To study a muscle-to-muscle standardised uptake value (SUV) ratio with FDG-PET/CT (FDG-PET) as a marker for the detection of disease activity in dermatomyositis (DM). Patients with DM (n = 24) who met the European Neuro-Muscular Centre diagnostic criteria were retrospectively identified over a 3-year period through a national survey. Muscle biopsy was performed in all patients. Maximum SUV was measured in proximal muscles (SUVPROX) that had the highest radiotracer uptake on visual grading as well as in the musculus longissimus thoracis (SUVMLT), whereas mean SUV was measured for the liver (SUVLIV). Muscle-to-liver SUV ratios for either muscle group were compared and a SUVPROX/SUVMLT ratio was calculated. SUVPROX/SUVMLT of DM patients were compared with age- and sex-matched control subjects (n = 24) with melanoma who had received FDG-PET scans. DM patients presented with proximal and symmetrical muscle uptake. Differences in SUVPROX/SUVLIV and SUVMLT/SUVLIV ratios in DM subjects were significant (p < 0.001). SUVPROX/SUVMLT ratios in DM and their controls also differed significantly (p = 0.0012). The SUVPROX/SUVMLT ratio threshold between DM subjects and controls was 1.73 with a sensitivity of 50% (CI95%, 29.1 to 70.9%) and specificity at 83.3% (CI95%, 62.6 to 95.3%). When amyopathic DM patients were removed from the analysis, specificity was increased to 95% (CI95%, 75.1 to 99.9%) with a likelihood ratio of 10 and an AUC of 83.4% (CI95%, 71.4 to 95.4%). A muscle-to-muscle SUVPROX/SUVMLT ratio with a cut-off value of 1.73 in FDG-PET imaging might serve as a non-invasive marker to determine disease activity in dermatomyositis. • [18F]-FDG PET-scanner standardised uptake value (SUV) could reflect disease activity in dermatomyositis (DM). • A ratio of SUV in proximal muscles (SUVPROX) to SUV in musculus longissimus thoracis (SUVMLT) could be used to determine active DM. • Active disease is suspected for SUV PROX /SUV MLT ratios greater than 1.73.

Several studies have reported a circadian variation in the occurrence of sudden cardiac death.To analyze the circadian, weekly and seasonal variations of sudden cardiac death occurring in northern Tunisia.We prospectively collected epidemiological and autopsic data of victims of sudden cardiac death occurring in the northern governorates of Tunisia between October 2010 and September 2012.The study population included 392 men and 108 women with a mean age of 52.3 ± 15.8 years. Physical inactivity and smoking were the most common risk factors, they accounted for 76.4% and 57.9% respectively. Family history of sudden death was identified in 9.8% of victims. The vast majority of deaths occurred in a public place (41.4%) or at home (36.6%). Ischemic heart disease was the most frequent causes of death (269 cases). Sudden cardiac death was homogeneously distributed over the day. A maximum of events occurred on Sundays (17.8%) and a minimum on Mondays (11.4%), we also recorded an excess cardiac mortality in winter with a peak in December and a nadir in September (13% vs. 4.4% P = 0.0001).In northern Tunisia, under Mediterranean climate, a winter excess cardiac mortality was found. Sudden cardiac death was homogeneously distributed over the day, however, an excess of mortality was recorded over the weekend with a nadir on Monday.Plusieurs travaux ont suggéré une variation temporelle de la survenue de la mort subite d’origine cardiaque.Analyser la variation circadienne, hebdomadaire et saisonnière de la mort subite d’origine cardiaque survenant dans les huit gouvernorats du nord de la Tunisie.Nous avons recueilli d’une manière prospective les données épidémiologiques et autopsiques des victimes de mort subite d’origine cardiaque survenant dans la région du nord de la Tunisie d’octobre 2010 à septembre 2012.La population regroupait 392 hommes (78,4 %) et 108 femmes (21,6 %) avec un âge moyen de 52,3 ± 15,8 ans. La sédentarité (76,4 % des cas) et le tabagisme (57,9 % des cas) étaient les facteurs de risque les plus fréquents. Des antécédents familiaux de mort subite étaient identifiés chez 9,8 % des sujets. La plupart des décès sont survenus soit dans un lieu public (41,4 %) soit à domicile (36,6 %). Les cardiopathies ischémiques étaient les causes de décès les plus fréquentes avec 269 cas (53,8 %). La distribution nycthémérale de la mort subite était homogène sans pic de mortalité. Un pic de décès a été constaté le dimanche (17,8 %), et l’incidence la plus basse le lundi (11,4 %). Nous avons observé un excès de mortalité cardiaque hivernal avec un pic pendant le mois de décembre et un nadir au mois de septembre (13 % versus 4,4 %, p = 0,0001).Dans le nord de la Tunisie, sous un climat méditerranéen tempéré, un excès de mortalité cardiaque hivernal a été constaté. La distribution nycthémérale de la MSC était homogène sans pic de mortalité, et une surmortalité subite a été enregistrée en fin de semaine avec un nadir le lundi.