Diagnostic Performance of 123I-Labeled Serum Amyloid P Component Scintigraphy in Patients with Amyloidosis

SAP scintigraphy is diagnostic of amyloid in most patients with AA and AL type but fewer with hereditary ATTR type, relating to differing distributions and burdens of amyloid in these disorders. It usually reveals more widespread organ involvement than is identified clinically, and certain distributions of amyloid are characteristic of particular fibril types.