Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
University for Applied Science Wiener Neustadt, Johannes Gutenberg-Straße 3, 2700, Wiener Neustadt, Austria.
Wien Klin Wochenschr. 2024 Nov;136(21-22):627-635. doi: 10.1007/s00508-024-02336-2. Epub 2024 Mar 8.
The diagnosis of large vessel vasculitis (LVV) is often challenging due to the various clinical appearances and the low prevalence. Hybrid imaging by positron emission tomography and computed tomography (PET/CT) is a highly relevant imaging modality for diagnostics and disease surveillance but may be associated with a significant amount of radiation dose especially in patients with complications.
The aim of this retrospective analysis was to compare the image quality and impact of hybrid imaging methods PET/CT and PET/MRI on the potential for dose reduction.
This retrospective single-center study included a cohort of 32 patients who were referred to PET/MRI for the evaluation of LVV, including graft infections and fever of unknown origin. This cohort was compared to a similar cohort of 37 patients who were examined with PET/CT in the same period. Mean radiation dose as well as image quality to establish a diagnosis were compared between the groups.
The mean radiation dose applied in PET/MRI was significantly lower when compared to PET/CT (mean 6.6 mSV vs. 31.7 mSV; p < 0.001). This effect was based on the partially multiphasic CT protocols. At the same time, diagnostic image quality using a 4-point scale showed similar results for both imaging modalities in the work-up of LVV.
With PET/MRI, the radiation exposure can be significantly reduced with similar image quality and diagnostic impact. Patients with LVV have a higher risk of receiving a clinically relevant cumulative effective dose (CED) and PET/MRI should be made available to them.
由于大血管血管炎（LVV）的各种临床表现和低患病率，其诊断常常具有挑战性。正电子发射断层扫描和计算机断层扫描（PET/CT）的混合成像对于诊断和疾病监测是一种非常相关的成像方式，但特别是在伴有并发症的患者中，可能会伴有相当大的辐射剂量。
本回顾性分析的目的是比较混合成像方法 PET/CT 和 PET/MRI 的图像质量和对降低剂量的影响。
这项回顾性单中心研究纳入了一组 32 名患者，他们因 LVV（包括移植物感染和不明原因发热）而接受 PET/MRI 评估。该队列与同期接受 PET/CT 检查的 37 名相似患者进行比较。比较了两组之间的平均辐射剂量和用于诊断的图像质量。
与 PET/CT 相比，PET/MRI 的平均辐射剂量明显降低（平均 6.6 mSV 比 31.7 mSV；p<0.001）。这一效果基于部分多期 CT 方案。与此同时，使用 4 分制评估两种成像方式在 LVV 检查中的诊断图像质量时，结果相似。
使用 PET/MRI 可以在不影响图像质量和诊断效果的情况下，显著降低辐射暴露。患有 LVV 的患者有更高的接受临床相关累积有效剂量（CED）的风险，应向他们提供 PET/MRI。
