OBJECTIVE: Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. MATERIALS AND METHODS: Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 x [measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. RESULTS: A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. CONCLUSION: The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials.
Adult ; Atlases as Topic ; Brain Mapping/*methods ; Female ; Humans ; Image Enhancement/methods ; Image Processing, Computer-Assisted/*methods ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Software ; Statistics, Nonparametric

Prevention, early diagnosis, and early treatment of skeletal-related events (SREs) are important in the treatment of potential or current cases of bone metastasis. In August 2020, our hospital established the bone metastasis team and the bone metastasis board (BMB) started actively engaging in activities aimed at improving the outcome of bone metastasis. We retrospectively examined whether a combined modality therapy started in the diagnosis of bone metastases could prevent the onset of SREs and whether it could prolong survival and improve activities of daily living. The 75 advanced cancer patients who underwent BMB at our hospital from August 1, 2020 to July 31, 2022 were divided into two groups according to when BMB performed before and after SREs for comparative analysis. Numerical Rating Scale improved, however Performance Status did not improve in both groups, and there was no difference in survival between the both groups (15.3 vs. 9.0 months, HR: 0.74, 95%; CI: 0.42–1.29, p=0.29). In conclusion, patients who suffered from SREs from the time of bone metastasis diagnosis were treated early. However, the incidence of SREs after BMB in our hospital was 22.6%, and it is necessary to actively work to prevent SREs in the future.