Abstract
PURPOSE: To characterize the changes in brain water diffusion caused by reversible posterior leukoencephalopathy syndrome (RPLS). MATERIALS AND METHODS: Twelve patients with the clinical features and conventional magnetic resonance (MR) imaging findings of RPLS underwent diffusion-tensor echo-planar MR imaging. The isotropic diffusion coefficient (D̄) and diffusion anisotropy (Aσ) were measured in posterior regions of diffusion abnormality and in anterior areas of normal-appearing brain. RESULTS: Across all 12 subjects, the mean D̄ of (1.09 ± 0.13 [SD]) × 10-3 mm2/sec in affected posterior regions was 26% greater than its value of (0.87 ± 0.07) × 10-3 mm2/sec in normal-appearing anterior regions. The mean Aσ of 0.15 ± 0.03 in posterior regions was 35% less than its value of 0.23 ± 0.02 in anterior regions (t11 = 9.58; P < .001). There was a significant inverse correlation between D̄ and Aσ in posterior regions (r = -0.67; P < .018) but not in anterior regions (r = -0.12; P = .719). A follow-up study performed in one patient after resolution of symptoms documented reversal of elevated isotropic diffusion and at least partial recovery of anisotropy loss. CONCLUSION: The increased magnitude of brain water diffusion characteristic of RPLS is accompanied by reduced Aσ. The magnitudes of these two effects are correlated and may be reversible. These observations support the proposal that vasogenic edema due to cerebrovascular autoregulatory dysfunction is the underlying pathophysiologic mechanism in uncomplicated RPLS.
Original language | English |
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Pages (from-to) | 756-765 |
Number of pages | 10 |
Journal | Radiology |
Volume | 219 |
Issue number | 3 |
DOIs | |
State | Published - Jun 2001 |
Keywords
- Anisotropy
- Brain, MR, 10.121413, 10.121416, 10.12144
- Brain, diffusion, 10.12144, 10.92
- Brain, diseases, 10.872
- Brain, gray matter, 10.92
- Brain, white matter, 10.92
- Diffusion tensor
- Magnetic resonance (MR), diffusion study, 10.12144, 10.92
- Magnetic resonance (MR), rapid imaging, 10.121413