牛骨皮质的超短 TE MR 成像：水分损失对 T1 和 T2*弛豫时间的影响。
Ultrashort TE MR imaging of bovine cortical bone: the effect of water loss on the T1 and T2* relaxation times.
机构信息
Department of Radiology, University of California, San Diego, California 92103-8226, USA.
出版信息
Magn Reson Med. 2011 Aug;66(2):476-82. doi: 10.1002/mrm.22859. Epub 2011 Feb 28.
The effects of water loss on the T1 and T2* of bovine cortical bone were investigated using ultrashort echo time sequences with signals excited either by a short hard pulse or by two longer half pulses. Nine bovine femur samples were prepared and sequentially air- and oven-dried. On average 3.42% of bone by weight was lost after air-drying for 3 days, with another 5.98% of bone weight loss after oven-drying at 100°C for 24 h. T1 and T2* were measured after every 1% decrease in weight, with 9-10% bone weight loss at the termination of the drying process. After both forms of drying, the overall T1 decreased 33% from 153±18 ms to 102±17 ms when measured using the hard pulse and from 186±25 ms to 122±23 ms when using the half pulses. T2* decreased by 45-50% from 368±29 μs to 201±19 μs using the hard pulse and from 379±35 μs to 191±17 μs using the half pulses. A steady decrease of 26-31% was observed in both T1 and T2* with the first 3-4% bone water loss after air-drying. Oven-drying at 100°C for 24 h resulted on an additional 4% T1 reduction but 25% T2* reduction.
采用超短回波时间序列，使用短硬脉冲或两个较长的半脉冲激发信号，研究了牛皮质骨的 T1 和 T2随水分损失的变化。制备了 9 个牛股骨样本，依次进行空气干燥和烘箱干燥。空气干燥 3 天后，平均有 3.42%的骨重量损失，100°C 烘箱干燥 24 h 后，再有 5.98%的骨重量损失。在每次重量损失 1%后测量 T1 和 T2，在干燥过程结束时达到 9-10%的骨重量损失。两种干燥方式后，使用硬脉冲测量时，整体 T1 从 153±18 ms 降低到 102±17 ms，降低了 33%；使用半脉冲时，从 186±25 ms 降低到 122±23 ms，降低了 33%。使用硬脉冲时，T2从 368±29 μs 降低到 201±19 μs，降低了 45-50%；使用半脉冲时，从 379±35 μs 降低到 191±17 μs，降低了 45-50%。空气干燥后，在前 3-4%的骨水损失中，T1 和 T2观察到稳定的 26-31%下降。100°C 烘箱干燥 24 h 后，T1 进一步降低了 4%，但 T2*降低了 25%。
Zotero 插件