Accurate measurement of brain changes in longitudinal MRI scans using tensor-based morphometry

作者：Hua Xue; Gutman Boris; Boyle Christina P; Rajagopalan Priya; Leow Alex D; Yanovsky Igor; Kumar Anand R; Toga Arthur W; Jack Clifford R Jr; Schuff Norbert; Alexander Gene E; Chen Kewei; Reiman Eric M; Weiner Michael W; Thompson Paul M^*

来源：NeuroImage, 2011, 57(1): 5-14.

DOI：10.1016/j.neuroimage.2011.01.079

This paper responds to Thompson and Holland (2011), who challenged our tensor-based morphometry (TBM) method for estimating rates of brain changes in serial MRI from 431 subjects scanned every 6 months, for 2 years. Thompson and Holland noted an unexplained jump in our atrophy rate estimates: an offset between 0 and 6 months that may bias clinical trial power calculations. We identified why this jump occurs and propose a solution. By enforcing inverse-consistency in our TBM method, the offset dropped from 1.4% to 0.28%, giving plausible anatomical trajectories. Transitivity error accounted for the minimal remaining offset. Drug trial sample size estimates with the revised TBM-derived metrics are highly competitive with other methods, though higher than previously reported sample size estimates by a factor of 1.6 to 2.4. Importantly, estimates are far below those given in the critique. To demonstrate a 25% slowing of atrophic rates with 80% power, 62 AD and 129 MCI subjects would be required for a 2-year trial, and 91 AD and 192 MCI subjects for a 1-year trial.

• 出版日期2011-7-1