis minor space), which extend from the cervical spine and mediastinum to the lower border of the pectoralis minor muscle. Dynamically induced compression of the neural, arterial, or venous structures crossing these compartments leads to thoracic outlet syndrome (TOS). The diagnosis is based on the results of clinical evaluation, particularly if symptoms can be reproduced when various dynamic maneuvers, including elevation of the arm, are undertaken. However, clinical diagnosis is often difficult; thus, the use of imaging is required to demonstrate neurovascular compression and to determine the nature and location of the structure undergoing compression and the structure producing the compression. Cervical plain radiography should be performed first to assess for bone abnormalities and to narrow the differential diagnosis. Computed tomographic (CT) angiography or magnetic resonance (MR) imaging performed in association with postural maneuvers is helpful in analyzing the dynamically induced compression. B-mode and color duplex ultrasonography (US) are good supplementary tools for assessment of vessel compression in association with postural maneuvers, especially in cases with positive clinical features of TOS but negative features of TOS at CT and MR imaging. US may also allow analysis of the brachial plexus. However, MR imaging remains the method of choice when searching for neurologic compression.

Diagnostic Imaging↗