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Biomedical subjects

A Cotten

Publications and source records attributed to A Cotten.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Imaging of the shoulder].

Except for instability, a variety of causes has been described in the painful shoulder. A thorough clinical examination may help establish the cause of shoulder pain. Even if modern imaging modalities (ultrasonography, computed tomography, MR imaging) allowed a precise diagnostic and therapeutic approach, plain radiographs are still necessary. Performed by an experienced radiologist, ultrasonography may be useful for the assessment of rotator cuff tears which are a common problem. CT arthrography and MR imaging are only recommended in preoperative assessment. In calcific tendinitis plain radiographs provide evidence of calcifications. It is not difficult to establish clinically the diagnosis of adhesive capsulitis and arthrography is the only technique to reveal the articular capacity limitation reliably. In degenerative osteoarthritis of the glenohumeral joint, CT arthrography is necessary to assess the rotator cuff changes and lenoid osseus findings before undergoing shoulder arthroplasty.

Diagnosis, Differential↗
PubMed1999

Image analysis of the distal radius trabecular network using computed tomography.

Bone texture analysis might provide information about bone structure in a noninvasive manner. In a prospective case-control cross-sectional study we investigated the value of computed tomography (CT) image analysis of the distal radius in the assessment of osteoporosis. Twenty patients suffering from postmenopausal osteoporosis were studied and compared with 21 age-matched controls. Eight slices were selected in each patient: four consecutive coronal slices and four consecutive cross-sectional slices. Bone texture analysis was performed using statistical, fractal and structural methods leading to the measurement of 32 features. Structural variables derived from histomorphometric parameters were measured after segmentation from a binary or a skeletonized image. Bone mineral density was measured by dual-energy X-ray absorptiometry both at the lumbar spine and the femoral neck. Eight of the 9 statistical features were significantly different in osteoporotic women as compared with controls (coronal slices, p < 0. 05). Seven structural variables were statistically different between the two groups on coronal slices (p < 0.05): valley surface area, bone volume/tissue volume, trabecular partition, Euler's number, trabecular bone pattern factor, node-to-node strut count and terminus-to-terminus strut count. The most significant results on coronal slices (p < 0.01) concerned 4 structural features: trabecular partition, Euler's number, trabecular bone pattern factor and terminus-to-terminus strut count. Three features were statistically different (p < 0.01) between the two groups on cross-sectional slices (skeletonization from gray levels). A few features yielded by texture analysis were correlated with both lumbar spine and femoral neck bone mineral density, but the level of these correlations was weak (r < 0.5). In conclusion, CT image analysis of the distal radius is a useful tool for characterizing bone texture alterations in osteoporotic women. These findings are in keeping with microarchitectural osteoporosis-related changes diagnosed on bone biopsies.

Aged↗
PubMed1999

[Muscle infarction. An unknown complication of diabetes mellitus].

INTRODUCTION: Diabetic muscle infarction (MI) is a rare and little-known complication of diabetes mellitus. CASE REPORT: We report a case of relapsing MI in which magnetic resonance imaging (MRI) suggested the diagnosis. A 53-year-old man with multi-complicated type II diabetes mellitus was admitted to our unit for illness and deep tumefaction of the right thigh. Because of unconclusive MRI, a muscular biopsy of the lesion was performed and MI confirmed. Three months after, a left relapse of MI occurred. Immediate treatment with immobilization and heparinotherapy permitted a rapid recovery. CONCLUSION: About 70 previously reported cases are reviewed. The mean age at presentation was about 40 years. MI was usually seen in patients with long-standing diabetes with multiple end organ microvascular complications. Homo- or heterolateral recurrences are reported in almost half of the patients. MRI is the best imaging technique for suggesting the diagnosis.

Diabetes Mellitus, Type 2↗
PubMed1999

Percutaneous vertebroplasty in the treatment of osteoporotic vertebral compression fractures: an open prospective study.

