Visualization And Quantitative Analysis Based On MRI Image Of Lumbar Disc

Lumbar disc herniation (LDH) is a common disorder of clinical orthopaedics and it is the major cause of low back pain or leg pain. Low back pain or leg pain are the main reasons why people with LDH seek for medical treatment. Many researches have been done since 1934. The high repetitive treatment rate is a serious problem faced by doctors as well as patients. Scientific classification and correct therapies can lower the recurrence rate and manifestly reduce the incidence of LDH. Due to the lack of qualitative or quantitative standards there are different opinions about the classification of LDH. Finding a new system of quantitative diagnoses and assessment to the LDH therapy is the problem to be solved urgently.Three-dimensional model, instead of two-dimensional image, has been used as an alternative technique to accurately classify and treat LDH. It can completely describe and show direct view of the anatomical information about lumbar disc. In particular, MRI has relatively high soft tissue resolution, which helps to characterizes the structural change better. Consequently, MRI shows better prospect than CT in quantitative assessment of lumbar disc.The objective of the research:In order to describe the relationship between the indexes and the grading of LDH and to evaluate their potential for lumbar disc herniation classification, this study designs and purposes series 2D and 3D indexes based on MRI image.The major content of this research:1) A visualization and quantitative analysis framework for the evaluation of lumbar disc herniation were developed with the VTK technology. In this framework the technology of image visualization, segmentation, three dimensional reconstruction and three dimensional quantitative measurement were involved. It provides methods for the quantitative measurement of these indexes related to the severity of LDH2) .Based on indexes and criteria that are used in clinics or have been reported useful for disc herniation, some 2D and 3D indexes were proposed, such as index of disc herniation (IDH), nucleus protrusion rate (NPR), kyphotic angle of the herniated disc (KA), the distribution of the protruded disc (DPD), the ratio between the protruded part and the dural sac (RPPDS) and relative signal intensity (RSI). These indexes were used to describe the changes of image and special structure caused by LDH.3) The feasibility of LDH quantitative classification was explored based on the statistical analysis of the measurement results. The validity of the system was verified by the comparison between the results of this research and the results reported by pertinent literature.4) Based on the data collected from 20 patients, Fisher discriminatory analysis has been done. Preliminary criterion function was obtained which provided initial basis for the classification of large sample experiments.The analysis results of 20 lumbar disc herniation patients based on MRI image indicate that 8 out of 9 indexes have statistical significance and have high correlativity with the severity of LDH. Fisher discriminatory analysis was obtained and 89.5% of cross-validated grouped cases were correctly classified.