17 research outputs found

    Global maps of the CRUST 2.0 crustal components stripped gravity disturbances

    No full text
    We use the CRUST 2.0 crustal model and the EGM08 geopotential model to compile global maps of the gravity disturbances corrected for the gravitational effects (attractions) of the topography and of the density contrasts of the oceans, sediments, ice, and the remaining crust down to the Moho discontinuity. Techniques for a spherical harmonic analysis of the gravity field are used to compute both the gravity disturbances and the topographic and bathymetric corrections with a spectral resolution complete to degree 180 of the spherical harmonics. The ice stripping correction is computed with a spectral resolution complete to degree 90. The sediment and consolidated crust stripping corrections are computed in spatial form by forward modeling their respective attractions. All data are evaluated on a 1 × 1 arc degree grid at the Earth's surface and provided in Data Sets S1–S5 in the auxiliary material for the scientific community for use in global geophysical studies. The complete crust-stripped gravity disturbances (globally having a range of 1050 mGal) contain the gravitational signal coming dominantly from the global mantle lithosphere (upper mantle) morphology and density composition and partially from the sublithospheric density heterogeneities. Large errors are expected because of uncertainties of the CRUST 2.0 model (i.e., deviations of the CRUST 2.0 model density from the real Earth's crustal density heterogeneities and the Moho relief uncertainties).Remote SensingAerospace Engineerin

    Noninvasive stratification of colon cancer by multiplex PET imaging

    Get PDF
    Purpose: The current approach for molecular subtyping of colon cancer relies on gene expression profiling, which is invasive and has limited ability to reveal dynamics and spatial heterogeneity. Molecular imaging techniques, such as PET, present a noninvasive alternative for visualizing biological information from tumors. However, the factors influencing PET imaging phenotype, the suitable PET radiotracers for differentiating tumor subtypes, and the relationship between PET phenotypes and tumor genotype or gene expression–based subtyping remain unknown. Experimental Design: In this study, we conducted 126 PET scans using four different metabolic PET tracers, [18F]fluorodeoxy-D-glucose ([18F]FDG), O-(2-[18F]fluoroethyl)-l-tyrosine ([18F]FET), 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT), and [11C]acetate ([11C]ACE), using a spectrum of five preclinical colon cancer models with varying genetics (BMT, AKPN, AK, AKPT, KPN), at three sites (subcutaneous, orthograft, autochthonous) and at two tumor stages (primary vs. metastatic). Results: The results demonstrate that imaging signatures are influenced by genotype, tumor environment, and stage. PET imaging signatures exhibited significant heterogeneity, with each cancer model displaying distinct radiotracer profiles. Oncogenic Kras and Apc loss showed the most distinctive imaging features, with [18F]FLT and [18F]FET being particularly effective, respectively. The tissue environment notably impacted [18F]FDG uptake, and in a metastatic model, [18F]FET demonstrated higher uptake. Conclusions: By examining factors contributing to PET-imaging phenotype, this study establishes the feasibility of noninvasive molecular stratification using multiplex radiotracer PET. It lays the foundation for further exploration of PET-based subtyping in human cancer, thereby facilitating noninvasive molecular diagnosis

    Figure 5 from Noninvasive Stratification of Colon Cancer by Multiplex PET Imaging

    No full text
    PET imaging phenotypic difference between primary and metastatic tumors. A, The generation of the KrasG12D/+ Trp53fl/fl Rosa26N1icd/+ (KPN) and KPN liver metastasis organoid lines and subsequent implantation. One pair of lines, generated from a matched mouse primary tumor and liver metastasis, which were then propagated and injected subcutaneously into recipient mice (n = 5). B, Transverse and coronal PET/MRI slice images showing uptake of four PET tracers ([18F]FDG, [18F]FET, [18F]FLT, [18F]ACE) in subcutaneously implanted KPN primary and KPN liver metastasis organoids. KPN primary tumor-bearing mice are the same four PET ([18F]FDG, [18F]FET, [18F]FLT, [18F]ACE) images (primary) as displayed in Figs. 2B and 4B and D. C, Standard uptake peak values (SUVpeak) PET quantification from images in B. Sample size (n) is displayed on the bars. Error bars represent SD. Data compared using unpaired t test. Details of all mice used in these studies are presented in Supplementary Table S1. D, Representative GLUT-1 IHC and Lat-1/Slc7a5 ISH. Black scale bars represent 50 ÎĽm (*, P P A, Created with BioRender.com.)</p

    Figure 3 from Noninvasive Stratification of Colon Cancer by Multiplex PET Imaging

    No full text
    PET imaging can distinguish different colon subcutaneous organoid cancer models and individual driver genes. A, The data processing workflow for comparing PET radiotracer discriminatory power and the model/gene uniqueness. B, Separation matrix and statistics of the area under the ROC curves for each tracer and model. C, Red highlighted box showing boxplot and ROC curves for [18F]FDG in the BMT (n = 6 subcutaneous organoid allografts) compared with other models (n = 19), each point represents a mouse. Numbers inside bars show sample size, n. Data compared using unpaired t test. D, Separation matrix and statistics of the area under the ROC curves for each tracer and gene. Tgfbr1/Alk5 fl/fl and Tgfbr2 fl/fl are combined as TGFb for this analysis. E, Red highlighted box showing boxplot and ROC curves for [18F]FLT in the Kras (n = 18) compared to other subcutaneous models (n = 6), each point represents a mouse. Numbers inside bars show n. Data compared using unpaired t test. Error bars in C and D represent SD. *, P P P t tests and AUC ROC. Each analysis stands on its own; no multiple comparison testing was used. See extended datasets in Supplementary Fig. S4. (A, Created with BioRender.com.)</p

    Figure 2 from Noninvasive Stratification of Colon Cancer by Multiplex PET Imaging

    No full text
    Distinct intermodel heterogeneity in PET imaging signatures. A, In the experimental imaging protocol, five colon cancer organoid models and four PET tracers were used to determine imaging signatures. Details of all mice used in these studies are presented in Supplementary Table S1. B, Representative transverse PET images from each model and tracer. The [18F]FDG PET/MR images of the KPN subcutaneous model are reproduced again in Figs. 4B and D and 5B for comparison against other tumors at different sites and stages. C, Imaging signature heatmap showing mean tracer uptake, models with highest tracer update highlighted with black outline (representation of the data matrix analyzed with two-way ANOVA). D, Correlation matrix of each tracer uptake based on Pearson correlation coefficient. E, Heatmap illustrating correlation of PET tracer uptake with gene expression in the Molecular Signatures Database (MSigDB) hallmark dataset, sorted by hierarchal clustering. (A, Created with BioRender.com.)</p
    corecore