Department of Radiology, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, United States; Department of Radiology, University of California, 200 West Arbor St., San Diego, CA 92103, United States.
Department of Radiology, University of California, 200 West Arbor St., San Diego, CA 92103, United States.
Eur J Radiol. 2014 Feb;83(2):349-53. doi: 10.1016/j.ejrad.2013.10.014. Epub 2013 Oct 27.
In this study we sought to evaluate the effects of multiple freezing and thawing cycles on two MR parameters to study Achilles tendon, T2 and T2.
Four fresh Achilles tendons were imaged on a 3T clinical scanner and again after 1, 2, 4, and 5 freeze-thaw cycles with spin-echo (SE) and ultrashort echo time (UTE) sequences. Regions of interest were manually drawn over the entire Achilles tendon and mono-exponential curves were used to determine T2 and T2 relaxation times.
There was no statistically significant difference in mean T2 or T2 values between the fresh specimens and after subsequent cycles of freeze-thaw treatment (p>0.1). Linear regression between SE T2 values at baseline and after successive freeze-thaw cycles demonstrated moderate agreement (r=0.60) whereas UTE T2 values at baseline and after successive-freeze thaw cycles demonstrated strong agreement (r=0.92).
These findings suggest that changes between specimens seen in vitro are due to factors other than frozen storage. Furthermore, our results suggest that there is stronger agreement between baseline (fresh) and successive freeze-thaw T2 values of tendon obtained with the UTE technique in comparison to T2 values obtained with a conventional clinical CPMG technique.
在这项研究中，我们试图评估多次冷冻和解冻循环对两种磁共振参数（即 T2 和 T2）的影响，以研究跟腱。
在 3T 临床扫描仪上对 4 个新鲜的跟腱进行成像，然后在 1、2、4 和 5 次冷冻-解冻循环后再次进行成像，使用自旋回波（SE）和超短回波时间（UTE）序列。在整个跟腱上手动绘制感兴趣区域，并使用单指数曲线来确定 T2 和 T2 弛豫时间。
在新鲜标本和随后的冷冻-解冻处理循环后，T2 和 T2 的平均数值之间没有统计学上的显著差异（p>0.1）。基线时 SE T2 值与随后的冷冻-解冻循环之间的线性回归显示出中度一致性（r=0.60），而基线时 UTE T2 值与随后的冷冻-解冻循环之间的线性回归显示出高度一致性（r=0.92）。
这些发现表明，体外标本之间的变化不是由于冷冻储存等因素造成的。此外，我们的结果表明，与传统的临床 CPMG 技术相比，UTE 技术获得的基线（新鲜）和连续冷冻-解冻 T2 值之间的跟腱具有更强的一致性。
