Chronic high salt (NaCl) intake is a major risk factor for cardiovascular diseases. Recent studies showed that excessive chronic NaCl intake affects immune response and thereby contributes to the pathogenesis of vascular injury. However, it remains unclear whether NaCl intake initially primes immune cell response by promoting memory T cells and sensitize the development of vascular injury in response to a subsequent stimulus. Therefore, we investigate whether 14 days of NaCl treatment (1% NaCl) followed by a 7 day washout period affects the incidence and outcome of abdominal aortic aneurysms (AAA) in apolipoprotein E deficient (ApoE-KO) mice infused chronically with angiotensin II (Ang II) (1000ng/kg/min) via osmotic minipumps for 10 days. Assessment of AAA was done by magnetic resonance imaging (MRI). To visualize vascular inflammation in vivo , perfluorocarbon nano-emulsions (PFC) injected intravenously before and 2, 4, 7 and 10 days after chronic Ang II infusion were detected by combining 1H/19F MRI using a 19 F RARE sequence. After 10 days of Ang II infusion, aortas with perivascular fat were dissected. Aortic inflammation and immune cells infiltration were analyzed by flow cytometery, immunohistology and realtime PCR. The survival rate of ApoE-KO mice pretreated with NaCl was significant lower and the AAA incidence rate was significant higher compared to non-NaCl treated apoE-KO mice. The amount of 19 F signal detected in areas of AAA was significantly increased in apoE-KO mice pretreated with NaCl. Histological analysis confirmed these results. At day 10, proinflammatory cytokines like TNF-alpha, iNOS and TGF-ß as well as numbers of neutrophils, monocytes as well as effector memory CD4 and CD8 T cells were significantly higher in aortas of NaCl pretreated apoE-KO mice compared to non-NaCl treated mice. In conclusion, these results suggest a significant role of NaCl in priming immune cell phenotype and thereby mediating vascular inflammation and damage in Ang II infused apoE-KO mice.