OBJECTIVE: To assess the efficacy and safety of percutaneous vertebroplasty in osteoporotic vertebral compression fractures responsible for severe and persistent pain. METHODS: Sixteen patients were included in this open prospective study. Inclusion criteria were: one or 2 vertebral fractures responsible for severe pain, i.e., higher than 50 mm on a visual analog scale (VAS: 0-100 mm), scores 3, 4 or 5 according to the McGill-Melzack scoring system, and evolving for more than 3 months. Assessment criteria were the changes over time (Days 3, 30, 90, 180) in VAS and McGill-Melzack scoring system. The changes over time in a generic health status instrument score [the Nottingham Health Profile (NHP)] were also assessed. Statistical comparisons were performed using the Wilcoxon T test. RESULTS: There were 9 women and 7 men: postmenopausal osteoporosis (n = 7), corticosteroid induced osteoporosis (n = 2), and male osteoporosis (n = 7). Vertebroplasty was performed in 20 vertebrae. A statistically significant decrease of both VAS (-53%, p < 0.0005) and McGill-Melzack scoring system (p < 0.005) was observed at Day 3. The results were also significant at Days 30, 90, and 180 for both scales (p < 0.005 and p < 0.01, respectively). A significant decrease over time for 5/6 dimensions of the NHP score was also noted: pain (p < 0.01), physical mobility (p < 0.05), emotional reactions (p < 0.05), social isolation (p < 0.05), and energy (p < 0.05). We observed no adverse event, and no vertebral fracture has occurred after 6 months of followup. CONCLUSION: Percutaneous vertebroplasty is a useful and safe procedure for treating persistent painful osteoporotic fractures. Controlled studies with longterm followup are required.

Aged↗
PubMed1999

Contribution of magnetic resonance imaging to the diagnosis of extraskeletal Ewing's sarcoma.

A case of extraskeletal Ewing's sarcoma presenting as a large gluteal mass is reported. This is a rare tumor with a frequently grim prognosis. Although the definitive diagnosis requires histological examination, magnetic resonance imaging is useful for determining the location of the tumor, evaluating its spread, and eliminating skeletal Ewing's sarcoma by establishing the integrity of the neighboring bone marrow. The tumor is seen on T1-weighted images as low signal with heterogeneous postgadolinium enhancement. Signal intensity on T2-weighted images is variable. In the case reported here, combination chemotherapy with external beam radiation therapy was ineffective, and the patient died 12 months after the diagnosis.

Adult↗
PubMed1998

Magnetic resonance imaging of the forearm: cross-sectional anatomy in a cadaveric model.

RATIONALE AND OBJECTIVES: Compartmental anatomy of the forearm is complex and controversial. The purpose of this investigation was to demonstrate via magnetic resonance the anatomy of forearm compartments and their preferential ways of communication in a human cadaveric model. METHODS: Twelve forearm spaces (11 muscles and one intermuscular) were injected with a solution containing gadopentetate dimeglumine. The extent and distribution of leakage were evaluated on axial fat-suppressed T1-weighted spin-echo images. The findings were related to known descriptions of compartmental anatomy of the forearm. RESULTS: Contrast leakage occurred mostly into the intermuscular space and into the muscles adjacent to the injected muscle. A frank communication within the classically described three forearm compartments (volar, radial, and dorsal) was not present. The interosseous membrane was not an absolute barrier between flexor and extensor compartments. CONCLUSION: The classic description of three forearm compartments may not be sufficient to explain distribution of soft tissue abnormalities.

Aged↗
PubMed1998

[Reproducibility of the radiographic analysis of dysplasia of the femoral trochlea. Intra- and interobserver analysis of 68 knees].

