Department of Radiology, Hospices Civils de Lyon, 69500 Bron, France; Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, 69621 Lyon, France.
Department of Nuclear Medicine, Hospices Civils de Lyon, 69500 Bron, France.
Diagn Interv Imaging. 2020 May;101(5):299-310. doi: 10.1016/j.diii.2020.02.006. Epub 2020 Mar 12.
To compare the quantitative and qualitative lung perfusion data acquired with dual energy CT (DECT) to that acquired with a large field-of-view cadmium-zinc-telluride camera single-photon emission CT coupled to a CT system (SPECT-CT).
A total of 53 patients who underwent both dual-layer DECT angiography and perfusion SPECT-CT for pulmonary hypertension or pre-operative lobar resection surgery were retrospectively included. There were 30 men and 23 women with a mean age of 65.4±17.5 (SD)years (range: 18-88years). Relative lobar perfusion was calculated by dividing the amount (of radiotracer or iodinated contrast agent) per lobe by the total amount in both lungs. Linear regression, Bland-Altman analysis, and Pearson's correlation coefficient were also calculated. Kappa test was used to test agreements in morphology and severity of perfusion defects assessed on SPECT-CT and on DECT iodine maps with a one-month interval. Wilcoxon rank sum test was used to compare the sharpness of perfusion defects and radiation dose among modalities.
RESULTS: Strong correlations for relative lobar perfusion using linear regression analysis and Pearson's correlation coefficient (r=0.93) were found. Bland-Altman analysis revealed a -0.10 bias, with limits of agreement between [-6.01; 5.81]. With respect to SPECT- CT as standard of reference, the sensitivity, specificity, PPV, NPV, accuracy for lobar perfusion defects were 89.4% (95% CI: 82.6-93.4%), 96.5% (95% CI: 92.1-98.5%), 95.6% (95% CI: 90.9-97.8%), 91.4% (95% CI: 85.6-94.9%) and 93.0% (95% CI: 87.6-96.1%) respectively. High level of agreement was found for morphology and severity of perfusion defects between modalities (Kappa=0.84 and 0.86 respectively) and on DECT images among readers (Kappa=0.94 and 0.89 respectively). A significantly sharper delineation of perfusion defects was found on DECT images (P<0.0001) using a significantly lower equivalent dose of 4.1±2.3 (SD) mSv (range: 1.9-11.85mSv) compared to an equivalent dose of 5.3±1.1 (SD) mSv (range: 2.8-7.3mSv) for SPECT-CT, corresponding to a 21.2% dose reduction (P=0.0004).
DECT imaging shows strong quantitative correlations and qualitative agreements with SPECT-CT for the evaluation of lung perfusion.
比较双能 CT（DECT）与大视野镉锌碲单光子发射 CT 与 CT 系统（SPECT-CT）联合采集的定量和定性肺灌注数据。
回顾性纳入 53 例因肺动脉高压或术前肺叶切除术而行双源 DECT 血管造影和灌注 SPECT-CT 的患者。其中男 30 例，女 23 例，平均年龄 65.4±17.5（SD）岁（18-88 岁）。通过将每个肺叶的放射性示踪剂或碘造影剂的量除以双肺的总用量来计算相对肺叶灌注。还计算了线性回归、Bland-Altman 分析和 Pearson 相关系数。使用 Kappa 检验测试 SPECT-CT 和 DECT 碘图上灌注缺损的形态和严重程度在一个月间隔内的一致性。Wilcoxon 秩和检验用于比较不同模式下灌注缺损的锐利度和辐射剂量。
线性回归分析和 Pearson 相关系数（r=0.93）发现相对肺叶灌注具有很强的相关性。Bland-Altman 分析显示存在-0.10 的偏差，其一致性界限为[-6.01；5.81]。以 SPECT-CT 为标准参考，肺叶灌注缺损的灵敏度、特异性、PPV、NPV、准确性分别为 89.4%（95%可信区间：82.6-93.4%）、96.5%（95%可信区间：92.1-98.5%）、95.6%（95%可信区间：90.9-97.8%）、91.4%（95%可信区间：85.6-94.9%）和 93.0%（95%可信区间：87.6-96.1%）。两种模式之间的灌注缺损形态和严重程度（Kappa=0.84 和 0.86）以及读者之间的 DECT 图像上的灌注缺损形态和严重程度（Kappa=0.94 和 0.89）均具有较高的一致性。DECT 图像上的灌注缺损显示出明显更锐利的轮廓（P<0.0001），使用的等效剂量为 4.1±2.3（SD）mSv（范围：1.9-11.85mSv），明显低于 SPECT-CT 的等效剂量 5.3±1.1（SD）mSv（范围：2.8-7.3mSv），剂量降低 21.2%（P=0.0004）。
DECT 成像在评估肺灌注方面与 SPECT-CT 具有较强的定量相关性和定性一致性。
