Several critical methodological gaps and interpretive oversights raise concerns about the robustness and generalizability of the reported findings:
1. Despite the claim that these fiber-based scintillators outperform rigid screens in non-planar imaging, there is no side-by-side quantitative comparison with commercial flat-panel detectors using metrics such as spatial resolution (e.g., MTF), signal-to-noise ratio (SNR), or X-ray absorption efficiency. How can such performance claims be justified without direct benchmarking?
2. The functionality of the fiber is critically dependent on uniform distribution of nanoemitters within the polymer matrix, yet the paper lacks cross-sectional or longitudinal mapping of luminescence intensity. What measures were taken to assess or control for heterogeneity in nanoemitter dispersion, especially over longer fiber lengths or multiple batches?
3. No data are provided on how the fibers and nanoemitters perform under repeated or prolonged X-ray exposure, conditions common in practical use. Has any assessment been done on photobleaching, radiation-induced degradation, or mechanical deterioration of the fiber matrix? If not, how can claims of applicability to real-world medical or industrial imaging be substantiated?
4. The imaging demonstrations are largely limited to simple mechanical parts and artificial 3D objects. Why were no realistic biological phantoms or clinically relevant models used to test the practical diagnostic capability of the platform? Without such validation, the claimed potential for biomedical applications remains speculative.
Following up on the earlier concerns regarding the lack of benchmarking and methodological rigor, a further issue arises with the data presented in Figures 2c and 2d. The light yield (LY) values are presented as a key performance metric, yet there is no evidence that they have been normalized for X-ray absorption efficiency or material density, despite clear differences in attenuation efficiency shown in Figure 2d. This is not a minor oversight. Given that Cu2I2-based composites exhibit significantly lower stopping power, reporting higher or comparable LY values without correction for absorbed dose introduces a serious interpretive flaw. Without normalizing LY to the actual energy deposited in the material (e.g., photons per MeV or per unit absorbed dose), it is impossible to distinguish whether observed differences arise from superior scintillation performance or simply from variations in X-ray attenuation.