- 期刊
3T磁振造影使用不同b值於腦梗塞擴散加權影像上的分析
Compare the Application of Two Different b-value in Diffusion Weighted Imaged to Diagnosis Brain Infarction on 3T MRI
摘要
磁振造影(Magnetic Resonance Imaging, MRI)之磁振擴散加權影像，常使用於腦梗塞的診斷。本文探討3T MR使用二種b值，分析判斷急性和亞急性腦梗塞影像的優劣。在40位急性和亞急性腦梗塞的病患中，我們採用了b值為1000 s/平方公厘和1500 /平方公厘進行DWI的檢查，將影像傳送到影像工作站處理，將腦梗塞區和對側正常區，圈選ROI以進行影像信號強度(Signal Intensity, SI)與擴散係數(Apparent Diffusion Coefficient, ADC)量測。我們發現使用大的b值1500/平方公厘與較小b值1000/平方公厘，其腦部正常組織和腦梗塞區的信號強度和ADC值均下降，而訊雜比(Signal to Noise Ratio, SNR)和CNR(Contrast to Noise Ratio)也因b值的增加而下降。3T MR儀器使用DWI診斷腦梗塞，b值1500/平方公厘與1000/平方公厘對腦梗塞影像上的分析，此結果上b值使用1000較1500好，比對CNR和SNR上在統計學上有顯著意義。
並列摘要
Diffusion-weighted imaging is a specific MRI modality which is important for diagnosing brain infarction clinically. In this study, we tried to find out that by using different b values in DWI on 3T MRI for better diagnosis of acute or subacute brain infarction. In 40 Patients with acute or subacute brain infarction, we used the b-value 1000s/mm^2 and 1500s/ mm^2 to proceed diffusion weighted images, and then these images were transferred to the imaging workstation for processing. We analyzed the signal intensity (SI and apparent diffusion coefficient (ADC) in the 1) infracted brain, 2) contralateral normal brain, 3) background area of the infracted brain by circling the region of interest (ROI). We discovered that the higher b-value (1500s/ mm^2 compared to 1000s/ mm^2) yield lower signal intensity and ADC value in both the normal brain tissue and the infracted area; The SNR (signal to noise ratio) and CNR (contrast to noise ratio) also decreased as the b-value increased, Applying diffusion weighted imaging generated by the 3T MRI machine different b-values (1000s/ mm^2 and 1500s/ mm^2) to diagnose the brain infraction, we will obtain better CNR and SNR by applying b-values 1000s/ mm^2 with statistically significant differences.