CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Apport de l'imagerie au traitement du cancer de prostate par ultrasons focalises de haute intensité

Nous avons tenté, dans ce travail, d'améliorer l'évaluation radiologique des patients traités par HIFU transrectaux pour cancer de prostate dans 4 directions différentes. 1. Meilleure définition de la cible : l'IRM dynamique après injection de gadolinium semble une technique prometteuse de localisation du cancer à l'intérieur de la glande. Dans un premier temps, nous avons obtenu les courbes de rehaussement du cancer de prostate et des tissus sains avoisinants et nous avons cherché à en déduire la meilleure fenêtre d'imagerie. Nous avons ensuite appliqué cette technique aux patients présentant une récidive après traitement radiothérapique et prouvé que, dans ce sous groupe, l'imagerie dynamique permettait une meilleure visualisation du cancer que l'IRM T2 classique. 2. Appréciation de la zone traitée : nous avons montré que l'IRM permettait une évaluation fiable des limites de la zone traitée par les HIFU; en revanche, elle ne permet pas d'apprécier la qualité de la nécrose. Une étude de faisabilité a montré que l'élastographie échographique pouvait aussi montrer les limites de la zone de nécrose induite par les HIFU. 3. Recherche de facteurs pronostiques : nous avons montré que la perfusion prostatique (appréciée par Doppler couleur) n'influait pas sur la qualité de la nécrose induite par les HIFU et que le Doppler ne pouvait donc pas prédire les résultats du traitement. 4.Suivi post-thérapeutique : le Doppler couleur peut détecter les foyers tumoraux résiduels après traitement HIFU mais notre évaluation a montré que ses performances ne permettaient pas de se passer des biopsies systématiques de contrôleLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Varicocèle et infertilité (à propos d'une étude rétrospective de 71 patients adultes évaluant la contribution diagnostique de l'échodoppler et l'impact thérapeutique de la scléro-embolisation radiologique)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Irradiation diagnostique accidentelle de grossesses (à propos de 18 observations)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Intratesticular varicocele: an easy diagnosis but unclear physiopathologic characteristics.

International audienceOBJECTIVE: Intratesticular varicocele (ITV) is an uncommon sonographic finding with controversial data concerning its prevalence and physiopathologic characteristics. The goal of this study was to determine the prevalence of ITV in a urogenital imaging department and to describe its sonographic features. METHODS: All identified cases of ITV were prospectively collected in the same imaging department. RESULTS: Intratesticular dilated veins (>2 mm) with a positive response to the Valsalva maneuver were referred to as ITV. Nine cases of ITV were detected in 8 patients (mean age, 60 years; range, 30-85 years) in a series of 1832 scrotal sonographic examinations performed over 5 years (0.4%). A history of homolateral scrotal surgery was found in 5 cases. In most cases, ITV was left sided (6/9) and located in the mediastinum testis (6/9) with associated extratesticular varicocele (8/9) and testicular hypotrophy (7/9). Five of the 7 hypotrophic testes had other causes of hypotrophy. CONCLUSIONS: Although variations do exist in the sonographic appearance of ITV, its specific sonographic and Doppler appearance should enable the radiologist to obviate further study. Intratesticular varicocele is often associated with ipsilateral testicular atrophy, but whether it is a cause or a consequence of testicular atrophy remains unclear

Agricultural Practices at Mentesh Tepe (Kura Valley, Azerbaijan) during the Neolithic, Chalcolithic and Bronze Age: An Overview from Sickle Elements and Botanical Remains

International audienceThe Neolithic process took place in the South Caucasus between the very end of the 7th and the early 6th millennium BCE, at least two millennia after it had already taken place in neighboring Anatolia and Iran. Agriculture appeared at that time, and was the main basis of the economy,together with herding. Cereals, mainly barley and different kinds of wheats, were the dominant cultivar. Mentesh Tepe, one of the rare multi-period settlements of the region, allows us to witness the development of ancient agricultural practices, since Neolithic, Chalcolithic and Bronze Age occupations have been identified there. The site is located in Azerbaijan in the vicinity of the Zeyem Cay, a tributary of the Kura River, some 10 km from the foothills of the Lesser Caucasus. We present here data originating from the analyses of botanical remains and techno-functional lithic tools studies. We have thus been able to identify trends and changes through time affecting cultivation and harvesting techniques. These are the result of economic and socio-cultural changes and reflect both the organization of communities and the technical skills of local inhabitant

Transient MR elastography (t-MRE) using ultrasound radiation force: theory, safety, and initial experiments in vitro.

International audienceThe purpose of our study was to assess the feasibility of using ultrasound radiation force as a safe vibration source for transient MR elastography (t-MRE). We present a theoretical framework to predict the phase shift of the complex MRE signal, the temperature elevation due to ultrasound, and safety indicators (I(SPPA), I(SPTA), MI). Next, we report wave images acquired in porcine liver samples in vitro. MR thermometry was used to estimate the temperature elevation induced by ultrasound. Finally, we discuss the implications of our results with regard to the feasibility of using radiation force for t-MRE in a clinical setting, and a specific echo-planar imaging (EPI) MRE sequence is proposed

Transrectal high-intensity focused ultrasound ablation of prostate cancer: effective treatment requiring accurate imaging.

International audienceTransrectal HIFU ablation has become a reasonable option for the treatment of localized prostate cancer in non-surgical patients, with 5-year disease-free survival similar to that of radiation therapy. It is also a promising salvage therapy of local recurrence after radiation therapy. These favourable results are partly due to recent improvements in prostate cancer imaging. However, further improvements are needed in patient selection, pre-operative localization of the tumor foci, assessment of the volume treated and early detection of recurrence. A better knowledge of the factors influencing the HIFU-induced tissue destruction and a better pre-operative assessment of them by imaging techniques should improve treatment outcome. Whereas prostate HIFU ablation is currently performed under transrectal ultrasound guidance, MR guidance with real-time operative monitoring of temperature will be available in the near future. If this technique will give better targeting and more uniform tissue destruction, its cost-effectiveness will have to be carefully evaluated. Finally, a recently reported synergistic effect between HIFU ablation and chemotherapy opens possibilities for treatment in high-risk or clinically advanced tumors

Influence of perfusion on high-intensity focused ultrasound prostate ablation: a first-pass MRI study.

International audienceOur aim was to evaluate the influence of regional prostate blood flow (rPBF) on high-intensity focused ultrasound (HIFU) treatment outcome. A total of 48 patients with clinically localized prostate cancer were examined by dynamic contrast-enhanced (DCE)-MRI prior to HIFU therapy. A prostate-specific antigen (PSA) nadir threshold of 0.2 ng/ml was used to define the populations of responders and nonresponders. A dedicated tracer kinetic model, namely "monoexponential plus constant" (MPC) deconvolution, was implemented to provide quantitative estimates of rPBF. The results were compared with those obtained by semiquantitative (steepest slope, mean gradient) and quantitative (Fermi deconvolution) approaches. Of the four methods studied, quantitative rPBF obtained by MPC deconvolution proved the most sensitive to the perfusion changes encountered in this study. Furthermore, blood-flow values obtained with MPC deconvolution in the prostate and muscle (12 +/- 8 and 5 +/- 3 ml/min/100 g, respectively) were in good agreement with literature data. The mean pretreatment rPBF obtained with MPC deconvolution was significantly higher in nonresponders compared to responders (16 +/- 9 vs. 10 +/- 6 ml/min/100 g), suggesting a correlation between baseline perfusion and treatment outcome. The present work describes and validates the use of dynamic MRI to estimate rPBF in patients, which in the future may help to refine the conduct of HIFU therapy