Objective: This research aims to explore the relationship between quantitative metrics derived from dual-energy CTA (DE-CTA) iodine substance mapping and the extent of branch vessel hypoperfusion in cases of aortic dissection (AD), along with evaluating their capacity to forecast short- and medium-term clinical outcomes. Methods: Eighty AD patients who underwent DE-CTA were retrospectively enrolled. Iodine concentration (IC) of branch vessels, normalized iodine concentration (NIC = branch vessel IC/aortic true lumen IC at the same level), and false lumen IC were measured. Parameters were compared between ischemic and non-ischemic groups, as well as between poor and good prognosis groups. Correlations between parameters and ischemia indicators, and prognostic factors were analyzed. Results: Branch vessel IC and NIC in the ischemic group were significantly lower than those in the non-ischemic group (P<0.001), while false lumen IC was significantly higher (P<0.001). Branch vessel NIC was negatively correlated with serum creatinine (r=-0.632) and lactate (r=-0.589) (P<0.001). Multivariate Logistic regression showed that decreased branch vessel NIC (OR=0.032, P<0.001) and Stanford type A (OR=4.826, P=0.026) were independent risk factors for poor prognosis. Conclusion: Quantitative parameters of DE-CTA iodine material map, especially branch vessel NIC, can effectively assess branch vessel ischemia and independently predict short-term prognosis in AD, providing imaging evidence for individualized diagnosis and treatment.