Clinic of Diagnostic and Interventional Radiology (DIR), Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany.
Medical Department V, Hematology/Oncology/Rheumatology, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
Eur Radiol. 2021 Oct;31(10):7664-7673. doi: 10.1007/s00330-021-07821-0. Epub 2021 Mar 30.
Virtual non-calcium (VNCa) images could improve assessment of plasma cell dyscrasias by enhancing visibility of bone marrow. Thus, VNCa images from dual-layer spectral CT (DLCT) were evaluated at different calcium suppression (CaSupp) indices, correlating results with apparent diffusion coefficient (ADC) values from MRI.
Thirty-two patients with initial clinical diagnosis of a plasma cell dyscrasia before any chemotherapeutic treatment, who had undergone whole-body low-dose DLCT and MRI within 2 months, were retrospectively enrolled. VNCa images with CaSupp indices ranging from 25 to 95 in steps of 10, conventional CT images, and ADC maps were quantitatively analyzed using region-of-interests in the vertebral bodies C7, T12, L1-L5, and the iliac bone. Independent two-sample t-test, Wilcoxon-signed-rank test, Pearson's correlation, and ROC analysis were performed.
Eighteen patients had a non-diffuse, 14 a diffuse infiltration in conventional MRI. A significant difference between diffuse and non-diffuse infiltration was shown for VNCa-CT with CaSupp indices from 55 to 95, for conventional CT, and for ADC (each p < 0.0001). Significant quantitative correlation between VNCa-CT and MRI could be found with strongest correlation at CaSupp index 65 for L3 (r = 0.68, p < 0.0001) and averaged L1-L5 (r = 0.66, p < 0.0001). The optimum CT number cut-off point for differentiation between diffuse and non-diffuse infiltration at CaSupp index 65 for averaged L1-L5 was -1.6 HU (sensitivity 78.6%, specificity 75.0%).
Measurements in VNCa-CT showed the highest correlation with ADC at CaSupp index 65. VNCa technique may prove useful for evaluation of bone marrow infiltration if MRI is not feasible.
• VNCa-CT images can support the evaluation of bone marrow infiltration in plasma cell dyscrasias. • VNCa measurements of vertebral bodies show significant correlation with ADC in MRI. • Averaging L1-L5 at CaSupp index 65 allowed quantitative detection of infiltration comparable to MRI ADC.
虚拟非钙（VNCa）图像可以通过增强骨髓的可视性来改善浆细胞异常的评估。因此，在不同的钙抑制（CaSupp）指数下评估双层光谱 CT（DLCT）的 VNCa 图像，并将结果与 MRI 的表观扩散系数（ADC）值相关联。
回顾性纳入 32 例初始临床诊断为浆细胞异常的患者，这些患者在任何化疗治疗前均接受了全身低剂量 DLCT 和 MRI 检查，且检查时间在 2 个月内。使用感兴趣区对 C7、T12、L1-L5 椎体和髂骨的 VNCa 图像进行定量分析，CaSupp 指数范围为 25 至 95，步长为 10，同时还对常规 CT 图像和 ADC 图进行定量分析。采用独立样本 t 检验、Wilcoxon 符号秩检验、Pearson 相关和 ROC 分析进行统计分析。
18 例患者在常规 MRI 中表现为非弥漫性浸润，14 例患者表现为弥漫性浸润。在 CaSupp 指数为 55 至 95 时，VNCa-CT、常规 CT 和 ADC 之间存在弥漫性浸润和非弥漫性浸润的显著差异（均 p<0.0001）。VNCa-CT 与 MRI 之间存在显著的定量相关性，在 CaSupp 指数为 65 时，L3（r=0.68，p<0.0001）和平均 L1-L5（r=0.66，p<0.0001）的相关性最强。在 CaSupp 指数为 65 时，用于区分平均 L1-L5 弥漫性和非弥漫性浸润的最佳 CT 值截断点为-1.6 HU（敏感性 78.6%，特异性 75.0%）。
在 CaSupp 指数为 65 时，VNCa-CT 测量值与 ADC 相关性最高。如果 MRI 不可行，VNCa 技术可能有助于评估骨髓浸润。
VNCa-CT 图像可辅助评估浆细胞异常中的骨髓浸润。
椎体 VNCa 测量值与 MRI 的 ADC 具有显著相关性。
在 CaSupp 指数为 65 时对 L1-L5 进行平均处理，可以定量检测到与 MRI ADC 相当的浸润。
