[en] Training specialists in medical radiation protection is ensured by the Continuous Training Center of University Rene Descartes since 1990. The necessity of updating knowledge has urged us to develop an Internet site (http://www.citi2.fr/RADIO). Besides the mandatory functions of the educational management (secretariat, information on the stages, registrations, etc.) this site provides: 1. Practical information (addresses of administrative and technical organisms, presentation of radiation protection programs); 2. Scientific information (bibliographic bulletin of the EDF service of radiation protection, updated every two months, description of recent radiation protection works); 3. Institutional documentation (analysis of recent basic texts, ICRP publications, European directives). The interrogation of general interest asked via e-mail and forum allowing communication between experts, graduated students and the education faculty will be available on the site. The communication will be augmented by tele-formation modules for continuous distant training

[en] This issue of the journal 'Medecine Nucleaire - Imagerie Fonctionnelle et Metabolique' contains the short communications, abstracts of the poster communications and lectures presented in the 36. French Language Colloquium on Nuclear Medicine held at Rennes - Saint-Malo on 1 to 3 October, 1997. According to their content the communications were bunched in the following sessions: Radioprotection-Environment, Cardiology-Pneumology, Endocrinology, Oncology-Diagnosis, Oncology-Therapy, Neurology, Radiobiology, Radioprotection, Osteo-articulary, Uro-Nephrology, Hepato-Gastroenterology, Radiopharmaceuticals, Immuno-analysis, Instrumentation-Image Processing. The overwhelming majority of the papers presented dealt with the use of radioisotopes and radiolabelled complexes in diagnosis and therapy especially, by means of PET and SPECT techniques. The colloquium proceedings are completed by two lectures on Radioimmunotherapy of lymphomas and use of PET in tumor imaging considered from the cost efficiency

[en] This retrospective study of 49 patients, carrying an internal mono-compartmental algic syndrome of the knee, determines the place of the dynamical osseous scintigraphy in three times: in comparison with the pan-goniometry (for 42 of them), in the diagnosis of the hyper-pressure syndrome and in the evaluation of its severity. The vascularization is augmented in 10 patients and the sanguinary pool in 14. Forty eight internal compartments exhibit a tracer hyper-fixation at late times. These anomalies have been classified according to their tibial or condylar localization and intensity, than compared with the pan-goniometric values of the deviation, which in case of a varus, entail an over-pressure risk. These comparisons show a good correlation between the hyper-fixation in the sub-chondral band of the internal tibial plateau and a syndrome of hyper-pressure by deviation in varus, whether this hyper-fixation was moderated and isolated or severe or associated to a condylar image; the intensity of the fixation indicates the severity. The tibial fixation intensity is always superior to that of the rest of compartment, what is essential for the differential diagnosis in case of a simple, without hyper-pressure, arthritis, or other pathology. From this exploration stem 8 osteotomies and 1 prosthesis

[en] The standard radiographical pictures are not able always to bring out the fracture of one of the fist bones. In an early study it was shown that 40% of patients presenting a suspicion of fracture and in which the radio- image was normal, have had a fracture confirmed with quantification by MRI and scintigraphy. The last one does not allow to specify the localization and consequently we developed a code to fusion entirely automatically the radiologic image and the scintigraphic image using no external marker. The code has been installed on a PC and uses the Matlab environment. Starting from the histogram processing the contours are individualized on the interpolated radio- and scinti-images. For matching there are 3 freedom degrees: one of rotation and 2 of translation (in x and y axes). The internal axes of the forearm was chosen to effect the rotation and translation. The forehand thickness, identical for each modality, allows to match properly the images. We have obtained an anatomic image on which the contour and the hyper-fixating zones of the scintigraphy are added. On a set of 100 examinations we observed 38 fractures while the difference between a fracture of the scaphoid and of another fist bone is confirmed in 93% of cases

[en] The evolution of a HD is unpredictable for 30% of patients. The goal of this study is to find whether the gallium citrate scintigraphy performed as a treatment means is predictable for relapse or survival. A retrospective study on 58 patients afflicted with diaphragmatic HD is here reported. The regression of the tumor volume is evaluated through the TDM at the end of chemotherapy and the scintigraphy is performed at the same time. The patients are separated into two groups: group 1, gallium negative; group 2, gallium positive, at the level of initial site or in another site. The relapse risk after 1 year and the survival with a minimum - 1 year recoil after the end of any treatment are studied. We have found that all the patients presented a TDM tumoral volume regression of at least 50%. In the group 1 (44 patients) there were recorded 7/44 relapse cases (16%) in less than 1 year, with 2 deceases while all the other patients are in remission (96%); in the group 2 (14 patients) only 1/14 has not relapsed in 36 months; 13/14 patients (93%) have progressed along a 2 to 10 month delay; 5 of these patients have deceased from HD (36%), 3 remained evolutive (21%) and 6 in remission after the recovering treatment (43%). In conclusion, the Ga-67 scintigraphy used as chemotherapy is a good indicator of the stage of HD evolution

