CA9 and Renal neoplasm: Due to the shortcomings of conventional imaging modalities, new imaging techniques have been developed to assess renal tumours, including contrast-enhanced ultrasound (CEUS), dual-energy CT (DECT), 18F-Fluorodeoxyglucose (FDG) PET/CT, prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT), technetium-99m sestamibi (99mTc-sestamibi) single photon emission computed tomography (SPECT)/CT, and carbonic anhydrase IX (CAIX) inhibitors.