PURPOSE OF THE STUDY: The relation between patello-femoral instability and trochlear dysplasia was identified by Dejour. Trochlear dysplasia, diagnosed on knee lateral Xray when the trochlear groove crosses both femoral condyles (the so-called "crossing sign"), must be corrected to improve patello-femoral stability. However surgery should be related to the severity and the shape of trochlear dysplasia, underlining the importance of a reproducible classification. The aim of this study was to establish intra and inter-observer reliability of Dejour's radiographic criteria. MATERIAL: 68 preoperative exact knee profile radiographs were harvested from clinical records of 64 patients who underwent trochleoplasty because of patello-femoral instability and trochlear dysplasia. On these 68 views, the crossing sign was identified by the senior surgeon (F.G.) who performed or supervised surgery. METHOD: The 68 radiographs were examined independently by 7 observers (2 juniors, 5 seniors) in order to assess interobserver agreement. Two juniors repeated the observation to test intraobserver agreement. Reproducibility for categorical data (7 shapes of trochlea according to Dejour (3 for dysplasia)) was evaluated by Kappa statistics, and for numerical data (depth and anterior projection of the trochlear groove with respect to anterior femoral cortex) we used the interclass correlation analysis. RESULTS: Two out of the 7 observers rated all the 68 trochleas as dysplastics. The 5 others rated as normal 1 to 6 trochleas out of the 68. None of the 68 trochleas were recognized with the same shape by the 7 examiners. At best, 6 observers agreed on the same shape and for only 12 trochleas. Disagreement was mostly related to mistakes between type I and type II of dysplasia. For trochlear morphology interobserver agreement was slight (Kappa = 0.17) and intraobserver agreement was fair (Kappa = 0.3). The mean prominence of the trochlea was 3 +/- 2.1 mm [-6 to 10], and the mean trochlea depth was 1 +/- 1.9 mm [0 to 11]. These measurements were more reliable since the interclass correlation coefficients were respectively 0.62 and 0.38. The level of experience of the observers had no influence for categorical or numerical data. DISCUSSION: Our results indicated a low interobserver agreement for trochlear shape identification according to Dejour. The most reliable criteria was measurement of the trochlear prominence which was mostly pathological in our series. The "crossing sign" was reliable to diagnose dysplasia since the probability to rate as normal a true dysplastic trochlea was only 3.1 per cent. However, once the dysplasia diagnosed, this classification gave inconsistent results to select the trochlear shape, particularly for type II. To improve reproducibility we propose to diagnose a type II only when 5 millimeters separate the crossings between the medial and lateral condyles. CONCLUSION: We recommend to use anterior projection of the trochlear groove to rate trochlear dysplasia and to determine the adequate type of trochleoplasty: elevating of the lateral facet if non prominent or deepening of the groove when prominent.

Adolescent↗
PubMed1998

Magnetic resonance imaging in focal myositis.

We describe 4 cases of focal myositis of the lower leg in which magnetic resonance imaging (MRI) was useful and sensitive in clearly revealing the detailed anatomic extent of muscle change and in guiding muscle biopsy. We also observed a correlation between MRI findings and severity of both clinical and histological manifestations, suggesting that MRI may provide prognostic criteria in focal myositis. MRI may be a helpful, noninvasive test for the followup of focal myositis, in assessing disease progression or resolution.

Adult↗
PubMed1998

CT scan texture analysis of the distal radius: influence of age and menopausal status.

OBJECTIVES: To gain information on bone architecture by performing bone texture analysis in a sample of women covering a broad age range. PATIENTS AND METHODS: We studied 29 healthy women aged 23 to 80 years (55 +/- 18 years), 19 of whom were postmenopausal. None was taking drugs known to influence bone mass or bone metabolism. Computed tomography of the nondominant distal radius was performed with 1 mm slice thickness and 1 mm gap. Four consecutive coronal and four consecutive axial sections were selected for each patient and entered into a PC-type computer. Bone texture was evaluated using grey level run length analysis (five parameters), differential local variation analysis (four parameters), fractal analysis (two parameters), trabecular network extraction and three-dimensional relief characterization. The mean of each study parameter for the four coronal sections and for the four axial sections was calculated. Absorptiometry was done in 16 patients. RESULTS: Linear correlations with age were strongest (P < 0.001) for parameters measured on coronal sections by trabecular network extraction, i.e., trabecular bone volume (r = -0.68), trabecular plate separation (r = -0.65), total skeletal length (r = -0.71), number of nodes (r = 0.73), number of node-node segments (r = -0.74) and trabecular bone pattern factor (r = 0.71). Also, these parameters were significantly different between premenopausal women (33 +/- 9 years) and postmenopausal women (67.3 +/- 9 years). Correlations between bone mineral density and texture parameters were few in number and modest in strength, suggesting that the parameters measured may reflect bone structure rather than bone mass. CONCLUSION: Bone texture in women undergoes changes with advancing age that may reflect alterations in bone microarchitecture.

Adult↗
PubMed1998

[Malignant melanoma of soft tissues. Apropos of a case].

