[Hip degeneration]. / La hanche dégénérative.

Hip degeneration is typically easily diagnosed, based on the combination of clinical findings and plain films showing the four classifical findings: joint space narrowing, osteophytes, subchondral sclerosis and subchondral cysts. Some degenerated hips may have misleading features such as when joint space narrowing is mainly posterior or the main finding is a large subchondral cyst. Rapidly destructive coxopathy results in joint space narrowing and joint destruction over a few months. MRI is helpful in early cases with normal radiographs or in patients with known hip degeneration presenting with acute worsening of symptoms. Follow-up is achieved by measuring the joint space on consecutive radiographs obtained using a standard technique.

[Plain films of pelvis]. / Les clichés simples du bassin.

Plain films of the pelvis remain informative and allow most of the diagnoses. Assesment of the hip joint space, bone and subchondral structures, sacrum as well as sacroiliac joints is made on the AP view. Oblique views are useful. Five different oblique views are described: Lequesne's view, Ducroquet's view, Arcelin's view, medical and urethral views. They particularly allow assement of the acetabulum, the femoral head and neck as well as the femoral superior third. Radiological technique and major indications for these views must be known. Angle measurement and evaluation of possible dysplasia are made on coxometry views.

[Imaging of traumatic injuries of the elbow]. / Imagerie des traumatismes du coude de l'adulte.

Traumatic injuries to the elbow may result in dislocations and/or fractures of the distal humerus or proximal radius or ulna. Multiple and associated lesions are common. Plain radiographs usually allow accurate diagnosis. These lesions may lead to joint stiffness with poor functional prognosis.

[Hyperechoic rotator cuff tendon tear]. / Ruptures hyperéchogènes de la coiffe des rotateurs.

PURPOSE: To describe unusual rotator cuff tendon tears which are hyperechoic at ultrasonography (US). MATERIALS AND METHOD: We retrospectively reviewed the shoulder US examinations of 100 patients with rotator cuff tear demonstrated by CT arthrogram with bursography. We included in this study hyperechoic foci without surrounding hypoechoic zone. A second US examination was performed after bursal distension. RESULTS: Six (6%) hyperechoic foci were detected. The initial US diagnosis was tendinosis in five cases (n=5) and full thickness tear in one case (n=1). At repeat US examination, the hyperechoic area was completely or partially hypoechoic, probably because the tears were filled with the injected hypoechoic fluid. CONCLUSION: Some rotator cuff tears, filled with fibrinoid fragments, are probably underdiagnosed at US.

[Shoulder imaging: what is the best modality?]. / Imagerie de l'épaule: quel examen choisir?

Specific pathologies of the shoulder include instabilities in young patients and tendinopathies in older patients. The choice of imaging modality depends on the information expected from each technique. In case of instability, plain films demonstrate bone abnormalities such as Hill Sachs and/or Bankart lesions. Arthro-CT or arthro-MRI need not be in all cases but can provide additional information performed about the intraarticular structures and the glenoid labrum. The rotator cuff is initially evaluated by plain films which demonstrate anatomical conditions resulting in impingement syndrome as well as indirect signs of tendinopathy. Direct visualization of tendons may be achieved by US, arthro-CT, arthro-MRI. US is a dynamic, non invasive and accurate technique for evaluation of rotator cuff tear but is very operator-dependent. Arthro-CT is more reproductive and reveals accurately partial tear as well as anterior tears involving biceps or subscapularis tendons. MRI is very useful to visualize the rotator cuff and adjacent bony structures. Nevertheless, MRI is still limited by its cost, accessibility and variable quality.

Study of the joint space of the hip on supine and weight-bearing digital radiographs.

