Citation, DOI & article data
For the phenomenon to occur a particular combination of ADC and T2 signal intensity is required:
increased T2 signal
facilitated diffusion (high ADC values)
Remembering that the signal of diffusion weighted images is the result of both diffusion and T2 signal, it becomes apparent that if the amount of expected T2 shine through from the increased T2 signal is balanced by elevated ADC values (which would result in lower DWI signal intensity), then DWI signal may appear normal 1-3.
T2 washout should not be confused with related phenomena in ischemic stroke; early DWI reversal, seen acutely (typically 3-6 hours) and ADC pseudonormalization seen somewhat later (around 1 week post stroke) but before T2 washout, which occurs between 10-15 days typically.
- 1. Casey S. "T2 washout": an explanation for normal diffusion-weighted images despite abnormal apparent diffusion coefficient maps. AJNR Am J Neuroradiol. 2001;22 (8): 1450-1. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 2. . Diffusion-Weighted MR Imaging of the Brain. Springer. (2009) ISBN:3540787852. Read it at Google Books - Find it at Amazon
- 3. Hiwatashi A, Kinoshita T, Moritani T et-al. Hypointensity on diffusion-weighted MRI of the brain related to T2 shortening and susceptibility effects. AJR Am J Roentgenol. 2003;181 (6): 1705-9. doi:10.2214/ajr.181.6.1811705 - Pubmed citation