Back to results
US 7,582,860 B2Granted
Method of measuring amount of missed tissue at chest wall side and phantom
AssigneeFUJIFILM Corporation
InventorTetsurou Kusunoki
Life of this patent
Estimating the term…
Abstract
A phantom is provided with: a reference marker at a predetermined position thereof; a positioning reference surface, to be placed into contact with a chest wall abutting surface of a support table of a mammography apparatus; and a pattern region for measuring distances from the reference surface, perpendicular to the reference surface. The amount of transmitted radiation changes within the pattern region in a direction perpendicular to the reference surface according to a predetermined rule. The phantom is placed on the support table to measure the amount of chest wall loss.
Claims9
A method for measuring an amount of missed tissue at chest wall side, the method comprising the steps of:
- placing a phantom used for measurement of the amount of missed tissue at chest wall side on a support table for breast radiography, the phantom comprising a reference marker located at a predetermined position in the phantom, a reference surface for positioning, to be placed in contact with a chest wall side of the support table, and a pattern region formed by a region wherein the amount of transmitted radiation used for measurement of a distance from the reference surface shows periodic changes, monotonic decrease or increase, or stepwise changes in a direction perpendicular to the reference surface according to a predetermined rule;
- recording a radiation image of the phantom in a radiation image conversion panel placed in the support table while radiographing the phantom;
- obtaining base image data representing a base radiation image of the phantom including the reference marker by performing readout of the radiation image conversion panel;
- finding a magnification ratio and a position of the phantom from a test radiation image obtained by further radiography of the phantom and from a position of the reference marker recorded in the test radiation image;
- determining a calculation region corresponding to the pattern region in the test radiation image, based on the position of the phantom and the base image data;
- finding the number of repetitions and/or the amount of change in the amount of transmitted radiation in the calculation region according to the predetermined rule;
- and
- finding the amount of missed tissue at chest wall side from the number of repetitions and/or the amount of the change.
5 more elements
A method for measuring an amount of missed tissue at chest wall side, the method comprising the steps of:
- correctly placing a phantom used for measurement of the amount of missed tissue at chest wall side on a support table for breast radiography, the phantom comprising a reference marker located at a predetermined position in the phantom, a reference surface for positioning, to be placed in contact with a chest wall side of the support table, and a pattern region formed by a region wherein the amount of transmitted radiation used for measurement of a distance from the reference surface shows periodic changes, monotonic decrease or increase, or stepwise changes in a direction perpendicular to the reference surface according to a predetermined rule;
- recording a radiation image of the phantom, which has been correctly placed on the support table, in a radiation image conversion panel placed in the support table by performing radiography;
- obtaining a base radiation image that represents the positional relationship between the reference marker and the radiation image conversion panel when the phantom is correctly placed on the support table, by performing readout of the radiation image conversion panel;
- placing the phantom on the support table;
- recording a radiation image of the phantom in the radiation image conversion panel, which is correctly placed in the support table, by performing radiography;
- obtaining an examination radiation image that represents the positional relationship between the reference marker and the radiation image conversion panel when the radiation image conversion panel is correctly placed in the support table, by performing readout of the radiation image conversion panel;
- comparing the base radiation image and the examination radiation image, to obtain the difference in the positional relationships between the reference marker and the radiation image conversion panel when the phantom is correctly placed on the support table and when the radiation image conversion panel is correctly placed in the support table;
- and
- correcting the position of a lost region within the distance measuring pattern region, which is not recorded within the examination radiation image, an amount corresponding to the difference in the positional relationships, to obtain the amount of missed tissue at chest wall side.
6 more elements
A phantom placed on a support table for breast radiography and used for measurement of an amount of missed tissue at chest wall side, the phantom comprising:
- a reference marker located at a predetermined position in the phantom;
- a reference surface for positioning, the surface in contact with a chest wall side of the support table;
- and
- a pattern region used for measurement of a distance from the reference surface and formed by a region wherein the amount of transmitted radiation changes in a direction perpendicular to the reference surface according to a predetermined rule,
- wherein the pattern region is an alternating geometric structure for forming a predetermined radiation image from a boundary of the missed tissue of the chest wall side to the reference marker disposed opposite to the chest wall side.
2 more elements
Dependencies are inferred from the claim text.