Radiomics is a promising tool that may increase the value of imaging in differential diagnosis (DDx) of glioma. However, implementation in clinical practice is still distant and concerns have been raised regarding the methodological quality of radiomic studies. Therefore, we aimed to systematically review the current status of radiomic studies concerning glioma DDx, also using the radiomics quality score (RQS) to assess the quality of the methodology used in each study. A systematic literature search was performed to identify original articles focused on the use of radiomics for glioma DDx from 2015. Methodological quality was assessed using the RQS tool. Spearman’s correlation (ρ) analysis was performed to explore whether RQS was correlated with journal metrics and the characteristics of the studies. Finally, 42 articles were selected for the systematic qualitative analysis. Selected articles were grouped and summarized in terms of those on DDx between glioma and primary central nervous system lymphoma, those aiming at differentiating glioma from brain metastases, and those based on DDx of glioma and other brain diseases. Median RQS was 8.71 out 36, with a mean RQS of all studies of 24.21%. Our study revealed that, despite promising and encouraging results, current studies on radiomics for glioma DDx still lack the quality required to allow its introduction into clinical practice. This work could provide new insights and help to reach a consensus on the use of the radiomic approach for glioma DDx.

BACKGROUND Radiomics is a promising tool that may increase the value of magnetic resonance imaging (MRI) for different tasks related to the management of patients with hepatocellular carcinoma (HCC). However, its implementation in clinical practice is still far, with many issues related to the methodological quality of radiomic studies. AIM To systematically review the current status of MRI radiomic studies concerning HCC using the Radiomics Quality Score (RQS). METHODS A systematic literature search of PubMed, Google Scholar, and Web of Science databases was performed to identify original articles focusing on the use of MRI radiomics for HCC management published between 2017 and 2023. The methodological quality of radiomic studies was assessed using the RQS tool. Spearman’s correlation (ρ) analysis was performed to explore if RQS was correlated with journal metrics and characteristics of the studies. The level of statistical signi-ficance was set at P < 0.05. RESULTS One hundred and twenty-seven articles were included, of which 43 focused on HCC prognosis, 39 on prediction of pathological findings, 16 on prediction of the expression of molecular markers outcomes, 18 had a diagnostic purpose, and 11 had multiple purposes. The mean RQS was 8 ± 6.22, and the corresponding percentage was 24.15% ± 15.25% (ranging from 0.0% to 58.33%). RQS was positively correlated with journal impact factor (IF; ρ = 0.36, P = 2.98 × 10-5), 5-years IF (ρ = 0.33, P = 1.56 × 10-4), number of patients included in the study (ρ = 0.51, P < 9.37 × 10-10) and number of radiomics features extracted in the study (ρ = 0.59, P < 4.59 × 10-13), and time of publication (ρ = -0.23, P < 0.0072). CONCLUSION Although MRI radiomics in HCC represents a promising tool to develop adequate personalized treatment as a noninvasive approach in HCC patients, our study revealed that studies in this field still lack the quality required to allow its introduction into clinical practice.

Spatial normalization is a critical preprocessing step in PET imaging. While MR-driven normalization represents the gold standard, MR-free approaches offer an alternative that may enhance accessibility. This study aims to evaluate the performance of MR-free normalization compared to MR-driven normalization across three PET modalities (18F-FDG, early-phase amyloid, and late amyloid PET), examinating regional agreement. 56 patients with dementia performing MR and the three PET modalities were retrospectively enrolled in the study. Three different spatial normalization methods were performed: MR-driven and two MR-free (¹⁵O-H₂O template and site-specific PET template). The agreement among different methods was pair-wise compared using intraclass correlation coefficients (ICCs). MR-free normalization showed strong agreement with MR-driven methods for FDG and early amyloid PET, with ICCs > 0.99 in cortical regions. The spatial normalization with early-phase amyloid site-specific template had a median ICC of 0.927, confirming its agreement with MR-driven approach. The performance was slightly lower with late amyloid-derived templates (ICC = 0.822) compared to the ¹⁵O-H₂O template. The worst reproducibility was observed in cerebellar and thalamic sub-regions, though aggregating sub-ROIs in parent regions brought to strong ICCs (> 0.920). MR-free normalization is a viable alternative to MR-driven approaches, particularly for FDG and early amyloid PET. In addition, the results confirm the similarity of early amyloid and FDG tracers distributions.