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Cysts of the glenoid labrum are ganglia cysts extending near the glenohumeral joint with frequent clinical signs and symptoms of a compression of the subscapularis nerve. They are detected through MR examination. They are frequently associated to instability of the glenohumeral joint.

The authors emphasize the misleading images of lumbar myelography encountered in common vertebral diseases: disk disease, posterior interapophyseal joint diseases, degenerative and narrow spinal canal, in which dynamic views in the upright position represent the most original contribution of lumbosacral myelography as compared to new techniques. The authors also describe the postoperative appearances observed on lumbosacral myelography and some rarer diseases which must not be missed, such as epidural arachnoid cysts and epidural lipomatosis.

The diagnosis of localized osteolysis (synonym: bone cyst, defect) must be analytical. The site, size, and shape of the defect, its limits, assessed according to the Lodwick classification, reflect the activity of the lesion, the type of any periosteal reaction and the presence of a soft tissue mass are analysed successively. Based on these criteria and the clinical and laboratory characteristics, the image can be classified as quiescent or active, allowing guidance of management.

Interrogation of patients still painful after lumbar intervertebral disk surgery provides with a series of informations each of them having only an indicative value, while they altogether compound a score helping assess the presence or the absence of a recurring disk herniation.

Cervical myelography is obtained after injection of contrast medium into the lumbar subarachnoid space through a lumbar puncture. The patient is prone with a large radiolucent block under the pelvis so that the site of lumbar puncture is at a higher level than that of the cervical spine lordosis. Lumbar contrast is injected gently so that the contrast fluid slides along the ventral aspect of the dural sac and immediately reaches the cervical subarachnoid space. Then AP and lateral (with a horizontal X-ray beam) views are obtained. The patient has to remain firmly immobilized during the whole procedure to avoid blending of the contrast medium with CSF. This procedure is safe and allows cervical myelography to reach the same quality as that obtained through cervical puncture.

Calcific deposit within soft tissues is frequently a clue for diagnosis. The radiological analysis of a calcific deposit within soft tissues includes the following aspects: the basic structure of the calcification, the grade of differentiation of the calcification, the site of the calcification, the number of calcific deposits, the shape of the calcification, the changes in the adjacent non-calcified soft tissues and in the adjacent bone, the course of the clinical signs, the course of the radiological abnormalities.

The discovery of an image of central bone calcification raises the differential diagnosis of bone infarction and chondroma. The matrix of chondroma is characteristic of cartilage. It produces typical cartilaginous calcifications: rings, arcs, coarse, irregular grains, moth-eaten appearance. These calcifications are predominantly observed in the centre of the image. They are situated in a bone defect, often multilocular, sometimes accompanied by multiple scratch marks of the cortical endosteum. In contrast, infarction is characterized by the presence of a serpiginous calcified border at the interface between live bone and dead bone. In the centre, the bony trabeculae are still visible on CT sections, in contrast with chondroma. On MRI, chondromas present a heterogeneous lobular appearance on T2-weighted sequences (checkerboard appearance) due to alternating zones of high signal intensity cartilaginous matrix and low signal intensity calcified or ossified fibrous septa. On MRI, bone infarction is characterized by a continuous peripheral line with a marked low signal intensity.

The radiological investigation of persistent or recurrent sciatica after lumbar diskectomy essentially consists of demonstrating recurrent disk herniation. Comparison between plain and contrast enhanced CT or MR examinations at the level of the diskectomy is the main step of the radiological survey. The meanings of the various radiological findings are discussed. Other lesions that may induce persistent sciatica after lumbar diskectomy include degenerative narrowing of the lateral recess, spinal instability, stress fracture of the remaining neural arch, pseudo-meningomyelocele after laminectomy.