AIM: To compare hip joint space on supine and weight-bearing anteroposterior digital radiographs. MATERIALS AND METHODS: Fifty anteroposterior views of the hip in 25 patients were taken in supine and weight-bearing positions on a fluoroscopic unit. Two observers in a double-blind study assessed the width of the joint space on an Easy Vision unit with an indirect method of measurement (metric index). RESULTS: Inter-observer and intra-observer variabilities of the metric index were less than 4.1%. There was no significant difference of the metric index of the hip (P>0.05), between supine and weight-bearing positions. CONCLUSION: There is no significant difference of the width of the joint space of the hip between supine and weight-bearing anteroposterior radiographs. Measuring joint space loss in osteoarthritis of the hip with anteroposterior views should be done with radiographs of the hip in the supine position to improve image quality.

Lumbar facet joint arthrography with the posterior approach.

Lumbar facet joint (LFJ) arthrography with intraarticular injections of long-acting steroids and local anesthetics is routinely used for therapeutic purposes in selected patients for relief of low back pain. The procedure may also be used for diagnostic reasons to establish the source of such pain. However, because direct access to the LFJ space is not always possible owing to degenerative changes such as osteophytes, another posterior approach has been proposed for LFJ arthrography. With the patient in the prone position, a spinal needle is inserted vertically into the inferior recess of an LFJ with fluoroscopic guidance and the patient under local anesthesia. To facilitate puncture, cushions are placed under the patient's abdomen to flatten normal lumbar lordosis, which enlarges the inferior recess of the LFJ. Use of cushions also results in a decrease in tissue thickness in the patient, thereby improving image quality and decreasing radiation exposure. LFJ arthrography can demonstrate the causative role of facet disease in abnormalities responsible for low back pain or sciatica and can be performed easily and rapidly with this direct posterior approach.

[MRI and articular cartilage]. / IRM et cartilage articulaire.

Although plain films are fundamental for routine imaging of degenerative chondral lesions, MRI is a promising tool of investigation for the articular cartilage. Its modalities are still imprecise and debated, but, because of its noninvasiveness, it is destined to be preferred over arthroCT. The small size of the cartilage requires thin slices of less than 3-mm thick. The various features of normal cartilage images must be well known. They depend on acquisition parameters, zonal structure of the cartilage and numerous artifacts (partial volume average, chemical shift, magnetic susceptibility, truncation, "magic angle"). Fast SE images provide a good compromise between contrast and the signal-to-noise ratio. T2-weighted images take advantage of an arthrographic effect in case of joint effusion. 3D GE images allow a more accurate evaluation with 1-mm thick slices. In all sequences, adding of a fat-suppression presaturation increases contrast between the cartilage and the surrounding structures. The diagnostic accuracies of the different sequences and of MR arthrography are discussed. Quantitative measurements of cartilage thickness and volume remain the topic of clinical research.

Longitudinal stress fractures of the tibia: comparative study of CT and MR imaging.

The aim of this study was to compare the performance of CT and MRI in the diagnosis of longitudinal stress fracture of the tibia (LSFT). A retrospective study of imaging findings was performed in 15 patients with LSFT. The CT and MR images were compared for detection of fracture line, callus, bone marrow edema, and soft tissues changes. The CT and MRI techniques allowed the detection of the fracture line in 82 and 73 % of cases, respectively. The callus was always visualized with CT or MRI. The MRI technique had a markedly higher sensitivity than CT in the detection of bone marrow edema (73 vs 18 %) and soft tissue lesions (87 vs 9 %). This may cause a misleading aggressive appearance on MRI. Computed tomography remains the best imaging modality for diagnosis of LSFT. However, MRI findings should be known to obviate the performance of CT or bone biopsy.

[Imaging]. / Imagerie.

The panoply of imaging techniques useful in podology is essentially limited to X-rays. Standard "standing" and "lying" X-rays furnish most of the required information. Arthrography is sometimes performed, in particular for trauma or tumour of the ankle. CT scan and MRI make a decisive contribution in difficult cases, notably in fractures and in small fractures without displacement. The two latter techniques are useful in tendon, ligament and muscular disorders, where echography is also informative. Rigorous analysis of radiographies and a good knowledge of foot disorders make these imaging techniques efficacious.

Image-Guided Spinal Steroid Injections.

