Medical DR equipment is currently the mainstream method for X-ray examinations. It offers numerous advantages, such as fast imaging, convenient storage, and ease of image post-processing, gradually replacing traditional X-ray machines. However, in practical applications, the image quality of DR equipment still presents some issues, such as low contrast, unclear images, excessive noise, and asymmetrical brightness. Poor image quality from DR equipment can lead to missed diagnoses, misdiagnoses, or even cause harm to patients due to inappropriate dosage. Therefore, ensuring the image quality of medical DR equipment is of utmost importance.
What Factors Affect the Image Quality of Medical DR Equipment?
Perlove Medical has summarized the following key factors:
- DQE (Detective Quantum Efficiency) The image quality of various detectors in medical DR equipment is measured by resolution and DQE. DQE is a primary metric representing the dose efficiency of the imaging system. It incorporates factors like system contrast, image resolution, and noise, and measures the conversion performance of input X-ray noise/signal to the image.DQE indicates the ratio of the signal-to-noise retained when converting X-ray images to digital images. In X-ray imaging, the noise of the radiation image is closely related to the exposure dose. Therefore, DQE also reflects the utilization efficiency of the incident dose by digital imaging equipment. Exposure dose is linked to the health of the personnel involved, making DQE a crucial technical indicator for digital medical X-ray diagnostic equipment. Selecting the appropriate DQE indicator ensures desired image quality and optimizes the advantages of DR technology.
- Pixel Size Digital images consist of pixels arranged in rows or columns in a matrix. Each pixel has its grayscale, forming distinguishable shadows in the image. The size of each pixel determines the spatial resolution of the image, indicating the smallest object that can be detected in the image.Generally, more pixels result in better image resolution, but this does not necessarily equate to better image quality. Beyond a certain point, increasing pixels can decrease image quality due to the smaller size of the photosensitive elements in the same-sized flat panel, resulting in less photoelectron information per element. Additionally, more photosensitive elements increase costs. Hardware and exposure conditions also affect the image, so it is important not to pursue extremely high pixel counts blindly.
- Signal-to-Noise Ratio (SNR) SNR is the ratio of image signal to noise. Higher SNR results in smaller image noise and better, clearer image quality; lower SNR results in larger image noise and rougher image appearance. SNR can be adjusted by changing exposure conditions (increasing kilovoltage or milliampere-seconds). However, smaller exposure conditions reduce SNR, increasing image noise and making the image grainier and rougher.
- Image Post-Processing Medical DR equipment offers robust image post-processing capabilities. Diagnostic doctors can adjust image contrast and other parameters based on the patient’s condition. Through a series of image post-processing techniques (such as automatic image processing, edge enhancement, zooming, window level and width adjustment, and measurement of distance, area, and density), rich and reliable clinical diagnostic information can be extracted, providing reliable diagnostic bases for diseases, especially early lesions.
DR Image Quality Comparison
Current domestic DR equipment places significant emphasis on upgrading image post-processing systems. For example, Perlove Medical’s dynamic DR (model: PLX8600) features the company’s proprietary tissue equalization technology, based on a multi-layer hierarchical detail equalization algorithm extending low grayscale areas to high grayscale intervals. This technology highlights image details, making small blood vessels at the ends of lung textures and the textures of bones and muscle layers clearly visible.
Other Factors Affecting DR Image Quality
In addition to the aforementioned factors, image quality can also be affected by human operation, the environment of the X-ray room, and issues with the DR equipment itself.
