Vulnerable plaque (VP) is the main cause of death from heart attacks. All currently available methods developed to diagnose VP lack sensitivity and or specificity and are still unable to identify VP. Our patent addresses the problem to diagnose VP in arteries. The teachings here disclose a vulnerable plaque optical analyzer (VPOA) and Imager (VOPAI) for monitoring arterial walls by measuring whether the fingerprint Raman spectrum of adipose (lipid) tissue using Resonance Raman (RR) and common Raman(R) signals of aortic intimal wall layer. The RR and R lines of lipid determine presentation of VP.