Abstract: Objective: To investigate the effect of high-flow-rate normal saline pre-injection based on individualized contrast medium protocol on image quality and extravasation in head and neck computed tomographic angiography (CTA). Methods: A total of 320 individuals scheduled for head and neck CTA at our hospital between January 2025 and June 2025 were randomly divided into observation and control groups (n = 160 each) using a random number table. Both groups received weight-based personalized contrast medium injection at a set rate of 0.06 mL/kg/s based on body weight over a fixed duration of 10 s. The control group received a 14 s normal saline flush administered at 1.3 times the contrast medium flow rate, following the contrast medium injection. The observation group received a 7 s high-flow-rate normal saline pre-injection at 1.3 times the contrast medium flow rate immediately before contrast administration, followed by contrast medium injection and a 14 s normal saline flush at the same rate. The subjective image quality, objective image quality, and contrast medium extravasation were compared between the groups. Results: The subjective image scores in both groups were consistently ≥3 points. The most frequent scores were 5 and 4 in the observation and control groups, respectively. With kappa values of 0.725 and 0.769, respectively, the differences were statistically significant (P < 0.001). The mean CT values of the aortic arch, right subclavian artery, carotid artery, and basilar artery were significantly higher in the observation group compared with the control group (t = −5.08, P < 0.001; t = −2.85, P = 0.005; t = −4.77, P < 0.001; and t = −3.78, P < 0.001, respectively), whereas that of the right subclavian vein was significantly lower in the observation group (t = 3.45, P < 0.001). Contrast extravasation occurred in one participant in the control group, whereas none occurred in the observation group. Conclusion: An injection protocol involving a high-flow-rate normal saline pre-injection, immediately followed by individualized contrast medium administration, enhances CT values of target vessels in head and neck CTA, reduces residual contrast medium artifacts in the injection route veins, and minimizes extravasation.