[en] The physical association of CT scan and PET scan allows integrating morphological and functional information on a single exam. It could be interesting to fully exploit the technical characteristics of CT scan, namely the possibility to inject intravenously iodinated contrast media in order to enhance image contrast. We present our experience in this domain by tackling technical problems, particularly that of the attenuation correction, displaying benefits brought by this practice both on clinical and radioprotection points of view. (authors)

[en] Objective: the material association of a scanner x and a PET camera (positron computed tomography), allows to get directly morpho-functional documents. The deep technical exploitation of the scanner features is current: scanner at diagnostic aim with injection of iodinated contrast product; multi-phase acquisition in accordance with the material conditions ( multislice scanner). Results: the analysis of the 50 first consecutive examinations showed a benefit in term of diagnosis, logistics and radiation protection accuracy, This is also showed by the literature data. well, with the SPECT-T.D.M. single photon emission computed tomography) cameras, the question of the contrast product injection arises in some indications. As conclusion: the quick technological evolution lead to modify our practices ( especially: iodine injection and reading sectional imaging) for an optimal exploitation of every side of the hybrid imaging. (N.C.)

[en] Introduction. - Small cell lung cancer (S.C.L.C.) is a neuroendocrine tumour representing 20% of bronchopulmonary cancers. Its metastatic potential is high, so 2/3 of diagnoses are made at disseminated stage. Anti H.u. antibodies are part of the anti neuronal antibodies, often associated to S.C.L.C.. However, 16% of cancers have positive anti H.u. with no para neoplastic syndrome (P.N.S.). (Graus, Brain, 2001). P.N.S. associated with anti H.u. are encephalomyelitis, sensitive neuropathy, chronic pseudo intestinal obstruction, cerebellar degeneration and limbic encephalitis. Case report. - A 75-year-old patient was hospitalized for exploration of an atypical tri-facial neuralgia. Anti H.u. antibodies were found and P.N.S. of a S.C.L.C. was therefore suspected. The biopsy of a thoracic parietal adenopathy confirmed the diagnostic of S.C.L.C. metastasis. Conventional imaging and ¹⁸F-FDG (Fluorodeoxyglucose) PET/CT (Positron Emission Tomography/Computed Tomography)) did not localize the primary tumour, despite advanced dissemination stage, only showing lymphatic secondary locations at the left axillary and under the diaphragm areas. Literature review. - Younes-Mhenni (Brain, 2004, 20 patients); and Linke (Neurology, 2004, 13 patients) studied patients presenting with anti H.u. antibodies (13 and eight respectively) and other anti neuronal antibodies (Y.o., Ri, C.V.2, Tr) associated with different cancers. PET sensitivity was respectively 83.3 and 90% with a specificity of 25 and 67%. In both series, specificity of anti H.u. antibodies for S.C.L.C. was estimated at 53% and 62.5%. Size is a limiting factor for S.C.L.C. detection and Watanabe (Nihon Kokyuki Gakkai Zasshi, 2001) showed that sensitivity for detection of less than 1 cm tumour was 0% in five patients. Moreover, P.N.S. can precess S.C.L.C. detection for many years and PET/CT has to be repeated. (Gaillard, Revue neurologique, 2005).In two other studies (Schumacher, EJNM, 2001, 30 patients; and Niho, Lung Cancer, 2007, 63 patients), PET and T.D.M. have been compared, showing the superiority of PET at initial staging for lymphatic node and distant metastases detection, leading to therapeutic modifications in 8% of cases. In a in vitro study, Fischer and al. (EJNMMI, 2006) showed that the number of cancerous cells to obtain a positive signal with PET was different according to the anatomo-pathological type of tumour, with a detection limit increased by a factor of 10 for S.C.L.C. detection compared to glioblastoma. Most of time S.C.L.C. are located at lung level but many extra-pulmonary locations are known. Immunohistochemical markers can help diagnosis, for instance association between T.T.F.1 and pulmonary location, without being completely specific (Ghosh, Current problems in surgery, 2005). Conclusion. - Despite some false negative, PET is a precious examination for diagnosis and staging of documented P.N.S., in particular suspicion of S.C.L.C. with anti H.u. antibodies, leading to repeat the examinations in case of negativity. (authors)

[en] Short communication

[en] Short communication

[en] Short communication

[en] The alteration of the written description of an image scene constitutes an early and sensible indicator in diagnosing the Alzheimer's disease (AD). Measurements of cerebral blood rates (CBR) by SPECT show characteristic regional anomalies. We have studied correlations between the neuro-psychological tests (NT), parameters of description (description of the image of a thief of crackers) and CBR in patients afflicted by AD. Ten patients afflicted by AD of slow onset (MMSE 20.2± 5.1) were subject to the following NTs: MMSE, Wounded A, Battery of Aphasia, BNT, verbal fluence, gesticulative practice, direct and inversion span, copy of a figure, immediate recall of a figure, immediate recall of a story. The description variables were the length of texts (words, phrases), the items of information, the grammatical, semantic and orthographic errors. The relative variations of CBR were obtained after injection by HMPAO - ^99mTc. The indices of asymmetry were calculated by the method of the regions of interest and the correlations were calculated between the NTs, description variables and L/R asymmetry by SPECT. For the temporal lobes the correlations are significant with: Battery of Aphasia and BNT (p < 0.01), and recall of a story (p < 0.05); in the anterior frontal lobes with: MMSE and direct span (p < 0.05); in the posterior frontal lobes with: Battery of Aphasia (p < 0.05), BNT and recall of a story (p < 0.01). For writing, the grammatical errors are correlated with the anterior frontal asymmetries (p < 0.03); the semantic errors with the anterior and posterior frontal lobes (p < 0.02) and with the temporal lobes (p < 0.05). Our results show a correlations of the frontal and temporal asymmetries with the early degradation of the scores of written semantic errors and the oral tests of language. The grammatical errors appearing later and in severe forms of AD as the attention abilities are connected only to anterior frontal asymmetries. Different functional networks could determine specific abilities of writing which are afflicted sequentially during the AD

[en] The ongoing development of hybrid imaging, with physical association of CT scan and PET or SPECT scan, allows integrating morphological and functional information on a single exam. This important technological evolution changes diagnostic and therapeutic strategy in a major manner, essentially in oncology. The possibility to inject intravenously iodinated contrast media in order to enhance CT image contrast is still a controversial question in France. We present our experience in this domain by approaching technical problems and diagnostic advantages. (authors)

[en] Short communication

[en] Short communication