[The role of imaging in the assessment of vascularity at hand and wrist]. / Apport de l'imagerie dans le diagnostic de la vascularisation osseuse à la main et au poignet.

The viability of the bone is compromised in two main situations at the wrist: Kienböck's disease and scaphoid nonunion with avascular necrosis. Plain radiography and CT allow an accurate anatomical approach of morphological changes associated with avascular necrosis of the lunate and the scaphoid fracture with complications. CT is readily available to detect nondisplaced fractures. However, early forms of necrosis can be misdiagnosed and evaluation of bone vitality is impossible. MRI is the best imaging modality to detect avascular necrosis and the intravenous injection of gadolinium improves the specificity of diagnosis of necrosis. The lack of enhancement of the proximal fragment of the scaphoid leads the surgeon to use a vascular graft in the treatment of nonunion. The technique has its limitations. The bone necrosis is histologically complex and contrast enhancement does not mean necessarily viability. However, MRI is still the most powerful imaging modality in the assessment of the bone marrow.

[MRI study before and after extracorporal shock wave therapy in calcifying tendinitis of the shoulder]. / Etude IRM avant et aprEs lithotritie des tendinopathies calcifiantes de l'épaule.

PURPOSE: Extracorporal shock wave therapy has recently been proposed with good results (70%) for treatment of persistent painful calcifying tendinitis of the shoulder. The aim of this study was to evaluate the early impact of shock wave therapy on the anatomic structures of the shoulder. MATERIALS AND METHODS: Eight patients (7 women and 1 man, with mean age of 48 years) were prospectively followed up after undergoing shock wave therapy (1500 pulses with 0.28 mJ/mm2 energy). MRI (T1: 500/12 [TR/TE] and STIR: 7200/60/180/180 [TR/TE/TI/alpha]) were obtained 2 hours before and 15 days after the procedure; in addition for 5 of them one more examination was carried out 6 hours after extracorporal shock wave therapy. RESULTS: There was no significant signal change of the humeral bone or rotator cuff, and the calcification size, when seen (6 times), was unchanged at successive MR examinations. One patient had subcutaneous fat signal change (STIR) next to the zone of impact, which resolved 15 days after the extracorporal shock wave therapy. No bursitis or joint effusion was found. CONCLUSION: Shock wave therapy has no early complications or significant impact on the anatomic structures of the shoulder.

[Imaging of complications following hip arthroplasty]. / Imagerie des complications des prothèses totales de hanche.

Acute complications include fractures and prosthesis dislocations. Most chronic complications involve mechanical or septic loosening and aggressive granulomatosis. Greater trochanteric pseudarthrosis, periprosthetic soft tissue ossifications or prosthesis conflict with the psoas muscle can also be responsible for groin pain. Most complications are detected with serial plain radiographs, but additional imaging techniques including CT scan and scintigraphy are sometimes necessary for pretreatment diagnosis. Pain generally indicates a complication but aggressive granulomatosis can be asymptomatic, thus warranting systematic annual plain radiographic control.

[Neurotrichinosis: a case report with MRI evaluation]. / Neurotrichinose: à propos d'une observation documentée par IRM.

Neurological complications are rare in trichinosis. A case of trichinosis involving the central nervous system documented by MRI is presented. To our knowledge, only three cases of neurotrichinosis with MRI abnormalities have been already reported. The physiopathological mechanism are discussed (transport of the parasite through the blood-stream, immuno-allergic reaction or eosinophilic neurotoxic effect).