Radiomics with 3-dimensional magnetic resonance fingerprinting: influence of dictionary design on repeatability and reproducibility of radiomic features

<jats:title>Abstract</jats:title><jats:sec> <jats:title>Objectives</jats:title> <jats:p>We aimed to investigate the influence of magnetic resonance fingerprinting (MRF) dictionary design on radiomic features using in vivo human brain scans.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>Scan-rescans of three-dimensional MRF and conventional T1-weighted imaging were performed on 21 healthy volunteers (9 males and 12 females; mean age, 41.3 ± 14.6 years; age range, 22–72 years). Five patients with multiple sclerosis (3 males and 2 females; mean age, 41.2 ± 7.3 years; age range, 32–53 years) were also included. MRF data were reconstructed using various dictionaries with different step sizes. First- and second-order radiomic features were extracted from each dataset. Intra-dictionary repeatability and inter-dictionary reproducibility were evaluated using intraclass correlation coefficients (ICCs). Features with ICCs > 0.90 were considered acceptable. Relative changes were calculated to assess inter-dictionary biases.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>The overall scan-rescan ICCs of MRF-based radiomics ranged from 0.86 to 0.95, depending on dictionary step size. No significant differences were observed in the overall scan-rescan repeatability of MRF-based radiomic features and conventional T1-weighted imaging (<jats:italic>p</jats:italic> = 1.00). Intra-dictionary repeatability was insensitive to dictionary step size differences. MRF-based radiomic features varied among dictionaries (overall ICC for inter-dictionary reproducibility, 0.62–0.99), especially when step sizes were large. First-order and gray level co-occurrence matrix features were the most reproducible feature classes among different step size dictionaries. T1 map-derived radiomic features provided higher repeatability and reproducibility among dictionaries than those obtained with T2 maps.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusion</jats:title> <jats:p>MRF-based radiomic features are highly repeatable in various dictionary step sizes. Caution is warranted when performing MRF-based radiomics using datasets containing maps generated from different dictionaries.</jats:p> </jats:sec><jats:sec> <jats:title>Key Points</jats:title> <jats:p>• <jats:italic>MRF-based radiomic features are highly repeatable in various dictionary step sizes</jats:italic>.</jats:p> <jats:p>• <jats:italic>Use of different MRF dictionaries may result in variable radiomic features, even when the same MRF acquisition data are used</jats:italic>.</jats:p> <jats:p>• <jats:italic>Caution is needed when performing radiomic analysis using data reconstructed from different dictionaries</jats:italic>.</jats:p> </jats:sec>