In:
Molecular Imaging and Biology, Springer Science and Business Media LLC, Vol. 24, No. 3 ( 2022-06), p. 359-364
Abstract:
Multimodal molecular imaging allows a direct coregistration of different images, facilitating analysis of the spatial relation of various imaging parameters. Here, we further explored the relation of proliferation, as measured by [ 18 F]FLT PET, and water diffusion, as an indicator of cellular density and cell death, as measured by diffusion-weighted (DW) MRI, in preclinical tumor models. We expected these parameters to be negatively related, as highly proliferative tissue should have a higher density of cells, hampering free water diffusion. Procedures Nude mice subcutaneously inoculated with either lung cancer cells ( n = 11 A549 tumors, n = 20 H1975 tumors) or colorectal cancer cells ( n = 13 Colo205 tumors) were imaged with [ 18 F]FLT PET and DW-MRI using a multimodal bed, which was transferred from one instrument to the other within the same imaging session. Fiducial markers allowed coregistration of the images. An automatic post-processing was developed in MATLAB handling the spatial registration of DW-MRI (measured as apparent diffusion coefficient, ADC) and [ 18 F]FLT image data and subsequent voxel-wise analysis of regions of interest (ROIs) in the tumor. Results Analyses were conducted on a total of 76 datasets, comprising a median of 2890 data points (ranging from 81 to 13,597). Scatterplots showing [ 18 F]FLT vs. ADC values displayed various grades of relations (Pearson correlation coefficient (PCC) varied from − 0.58 to 0.49, median: -0.07). When relating PCC to tumor volume (median: 46 mm 3 , range: 3 mm 3 to 584 mm 3 ), lung tumors tended to have a more pronounced negative spatial relation of [ 18 F]FLT and ADC with increasing tumor size. However, due to the low number of large tumors ( 〉 ~ 200 mm 3 ), this conclusion has to be treated with caution. Conclusions A spatial relation of water diffusion, as measured by DW-MRI, and cellular proliferation, as measured by [ 18 F]FLT PET, cannot be detected in the experimental datasets investigated in this study.
Type of Medium:
Online Resource
ISSN:
1536-1632
,
1860-2002
DOI:
10.1007/s11307-021-01673-2
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2022
detail.hit.zdb_id:
2079211-6
SSG:
12
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