摘要:
The radial dose function of an electronic x-ray brachytherapy source is flattened by filtering with transition metals in the fourth row of the periodic table, i.e. titanium through nickel. Titanium-walled applicator devices of small diameter, under 10 mm, and with wall thicknesses of about 0.2 mm to 0.6 mm, are disclosed. The walls can be of titanium or alloys thereof, providing adequate strength and flattening the radial dose function curve particularly for x-rays in an energy range of about 45 kV to 55 kV.
摘要:
A device, system and method for administering radiation therapy to a tissue surface of a patient utilizes an applicator capable of controlled movement and repositioning over a selected area of tissue, under the control of a computer or controller. A servo-controlled manipulator can effect a raster scan of the desired area, such as an area of the skin, and this can be in any desired pattern such as serpentine, spiral, parallel but unidirectional, or irregular patterns. Preferably a third direction of control is included, i.e. a depth direction, with an appropriate form of depth sensor, a signal from which can be used to adjust the radiation source so that radiation of the tissue surface is consistent over varied contoured.
摘要:
A device, system and method for administering radiation therapy to a tissue surface of a patient utilizes an applicator capable of controlled movement and repositioning over a selected area of tissue, under the control of a computer or controller. A servo-controlled manipulator can effect a raster scan of the desired area, such as an area of the skin, and this can be in any desired pattern such as serpentine, spiral, parallel but unidirectional, or irregular patterns. Preferably a third direction of control is included, i.e. a depth direction, with an appropriate form of depth sensor, a signal from which can be used to adjust the radiation source so that radiation of the tissue surface is consistent over varied contoured.
摘要:
A subject (22), such as a human patient, is positioned with a region of interest (24), such as the liver, close proximity to a phantom (12). A Volume image through the liver, the phantom, and adjacent portions of the subject are collected (40) with a magnetic resonance scanner. The phase component of the magnetic resonance data is reconstructed (50) into a three-dimensional phase map. An actually measured field map H.sub.m (r) is determined (42) from the phase map. A geometric model of the volumes occupied by the liver, the phantom, and adjacent portions of the subject are defined mathematically (44). A calculation routine (46) calculates a calculated or estimated field map H.sub.c (r) of the distortions to the magnetic field in the phantom which would be caused by the model. A least squares fit routine (48) (i) compares the calculated field map and the measured field map, (ii) based on the difference adjusts a susceptibility of material in the region of interest as defined in the model, and (iii) recalculates the field map. This fitting procedure is iteratively repeated until a susceptibility is determined for the region of interest which predicts the actually measured field map. This susceptibility is proportional to iron concentration.