Institute of Radiology, University Medical Center Regensburg, Regensburg, Germany.
Clin Hemorheol Microcirc. 2010;46(2-3):77-87. doi: 10.3233/CH-2010-1335.
Early detection of a compromised circulation of free flaps and an immediate revision may lead to higher rates of flap salvage. The aim of this study was to evaluate the perfusion of the entire flap using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). DCE was performed in 11 patients after flap transplantation using an optimized 3D gradient echo sequence to cover the whole flap. The percentage increase of signal intensity over time was evaluated for the free flap as well as for a reference tissue. Furthermore, normalized signal increase was calculated as the ratio of signal increase within the flaps to the signal increase in the reference tissue. Signal increase in free flaps and reference tissue was compared using the Wilcoxon-test (p < 0.05), normalized signal increase in normally perfused (n = 9) and in flaps with compromised perfusion (n = 2) using Mann-Whitney-test (p < 0.05). Signal increase within normally perfused flaps was similar to the reference tissue. In flaps with compromised perfusion the increase was significantly lower than in reference tissue. Normalized signal increase in adequately perfused flaps and flaps with compromised perfusion also showed a significant difference. DCE MRI may be a valuable non-invasive tool to evaluate tissue perfusion of the complete free flap.
早期发现游离皮瓣循环受损并立即进行修复，可能会提高皮瓣存活率。本研究旨在使用动态对比增强（DCE）磁共振成像（MRI）评估整个皮瓣的灌注情况。在皮瓣移植后，11 名患者使用优化的 3D 梯度回波序列进行 DCE，以覆盖整个皮瓣。评估了游离皮瓣以及参考组织的信号强度随时间的百分比增加。此外，还计算了标准化信号增加，即皮瓣内信号增加与参考组织信号增加的比值。使用 Wilcoxon 检验（p < 0.05）比较游离皮瓣和参考组织的信号增加，使用 Mann-Whitney 检验（p < 0.05）比较正常灌注（n = 9）和灌注受损（n = 2）皮瓣的标准化信号增加。正常灌注皮瓣内的信号增加与参考组织相似。灌注受损的皮瓣中，信号增加明显低于参考组织。正常灌注皮瓣和灌注受损皮瓣的标准化信号增加也存在显著差异。DCE MRI 可能是评估游离皮瓣整体组织灌注的一种有价值的非侵入性工具。
