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Granulosa cell tumor (GCT) of the ovary is a rare tumor accounting for 2%-5% of ovarian malignancies. Although the usefulness of 18F-FDG PET/CT is well demonstrated in the staging and follow-up of the great majority of ovarian cancers, GCTs are known to cause false-negative results on FDG PET because of very low FDG avidity. We present a case of a GCT in which an 18F-FDG PET/CT proved very useful in the detection of recurrence.

Resume Nous presentons le cas d’un patient de 74 ans qui a consulte pour apparition de troubles cognitifs. Les examens d’imagerie morphologique realises ont mis en evidence une tumeur qui a ete consideree comme un meningiome. Une intervention chirurgicale pour resection de la tumeur a ete realisee et l’examen anatomopathologique a mis en evidence une metastase meningee d’un cancer thyroidien. Le patient avait un antecedent de thyroidectomie avec un diagnostic initial de benignite. Les metastases meningees de cancer thyroidien sont rares et les metastases meningees revelatrices de cancer thyroidien sont exceptionnelles.

Resume Objectifs Les methodes utilisees habituellement pour le suivi de l’efficacite de la radiofrequence (RF) (l’IRM et la TDM) ne suffisent pas pour montrer precocement les reliquats tumoraux. Nous avons evalue l’interet d’un suivi utilisant la morpho-TEP chez des patients ayant beneficie d’un traitement par RF. Materiel et methodes Des examens morpho-TEP ont ete realises avant et apres cinq gestes de RF chez trois patients. L’efficacite a ete consideree complete devant l’absence d’hyperfixation focalisee sur l’examen morpho-TEP realise apres le geste de RF et incomplete devant la persistance d’hyperfixation focalisee. L’efficacite a ete estimee sur des examens morpho-TEP realises sur une periode allant jusqu’a trois mois apres le geste de RF. Chaque geste de RF a ete suivi par au moins deux examens morpho-TEP. L’evolution radiologique du patient a servi de « controle » afin de confirmer les resultats de la morpho-TEP. Resultats La morpho-TEP a montre une efficacite complete de trois gestes de RF et une efficacite incomplete dans deux cas. L’evolution des patients a confirme les resultats de la morpho-TEP dans cinq sur cinq gestes de RF. Conclusion Cette etude preliminaire a montre l’interet de l’examen morpho-TEP afin d’evaluer l’efficacite du traitement par RF. Les resultats ont montre la possibilite pour la morpho-TEP de mettre en evidence tres precocement la presence de reliquat tumoral.

Resume Nous presentons le cas d’un patient de 28 ans qui a ete opere d’un abces du muscle fessier gauche. Des prelevements multiples ont ete realises au niveau de l’abces ainsi qu’au niveau de l’ischion gauche. Ces prelevements ont conclu a un abces a staphylocoque coagulase negative ainsi qu’a une osteite de l’ischion, au meme germe. La scintigraphie osseuse a mis en evidence une hyperfixation de l’ischion et la scintigraphie au sulesomab a mis en evidence une hypofixation du meme os. Si une hypofixation du sulesomab a deja ete decrite en cas d’infection rachidienne, elle n’a pas ete decrite, a notre connaissance, en cas d’osteite extrarachidienne d’origine infectieuse.

We report the case of a 63-year-old woman with Erdheim-Chester disease (ECD) and histologic features of Langerhans cell histiocytosis, both extremely rare histiocytic proliferations responsible of skeletal and extraskeletal involvement. 18F-Fluoride PET/CT revealed multiple intense focal uptake scattered throughout the skeleton. We also performed an 18F-FDG PET/CT which point out visceral and vascular involvement. This case illustrates the interest of PET/CT in ECD, a rare polymorphus and systemic disease, and in our knowledge, this is the first reported illustration of 18F-fluoride PET/CT findings in this pathology.

Computer simulation of biological systems for in silico validation has the potential of increasing the efficiency of pharmaceutical research and development by expanding the number of parameters tested virtually. Then only the most interesting subset of these has to be probed in vivo. By focusing on variables with the greatest influence on clinical end points, valuable drug targets can be advanced more quickly. A large number of methods have been developed to rebuild a three-dimensional (3D) model of a liver, mostly to prepare a liver surgery. These models are often not accurate and most of the them don't take into account the fluidics inside the vessels. The aim of this work is to provide an accurate computational multi-compartement model of the healthy and the pathological liver with their network of blood vessels (vasculature) using a finite-element-modeling software. Computed tomography (CT) slices, in DICOM format, from two different patients were used to provide the datasets of transverse images for the modeling. Each dataset of images was segmented in order to extract the liver’s shape and define the vein and artery networks. On CT images, the contrast between the liver and the nearby organs (background) is very low because all these structures are a similar density. Thus, we used semi-automatic tools to determine liver contours. Manual segmentation was used as a last resort. Then, strong filtering (bilateral filter) and confidence-connected-region-growing algorithm were applied to rebuild from each - healthy and pathological - liver a multicompartment model including parenchyma, arteries and veins. The precision of the obtained vasculature model allowed anatomical classification of hepatic segments and the quantification of their volumes. Although our study demonstrated the difficulties in use of CT images for computational modeling of the liver, it also confirmed that semi-automatic tools can be used to develop anatomically accurate models of hepatic vasculature.

