320排CT灌注成像评价兔下肢缺血再灌注损伤

目的 观察兔下肢急性缺血再灌注损伤CT灌注成像（CTPI）参数的演变规律及与血清酶学检测指标（CK、LDH、MDA、SOD）的相关性。方法 将30只新西兰大白兔随机分为缺血再灌注（I/R）组与假手术组。将I/R组分为再灌注即刻、6、12、24 h亚组，每组6只，分别在右下肢缺血3 h后再灌注即刻、6 h、12 h、24 h时间点行双下肢CTPI并采血，得到CT灌注值血流量（AF）、血容量（BV）、对比剂清除率（C），计算右下肢与左下肢各参数的比值，即rAF、rBV、rC，并测定血清CK、LDH、MDA、SOD；最后分别对rAF、rBV、rC与生化指标进行相关性分析。 结果 与假手术组比较，I/R组再灌注即刻、6、12、24 h亚组的rAF均值分别为0.92±0.14、0.89±0.12、0.88±0.20、0.75±0.11，随再灌注时间延长逐渐降低（P<0.05）；I/R各亚组血清CK、LDH及MDA显著高于假手术组（P均<0.05），而SOD随再灌注时间延长而逐渐降低（P<0.05）。rAF与LDH、CK、MDA、SOD的相关系数分别为-0.64、-0.47、-0.68、0.59（P均<0.05），仅rBV与LDH存在相关性（r=-0.45，P<0.05）。结论 320排CTPI可无创、半定量、较准确地监测兔下肢骨骼肌随再灌注时间推移的微循环改变；rAF较rBV、rC能更好地反映肌肉组织再灌注后损伤情况。

320-slice CT perfusion imaging evaluation on ischemia reperfusion injury in rabbit lower limb

Objective To observe the changes of CT perfusion imaging (CTPI) parameters and their correlation with serum amylase (CK, LDH, MDA, SOD) in lower limb ischemia reperfusion injury (I/R) rabbit models. Methods Thirty New Zealand white rabbits were randomly assigned to I/R group and sham group. Rabbits in I/R group were assigned immediately, 6 h, 12 h, 24 h subgroups after reperfusion (each n=6). Blood supply of right lower limbs were clamped for 3 h and recovered reperfusion, CTPI parameters, including blood flow (AF), blood volume (BV) and contrast clearance rate(C) were obtained, while blood samples were taken immediately, 6 h, 12 h, 24 h after reperfusion in I/R group. Reperfusion parameters ratio between the right side and left side (rAF, rBV, rC) were calculated, and the serum level of CK, LDH, MDA, SOD were tested. The relationship between CTPI parameters and biochemical indexes were analyzed. Results Compared with sham group, rAF mean value was 0.92±0.14, 0.89±0.12, 0.88±0.20, 0.75±0.11 in I/R subgroups, respectively, gradually decreased with reperfusion time extension (P<0.05). Serum CK, LDH and MDA of each I/R subgroup were significantly higher than those in sham group (P<0.05), SOD decreased gradually with time going (P<0.05). The correlation coefficients of rAF and LDH, CK, MDA, SOD were -0.64, -0.47, -0.68 and 0.59, respectively (P<0.05), rBV had correlation with LDH (r=-0.45, P<0.05). Conclusion 320-slice CTPI parameters can noninvasively, semi-quantitatively and accurately reflect the microcirculation changes over time of lower limb IR injury of rabbit. rAF can reflect degree of muscle injury after reperfusion better than rBV and rC.