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Abstract. Among electron beam microanalytical techniques, electron energy loss spectrometry (EELS) offers unique advantages in terms of information content, sensitivity, limits of detection. This paper describes new methods and tools for acquiring families of spectra over many pixels on the specimen, i.e. spectrumimages, and for processing them. Applications in different fields of research, both in materials science and in life sciences, demonstrate the potential impact of the technique for characterizing nano-sized structures.Key words: electron microscopy, nanoanalysis, electron energy loss spectrum, image-spectrum aquisition and processing.Electron energy loss spectrometry (EELS) measures the energy loss suffered by high energy incident electrons transmitted through the specimen prepared as a thin foil. Its information content is very diversified. The low loss range, between 5 and 50 eV, reflects mostly the collective behaviour of the conduction electron gas through the appearance of plasmon peaks, the energy of which is determined by the average electron density. After some lengthy data analysis one can also have access to optical properties and to localized surface electronic properties. The high energy range, from 50 eV up to 1000 or 2000 eV, exhibits the core-edges associated with the excitation of inner-shell atomic levels. Its main interest is for elemental identification. Moreover the study of the fine structures on these edges offers fingerprints for the determination of site symmetry and for the evaluation of bond lengths.When recorded in the electron microscope, EELS data also contain spatial information [1], which is usually intended for chemical analysis. In essence, one makes a map of the spatial origin of chemically significant signals such as the characteristic core-edges and this technique complements the standard X-ray compositional imaging mode. However it constitutes only one aspect of the richness of the field of applications for EELS mapping. The present paper discusses recent progress in spatially resolved EELS and its use as a nanoanalytical tool, in which spectra can be acquired from many adjacent nanosized areas in a heterogeneous material and processed quantitatively.

Our data show that the TgD5/TgD0 ratio may be used as a new prognostic indicator of (131)I treatment efficacy in patients with DTC.

The visualization of symmetric structure by [₁₈F]-FluoroDeoxyGlucose-Positron Emission Tomography (FDG-PET), corresponding to adipose density in computed tomography (CT), has led to the idea that Brown Adipose Tissue (BAT) could be present in adult human. This article studies the FDG uptake in a mice model deficient on Uncoupling Protein 1 (UCP1), in a simple thermal activation protocol. Methods: FDG were injected in mice, control and knock out (K.O.) for the UCP1. Before imaging mice were placed either in cold or warm environment. BAT uptake was evaluated by ratio named RISC. Results: In warm condition, mean value of the Ratio of Inter-Scapular uptake (RISC) was 1.34 +/﹣ 0.27. After cold exposure, RISC increased 2 fold for control mice, male K.O. did not increase their RISC, female K.O. increased their RISC up to 2.45. Conclusion: Our study brought a further confirmation that FDG-PET visualised activated Brown Adipose Tissue. It gives a direct proof of the role of UCP1 in this process. The FDG uptake by cold female K.O. mice was unexpected.

Many patients referred with the hypothesis of hyperplasia of a subtotally resected parathyroid gland or autograft were found to harbour a supernumerary parathyroid gland missed at the initial surgery.

Preoperative subtraction scanning is useful in planning parathyroid surgery and appears to be cost-effective.

Functioning pulmonary metastases are the most common distant lesions of differentiated thyroid cancer. About 50% of patients with such metastases die within 10 years. The impact of iodine-131 therapy is controversial. In this study we examined: (1) the early diagnostic value of post-surgery (131)I ablation for lung invasion and (2) the survival of patients receiving periodic (131)I therapy. Between January 1970 and December 1995 we provided initial treatment for 509 patients with thyroid cancer. Most of them (74%) underwent total thyroidectomy and (131)I ablation. Functioning pulmonary metastases occurred in 20 patients. All these patients received periodic (131)I therapy for as long as (131)I uptake persisted. Additional therapy consisted of lung surgery in three patients and local treatment of bone lesions in four patients. Follow-up data were recorded up to December 2001. Functioning pulmonary metastases occurred late in one patient, and were visible on the post-surgery (131)I therapy scan in the other 19 patients. At diagnosis of lung invasion, 11 patients had negative chest X-ray findings, and serum thyroglobulin levels were not suggestive of metastatic disease in 56% of these cases. One of the 11 patients with negative chest X-ray findings died with a neck recurrence, two have persistent pulmonary (131)I uptake, and the other eight are in apparent remission after receiving an average cumulative (131)I activity of 338 mCi (12.51 GBq). The nine patients with positive chest X-ray findings received an average of 939 mCi (34.74 GBq); two of them died, five are continuing to receive therapy and two are in apparent remission. Overall survival at 10 years is 84%. The average follow-up of the 17 survivors is 12.7 years. These results suggest that patients with functioning pulmonary metastases, even in advanced stages, may survive for many years on (131)I therapy. Early diagnosis, during post-surgery (131)I scanning, of radiologically inapparent metastases is associated with a better prognosis.

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