Experimental studies using laboratory animal models have shown a potential vasoactive effect of natural metabolites such as glycine. The present study used intravital microscopy in laboratory rat models to study the microcirculation in the brain pial and mesentery vessels. To investigate the pial microvasculature, a stereotaxis-like animal fixing device was used. The intravital microscopy unit consisted of a binocular microscope equipped with a digital photo-video camera, processor, monitor and printer. Using reflected light, a special contact lens with an amplified focus depth provided high-resolution images of nontransparent tissue objects that typically have insufficient light exposure. Glycine had a vasodilatory effect on microvessels in the rat brain and mesenterium. The diameter of pial arterioles increased after glycine application especially markedly (up to 250% of initial size). These changes were not observed when physiological saline was used. Even a very small amount of glycine (a drop on the needle) was sufficient to stop the early stages of histamine-induced blood stasis development in 3-5 s in mesenterial microvessels. The vasodilatory effect of glycine on the pial microcirculation correlates with its reported positive therapeutic effect in cerebral ischemic stroke. The ability of glycine to avoid or prevent histamine-induced microcirculatory alterations in mesenterial microvessels may have potential clinical applications.

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Fluorodeoxyglucose (FDG) positron emission tomography (PET) has been shown to be useful in the diagnosis and staging of various malignancies. The main advantage of PET is its high sensitivity in identifying malignancies at an early stage. The authors present a patient in whom transthoracic echography and MRI revealed a right atrial mass. The diagnosis was difficult between tumor and thrombus, but PET imaging correctly suggested a malignant tumor.

Background The ASAS group has defined criteria for the diagnosis of axial or peripheral spondyloarthritis (SpA). Sacroiliac joint MRI is included in these criteria and is a pivotal tool in daily practice to evaluate the patients with suspected early and non radiographic SpA. A substantial proportion of patient responds to the ASAS criteria (i.e. the clinical arm) despite negative MRI. Positron emission tomography/computed tomography (PET/CT) is a new imaging technique of potential interest in inflammatory rheumatic diseases. PET/CT has been rarely evaluated in patients with SpA and mainly used [18 F] fluorodeoxyglucose, a marker of inflammation. [18 F] fluoride is a specific bone tracer that may have potential in SpA imaging, a condition associated with spinal ossifications and sacroiliac ankylosis. Objectives to evaluate the clinical utility of [18 F] fluoride PET/CT in patients with negative sacroiliac joint MRI but fulfilling the ASAS criteria for SpA. Methods consecutive outpatients seen for inflammatory back pain and responding to the ASAS criteria for SpA were included. Patients were previously evaluated by sacroiliac joint MRI (STIR) which must be normal (no bone marrow edema). Whole body [18 F] PET/CT was performed using a SIEMENS Biograph device. Areas of interest (spine, entheseal structures and sacroiliac joints) were examined on whole body scan for the detection of increased uptake. Increased activity was defined as an activity greater than the activity of an adjacent normal bone. Patients with defined ankylosing spondylitis (AS) and positive sacroiliac joint MRI were used as positive controls. Results 10 patients were evaluated (8F, 2 M, mean age : 41.8, symptom duration: 3.2 years, HLA B27 positive 9/10 ; mean BASDAI : 5.6, mean ASDAS: 2.3). 9 responded to axial SpA ASAS criteria and I to peripheral SpA ASAS criteria. They all received or had received NSAIDs. No patients had DMARD or TNF inhibitors. All the patients had normal sacroiliac joint MRI. [18 F] fluoride PET/CT did not show increase activity for any patients. 3 patients with radiographic AS and positive MRI were also evaluated: for 2 patients, active lesions were detected with [18 F] fluoride PET/CT showing increased uptake in the sacroiliac joints, the spine and sternoclavicular joints. Conclusions [18 F] fluoride PET/CT does not seem useful in patients with inflammatory back pain, negative MRI and responding to the ASAS criteria. Thus, using this bone tracer, PET/CT does not give additional information relevant for the diagnosis of SpA. Conversely, this imaging technique using [18 F] fluoride may be able to detect lesions in patients with defined disease and positive MRI. Measurement and quantification of maximal standard uptake value may be useful for improving the sensibility of this imaging modality in the diagnosis of SpA. Disclosure of Interest None Declared