FIG 6. Images in a 74-year-old man with an onset of left-sided weakness 90 days before imaging.

A, Ratio DW image was computed as the 1000 times the ratio of the image with b = 1000 s/mm² image divided by the image with b = 0 s/mm². Image shows that the infarct has a signal intensity 56% less than that of the control tissue.

B, Fluid-suppressed image (b = 0 s/mm², TE_eff = 101 milliseconds, TI = 2200 milliseconds) shows infarct signal intensity 37% greater than that of the control tissue.

C, Standard DW image (b = 1000 s/mm², TE_eff = 101 milliseconds, TI = 2200 ms) with both ADC and T2 effects shows infarct signal intensity 39% less than that of the control tissue. This is an example of a patient in period 4 (later than 57 days). For patients imaged during this time period, the large negative effect of ADC on infarct signal intensity on DW images is greater than the smaller positive contribution of T2 effect.

D, ADC map shows that infarct ADC value is increased 119% compared with that of the contralateral tissue.