直肠癌术后复发CT灌注参数测量优化研究

胡娟; 唐光健; 杨学东; 王霄英; 刘婧; 郭小超

doi:10.15953/j.1004-4140.2019.28.02.07

摘要: 目的：探索直肠癌Mile’s术后局部复发与术后瘢痕CT灌注定量参数的优化测量方法。方法：连续入组因症状或复查怀疑直肠癌局部复发的直肠癌Mile’s术后患者10例，所有患者均行病变区CT灌注成像（对比剂70mL，延迟10s，扫描周期1s，扫描时间60s），CT灌注后处理工作站进行不同方式感兴趣区（ROI）勾画，包括：固定面积ROI（24mm²）、热点（单体素）、热区（24mm²）及肿块整体。分别获得各自血流量（BF），血容量（BV），平均通过时间（MTT），表面通透性（PS）及相应灌注图。通过工作站横断面直方图分析软件，分别获得各定量灌注参数最高5％、10％、20％、40％和60％平均值。相隔两周，对以上参数进行二次测量。CT灌注扫描后一周内对所有病灶进行CT引导下穿刺活检，并长期随访证实病灶性质。SPSS软件对不同测量方法测量值行单因素方差分析，对前后两次测量结果进行配对样本t检验。结果：10例患者，共11个病灶（复发组6个，瘢痕组5个）。不同测量方法的测量值差异大，肿块整体测量值最低，最高5％平均值最高。除固定ROI测量MTT、热点测量MTT和PS在复发组和瘢痕组的差异无统计学意义（P均>0.05）外，复发组的其余各测量方法的各灌注参数均高于对照组（P均<0.05）；除热区测量PS外（P<0.05），其他方法前后两次测量值差异均无统计学意义（P均>0.05）。其中以肿块整体测量值及各项直方图最高百分比平均值稳定性最高（r≥0.960，P均<0.05）。结论：相较传统测量方法，利用横断面直方图分析软件获得最高百分数平均值对直肠癌术后骶前肿块灌注定量参数进行测量对直肠癌术后复发和瘢痕的鉴别更为客观、稳定，其中推荐使用最高5％平均值。

Abstract: Objective: To optimize measurement of CT quantitative perfusion parameters for local recurrence and postoperative scar of rectal carcinoma. Method: Ten consecutive rectal carcinoma patients who had undergone Mile's operation were recruited. They were suspected recurrence of cancer because of symptom or review examination. A cine-mode CT perfusion acquisition was performed covering each lesion. The acquisition started 10s after intravenous injection of contrast material (70mL) and lasted 60s. On a perfusion dedicated workstation, regions of interest (ROI) were placed in different ways which contained fixed ROI (24mm²), hot spot (single voxel), hot zone (24mm²) and whole mass. Blood flows (BF), blood volume (BV), mean transit time (MTT) and permeability-surface product (PS) were calculated. Perfusion functional maps were obtained. With the cross-section histogram tool of workstation, the mean value of the highest 5%, 10%, 20%, 40% and 60% of BF, BV, MTT and PS were acquired respectively. All the parameters were measured twice separated by two weeks. All patients with 11 masses received CT guided needle biopsy within one week. Long-term follow-up confirmed the character further. All the perfusion parameters by each method were compared by One-Way ANOVA and two times measurements were compared by Paired-Samples t Test. Results: There were ten patients and 11 lesions(recurrence group: n=6; scar group: n=5). Perfusion parameters varied obviously of different ways of measurement. The lowest value was acquired by whole mass measurement, while the highest value was acquired by the highest 5% measurement. BF, BV, MTT and PS of recurrence group were higher compared with scar group (P<0.05) except the MTT using fixed ROI measurement,MTT and PS using hot spot measurement (P>0.05). There was no statistical difference of perfusion parameters between the first and second measurements (P>0.05) except PS using hot zone (P<0.05). And the whole mass and highest ratio perfusion parameters were more stable (r ≥ 0.963, P<0.05). Conclusion: Compared with conventional measurement, the highest ratio perfusion value obtained by the cross-section histogram tool is more useful, objective and stable for differentiation of local recurrence and postoperative scar of rectal carcinoma. The recommendatory ratio was the highest 5%.

直肠癌术后复发CT灌注参数测量优化研究

Optimization of the Measurement of CT Perfusion Parameters of Rectal Carcinoma Recurrence