Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：European Journal of Radiology  

Objectives: To investigate whether warming gadoxetic acid affects the frequency and degree of artifacts in the arterial phase of MRI. Methods: This prospective study included patients who underwent gadoxetic acid-enhanced MRI (April 2016−November 2017 and June−November 2018) at a single center. Either warmed (37 °C, n = 134) or non-warmed (24 °C, n = 137) gadoxetic acid was intravenously injected at a dose of 0.025 mmol/kg for 5 s. Breath-hold time for each phase was fixed at 20 s. Artifact severity was graded using a four-point scale. Patient background and artifact scores in precontrast, arterial, and portal phases were compared between groups. Results: Two hundred and seventy-one patients (mean age 64 ± 14 years, 149 male) were included. Patient background including the presence of pleural effusion, ascites, cirrhosis, and pulmonary disease, did not differ significantly between the two groups. The mean artifact score in the arterial phase was significantly lower in the 37 °C group than in the 24 °C group (1.4 ± 0.8 vs. 1.6 ± 0.9, p = 0.017), whereas no significant difference was observed in the precontrast and portal phases. The rate of substantial artifact (score = 3 or 4) in the arterial phase was significantly lower in the 37 °C group than in the 24 °C group (11.2 % vs. 21.1 %, p = 0.031). The number of patients with high artifact scores in the arterial phase compared to those in the precontrast image was also lower in the 37 °C group than in the 24 °C group (21.6 % vs. 36.0 %, p < 0.01). Conclusions: Warmed gadoxetic acid could reduce artifacts in the arterial phase of dynamic MRI.

DOI： 10.1016/j.ejrad.2025.112384

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PubMed

Language：English   Publisher：Japanese Society for Magnetic Resonance in Medicine  

<p>Purpose: To compare diagnostic reliability between an intravoxel incoherent motion (IVIM) imaging and an arterial spin labeling (ASL) in assessment of renal blood flow in rodents.</p><p>Methods: We first evaluated 3 different fitting methods on 5 datasets of diffusion-weighted imaging (DWI) with 10 b-values (0–1000 s/mm²) for bi-exponential analysis in IVIM imaging to calculate pseudo-diffusion parameters. Coefficient of variation (CV) for each parameter and correlation among the parameters was assessed to test the robustness of the 3 fitting methods. Subsequently, DWI and ASL methods were performed before and 14 days after onset of acute kidney injury (AKI) in a rat model. Temporal change before and after AKI onset in the pseudo-diffusion parameters in 3 fitting methods was compared with that in the renal blood flow (RBF) derived in the ASL method.</p><p>Results: The CVs in all IVIM parameters were the lowest in the fitting method that estimated pseudo-diffusion parameters after a fixed true-diffusion was determined where the pseudo- and true-diffusion coefficients had no correlation. The RBF substantially reduced (~50%, <i>P</i> < 0.001) due to the AKI onset; however, no pseudo-diffusion parameters in any of 3 fitting methods could not detect the change. Further, any pseudo-diffusion parameters showed no correlation with the RBF.</p><p>Conclusion: Pseudo-diffusion parameters in the IVIM concept were not reliable to estimate RBF in the study. Since the kidney has a unique profile in the “tissue flow”, our data indicate that study design and interpretation of results needs to be carefully considered when IVIM imaging is used for evaluation of blood flow in tissue, especially in the kidney.</p>

DOI： 10.2463/mrms.mp.2023-0169

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Scopus

PubMed

CiNii Research

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2463/mrms.mp.2023-0169.

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