Application of a hybrid pixel detector to powder diffraction

Results obtained using a hybrid pixel photon-counting detector in powder diffraction experiments are presented. The detector works at room temperature and its dynamic response ranges from 0.01 photons pixel(-1) s(-1) up to 10(6) photons pixel(-1) s(-1). The pixel sizes are 0.33 mm x 0.33 mm for a total area of 68 mm x 68 mm. On recording high-resolution diffraction patterns of powders, a reduction of the experimental time by more than a factor of 20 is obtained without loss of data quality. The example of an X-zeolite shows that such detectors can be used for very demanding anomalous experiments. In situ experiments of quenching liquid oxides show that frames of 0.01 s can be achieved for studying such processes.

[Thyroid carcinoma in a thyroglossal duct cyst: tumor resection alone or a total thyroidectomy?]

Tumours arising in a thyroglossal duct cyst are very rare. Most of them develop from ectopic thyroid remnants. Controversies persist concerning th treatment of these neoplasms, some authors preferring local excision (Sistrunk procedure), while others prefer a more radical approach (associated total thyroidectomy). From 1977 to 1996 we observed and treated 10 patients with by a thyroglossal duct tumour: 8 females and 2 males. A mass in the midline of the neck was the presenting complaint in all cases. Each patient was treated by a Sistrunk procedure associated with total thyroidectomy. Histopathology reports showed 7 papillary carcinomas, 1 Hürthle cell carcinoma, 1 follicular carcinoma and 1 insular carcinoma. Systematic examination of the thyroid gland revealed foci of papillary cancer in 4 cases (40%), with only 1 tumour being larger than 1 centimetre. Cervical metastases were found at operation in 1 case. This series suggests that total thyroidectomy for tumours of thyroglossal cysts could be justified by the high incidence of associated papillary carcinomas of the thyroid and by the relatively aggressive nature that some tumors. In these cases, a radical therapeutic attitude allows, better patients management (total scintigraphy, serum thyroglobulin measurement) and allows the possibility of a complementary radioiodine treatment.