Accurate　diagnosis　of　cancer　at　an　early　stage　is　the　key　to　reduce　cancer　mortality　and　improve　survival.　PET　imaging　has　high　sensitivity　but　low　spatial　resolution,　while　CT　imaging　has　good　spatial　location　information.　Therefore,　the　combination　of　PET　and　CT　imaging　can　provide　complementary　advantages　to　achieve　accurate　early　diagnosis　of　tumors.　However,　currently　developed　PET　or　CT　imaging　agents　have　only　a　single　function.　Here,　we　designed　and　constructed　a　self-assembled　lipid　nanocapsule　encapsulated　with　iodixanol　and　labeled　with　self-chelated　64Cu　for　precise　PET/CT　imaging　of　tiny　lung　tumor.　The　lipid　nanocapsule　self-assembled　in　water　using　LPPC-Ce6,　a　conjugate　of　chlorin　e6　(Ce6)　and　lysophosphatidylcholine　(LPPC),　to　form　a　bilayer　vesicular　structure.　64Cu　was　embedded　in　the　center　of　the　tetrapyrrole　ring　of　Ce6　by　natural　capture　ability　for　Cu2+　ions.　GLT21.T,　the　aptamer　targeting　lung　cancer,　was　conjugated　to　the　surface　of　the　lipid　nanocapsules.　Iodixanol　was　loaded　into　the　cavity　of　the　lipid　nanocapsule　(64Cu@LCI-apt).　In　the　nanostructure,　the　loading　of　iodixanol　was　sufficiently　high,　and　the　specific　activity　could　be　flexibly　adjusted　according　to　imaging　requirements.　The　prepared　64Cu@LCI-apt　achieves　excellent　radiolabeling　efficiency,　stability　and　effective　targeting　of　lung　tumor.　In　an　early　orthotopic　lung　cancer　model,　64Cu@LCI-apt　demonstrated　the　capabilities　of　sensitive　PET　imaging　and　enhanced　contrast　CT　imaging　to　enable　efficient　high-quality　PTE/CT　imaging　of　tiny　orthotopic　lung　tumor　with　a　diameter　of　500　μm.　64Cu@LCI-apt　has　great　potential　for　early,　sensitive,　and　accurate　diagnosis　of　tumors　through　dual-mode　PET/CT　imaging.　Copyright　©　2019　American　Chemical　Society.