Kerber Bjarne, Hüllner Martin, Maurer Alexander, Flohr Thomas, Ulrich Silvia, Lichtblau Mona, Frauenfelder Thomas, Franckenberg Sabine
From the Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich, Zurich, Switzerland (B.K., T.Fl., T.Fr., S.F.); Department of Nuclear Medicine, University Hospital Zurich, University Zurich, Zurich, Switzerland (M.H., A.M.); Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre+, Maastricht, the Netherlands (T.Fl.); and Clinic of Pulmonology, University Hospital Zurich, Zurich, Switzerland (S.U., M.L.).
Invest Radiol. 2025 Feb 28. doi: 10.1097/RLI.0000000000001163.
The aim of this study was to compare the accuracy of photon-counting detector computed tomography (PCD-CT) iodine maps of the lung parenchyma with perfusion scintigraphy for detection and extent estimation of pulmonary perfusion defects.
This institutional review board-approved retrospective study included 26 subjects (11 male, aged 57.2 ± 15.8 years; 15 female, aged 55.2 ± 15.7 years) who underwent clinically indicated PCD-CT and perfusion SPECT/CT to assess for chronic thromboembolic pulmonary hypertension (CTEPH). Two blinded radiologists used CT iodine maps and corresponding sharp-kernel CT reconstructions in lung window to evaluate presence and extent of lobar perfusion defects and detect patients with CTEPH (or CTEPH overlap with other causes of PH). Accordingly, 2 blinded nuclear medicine physicians/radiologists evaluated perfusion SPECT/CT scans. The clinical diagnosis was reviewed in an interdisciplinary clinical setting. Quantitative analyses were calculated for both modalities. Perfusion defect estimation was compared with right heart catheter measurements.
Of the 26 subjects included, 10 were diagnosed with CTEPH or CTEPH overlap, 12 were diagnosed with PH associated with other pathologic mechanisms, 3 had no PH, and 1 had previous acute pulmonary embolism, which resolved. Radiation dose was greatly reduced for PCD-CT compared with SPECT/CT (1.19 [±0.33] mSv; 6.34 [±1.68] mSv, respectively, P < 0.001). Both PCD-CT readers (R1, R2) showed a trend toward higher accuracy, sensitivity, and specificity for CTEPH diagnosis compared with the scintigraphy consensus (SC) (accuracy: R1 0.85, R2 0.88, SC 0.73; sensitivity: R1 0.90, R2 0.90, SC 0.80; specificity: R1 0.81, R2 0.88, SC 0.69), although there was no significant difference observed (P > 0.688). There was good to excellent agreement between both PCD-CT readers for perfusion defect estimation. Moderate intermodality agreement was observed for CTEPH diagnosis certainty and perfusion defect estimation. The quantitative evaluation showed strong to excellent correlation between PCD-CT and SPECT/CT relative perfusion. There was a significant moderate correlation between PCD-CT perfusion defect estimations and mean pulmonary artery pressure (R1: r = 0.49, P = 0.020; R2: r = 0.49, P = 0.021), pulmonary vascular resistance (R1: r = 0.60, P = 0.003; R2: r = 0.52, P = 0.013), and cardiac index (R1: r = -0.45, P = 0.042).
PCD-CT iodine maps allow for accurate CTEPH detection and are comparable to perfusion SPECT/CT with good quantitative correlation, but only moderate qualitative agreement, at greatly reduced radiation dose. Furthermore, visual PCD-CT perfusion defect extent was associated with prognostic right heart catheter measurements.
本研究旨在比较肺实质的光子计数探测器计算机断层扫描（PCD-CT）碘图与灌注闪烁扫描在检测和评估肺灌注缺损范围方面的准确性。
本研究经机构审查委员会批准，为回顾性研究，纳入26例受试者（11例男性，年龄57.2±15.8岁；15例女性，年龄55.2±15.7岁），这些受试者因临床需要接受了PCD-CT和灌注单光子发射计算机断层扫描/计算机断层扫描（SPECT/CT）以评估慢性血栓栓塞性肺动脉高压（CTEPH）。两名盲法放射科医生使用CT碘图和肺窗对应的锐核CT重建图像来评估肺叶灌注缺损的存在及范围，并检测CTEPH患者（或CTEPH与其他肺动脉高压病因重叠的患者）。相应地，两名盲法核医学医师/放射科医生评估了灌注SPECT/CT扫描。在多学科临床环境中对临床诊断进行了复查。对两种检查方法均进行了定量分析。将灌注缺损评估结果与右心导管测量结果进行比较。
纳入的26例受试者中，10例被诊断为CTEPH或CTEPH重叠，12例被诊断为与其他病理机制相关的肺动脉高压，3例无肺动脉高压，1例既往有急性肺栓塞，已缓解。与SPECT/CT相比，PCD-CT的辐射剂量大幅降低（分别为1.19[±0.33]mSv和6.34[±1.68]mSv，P<0.001）。与闪烁扫描共识（SC）相比，两位PCD-CT阅片者（R1、R2）在CTEPH诊断方面均显示出更高的准确性、敏感性和特异性趋势（准确性：R1为0.85，R2为0.88，SC为0.73；敏感性：R1为0.90，R2为0.90，SC为0.80；特异性：R1为0.81，R2为0.88，SC为0.69），尽管未观察到显著差异（P>0.688）。两位PCD-CT阅片者在灌注缺损评估方面的一致性良好至优秀。在CTEPH诊断确定性和灌注缺损评估方面观察到中等程度的模态间一致性。定量评估显示PCD-CT与SPECT/CT相对灌注之间存在强至优秀的相关性。PCD-CT灌注缺损评估与平均肺动脉压（R1：r = 0.49，P = 0.020；R2：r = 0.49，P = 0.021）、肺血管阻力（R1：r = 0.60，P = 0.003；R2：r = 0.52，P = 0.013）和心脏指数（R1：r = -0.45，P = 0.04）之间存在显著的中度相关性。
PCD-CT碘图能够准确检测CTEPH，与灌注SPECT/CT具有良好的定量相关性，但定性一致性仅为中等程度，且辐射剂量大幅降低。此外，PCD-CT视觉上的灌注缺损范围与右心导管测量的预后相关。
