## 3 Results  
### In Vitro Experiment Results  
After using D.D. water for in vitro T1W and T2W pulse sequence imaging, visualized grayscale numerical statistics were conducted to verify the feasibility of applying T1W and T2W pulse sequences in the scheme, as shown in Figure 1. Figure 1A shows that with T1W and T2W pulse sequence D.D. water sample imaging, it could be clearly distinguished from the MRI DICOM grayscale image that T1W presented low signal images (dark) and T2W presented high signal images (bright). With the T1W pulse sequence setting, during the interval of the repetition time (TR), most of the longitudinal magnetization intensity could not be recovered, and the MR received signal was weak, showing dark images. In the MRI image on the left of Figure 1A, the richer the hydrogen atom signals, the darker the grayscale display of MRI images. Correspondingly, the grayscale values of the images were lower, as shown in the color gradation diagram on the left side of Figure 1B and the numerical visual diagram on the left side of Figure 1C. With the T2W pulse sequence setting, a relatively long receiving TE was generated, the MR received signals were relatively strong, and bright images were presented, as shown in the MRI images on the right side of Figure 1A. The richer the hydrogen atom signals, the brighter the grayscale display of the MRI images. Correspondingly, the grayscale values of the images were also higher, as shown in the color gradation diagram on the right side of Figure 1B and the numerical visual diagram on the right side of Figure 1C. Grayscale value visual matrix image color layer analysis was carried out on the DICOM grayscale images, and statistical analysis was performed by one-way ANOVA. The results are shown in Figure 1D, with \(p<0.05\) (\(p=0.022\)), indicating that there was statistically a significant difference between T1W and T2W, which also verified the consistency between the qualitative comparison of MRI images and quantitative analysis of grayscale values. The analysis of in vitro experiments is shown in Figure 2. Figures 2A and 2C are the T1W and T2W images of paramagnetic contrast agent Gd-DTPA-BMEA and superparamagnetic contrast agent ferucarbotran, respectively. The tables in the lower parts of Figure 2A,C show the contrast agents in different dilutions, sorted from large (upper left well) to small (lower right well). In Figure 2A, the percentages range from 2.3% to 0%, with a decreasing step of 0.1%, and the dilution percentages of Gd-DTPA-BMEA were optimized by investigating the highest signal among the 24 well dishes. The highest signal represents that the optimized concentration of Gd solutions attained the maximum increase of the relaxation rates of nearby water protons. In Figure 2C, the non-uniform magnetic field generated by iron oxide particles caused a marked decline (dark) in MRI signal intensity and an increase in the T2 relaxation rate. Different dilution ratios were deployed in a staggered 24 well dish in a multiple-decreasing manner, with the volume percentage concentration decreasing from 1% to 0.00025% over a total of 12 images. As the dilution volume percentage increased, the effect of iron oxide particles on the field of low-signal was weakened. The low-signal image (darkness) also gradually turned into a high-signal image (brightness). Figure 2B,C convert the grayscale images in Figure 2A,C into color images for convenient visualization. However, it is difficult to find the best  
Figure 1: (**A**) T1W (dark) and T2W (bright) pulse sequence imaging was carried out with D.D. water as the sample. (**B**) The images in Figure 1A were subjected to grayscale image visualization color gradation, and the lower left corner of Figure 1B is the grayscale value color distribution table of each image. (**C**) The layered numerical information in Figure 1B was converted into a graphic numerical visual diagram. (**D**) Statistical analysis and comparison were carried out on the numerical information in Figure 1C.