[en] Since 1992 the radiopharmaceuticals are reckoned as medicines. Already subject to the legislation of unsealed radioactive sources, their double nature imposes new constraints upon nuclear medicine services. It is presented here the OrdoCMN, a program capable to offer a simple solution for new-data management. It was developed starting from the management system for a 4-Dimension database which comprises the tools necessary in developing applications. The utilized configuration is of client/server type and is implanted on Macintosh microprocessors. OrdoCMN offers the ensemble of functionalities allowing to manage the totality of the data relative to a scintigraphic examination: planning the examinations, patients' files, ordinance issues, labels, records and radiopharmaceutical management. This program which can operate both in mono-station and network appears to be in the second case a communication tool linking different elements of a nuclear medicine service. It brings in time saving and optimization of each-other depending actions implied in making scintigraphic examinations. Centered upon the patient's file, by making use of passwords it warrants the reliability and confidentiality of information. Easy to be elaborated, it may be adapted to the specific needs of any center. Now in phase of validation, it incorporate around 6000 patient's files and 10,000 examination records and is the object of an accreditation request from CNIL. Initially developed to respond to regulations' constraints, the OrdoCMN became a entirely integrated tool as part of operation of a nuclear medicine center

[en] We have earlier shown that the method of singular value decomposition (SVD) allows the image reconstruction in single-photon-tomography with precision higher than the classical method of filtered back-projections. Actually, the establishing of an elementary response matrix which incorporates both the photon attenuation phenomenon, the scattering, the translation non-invariance principle and the detector response, allows to take into account the totality of physical parameters of acquisition. By an non-consecutive optimized truncation of the singular values we have obtained a significant improvement in the efficiency of the regularization of bad conditioning of this problem. The present study aims at verifying the stability of this truncation under modifications of acquisition conditions. Two series of parameters were tested, first, those modifying the geometry of acquisition: the influence of rotation center, the asymmetric disposition of the elementary-volume sources against the detector and the precision of rotation angle, and secondly, those affecting the correspondence between the matrix and the space to be reconstructed: the effect of partial volume and a noise propagation in the experimental model. For the parameters which introduce a spatial distortion, the alteration of reconstruction has been, as expected, comparable to that observed with the classical reconstruction and proportional with the amplitude of shift from the normal one. In exchange, for the effect of partial volume and of noise, the study of truncation signature revealed a variation in the optimal choice of the conserved singular values but with no effect on the global precision of reconstruction

[en] The aim of this work was to ensure the surveillance of low irradiation doses cumulated at the level of fingers by means of a sensible, reliable and low-cost method. The skin capillary network represents an indicator of high sensibility for alteration caused by ionizing radiations. The capillary-metry is a method which consists in exploiting numerically the parameters deduced from capillary-scopic observation. A stereo-microscope of low magnifying power and large frontal distance permits a tridimensional visualisation of capillary loops after trans-illumination of the skin (immersion oil). The photographic and numerical recording on diskettes is achieved on the pathological zones of all fingers of both hands. The multi-criteria exploitation (the characteristics of capillaries, their environment and populations) allows their interpretation. Twenty-one subjects were controlled in the frame of a radio-pathological surveillance at Institut Curie de Paris. The case study presenting a confirmed chronic irradiation has evidenced alteration in organisation, in the distribution of capillaries and also a decrease in their number and a diminution of their diameter. Finally, the presence of ecstasies and stenoses is frequent as the presence of desert zones. In conclusion, these alterations, although less spectacularly then the acute irradiation are sufficiently marked to be not confounded with the microvascular chronic anomalies observed in chemists, masons or musicians, as those of current vascular pathology

[en] The gamma-angio-cardiography at equilibrium is the reference method for the calculation of the left ventricular function (FEVG). We have studied the percentage of centro-cavitary activity (PCCA) by myocardium tomo-scintigraphy. The PCCA was calculated on the basis of the measurement of activity at the center of left ventricular cavity (C) of a small-axis medial cross section, divided to myocardium maximal activity (M_max): PCCA (C/M_max) x 100. The obtained values were compared with that of isotopic FEVG in 251 consecutive patients who benefited both by a Tl-201 tomo-scintigraphy (stress/redistribution) and a gamma-angio-cardiography at equilibrium. The correlation between PCCA and FEVG was: r = 0.82 (y = 0.75 x + 1.69; P 0.0001). The PCCA is easily obtainable on the basis of Tl - 201 myocardial tomo-scintigraphies and allows a rapid evaluation of the global left ventricular function

[en] A study on 30 files of hypertensive patients with an associated hypokalemia was achieved from January 1996 to May 1997. The technique was that of a basic examination effected by MAG 3 (80 MBq), followed by oral intake of 25 to 50 mg of Captopril; one hour after, a new examination was done by MAG 3, with 130 MBq. The classical aspect of isotopic nephro-gram (IN) was not constantly found in case of renal artery stenosis. The reduction of the peak of the level approached might be the only sign, even without any delay of this summit; the lowering of the peak after Captopril of at least 50% should be taken into account. Thus, on the basis of these arguments, we have found 5 stenoses of renal artery. Twenty patients considered as normal have had not arteriography and are relatively well-equilibrated by medical treatment. Among the false negatives, one is explained by a renal insufficiency given an IE of bad quality, while the other is a dysplasia of renal arteries. The 3 false positives presented a discrete difference between the two examinations by MAG 3. Consequently, we considered that the discrete signs should not be retained. The slowing down of transit time, the net lowering of the peak or its delay (classically, 11 min) are good arguments