[Herpetic meningoencephalitis and acute disseminated encephalomyelitis: magnetic resonance imaging sequence]. / Méningo-encéphalite herpétique et encéphalomyélite aiguë disséminée : séquence en imagerie par résonance magnétique.

We report a case of herpetic encephalitis in a 2-year-old girl. Diagnosis was made at 1st by clinical symptoms and MRI and confirmed by lumbar puncture. Forty days later, new neurologic symptoms appeared and MRI diagnosed acute disseminated encephalomyelitis. MRI better demonstrates CNS abnormalities in herpetic encephalitis and may play a major role as a 1st step in early diagnosis, in particular for acute disseminated encephalomyelitis.

[Myositis ossificans circumscripta: the contribution of imaging]. / La myosite ossifiante circonscrite: apport de l'imagerie.

OBJECTIVES: Illustrate the specific and nonspecific aspects of myositis ossificans circumscripta (MOC) in standard imaging, cross-sectional imaging (sonography, CT, and MRI), and bone scintigraphy. PATIENTS AND METHODS: Eight patients presenting with MOC (three men and five women) were explored using standard radiography (eight cases), sonography (seven cases), scintigraphy (four cases), CT (six cases), and MRI (four cases). RESULTS: Standard x-rays and sonography of the soft tissue showed a well-defined mass containing calcifications in 75% of the cases. The CT scan diagnosed MOC in four cases, showing calcified masses separated from the adjacent bone by a clear radiotransparent border or afferent peripheral tumoral calcifications highly suggestive of MOC. MRI was nonspecific. Bone scintigraphy showed hyperfixation in the four cases imaged. CONCLUSION: Standard x-rays were useful to demonstrate the calcifications of MOC and to identify their relation with the subjacent bone. Sonography and bone scintigraphy were interesting in monitoring the lesion's maturation. In addition to early detection of calcifications, CT can precisely localize the lesion before surgical ablation. MRI is a very sensitive technique in detecting small lesions at an early stage, but it is nonspecific and does not remove the necessity of biopsy to eliminate the possibility of a malignant disease.

[Discoid menisci in children: ultrasonographic features]. / Le ménisque discoïde chez l'enfant: aspects échographiques.

OBJECTIVE: Discoid meniscus is a rare congenital pathology affecting mainly the lateral meniscus. Radiological diagnosis, initially based on arthrographic findings, is now established on well defined MRI criteria. In this study, ultrasonography (US) was the modality proposed for diagnosing discoid meniscus and compared to the normal sonographic meniscal pattern. Subjects and methods. 8 children aged from 6 to 11 years, with a symptomatology highly suggestive of meniscal pathology, were investigated by US of both knees, followed by MRI in 3 and arthroscopy in all cases. RESULTS: In all 8 cases, a meniscus was diagnosed as discoid when it no longer had its normal triangular shape, was abnormally elongated and thick and demonstrated a heterogeneous central pattern. Associated lesions (fracture, cystic degeneration) were well demonstrated on US. The lateral meniscus was involved in all 8 cases, the pathology was bilateral in 5 cases and MRI/US correlation was good in 3 cases. Arthroscopy confirmed US findings in all cases. CONCLUSION: US, a more widely available imaging modality, is a reliable technique for the diagnosis of discoid meniscus in children.