Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
Department of Diagnostic Radiology, Queen's University, Kingston, ON, Canada.
Epilepsy Res. 2021 May;172:106583. doi: 10.1016/j.eplepsyres.2021.106583. Epub 2021 Feb 16.
Hybrid PET/MRI may improve detection of seizure-onset zone (SOZ) in drug-resistant epilepsy (DRE), however, concerns over PET bias from MRI-based attenuation correction (MRAC) have limited clinical adoption of PET/MRI. This study evaluated the diagnostic equivalency and potential clinical value of PET/MRI against PET/CT in DRE.
MRI, FDG-PET and CT images (n = 18) were acquired using a hybrid PET/MRI and a CT scanner. To assess diagnostic equivalency, PET was reconstructed using MRAC (RESOLUTE) and CT-based attenuation correction (CTAC) to generate PET/MRI and PET/CT images, respectively. PET/MRI and PET/CT images were compared qualitatively through visual assessment and quantitatively through regional standardized uptake value (SUV) and z-score assessment. Diagnostic accuracy and sensitivity of PET/MRI and PET/CT for SOZ detection were calculated through comparison to reference standards (clinical hypothesis and histopathology, respectively).
Inter-reader agreement in visual assessment of PET/MRI and PET/CT images was 78 % and 81 %, respectively. PET/MRI and PET/CT were strongly correlated in mean SUV (r = 0.99, p < 0.001) and z-scores (r = 0.92, p < 0.001) across all brain regions. MRAC SUV bias was <5% in most brain regions except the inferior temporal gyrus, temporal pole, and cerebellum. Diagnostic accuracy and sensitivity were similar between PET/MRI and PET/CT (87 % vs. 85 % and 83 % vs. 83 %, respectively).
We demonstrate here that PET/MRI with optimal MRAC can yield similar diagnostic performance as PET/CT. Nevertheless, further exploration of the potential added value of PET/MRI is necessary before clinical adoption of PET/MRI for epilepsy imaging.
杂交 PET/MRI 可能会提高耐药性癫痫（DRE）患者的致痫灶（SOZ）检出率，但基于 MRI 的衰减校正（MRAC）PET 偏倚问题限制了 PET/MRI 的临床应用。本研究旨在评估在 DRE 中，PET/MRI 与 PET/CT 的诊断等效性及其潜在临床价值。
对 18 例患者分别进行了杂交 PET/MRI 和 CT 扫描仪的 MRI、FDG-PET 和 CT 扫描。为了评估诊断等效性，使用 MRAC（RESOLUTE）和 CT 衰减校正（CTAC）分别重建 PET 数据，以生成 PET/MRI 和 PET/CT 图像。通过视觉评估对 PET/MRI 和 PET/CT 图像进行定性比较，并通过区域标准化摄取值（SUV）和 z 分数评估进行定量比较。通过与参考标准（分别为临床假设和组织病理学）进行比较，计算 PET/MRI 和 PET/CT 对 SOZ 检测的诊断准确性和敏感度。
对 PET/MRI 和 PET/CT 图像的两位观察者间的视觉评估一致性分别为 78%和 81%。在所有脑区，PET/MRI 和 PET/CT 的平均 SUV（r = 0.99，p < 0.001）和 z 分数（r = 0.92，p < 0.001）均呈强相关。除了颞下回、颞极和小脑外，大多数脑区的 MRAC SUV 偏差<5%。PET/MRI 和 PET/CT 的诊断准确性和敏感度相似（分别为 87%比 85%和 83%比 83%）。
本研究表明，采用最优 MRAC 的 PET/MRI 可以获得与 PET/CT 相似的诊断性能。然而，在将 PET/MRI 应用于癫痫成像之前，有必要进一步探索其潜在的附加价值。
