Warm regards,
The CaliberMRI Team
Topic: Multisite MRI Intravoxel Incoherent Motion Repeatability and Reproducibility across 3 T Scanners in a Breast Diffusion Phantom: A BReast Intravoxel Incoherent Motion Multisite (BRIMM) Study
Monoexponential apparent diffusion coefficient (ADC) and biexponential intravoxel incoherent motion (IVIM) analysis of diffusion-weighted imaging (DWI) is helpful in the characterization of breast tumors. However, repeatability and reproducibility studies across scanners and across sites are scarce. Therefore, the purpose of this study is to evaluate the repeatability and reproducibility of ADC and IVIM parameters (tissue diffusivity (Dt), perfusion fraction (fp) and pseudo-diffusion (Dp)) within and across sites employing MRI scanners from different vendors in a customized breast diffusion phantom (built in collaboration with CaliberMRI). The studies were performed twice in each of two scanners (different vendors and institutions), on each of 2 days, resulting in four studies per scanner. A bipolar gradient twice-refocused spin echo sequence and monopolar gradient single spin echo sequence at 3 T were used in the two scanners. ADCs of the polyvinylpyrrolidone (PVP) and water were compared with the vendor-calibrated values at the temperature indicated by the in situ liquid crystal thermometer.
ADC and IVIM repeatability and reproducibility within and across sites were estimated via the within-system coefficient of variation (wCV). Pearson correlation coefficient (r) was also computed between IVIM metrics and flow speed. ADC and Dt demonstrated excellent repeatability and reproducibility at the two sites. fp and Dp exhibited good and moderate reproducibility. fp and Dt demonstrated high correlations with flow speed while Dp showed lower correlations. fp correlations with flow speed were significant at both sites. IVIM results were reproducible within both sites, and a progressive trend towards reproducibility across sites except for fp, which may have been impacted by different gradient waveforms.
Presenters:
Dr. Eric Sigmund is a Professor in the Department of Radiology at NYU Grossman School of Medicine. Prof. Sigmund’s group actively researches advanced diffusion MRI applications throughout the body, including intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI) in a range of applications (especially oncologic imaging in breast and kidney, renal function).
Dr. Basukala is a postdoctoral fellow in the Department of Radiology at NYU Grossman School of Medicine working with Dr. Sigmund. He has worked on evaluation and translation of intravoxel incoherent motion (IVIM) for characterization of breast cancer malignancy and prediction of treatment response. He has experience in biomedical imaging, phantoms and retrospective multicenter and multivendor breast cancer studies using multiple software platforms including deep learning.
Recent papers by Drs. Sigmund and Basukala
Motion and Flow Robust Free-Breathing Diffusion Kurtosis Imaging of the Kidney
Evaluating Breast Cancer Intravoxel Incoherent Motion MRI Biomarkers across Software Platform
Cardiac gated diffusion-weighted MR imaging assessment of kidney function in kidney cancer patients