[en] While Particle Induced X-ray Emission technique (PIXE) is an accurate technique to quantify Active Pharmaceutical Ingredients (API’s) via the analysis of their heteroatoms, each drug (formulation) may require a specific quantification procedure due to its distinct matrix composition. The commercial Fludinium drug, which has two active ingredients Clidinium Bromide (C22H26NO3Br) and Dihydrochloride Trifluoperazine (C21H24N3F3S. 2HCl) has been taken as a case study in this work. Different amounts of its API’s and its placebo were mixed to provide various formulations. The matrix effect on the quantification of the three heteroatoms (chlorine, sulfur and bromine) related to the above API’s in different formulations has been studied. In fact, chlorine which is in its hydrochloride form in the API was not eventually considered for calculation due to its instability under beam. The calculation of bromine amount via its Ka or its La rays was found to be independent of the matrix composition and it was rapidly done by simple comparison to an external standard. However, the calculation of sulfur, via its Ka, was highly dependent on the matrix composition. Therefore, to achieve an accurate quantification a more sophisticated calculation method was used by means of the GUPIX code. (author)

[en] Crystallization of the poorly durable Na₂MoO₄ phase able to incorporate radioactive cesium must be avoided in SiO₂-Al₂O₃-B₂O₃-Na₂O-CaO glasses developed for the immobilization of Mo-rich nuclear wastes. Increasing amounts of B₂O₃ and MoO₃ were added to a SiO₂-Na₂O-CaO glass, and crystallization tendency was studied. Na₂MoO₄ crystallization tendency decreased with the increase of B₂O₃ concentration whereas the tendency of CaMoO₄ to crystallize increased due to preferential charge compensation of BO₄^- entities by Na⁺ ions. ²⁹Si MAS NMR showed that molybdenum acts as a reticulating agent in glass structure. Trivalent actinides surrogate (Nd³⁺) were shown to enter into CaMoO₄ crystals formed in glasses. (authors)

[en] High molybdenum concentration in glass compositions may lead to alkali and alkaline-earth molybdates crystallization during melt cooling that must be controlled particularly during the preparation of highly radioactive nuclear glassy waste forms. To understand the effect of molybdenum addition on the structure of a simplified nuclear glass and to know how composition changes can affect molybdates crystallization tendency, the structure of two glass series belonging to the SiO₂-B₂O₃-Na₂O-CaO-MoO₃ system was studied by ²⁹Si, ¹¹B, ²³Na MAS NMR and Raman spectroscopies by increasing MoO₃ or B₂O₃ concentrations. Increasing MoO₃ amount induced an increase of the silicate network reticulation but no significant effect was observed on the proportion of BO₄^- units and on the distribution of Na⁺ cations in glass structure. By increasing B₂O₃ concentration, a strong evolution of the distribution of Na⁺ cations was observed that could explain the evolution of the nature of molybdate crystals (CaMoO₄ or Na₂MoO₄) formed during melt cooling.

[en] Complete text of publication follows: Aim/Introduction: To assess the feasibility of a fully integrated dynamic PET-MRI approach applied to the characterization of lung lesions specifically. Materials and Methods: A total of 9 patients underwent a one-hour dynamic PET-MRI imaging protocol for suspected lung cancer. FDG PET and DCE MRI full kinetic analyses (Sokoloff and extended Toft models respectively), together with DWI-ADC and T1/T2-mapping were performed. All the PET-MRI data were warped into the same isotropic reference space before analyses. For each lung lesion, voxel-wise 3D maps of 14 biological features / 4 main categories were computed using an in-house fully integrative multimodal post-processing pipeline developed for this purpose specifically : perfusion/vascularization (K_trans, K_ep, V_e and V_p); metabolism (SUV, k1, k2, k3, Ki, V_b, and MRGlu); diffusion (ADC); and tissular characterization (T1 and T2 mapping). For each lesion, voxel-wise monotonic relationships between all the PET-MRI features were explored (Spearman correlations). Finally, all the lesions were partitioned by using multidimensional unsupervised gaussian mixture approach, and features profiles/relationships were explored at the supervoxel regional level. Results: Relationships between the perfusion/vascularization, metabolism, diffusion and tissular feature categories differed among the lesions. At the feature level, strong correlations (absolute r value superior to 0.5) were observed for the perfusion/vascularization features pairs and the metabolic feature pairs. At the category level, absolute r values were inferior to 0.5 for the vast majority of the feature pairs. Combining the 14 features together, unsupervised clustering provided 2 to 4 supervoxels depending on the lesion. At the supervoxel regional levels, feature profiles differed, as well as their monotonic relationships. Conclusion: Our one-stop-shop fully integrative dynamic PETMRI protocol provided 14 biological features (4 main categories) in the same examination. For all lesions, the heterogeneity of features profiles/relationships at the regional supervoxel level highlights the unique capability of PET-MRI to get better insight of the biological characterization of lung masses

[en] Complete text of publication follows: Aim/Introduction: To evaluate the impact of geometric distortions inherent to diffusion weighted imaging (DWI) in the field of PET-MRI lung oncology. Materials and Methods: 10 patients were prospectively recruited and underwent an ¹⁸F-FDG PET-MRI for lung oncology purpose. For all patients, the imaging protocol included several thoracic PET-MRI acquisitions: a PET acquisition performed one hour after the intra veinous injection of ¹⁸F-FDG; a set of DWI acquisitions with anteroposterior phase encoding (b values of 0,500, 800 s/mm²) and reverse-phase encoding polarity (b value = 0 s/mm²); a high resolution post contrast-enhanced 3DT1-weighted FSPGR sequence. DWI data were corrected for geometric distortions using the reverse phase encoding method. All the DWI data (non corrected and corrected from the distortion) were warped to the same T1 weighted PET-MRI isotropic reference space before analyses. Quality of the co-registrations to the reference T1 PET-MRI was quantitatively assessed using mutual information metric. The percentage gain compared to non-warped DWI data was also computed. ADC feature maps of each lung lesion were computed from the DWI data non-corrected and corrected from the distortion, and voxel-wise percent differences together with paired t-test were computed. Finally, regional ADC-SUV monotonic correlations were explored from optimal realigned DWI-PET data. Results: Quality of the co-registration between DWI and T1 PET-MRI data was significantly improved by the reverse phase encoding method (relative gain on mutual information compared to non-warped DWI data : 4-46%, vs 0.4-27% for warped data without distortion correction, p inferior to 0.05). The between-ADC feature maps regional differences ranged from -100% to more than +150%. Regional correlations between ADC and SUV computed from optimal realigned DWIPET data revealed only weak monotonic relationships between the two features at the voxel level (Spearman coefficients inferior to 0.5 in all the cases). Conclusion: DWI-related distortions are significant in thoracic PET-MRI, and should be corrected for accurate DWI-PET multimodal analyses. ADC and SUV showed weak monotonic relationship at the voxel level, emphasizing their complementarity