Biomedical subjects
Publications and source records attributed to X Demondion.
The purpose of this paper is to present the contribution of imaging in the assessment of synovial diseases, especially in the differentiation between infectious synovitis and rheumatoid arthritis, and in the diagnosis of tumoral and pseudotumoral synovial lesions (idiopathic (osteo)chondromatosis, pigmented villonodular synovitis, synovial hemangioma, lipoma arborescens...).
The recent developments in Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) allow an accurate analysis of the anatomical structures of the lateral recess and of the neural foramen (vertebral body, pedicle, zygapophyseal joints, ligamentum flavum, intervertebral disk) and their contents (spinal ganglion, nerves roots, foraminal veins, surrounding fat). The aim of this study is 1) to describe the normal anatomy and variants of the lateral recess and of the lumbar neural foramen, and 2) to present the main diseases involving this anatomical area.
The epidural space which extends along the spine, surrounds the dural sac and is bounded by the bony and ligamentous structures of the vertebral canal. The knowledge of the anatomy of this region is important because the high frequency of the pathological processes in this area (tumoral, infections, vascular). The purpose of this presentation is to present the normal radio-anatomy of the lumbar epidural space and then the main pathological processes of this region.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We report a case of carpal injury not previously described, associating three lesions of the carpus secondary to a hyperextension mechanism: fracture of the capitate, scapho-trapezio-trapezoid sprain and lunotriquetral ligament rupture. The patient was operated by percutaneous pinning after closed reduction. The capitate fracture was not fixed. At follow-up, the patient had no restriction of his everyday activities and was very satisfied.
The thumb has only two phalanges whereas the other fingers present three. For two millennia, many anatomists tried to solve this riddle. Four different theories can be found in the review of literature, to explain what element misses in the radial column. In the first theory (Galen), the first metacarpal should be the proximal phalanx of the thumb. The particular ossification of the first metacarpal advocates for this theory. In the second theory (Sappey), the first metacarpal should result from the fusion between the true first metacarpal and the proximal phalanx of the thumb, and the proximal epiphysis should be constituted from both metacarpal and phalangeal parts. In the third theory (Paturet), the middle phalanx is thought to be missing. Apart morphological considerations, the main argument refers to symbrachydactyly, which consists in decreasing digital ray length (by reducing the middle phalanx), and usually affects digits excluding the thumb. In case the thumb is affected (in complex symbrachydactylies), the reduction concerns thus the first metacarpal, suggesting that the thumb middle phalanx has already disappeared. In the fourth theory (Pfitzner), the distal phalanx of the thumb should result from the fusion between the second and third phalanges of the thumb. This mechanism, named symphalangy, is well known in the foot, especially in the fifth toe, but also for the other toes, and even in the two ulnar fingers.
Dejour's radiographic criteria are commonly used to diagnose and assess femoral trochlear dysplasia in case of patello-femoral instability. The aim of this study was to establish the intra- and interobserver reliability of these radiographic criteria. Sixty-eight lateral knee radiographs were examined independently by 7 observers (2 juniors, 5 seniors) to assess interobserver agreement, and the 2 juniors repeated the observations to test intraobserver agreement. These 68 true lateral views were harvested from clinical records of 64 patients who underwent a trochleoplasty because of patellofemoral instability. To evaluate the agreement on analytic data (morphologic type of trochlea) we used the kappa statistical method, and to evaluate the agreement on numerical data (depth and prominence of the trochlear groove) we used interclass correlation analysis. The "crossing sign" (between the trochlear groove and the anterior aspect of both condyles) was reliable since the probability of rating as normal a pathologic trochlea was only 3.1% (0 to 8.8%). In classifying trochlear morphology interobserver agreement was slight (kappa = 0.17) and intraobserver agreement was fair (kappa = 0.3). On the other hand, the measurements of the depth and prominence of the trochlear groove were more reliable since the interclass coefficients between observers were 0.62 and 0.38 respectively. The most frequent interobserver error was related to misdiagnosis of type II. To clarify Dejour's criteria we propose a diagnosis of type II only when 5 mm or more are measured between the intersections with the medial and lateral femoral condyles. We recommend the use of the prominence of the trochlear groove to evaluate the grade of bony trochlear dysplasia.
