Article Figures & Data
Figures
- Fig 1.
MR images from a 76-year-old woman with a right corona radiata infarction. Images (T2WI, DWI, ADC, Krad, Kax) were acquired on days 2, 10, 16, and 30 after onset of infarction. On T2WI, the lesion showed uniform high signal intensity. DWI demonstrated a prominent high-signal-intensity area, particularly on the image from day 2. The signal retained its high intensity even on the image from day 30. ADC was low immediately after infarction, and this became less obvious on the images from days 16 and 30. The white matter exhibited high Krad; in this case, the infarction showed higher values compared with the contralateral normal region. This elevation in Krad decreased soon after the infarction, and on the image from day 16, Krad was lower than that in the normal region. Kax values were similar in both white and gray matter, and Kax images appeared homogeneous. The infarction lesion showed a very high Kax value compared with the normal region immediately after the onset of infarction, but this soon diminished to the negative value shown in the later images.
- Fig 2.
Plot of ratios (lesion versus normal tissue) of each variable and duration after onset of infarction. Linear regression lines are provided with their coefficient of determination (R2). Because a logarithmic scale was used for the time axis, the first-order linear regression lines are drawn as exponential curves. A, Perforator infarction group. B, White matter territorial infarction group. C, Cortical infarction group. D, Watershed infarction group. For each variable (T2WI signal, DWI signal, ADC, FA, Drad, Dax, Krad, and Kax), the ratio of the value in the lesion compared with that in the contralateral normal tissue was plotted against time after infarction (days). The times at which pseudonormalization occurred are indicated by arrows. In general, T2WI showed increased signal intensity with time after infarction onset. DWI signal tended to be higher immediately after onset and decreased with time after infarction onset. ADC was lowest soon after onset and increased with time. Fractional anisotropy diminished throughout the observation period. Drad and Dax were lowest immediately after onset and increased with time; this increase was faster in Drad. Krad and Kax were highest immediately after onset and decreased with time.
- Fig 3.
The absolute values of Krad and Kax (a logarithmic scale was used for the time axis). As was the case for the ratios, absolute values of these diffusion kurtosis variables were highest in the acute-to-subacute period and decreased until pseudonormalization, after which they fell further in the chronic period.
- Fig 4.
Pseudonormalization periods and their statistically significant differences between variables. Pseudonormalization periods of the 4 groups are shown with their SDs. A linear scale is used for the time axis. Statistical differences (P < .01) between the variables are shown.
