Aims and objectives: Replacing model fitting with patient data to improve reproducibility of Blood Flow (BF) values computed with different software in Computed Tomography perfusion (CTp) studies of liver. Methods and materials: 46 patients with colorectal cancer and normal liver underwent a CTp examination at diagnosis, consisting in 60 scans lasting 120 sec (1scan/sec for the first 30 sec, 1scan/3sec after). A first passage analysis is considered. While proper parametric models are used to represent the dynamic (i.e., Time Concentration curves, TCCs) of Contrast Agent (CA) in arterial and portal input, the tissue TCCs were achieved by convolving the voxel-based response function (IRF) characteristic of the patient’s liver with portal and arterial models. In-house deconvolution (DV) and maximum slope (MS) software was used to compute BF values. ANOVA was employed to measure MS and DV reproducibility (p-value>0.05) with this method against classical model fitting. Linear correlation is also measured (R2) between voxel-based MS and DV BF colormaps. Results: ANOVA reports reproducibility of mean BF computed with MS and DV for of both methods, with p-value=0.85 (patient-based) and p-value=0.24 (classical), with excellent correlation (R2≥0.99) in 42 and 28 examinations, respectively. Conclusion: Exploiting the original patient's enhancement curves rather than their mathematical representation allows robust perfusion software to improve voxel-based reproducibility of BF colormaps of single patients as well as the reproducibility of the mean BF in the whole cohort. These findings make CTp to take a step forward towards standardization and precision medicine as well.

A patient-driven approach to improve reproducibility of blood flow values in CT perfusion of liver

Alessandro Bevilacqua;Margherita Mottola
2019

Abstract

Aims and objectives: Replacing model fitting with patient data to improve reproducibility of Blood Flow (BF) values computed with different software in Computed Tomography perfusion (CTp) studies of liver. Methods and materials: 46 patients with colorectal cancer and normal liver underwent a CTp examination at diagnosis, consisting in 60 scans lasting 120 sec (1scan/sec for the first 30 sec, 1scan/3sec after). A first passage analysis is considered. While proper parametric models are used to represent the dynamic (i.e., Time Concentration curves, TCCs) of Contrast Agent (CA) in arterial and portal input, the tissue TCCs were achieved by convolving the voxel-based response function (IRF) characteristic of the patient’s liver with portal and arterial models. In-house deconvolution (DV) and maximum slope (MS) software was used to compute BF values. ANOVA was employed to measure MS and DV reproducibility (p-value>0.05) with this method against classical model fitting. Linear correlation is also measured (R2) between voxel-based MS and DV BF colormaps. Results: ANOVA reports reproducibility of mean BF computed with MS and DV for of both methods, with p-value=0.85 (patient-based) and p-value=0.24 (classical), with excellent correlation (R2≥0.99) in 42 and 28 examinations, respectively. Conclusion: Exploiting the original patient's enhancement curves rather than their mathematical representation allows robust perfusion software to improve voxel-based reproducibility of BF colormaps of single patients as well as the reproducibility of the mean BF in the whole cohort. These findings make CTp to take a step forward towards standardization and precision medicine as well.
Electronic Posters of the 31st European Congress of Radiology (ECR 2019)
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Alessandro Bevilacqua; Margherita Mottola
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/651271
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