A newborn suffered immediate neonatal respiratory distress because of an obstructive, soft-tissue nasal mass. Clinical examination revealed a cleft palate with a protruding polypoid mass. CT and MRI showed a heterogeneous nasopharyngeal mass and associated intracranial abnormalities - duplication of the hypophysis and hypoplasia of the corpus callosum. Duplication of the hypophysis is a very rare malformation, only 13 cases having been previously described. The suggested pathogenesis is duplication of the prechordal plate and anterior end of the notochord during early embryological development.
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.
Palmoplantar pustulosis and severe acne are sometimes associated with aseptic skeletal lesions, but such skeletal conditions can be observed without skin lesions. The acronym SAPHO (Synovitis, Acne, Palmoplantar pustulosis, Hyperostosis, Osteitis) has been suggested for this cluster of manifestations. The most frequent site of the disease is the upper anterior chest wall, characterized by predominantly osteosclerotic lesions, hyperostosis, and arthritis of the adjacent joints. Osteosclerosis of the vertebral bodies, hyperostosis, and erosions of the vertebral plates can be encountered. Unilateral sacroiliitis of frequently observed. Long bone involvement consists of osteosclerosis or osteolysis with periosteal new bone formation. Peripheral arthritis is rarely associated with joint destruction. The pathogenesis of this syndrome remains unknown, but a link with seronegative spondylarthropathies is probable. Awareness of the SAPHO syndrome should facilitate proper diagnosis and treatment.
Chylous cysts are in frequent entities which may have a variable pathogenesis. Their clinical and radiological presentation is fairly similar in each case report. Their CT appearance is very specific, but only histopathology can certify their etiology and their benign nature.
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PURPOSE: The purpose of this study was to describe the MR appearance of the acetabular labrum in asymptomatic hips on high resolution MRI. METHOD: Fifty-two hips in 46 asymptomatic volunteers with an age range of 15-85 years were evaluated with coronal and axial T1-weighted and T2-weighted sequences. The shape, margin, size, and signal intensity of the acetabular labrum were analyzed. RESULTS: The labrum was absent in its anterosuperior aspect in five hips (10%). Intralabral regions of intermediate of high signal intensity were detected in 30 hips (58%) imaged with T1-weighted and proton density-weighted sequences. Intralabral linear hyperintense foci reaching the articular surface and consistent with a labral tear were detected in four labra on T2-weighted images. Intralabral microcysts were seen in three labra. CONCLUSION: The MR appearance of the hip labrum is varied in asymptomatic volunteers. Intralabral increased signal intensity and absent anterosuperior labra are especially frequent and may represent asymptomatic lesions or normal variations.
Vertebroplasty is an effective new radiologic procedure consisting of the percutaneous injection of a biomaterial, usually methyl methacrylate, into a lesion of a vertebral body. This technique allows marked or complete pain relief and bone strengthening in most cases. The principal indications for vertebroplasty are osteolytic metastasis and myeloma, painful or aggressive hemangioma, and osteoporotic vertebral collapse with debilitating pain that persists despite correct medical treatment. Radiography and computed tomography must be performed in the days preceding vertebroplasty to assess the extent of vertebral collapse, the location and extent of the lytic process, the visibility and degree of involvement of the pedicles, the presence of cortical destruction or fracture, and the presence of epidural or foraminal stenosis caused by tumor extension or bone fragment retropulsion. Leakage of methyl methacrylate during vertebroplasty may cause compression of adjacent structures and necessitate emergency decompressive surgery; thus, the procedure should be performed only in a surgical center. The decision to perform vertebroplasty should be made by a multidisciplinary team because the choice between vertebroplasty, surgery, radiation therapy, medical treatment, or a combination thereof depends on a number of factors. Radiologists need to be aware of the various indications for vertebroplasty and of potential future developments and applications of the procedure.