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Resume La tomographie par emission de positons au 18F-fluorodeoxyglucose (TEP-FDG) avait prouve son utilite dans l’arterite giganto-cellulaire, dans la maladie de Takayasu et dans les aortites indifferenciees. La TEP-FDG pourrait etre plus interessante que la tomodensitometrie (TDM) ou l’IRM dans la detection des stades les plus precoces de l’inflammation de la paroi vasculaire. Les donnees manquent quant a sa precision dans le diagnostic et le suivi des lesions vasculaires de la maladie de Behcet (MB). Nous rapportons le cas d’une femme âgee de 32 ans presentant une MB associee a une fievre d’origine inconnue, revelant des anevrismes volumineux de l’artere pulmonaire. La TEP-FDG a revele une fixation peripherique des anevrismes pulmonaires, soulignant l’etat inflammatoire de la paroi vasculaire de l’anevrisme. Notre patiente a ete traitee par corticoides et cyclophosphamide intraveineux, ce qui a induit une remission de sa MB. Durant le suivi, la TEP-FDG avait permis d’objectiver une reponse therapeutique favorable a quatre mois de traitement, alors que l’angio-TDM etait restee inchangee. Nous rapportons le premier cas decrivant l’utilite de la TEP-FDG dans l’evaluation therapeutique des anevrismes arteriels de la MB. D’autres etudes sont requises sur des cohortes plus larges afin de determiner la precision de la TEP-FDG chez les malades de Behcet avec une atteinte vasculaire.

BACKGROUND Some preparations of 99mTc-colloidal rhenium sulfide (Nanocis) contain excess free pertechnetate (99mTcO4) impurity (>5%). OBJECTIVES To improve the radiochemical purity of Nanocis preparations and the quality of preoperative lymphoscintigraphy in sentinel node localization of breast cancer patients, we investigated the effects of temperature on the presence of free 99mTcO4 and nanocolloid size modification. METHODS A Nanocis kit was reconstituted with sodium pertechnetate (650-850 MBq) in a final volume of 3.5 ml and heated for 30 min at 100, 115, or 130 degrees C. The radiochemical purity was determined by paper chromatography, in triplicate. The particle size was evaluated by membrane filtration through a 200-nm and 100-nm filter. The preoperative lymphoscintigraphy images were acquired about 2 h after tracer administration. RESULTS Significantly higher radiochemical purity values were observed with 28 Nanocis preparations heated at 130 degrees C (median: 99.8%, min-max: 97.0-99.9%) compared with values from 37 Nanocis preparations heated at 100 degrees C (median: 96.3%, min-max: 85.2-99.5%) or 26 Nanocis preparations heated at 115 degrees C (median: 95.1%, min-max: 85.7-99.8%). The interbatch variations of the radiochemical purity were reduced at 130 degrees C. A high temperature level (130 degrees C) did not modify the particle size. In lymphoscintigraphy, free 99mTcO4 uptake by the thyroid or stomach, which was sometimes observed with a Nanocis preparation heated at 100 or 115 degrees C, was never visualized with a Nanocis preparation heated at 130 degrees C. CONCLUSION These results indicate that increasing temperature from 100 to 130 degrees C can be used in routine clinical practice to improve the radiochemical purity of the Nanocis preparation.

[(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET) has demonstrated its usefulness in giant cell arteritis, Takayasu's arteritis, and unclassified aortitis. FDG-PET imaging could be more effective than CT-scan or magnetic resonance imaging in detecting the earliest stages of vascular wall inflammation. Data are lacking regarding its accuracy for diagnosis and follow-up of vascular lesions in Behcet's disease. We report the case of a 32-year-old woman with history of Behcet's disease and fever of unknown origin revealing voluminous pulmonary arterial aneurysms. FDG-PET scan revealed a peripheral uptake of pulmonary aneurysms, underlying the inflammatory status of arterial aneurysms wall. Our patient was treated by glucocorticoids and intravenous cyclophosphamide and achieved remission of Behcet's disease. During follow-up, FDG-PET scan enabled to detect an early radiologic therapeutic response after 4 months, while CT angiography remained unchanged. We report the first evidence of usefulness of FDG-PET scan for therapeutic evaluation of arterial aneurysms in Behcet's disease. Further studies are warranted to determine the accuracy of FDG-PET scan in larger cohort of Behcet's disease patients with vascular involvement.