In the hospital, X-ray, B-ultrasound, etc. It's all medical imaging technology, so how much do you know about medical imaging? Here, I would like to share my graduation thesis on medical imaging with you. Let's study together!
This paper introduces the development of medical imaging, the advantages of CT imaging technology and the development of imaging technology in digitalization, and expounds the basic principle and structure of PACS system and the significance of adopting this architecture. It is pointed out that the development of imaging is of great significance to the medical diagnosis process.
Keywords: developing digital imaging technology
General situation and characteristics of image development
Imaging diagnosis is one of the most important and fastest developing fields in medical diagnosis in this century. The development of CT began in the 1960s. From 65438 to 0967, the British engineer Hansfield began the research work of pattern recognition. X-ray fluoroscopy and X-ray radiography were the most commonly used methods in clinical diagnosis in 1950s, but today, due to the appearance and application of X-ray CT technology, the level of image diagnosis has made a leap, thus greatly improving the level of clinical diagnosis. Computed tomography (CT) is the use of computer technology to process the tomographic images of human tissues and organs. X-ray CT films provide doctors with much more information than ordinary X-ray films.
Advantages of CT imaging technology: Compared with conventional imaging methods, CT has the following four advantages.
Real cross-sectional image: CT can obtain cross-sectional images without interference from off-plane tissue structure through the collimation of X-ray collimation system. Compared with conventional X-ray tomography, the tomographic images obtained by CT have accurate thickness, clear density and high resolution, and are not interfered by out-of-plane structures.
High density resolution: CT has the highest density resolution compared with conventional image examination. The reasons are as follows: (1) The X-ray beam of the first CT passes through the object and reaches the detector through the scattered line which is not strictly collimated; The second CT machine adopts a highly sensitive and efficient receiver; Thirdly, CT can control the gray level through computer software and adjust the observation range suitable for human vision according to the needs of diagnosis. The density resolution of ordinary CT is about 1 times higher than that of conventional X-ray examination.
Can be used for quantitative analysis: CT can accurately measure the X-ray absorption attenuation value of each tissue, and can be used for quantitative analysis through various calculations.
The computer can carry out various image processing: with the help of the computer and some image processing software, the shape and structure of the lesion can be analyzed. Spiral scanning can obtain high-quality three-dimensional images and multi-plane cross-sectional images.
Main image new technology
Digital imaging technology: With the advent of the information age, digital, standardized and networked operations have entered the field of medical imaging, and they have developed rapidly, and some brand-new digital imaging technologies have been applied to clinic one after another. The emergence and rapid development of medical image archiving and communication system (PACS) and medical image diagnosis report system have greatly changed the whole radiology department and improved the position and role of imaging in clinical medicine.
Basic principle and structure of PACS: PACS is composed of computer-centered image information collection, transmission, archiving and processing.
Acquisition of image information: Digital image information such as CT, MRI, DSA, CR, ECT can be directly input into PACS, and many X-ray images need to be converted into digital image information by signal converter.
Transmission of image information: The transmission system plays a bridge role in the input, retrieval and processing of digital image information in PACS.
Storage and compression of image information: image information can be stored by magnetic tape, magnetic disk, optical disk and various memory cards. It is very necessary to compress and store image information. Because an X-ray photo contains a lot of information, which is equivalent to 15 pages of manuscript paper filled with Chinese characters, and a.8 cm CD can only store the information of one X-ray photo. Multipurpose compression methods: median and Huffman symbol compression. Image information compression1/5 ~11can still maintain the original image quality.
Processing of image information: The processing of image information is completed by the computer center. Computer capacity, processing speed and the number of connectable terminals determine the scale and overall function of PACS. The software involves retrieval ability, editing and image reprocessing functions. The computer system of CT belongs to the general small computer. In order to meet the working requirements of CT machine, the computer system of CT generally has two characteristics: fast operation speed and large storage capacity.
conclusion
Medical imaging has great development potential. If each imaging mode can successfully seize the opportunities and challenges in technological development, this potential can be realized, which requires the joint efforts of physicists, engineers, mathematicians, information scientists and doctors.
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