CURRENT OPPORTUNITIES OF SONOGRAPHIC DIAGNOSTICS TIBIAL OSTEOCHONDROMAS

Osteochondroma is the most common tumor of the skeleton. Its frequency is more than 40% of benign and at least 20% of all human bone tumors. The objective of this study was to improve methods of diagnostics of shin bone osteochondromas with using of modern imaging techniques. There were treated 81 patients with primary tibia osteochondroma and one with a secondary chondrosarcoma during the period from 2000 to 2011 in the Clinic of Traumatology and Orthopedics of the Astrakhan Medical Academy Diagnostics was based on the data of anamnesis, physical examination, standard X-rays and computed tomography. We applied ultrasound studies of shin bones in 11 patients. The ultrasonography has allowed revealing two main forms of osteochondromas: “globular-shaped” and “hill-shaped”. The tumor goes into the third “cauliflower-shaped” form in the case of malignant transformation. The distribution of the cartilage on the osteochondroma surface is irregular and depends on the tumor shape. The indirectly malignant signs are the loss of sharpness and smoothness of the contour, hyperechoic inclusions in the cartilage cap

Study of the background in the measuring station at the n_TOF facility at CERN: sources and solutions

A background roughly two orders of magnitude higher than tolerable was found in the n_TOF facility at CERN during the first measurements [1]. This note describes a series of additional measurements performed in the n_TOF experimental area to study the origin and the characteristics of the background. The program of these measurements was determined taking into account the results from the simulations carried out by the EET group [2]. A first phase of measurements confirmed what was expected from the simulations, namely that the dominant source of background was due to neutrons generated by negative muon capture. Actions to reduce the background were taken according to the results from both measurements and simulations. An iron shielding wall 3.2 m thick was then placed in between the sweeping magnet and the second collimator, with the purpose of stopping most of the muons. In a second phase of measurements, results showed that the additional shielding reduced the main component of the background by about a factor of 30