This is a review article on fibrous dysplasia of bone. All aspects of this condition including, macroscopic and histologic findings, lesion distribution, clinical, radiological and biological findings as well as evolution and treatment are discussed. A classification of skeletal lesions based on then appearance on plains films and computed tomography is proposed; 3 radiological types are differentiated: non-expanding bone lesions, expanding lesions with a thick periosteal reaction and expanding lesions with a thin periosteal shell. Main features of osteofibrous dysplasia are also discussed.

The spinal vacuum phenomenon is a collection of gas within the disk space, the vertebral body, the apophyseal joint or the spinal canal. The intradiscal vacuum phenomenon is frequently observed in degenerative disk disease and crystal-induced diskopathy. This has obvious significance to the radiologist, who, on observing a narrowed disk space or collapsed vertebral body, might otherwise consider infectious or neoplastic spondylitis, a likely possibility. The presence of vacuum phenomenon militates against the diagnosis of infection or tumor.

Degenerative vertebral dislocations (laterolisthesis) are responsible for progressive transverse intervertebral shift. These changes appear like a translation of the lateral edge of a vertebra compared to that of the underlying vertebra and are easily diagnosed. Vertebral dislocations can be secondary to active lumbar scoliosis or unilateral or asymmetrical degenerative spondylolisthesis. In every case, the appearance of laterolisthesis is reflected by the onset or aggravation of scoliosis which may become self-perpetuating. This lesion is secondary to osteoarthritic disruption of the integrity of the intervertebral disk and ligaments. Open and closed patterns have been described depending on the side of the associated disk opening. The onset of a rotatory dislocation reflects the progressive evolution of the deformity, which may require medical treatment, or surgical reduction and fixation by vertebral arthrodesis.

Imaging of the knee is one of the main indications of MRI in musculo-skeletal diseases. Some of the most recent papers dealing with MR imaging of the knee are discussed in this review article. Abnormal conditions reviewed are meniscal injuries including those occurring in previously operated menisci, osteochondral fractures, osteochondritis dissecans and rheumatoid arthritis.

This study of the topographic distribution of tumoral and pseudotumoral lesions of the proximal femur shows that certain lesions have a preferential site, for example osteoid osteoma affects the internal cortex of the neck and diaphysis or the intertrochanteric zone; chondroblastoma occurs in zones of epiphyseal ossification of the head; fibrous dysplasia affects the femoral neck, while sparing the epiphyseal femoral head and trochanters. The island of osteosclerosis is situated, at least partially, in the support fan; so-called physiological cysts are situated on or above the midline of the neck and below the basicapital line. Osteolytic or mixed metastases preferentially involve Ward's triangle in the femoral neck and the intertrochanteric region. The sites of these lesions therefore appears to depend on the bony architecture which, in turn, is dependent on mechanical stresses. However, this purely morphological study fails to demonstrate whether mechanical stresses influence the development of these lesions.

The authors review the embryology of the hip joint with its pathological implications. The radioanatomy is presented in an elementary fashion, with the appearance of each component as seen on the various imaging techniques (conventional X-rays, CT scan, MRI). The authors also describe the views used in conventional radiology and the invasive techniques of arthrography and arthroscanning.

Nuclear magnetic resonance has shed new light on our understanding of osteonecrosis of the femoral head. It is at present the most sensitive and most specific imaging technique for the diagnosis of this condition. Studies involving correlations between MR images and anatomical findings have facilitated the understanding of tissue changes responsible for magnetic appearances. However, all problems are not resolved. At an early stage, fortunately almost always asymptomatic, false negative MRI or MR findings similar to those of algoneurodystrophy of the hip can be encountered. The aim of this article is to pinpoint the current status of these questions on the basis of a review of the recent literature. The contribution of MRI with injection of Gadolinium and future prospects are also discussed.

The understanding of carpal instability and their radiological signs are based on a knowledge of the anatomy and complex physiology of the wrist. This article successively deals with the physiological anatomy, radiological technique, normal static and dynamic radiological features, radiographic signs of various types of instability and therapeutic principles.