Fig 1.
Description of contrast-to-noise ratio (CNR) measurement for deep medullary veins (DMV) in a combined multi-echo susceptibility weighted image.
A, Each red region of interest (ROI) for periventricular DMV was drawn with one pixel width along the center of vein. Each blue ROI for neighboring white matter tissues was drawn surrounding the vein by the same pixel size of red ROI. Three different regions of DMV and adjacent white matter tissues (yellow rectangle in A) were shown (B to D, magnification of the three regions in A). CNR was calculated based on values obtained from the two ROIs.
Table 1.
The clinical characteristics of stroke patients.
Fig 2.
Comparisons of peak signal-to-noise ratio (PSNR), mean opinion score (MOS), contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) between three different echoes of single-echo susceptibility weighted imaging (SWIs) images (blue histogram, SWIs1 represented TE = 23.144 ms, SWIs2 represented TE = 29.192 ms, SWIs3 represented TE = 35.240 ms) and combined multi-echo SWI images (red histogram, SWIc represented combined multi-echo SWI).
Note. *** indicated P < 0.001; ** indicated P < 0.01; * indicated P < 0.05. Horizontal line represented the two groups had the same value when rounding to one decimal.
Fig 3.
Evaluation of asymmetric medullary veins (AMV) in single-echo and combined multi-echo susceptibility weighted imaging (SWI) images.
Contrast between veins and adjacent white matter tissues was better visible in the combined multi-echo SWI (SWIc) image than different echoes of single-echo SWI (SWIs) images. Detection of AMV in SWIs2 (TE = 29.192 ms) and SWIs3 (TE = 35.240 ms) was the same as that in SWIc. However, AMV was ambiguous in SWIs1 (TE = 23.144 ms).