Ng Quan Sing, Goh Vicky, Klotz Ernst, Fichte Heinz, Saunders Michele I, Hoskin Peter J, Padhani Anwar R
Marie Curie Research Wing, Mount Vernon Hospital, Northwood, Middlesex, United Kingdom.
AJR Am J Roentgenol. 2006 Oct;187(4):1079-84. doi: 10.2214/AJR.05.0889.
To date, quantitative assessment of tumor vascularity using perfusion CT has been limited to a single tumor level, with the potential for measurement error in heterogeneous tumors. We aimed to determine if greater z-axis tumor coverage improves the reproducibility of perfusion CT measurements in lung cancer.
Paired perfusion studies were performed on 10 patients who had histologically confirmed advanced non-small cell lung cancer. Using 16-MDCT, multiple sequential volumetric acquisitions encompassing the entire tumor were acquired after infusion of i.v. contrast material. Using Patlak analysis, median values of tumor permeability (mL/100 mL/min) and blood volume (mL/100 mL) were measured for 10-mm z-axis coverage, and for 40-mm z-axis coverage in each of the paired perfusion studies. Measurement reproducibility was evaluated using Bland-Altman statistics.
Mean difference (95% limits of agreement) for tumor permeability was 1.4 (-4.0 to 6.8) for 10-mm coverage and 0.8 (-3.6 to 5.2) for 40-mm coverage. Mean difference (95% limits of agreement) for blood volume was 1.9 (-5.1 to 8.9) for 10-mm coverage and 1.4 (-3.7 to 6.6) for 40-mm coverage. The coefficient of variation for permeability was 18.7% for 10-mm coverage, improving to 11.9% for 40-mm coverage. The coefficient of variation for blood volume was 41.7% for 10-mm coverage, improving to 32.6% for 40-mm coverage.
Our results show that an improvement in tumor perfusion measurement reproducibility may be achieved with greater z-axis coverage.
迄今为止，使用灌注CT对肿瘤血管进行定量评估仅限于单个肿瘤层面，而异质性肿瘤存在测量误差的可能性。我们旨在确定更大的z轴肿瘤覆盖范围是否能提高肺癌灌注CT测量的可重复性。
对10例经组织学证实为晚期非小细胞肺癌的患者进行了配对灌注研究。使用16层MDCT，在静脉注射造影剂后，对包含整个肿瘤的多个连续容积采集图像。采用Patlak分析，在配对灌注研究中，分别测量10毫米z轴覆盖范围和40毫米z轴覆盖范围下肿瘤通透性（毫升/100毫升/分钟）和血容量（毫升/100毫升）的中位数。使用Bland-Altman统计方法评估测量的可重复性。
10毫米覆盖范围下肿瘤通透性的平均差异（95%一致性界限）为1.4（-4.0至6.8），40毫米覆盖范围下为0.8（-3.6至5.2）。10毫米覆盖范围下血容量的平均差异（95%一致性界限）为1.9（-5.1至8.9），40毫米覆盖范围下为1.4（-3.7至6.6）。10毫米覆盖范围下通透性的变异系数为18.7%，40毫米覆盖范围下提高至11.9%。10毫米覆盖范围下血容量的变异系数为41.7%，40毫米覆盖范围下提高至32.6%。
我们的结果表明，更大的z轴覆盖范围可能会提高肿瘤灌注测量的可重复性。
