Figure 26. Whole-body scintigraphy and planar chest images with technetium-99m-labeled pyrophosphate showing light-intensity accumulation (grade 1) projecting from the heart (arrow) of a patient with subsequent confirmation of light-chain amyloidosis due to a monoclonal spike in serum and urine electrophoresis, increased serum free light-chain antibodies, and bone marrow aspirate showing plasma cell infiltrate < 10%. Final confirmation was performed by abdominal fat biopsy, which was positive for amyloidosis.