Table 1.
Sequence parameters for the diagnostic MR-sequences used in PET/MRI for NSCLC patients.
Figure 1.
44y old male patient suffering from NSCLC (tumor stage IV, adenocarcinoma, unknown tumor grading) Note the FDG-avid lymph node in the aortopulmonary window in the fused PET/MR (A) and PET (B) images.
For ADCmean evaluation, a polyginal ROI was drawn around the lymph node on the b0 image in DWI and then copied to the ADCmap.
Figure 2.
55y old male patient suffering from NSCLC (tumor stage IV, adenocarcinoma, G2) Central necrotic lymph node in the mediastinum (see arrow) with a high T2 signal in MRI (A) and a low FDG-uptake in the fused PET/MR images (B).
In DWI, no diffusion restriction can be observed (C) and a T2 shine through effect can be seen on the corresponding ADC-map (D).
Table 2.
Tumor characteristics in all 25 included patients with lymph nodes suspicious for malignancy in PET/CT and PET/MRI.
Figure 3.
Flow-chart depicting the process of inclusion for all analyzed lymph nodes.
Figure 4.
57y old male patient suffering from NSCLC (tumor stage IIIb, squamous cell carcinoma, unknown tumor grading) Clearly malignant lymph nodes to the left of the aortic arch and right to the trachea in a contrasted enhanced, fused PET/CT-image (A) and in a T2-weighted, fused PET/MR-image (B).
The lymph nodes are clearly depicted in the diffusion weighted b1000-image (C) and show low ADC-values in the corresponding, monoexponential ADC-map. The additional, smaller lymph nodes in the anterior mediastinum were not visible in DWI (C) and were therefore excluded from further analysis.
Table 3.
Pearson’s correlation coefficient between SUVmax / ADCmean and SUVmean / ADCmean in different subgroups of malignant lymph nodes (n = 91).
Figure 5.
Scatter plots including the corresponding regression grade for all lymph node metastases (A, n = 91), lymph node metastases of adenocarcinoma (B, n = 54) and lymph node metastases of SCC (C, n = 29) between SUVmax and ADCmean.
Figure 6.
Bland-Altmann plots for SUVmax (Limits of agreement: 3.99 and -4.21) and SUVmean (Limits of agreement: 2.99 and -1.89) between PET/CT and PET/MRI.