Blood analogs are widely employed in in vitro experiments such as particle image velocity (PIV) to secure hemodynamics, assisting pathophysiological diagnoses of neurovascular and cardiovascular diseases, as well as pre-surgical planning and intraoperative orientation. To obtain accurate physical parameters, which are critical for diagnosis and treatment, blood analogs should exhibit realistic non-Newtonian shear-thinning features. In this study, two types of blood analogs working under room temperature (293.15 K) were created to mimic the steady-state shear-thinning features of blood over a temperature range of 295 to 312 K and a shear range of 1~250 s⁻¹ at a hematocrit of ~40%. Type I was a general-purpose analog composed of deionized (DI) water and xanthan gum (XG) powder, while Type II was specially designed for PIV tests, incorporating DI water, XG, and fluorescent microspheres. By minimizing the root mean square deviation between generated blood analogs and an established viscosity model, formulas for both blood analogs were successfully derived for the designated temperatures. The results showed that both blood analogs could replicate the shear-thinning viscosities of real blood, with the averaged relative discrepancy < 5%. Additionally, a strong linear correlation was observed between body temperature and XG concentration in both blood analogs (coefficient of determination > 0.96): for Type I, 295–312 K correlates with 140–520 ppm, and for Type II, 295–315 K correlates with 200–560 ppm. This work bridges the gap between idealized steady-state non-Newtonian viscosity models of blood and the complexities of real-world physiological conditions, offering a versatile platform for advancing particle image velocimetry tests and hemodynamics modeling, optimizing therapeutic interventions, and enhancing biomedical technologies in temperature-sensitive environments.

Purpose: The intracranial aneurysm (IA) model reconstruction is critical for pathophysiology diagnosis and computational simulations. This study aimed to quantify the impact of segmentation thresholds and software platforms on the reconstruction of IA geometry as well as the impact of inter-user variability on the assessment of morphology. Methods: 600 IA models were reconstructed from 100 patient DSA datasets using Materialise Mimics and 3D Slicer at three grey value (GV) thresholds; 1000, 1500, and 2500. Geometric measurements were performed in 3-matic by three users. Measurements included vessel diameters and aneurysm morphology parameters. Mimics, the 2500 GV threshold, and the most experienced user (R1) served as baselines for comparison. Normality was evaluated using Shapiro-Wilk tests, and statistical differences were assessed with paired t-tests and relative percent differences. Results: All anatomical regions showed statistically significant geometric variation across software and threshold. Model evaluation showed potential statistically significant variation between users. Models from 3D Slicer were consistently smaller than those from Mimics with percent differences ranging from − 1.27 to − 4.38% (all p < .05). Lower thresholds produced consistently larger models; decreasing from 2500 to 1000 GV increased average diameters by up to 15.9%, depending on specific region. User-related variability was most pronounced in the least experienced user, with size measurements deviating by up to 22.67% from the baseline. Conclusion: Segmentation software, threshold selection, and user interaction each introduce meaningful and statistically significant variability into IA model geometry and evaluation. Standardization of segmentation protocols—especially threshold values and operator training—is essential to improve reproducibility.

Blood analogs are widely employed in in-vitro experiments such as particle image velocity (PIV) to study hemodynamics, assisting pathophysiological diagnosis of neurovascular and cardiovascular diseases, as well as pre-surgical planning and intraoperative orientation. To obtain accurate physical parameters critical for diagnosis and treatment, blood analogs should exhibit realistic non-Newtonian shear-thinning features. In this study, two types of blood analogs were created to mimic the shear-thinning behavior of blood over a temperature range of 295 to 312 K. Type-I is a general-purpose analog composed of deionized (DI) water and Xanthan gum (XG) powder, while Type-II is specially designed for PIV tests, incorporating DI water, XG and fluorescent microspheres (450 ppm). By minimizing the root mean square deviation between the generated blood analog and an established viscosity model, formulas for both blood analogs were successfully derived for the designated temperature range. Results show both blood analogs can replicate the shear-thinning properties of real blood, with the averaged relative discrepancy < 5%. Additionally, a strong linear correlation was observed between body temperature and XG concentration in both blood analogs (coefficient of determination > 0.96): for Type-I, 295-312 K correlates with 140-520 ppm and for Type-II, 295-315 K correlates with 200-560 ppm. This work bridges the gap between idealized blood viscosity models and the complexities of real-world physiological conditions, offering a versatile platform for advancing hemodynamic research, optimizing therapeutic interventions, and enhancing biomedical technologies in temperature-sensitive environments.