The NMR Lipoprotein Fractionation Test uses nuclear magnetic resonance to measure particle size and concentration of LDL, HDL, and VLDL cholesterol. Unlike a standard lipid panel, it provides detailed information on lipoprotein subfractions linked to cardiovascular risk. Doctors use this test to assess heart disease risk, guide cholesterol management, and monitor therapy effectiveness. It offers deeper insight into lipid metabolism and cardiovascular health.