This paper has been written to stimulate the radiologist to consider the various aspects of spinal steroid injections as therapeutic procedures. Special emphasis is placed on needle guidance, asepsis, and possible problems involved. It constitutes a highly practical and variously illustrated and informative guide for the choice of steroids and various spinal joint approaches. It details the following target areas: lumbar facet joints, cervical facet joints, costovertebral joints, C1-C2 joint, intervertebral discs, epidural space, and interspinous bursa. Safety is the key element of the above-mentioned techniques. The radiologist must pay special attention to the omnipresent risk of iatrogenic infection.

Correlative imaging and pattern approach in ultrasonography of bone lesions: a pictorial essay.

The purpose of this paper is to sensitize musculoskeletal and general sonographers to a wide variety of bony abnormalities that may be noted adjacent to soft tissues of interest. The authors gathered sonographic images displaying abnormalities involving the periosseous, periosteal and cortical tissues from numerous patients who underwent imaging in their department. When available, correlative imaging or the pathological diagnosis (or both) is provided. The authors conclude that musculoskeletal ultrasonography, when used to its full potential, can reveal corroborative and occasionally unsuspected evidence of underlying bony abnormalities, so that correlative imaging (e.g., plain radiography, computed tomography, magnetic resonance imaging or bone scanning) can be performed as appropriate.

Tophaceous gout of the lumbar spine mimicking an epidural abscess: MR features.

We present the MR findings in a case of tophaceous gout of the lumbar spine with cauda equina compression, mimicking an epidural abscess. The diagnosis was clinically unsuspected and confirmed at laminectomy. Tophus material in the paraspinal soft tissues appeared intermediate in signal intensity and showed heterogeneous contrast enhancement.

[Spiral X-ray computed tomography: a new modality of scanner imaging]. / Tomodensitométrie hélicoïdale: une nouvelle modalité d'imagerie scanographique.

Spiral computed tomography is a new imaging modality that presents several advantages when compared to conventional and dynamic computed tomography. It consists in a continuous rotation of the X-Ray tube around the anatomical area to be explored, simultaneously with a move of the examination table at a constant speed. Advantages are the short acquisition time (below one minute), optimization of the intravenous injection of the iodinated contrast material, acquisition of a gapless volume of data which can be post-processed, permitting axial reconstructed sections which are perfectly contiguous, as well as an easy access to 2D multiplanar and 3D reconstructions, with the benefit of a substantial decrease in patients' radiation. This paper will review the prominent advantages, as well as the current limitations, of this new imaging modality.

Magnetic resonance imaging of lateral ventricular tumours.

The authors review their experience with magnetic resonance imaging (MRI) of giant lateral ventricular tumours, placing special emphasis on the imaging features that aid in the differential diagnosis. The tumours illustrated include astrocytoma, oligodendroglioma, neurocytoma, subependymoma, metastatic lesions and subependymal giant cell astrocytoma. Because of their large size, most of these lesions cause hydrocephalus. The presence of associated edema indicates direct brain invasion or a higher grade of tumour differentiation. The degree and pattern of contrast enhancement, as well as the signal characteristics before administration of contrast agent, are nonspecific. The location of the tumour within the lateral ventricles and the patient's age are the most helpful diagnostic clues. Giant lateral ventricular tumours are uncommon, and the patients usually come to clinical attention with symptoms related to increased intracranial pressure. MRI assists in surgical planning by defining the exact location of the lesion and its relation to adjacent structures. Although the signal characteristics and patterns of contrast enhancement are nonspecific, preoperative diagnosis is possible in most cases if the imaging findings are correlated with the patient's age and the specific location of the tumour within the lateral ventricles.

Soft-tissue recurrence of osteosarcoma: ultrasound findings.

The authors describe a 26-year-old woman with soft-tissue recurrence of osteosarcoma, which presented as focal soft-tissue swelling after limb salvage surgery and insertion of a metallic endoprosthesis. Because of the clinical presentation, ultrasonography was performed. The characteristic ultrasonographic pattern of soft-tissue tumours is summarized here, and the role and limitations of ultrasonography in this situation are discussed.