Логіко-лінгвістична модель як засіб відображення синтаксичних особливостей текстової інформації

Запропоновано використовувати логіко-лінгвістичні моделі як засіб відображення синтаксичних особливостей текстової інформації, перелічено та обґрунтовано правила їх формування, наведено алгоритм створення всіх складових таких моделей.Предложено использовать логико-лингвистические модели как способ отображения синтаксических особенностей текстовой информации, перечислены и обоснованы правила их формирования, приведен алгоритм создания всех составных таких моделей.It is suggested using a logico-linguistic model as a method of display the syntactical features of text information. There are listed and justified the rules for their forming and also are shown an algorithm of creation of all components of such models in this paper

Loco-regional conformal radiotherapy of the breast: delineation of the regional lymph node clinical target volumes in treatment position.

Contains fulltext : 57546.pdf (publisher's version ) (Closed access)BACKGROUND AND PURPOSE: As the location of the regional lymph nodes (LNs) of the breast varies largely between patients and may be dependant on the position of the arm, adequate localization of these nodes is mandatory in order to fully take advantage of optimized conformal radiotherapy. For this purpose, the anatomical boundaries of the regional lymph node (LN) clinical target volumes (CTVs) for delineation on transverse CT-slices, made in treatment position, were established. PATIENTS AND METHODS: Anatomical and surgical descriptions of the regional LNs of the breast, as well as a shoulder dissection, were studied. Axial slices of a human cadaver with one arm in abduction and the other in adduction were investigated, to assess the displacement of LNs by abduction of the arm into treatment position. Based on these findings, we defined the anatomical boundaries of the regional LN CTVs visible on transverse CT-slices. RESULTS: Standard anatomical and surgical descriptions appeared to be inadequate for determination of the boundaries of the regional LN CTVs in treatment position. With abduction of the arm, a change in position of all regional LNs, except for the medial supraclavicular LNs and internal mammary LNs, was observed in the anatomical cross-sections. This was also taken into account in our delineation protocol proposal. CONCLUSIONS: Anatomically based guidelines for delineation of the regional LN CTVs for loco-regional irradiation of the breast on transverse CT-slices, made in treatment position, have been developed in this study. These could be used as a basis for conformal radiotherapy

Dose uniformity in MECS interstitial hyperthermia: the impact of longitudinal control in model anatomies

The quality of temperature distributions that can be generated with the multi-electrode current source (MECS) interstitial hyperthermia system, which allows 3D control of the spatial SAR distribution, has been investigated. For the investigations, computer models of idealized anatomies were used. These anatomical models did not contain discrete vessels. Binary-media anatomies, containing media interfaces oriented parallel, perpendicular or oblique with respect to the long axis of the implant, represent simple anatomies which can be encountered in the clinic. The implant volume was about . A seven-catheter hexagonal implant geometry with a nearest-neighbour distance of 15 mm was used. In each interstitial probe between one and four electrodes with a diameter of 2.1 mm were placed along an `active section' with a length of 50 mm. The electrode segments had lengths of 50, 20, 12 and 9 mm. This study shows that even with high contrasts in electrical and thermal conductivity in the implant it remains possible to obtain satisfactory temperature distributions with the MECS system. Due to its 3D spatial control the temperature homogeneity in the implant can be made quite satisfactory, with of the order of 2 - 3 K. Treatment planning must ensure that the placement of the current source electrodes is compatible with the media configuration

A dual-purpose MRI acquisition to combine 4D-MRI and dynamic contrast-enhanced imaging for abdominal radiotherapy planning

Item does not contain fulltextFor successful abdominal radiotherapy it is crucial to have a clear tumor definition and an accurate characterization of the motion. While dynamic contrast-enhanced (DCE) MRI aids tumor visualization, it is often hampered by motion artifacts. 4D-MRI characterizes this motion, but often lacks the contrast to clearly visualize the tumor. This dual requirement is challenging due to time constraints. Here, we propose combining both into a single acquisition by reconstructing the data in various ways in order to achieve both high spatio-temporal resolution DCE-MRI and accurate 4D-MRI motion estimates. A 5 min T1-weigthed DCE acquisition was collected in five renal-cell carcinoma patients and simulated in a digital phantom. Data were acquired continuously using a 3D golden angle radial stack-of-stars acquisition. This enabled three types of reconstruction; (1) a high spatio-temporal resolution DCE time series, (2) a 5D reconstruction and (3) a contrast-enhanced 4D-MRI for motion characterization. Motion extracted from the 4D- and 5D-MRI was compared with a separately acquired 4D-MRI and additional 2D cine MR imaging. Simulations on XCAT showed that 5D reconstructions severely underestimated motion ([Formula: see text]), whereas contrast-enhanced 4D-MRI only underestimated motion by [Formula: see text]. This was confirmed in the in vivo data where motion of the contrast-enhanced 4D-MRI was approximately [Formula: see text] smaller than the motion in the 2D cine MRI (5.8 mm versus 6.5 mm), but equal to a separately acquired 4D-MRI (5.8 mm versus 5.9 mm). 5D reconstructions underestimated the motion by more than [Formula: see text], but minimized respiratory-induced blurring in the contrast enhanced images. DCE time-series demonstrated clear tumor visualization and contrast enhancement throughout the entire field-of-view. DCE- and 4D-MRI can be integrated into a single acquisition that enables different reconstructions with complementary information for abdominal radiotherapy planning and, in an MRI-guided treatment, precise motion information, input for motion models, and rapid feedback on the contrast enhancement.10 p