Abstract: X-ray compensation masks (51) are prepared by exposing an X-ray target object (43), such as a patient, to a first beam of X-rays. The X-ray fluence from the patient is received by an electronic image receptor (44) which provides an output signal indicating the intensity of the X-rays at all positions in the image field. The image information is converted by an image processor (47) to transformed X-ray intensity values for a plurality of pixels which cover the image field. A mask generating controller (48) determines the minimum transformed intensity value for any pixel, assigns to each pixel an attenuation number which is proportional to the difference between the transformed intensity value for the pixel and the minimum transformed intensity value, and issues control signals to a mask former (49) which deposits on a non-attenuating substrate (50) attenuating masses in a two dimensional array of pixels with the mass thickness in each pixel proportional to the attenuation number.

Abstract: A method and apparatus is disclosed for providing therapeutic occlusions of blood vessels and other body tubular structures using an inflatable balloon (11) mounted at the end of a catheter (15). The balloon (11) and catheter (15) are passed through a blood vessel (12) until the balloon (15) reaches the desired location of the occlusion; a suspension of solid filler particles (27) in a carrier liquid is then pumped through the catheter tube (15) and inflates the blloon (11) until it blocks off the blood vessel. The carrier liquid is forced out through the porous walls of the balloon, leaving a compacted mass of filler particles which will not allow the balloon to shrink. Ridges (20) on the end of the catheter tube (15) engage mating grooves (21) in the neck portion (14) of the balloon structure during insertion and filling of the balloon; the size, shape, and number of these ridges and grooves can be selected to provide a desired force required to detach the catheter tube from the balloon.