Effects Of Reducing Temporal Resolution Of Dual Source CT On Image Of Perfusion In Stroke Patients

ObjectiveBased on the maximum slope method (maximal slope, MS) mathematical model, we explored the evaluation of cerebral ischemic disease Perfusion CT (CT perfusion imaging, CTPI) image quality and the impact of the perfusion parameters to investigate that clinics requirements under the premise the lower CT perfusion radiation dose of new ideas using different methods to reduce the time resolution.Method29patients datas of our hospital diagnosed by clinical and imaging data with cerebral ischemia CT perfusion images were analyzed by a retrospective analysis. Time-density curve (T-DC) were used on the time-the use of all the image data (the original group), every two selected layer interval select the image data (the experimental group1) and in the guarantee of key image data, select the interval selected under the premise of image data (experimental group2) three methods were used. We evaluated the perfusion pseudo-color image in different experiments set of images, and the same region of interest on the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and other parameters were measured, and the resulting perfusion parameters were statistically analyzed.Result1、the time resolution changes had some impact on the perfusion of subjective visual rating of the pseudo-color image, and subjective ratings all declined than the original group. Compared to group2, group1decreased more obvious, including subjective ratings of MTT, CBF images obviously, but did not affect lesion detection.2、(1) The CBV, CBF in group1, and the original group were significantly difference (P <0.05), while the MTT changes had no significantly difference (P>0.05).(2)The CBF in group2and the original group were significantly difference (P<0.05), while the CBV, MTT changes had no significantly difference (P>0.05).(3) Making the contralateral cerebral hemisphere as a reference, the ratio of the ischemic side/contralateral perfusion parameters as research subjects in group1with the original group, the group2with the original group were compared, the relative changes in parameter values had no significantly difference (P>0.05)/.ConclusionWithin a certain range, we reduced the time resolution, perfusion pseudo color image quality was decreased, but it did not affect the detection of the lesion which could meet clinical needs; However, if we studied the perfusion parameters vaules, it was recommended to use a higher time resolution of the perfusion image acquisition; the relative value of the impact of the reduction of the time resolution of the perfusion parameters was smaller than the absolute value of perfusion parameters; under the premise of guaranteeing the main image datas, we changed the temporal resolution ensuring the accuracy of the perfusion parameters more than mechanical interval.