A case of malignant melanoma of the quadriceps tendon is reported. This is an uncommon soft tissue sarcoma of melanocytic origin. The appearance on MRI depends on its melanin content. The microscopic appearance is distinctive and prognosis is poor. This tumor should be kept in mind when a nodular lesion is detected in specific tendon or aponeurosis.

Diagnosis, Differential↗
PubMed1997

Natural course of erosive arthropathy of the hand in patients undergoing hemodialysis.

OBJECTIVE: To assess the radiographic features of erosive arthropathy of the hands occurring in patients undergoing hemodialysis, and its relationship with metabolic abnormalities. PATIENTS AND DESIGN: A retrospective study of hand radiographs of 80 patients on maintenance hemodialysis was performed with the aim of detecting erosive arthropathy. RESULTS AND CONCLUSIONS: Ten patients showed erosive arthropathy of the hands with a predilection for distal interphalangeal joints. The first joint abnormality was joint space narrowing with or without erosion. The mean duration of hemodialysis was 5 years (range 1-15 years). The development of arthropathy could not be related to a metabolic factor. The pathogenesis of arthropathy of the hands is possibly multifactorial, accounting for the disparate descriptions of the radiographic features in the literature.

Adult↗
PubMed1997

Collateral ligaments of the elbow: conventional MR imaging and MR arthrography with coronal oblique plane and elbow flexion.

PURPOSE: To determine the best plane and position of the elbow for optimal visualization of normal and abnormal collateral ligaments with conventional magnetic resonance (MR) imaging and MR arthrography, to determine the normal appearance of the collateral ligaments at MR arthrography and to assess use of MR arthrography in evaluation of collateral ligamentous lesions. MATERIALS AND METHODS: Nine cadaveric elbow specimens were imaged with and without intraarticular administration of gadolinium-containing solution in several planes that were identified as potentially useful in a pilot study in two specimens. MR imaging findings were compared with anatomic findings. RESULTS: Normal and abnormal ligaments were best depicted in a 20 degrees posterior oblique coronal plane in relation to the humeral shaft with the elbows extended and a coronal plane aligned with the humeral shaft with the elbows slightly flexed (20 degrees-30 degrees of flexion). Gadolinium enhancement improved the delineation of normal and abnormal ligaments on T1-weighted images in each case. CONCLUSION: The posterior oblique coronal plane with the elbows extended or the coronal plane aligned with the humeral shaft with the elbows slightly flexed allows accurate assessment of the collateral ligaments. Gadolinium-enhanced MR arthrography of the elbow seems to be a promising technique.

Aged↗
PubMed1997

Percutaneous vertebroplasty in patients with osteolytic metastases or multiple myeloma.

UNLABELLED: Osteolytic metastases and spinal myeloma lesions are difficult to treat because they denote disseminated malignant disease. The pain-relieving and other effects of radiation therapy are delayed. We evaluated short- and medium-term outcomes of vertebroplasty in this indication, in patients with severe or excruciatingly severe pain (McGill-Melsack score 4 or 5) unresponsive to narcotics. PATIENTS AND METHODS: forty vertebras were treated in 37 patients including 29 with bone metastases and eight with multiple myeloma. Mean age was 58 years (range 36-83). The spinal segment involved was the cervical spine in five cases, the thoracic spine in 12 and the lumbar spine in 23. Vertebroplasty was done under fluoroscopy guidance after premedication and local anesthesia. RESULTS: thirty-six patients (97.3%) reported a decrease in their pain 48 hours after the procedure; five of these patients (13.5%) were completely free of pain, 20 (55%) were significantly improved and 11 (30%) were moderately improved. One patient failed to respond. The clinical results were not correlated to the extent of vertebral body filling. Beneficial effects were increased or unchanged in 100% of cases after one month, 88.9% after three months and 75% after six months. Leakage of the cement outside the vertebral body occurred in 29 cases (72.5%), usually into the paraspinal soft tissues (n = 21,52.5%). Leakage was usually clinically silent and only two patients developed severe nerve root pain due to leakage into a neural foramen, with in both instances a favorable outcome after surgery. CONCLUSION: Vertebro- plasty is simple and effective for the treatment of osteolytic metastases and multiple myeloma lesions, but should be performed only in centers with neurosurgical and/or orthopedic surgery units because of the possibility of severe complications.

Adult↗