Radiographic Apparatus Dynamic Gain Adjustment
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Solution Overview
Problem
Conventional radiographic apparatus exposes subjects to higher doses of radiation in tomography mode and spot radiography, leading to increased noise and reduced contrast in images due to fixed analog gain and radiation settings.
Innovation Solution
The apparatus includes a radiation source, a radiation source controlling device, a radiation detecting device, a moving device, an image generation device, and a superimposing device, with adjustable amplification factors and radiation output for tomography and spot radiography modes, allowing higher amplification in tomography mode and reduced radiation intensity to minimize exposure and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high analog gain is used to amplify the electric signal for obtaining a radioscopic image with low radiation dose, then the radiation dose to the subject is reduced, but the noise component is also amplified resulting in granular false images and reduced contrast
Solution Approach 1:
The patent applies dynamics by making the analog gain adjustable based on imaging mode. In tomography mode, a high analog gain is used to amplify weak signals from low-dose radiation, while in spot radiography mode, a low analog gain is used to prevent noise amplification. This dynamic adjustment resolves the contradiction between reducing radiation dose and maintaining image quality.
Solution Approach 2:
The patent changes the parameter of analog gain according to the imaging mode. By setting different gain values (high for tomography, low for spot radiography), the system optimizes the balance between radiation dose reduction and image quality preservation for each specific imaging scenario.
2Adaptability or versatility
If multiple fluoroscopic images are taken in spot radiography mode to perform tomography, then a tomographic image can be obtained, but the subject is exposed to higher total radiation dose (74 times the exposure)
Solution Approach 1:
The system dynamically switches between spot radiography mode and tomography mode, with each mode optimized for its specific purpose. The analog gain and radiation output are dynamically adjusted based on the selected mode, allowing the system to provide both imaging types while minimizing overall radiation exposure through appropriate parameter selection in each mode.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables higher contrast tomographic images with reduced noise by adjusting amplification factors and radiation intensity, minimizing exposure and ensuring clear images without false noise components, while maintaining image quality for diagnosis.
Implementation Method 1
a radiation conversion device for converting radiation entering the radiation detecting device into an electric signal
Implementation Method 2
an amplifying device for amplifying the electric signal by a given amplification factor
Data Source
AI summary
One object of this invention is to provide radiography apparatus with suppressed exposure to a subject in tomography mode. An FPD provided in X-ray apparatus according to this invention converts X-rays into electric signals, and thereafter amplifies the signals to output them to an image generation section. According to this invention, an amplification factor is higher in a tomography mode than in a spot radiography mode. A tomographic image is obtained through superimposing two or more fluoroscopic image. In comparison of the fluoroscopic images, they differ from one another in appearance of the false image. Accordingly, superimposing the images may achieve cancel of the false images. In this way, the tomographic image finally obtained has no false image.