双源CT降低时间分辨率对脑缺血疾病灌注图像的影响

发布时间：2018-02-05 22:29

本文关键词： 时间分辨率灌注成像辐射剂量体层摄影术 X线计算机　出处：《滨州医学院》2013年硕士论文　论文类型：学位论文

【摘要】：目的探讨基于最大斜率法(maximal slope, MS)数学模型,利用不同方法降低时间分辨率,评价其对脑缺血疾病CT灌注(CT perfusion imaging, CTPI)图像质量及灌注参数的影响,寻求在保证诊疗要求的前提下降低CT灌注辐射剂量的新思路。方法回顾性分析我院经临床及影像学资料确诊的29例脑缺血患者CT灌注图像资料。对时间-密度曲线(Time-density curve, T-DC)分别利用全部图像数据(原始组)、每两层选取一层间隔处理图像数据(实验组1)及在保证关键图像数据选取的前提下间隔选取图像数据(实验组2)三种方法进行处理,然后对灌注伪彩图像进行主观视觉评价,并在不同组别图像中选取相同感兴趣区对脑血流量、脑血容量、平均通过时间等参数进行测量,对所得灌注参数值进行统计学分析。结果 1、时间分辨率的改变对灌注伪彩图像主观视觉评分有一定影响,主观评分较原始组均有所下降,实验组1较实验组2下降更为明显,其中对MTT、CBF图像主观评分影响较为明显,但不影响病灶检出。 2、(1)实验组1与原始组比较,CBF、CBV变化具有统计学意义(P0.05),而MTT变化则无统计学意义(P0.05)。(2)实验组2与原始组比较,CBF变化具有统计学意义(P0.05),而CBV、MTT变化则无统计学意义(P0.05)。(3)将缺血侧/健侧灌注参数的比值作为研究对象,实验组1与原始组、实验组2与原始组分别进行比较,各相对参数值变化均无统计学意义(P0.05)。结论在一定范围内降低时间分辨率,灌注伪彩图像质量下降,但不影响病灶的检出；但若对灌注参数值进行研究,建议使用较高时间分辨率对灌注图像进行采集；时间分辨率的降低对灌注参数相对值的影响比对灌注参数绝对值的影响要小；在保证关键图像数据前提下改变时间分辨率较机械间隔选取图像数据更能保证灌注参数的准确性。
[Abstract]:Purpose Based on the maximum slope method and maximum slope (MS) mathematical model, different methods are used to reduce the temporal resolution. Objective: to evaluate the effect of CT perfusion CT perfusion imaging (CTPI) on the quality and perfusion parameters of cerebral ischemia. To find a new way to reduce the dose of CT perfusion radiation on the premise of ensuring diagnosis and treatment. Method Ct perfusion imaging data of 29 patients with cerebral ischemia confirmed by clinical and imaging data in our hospital were retrospectively analyzed. Time-density curve of time-density curve were analyzed. T-DC) uses all the image data (original group) respectively. There are three methods for processing image data (experimental group 1) and for processing image data (experiment group 2) at interval under the premise of ensuring the selection of key image data. Then the perfusion pseudochromatic images were evaluated by subjective vision, and the same regions of interest were selected from different groups of images to measure the parameters of cerebral blood flow, cerebral blood volume, mean transit time and so on. The perfusion parameters were statistically analyzed. Results 1. The change of time resolution had a certain effect on the subjective visual score of perfusion pseudochromogram, the subjective score was lower than that of the original group, and the decrease of experimental group 1 was more obvious than that of experimental group 2, in which MTT was more obvious. The subjective score of CBF images was more significant, but it did not affect the detection of lesions. (2) compared with the original group, the change of CBV in experimental group 1 was statistically significant (P 0.05). But the change of MTT was not statistically significant (P 0.05) the change of MTT in experimental group 2 was statistically significant compared with the original group (P 0.05), but CBV. The ratio of perfusion parameters of ischemic side to normal side was taken as the research object. The experimental group 1 was compared with the original group, and the experimental group 2 was compared with the original group. No statistical significance was found in the changes of relative parameters (P 0.05). Conclusion In a certain range, the time resolution was reduced, the quality of perfusion pseudochromogram was decreased, but the detection of lesions was not affected. However, if the perfusion parameters are studied, it is suggested to use higher temporal resolution to collect the perfusion image. The decrease of time resolution has less effect on the relative value of perfusion parameters than on the absolute values of perfusion parameters. The accuracy of perfusion parameters can be ensured by changing the time resolution than selecting the image data at mechanical intervals under the premise of ensuring the key image data.
【学位授予单位】：滨州医学院
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R743;R816.2

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