T1-Weighted Image, Table 1 Appearance of tissues on T1-weighted images Signal intensity Tissues Dark Air, mineral-rich tissue (cortical bone, stones), fast-flowing blood Low Collagenous tissue (ligaments, tendons, scars), high free water tissue (kidneys, gonads, edema, fluids [urine, bile], simple cysts, bladder, gallbladder, spleen, CSF), high bound-water tissues (liver, pancreas, adrenals, hyaline cartilage, muscle) Intermediate Proteinaceous tissue (abscess, complex cysts, synovial fluid) Bright Fat, fatty bone marrow, blood products (methemoglobin, slow-flowing blood, radiation change, paramagnetic contrast agents)