A SAP scan is a type of

nuclear medicine Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emitting ...

imaging test which uses iodine-123 (¹²³I) and serum amyloid P component (SAP) to diagnose

amyloidosis Amyloidosis is a group of diseases in which abnormal proteins, known as amyloid fibrils, build up in tissue. There are several non-specific and vague signs and symptoms associated with amyloidosis. These include fatigue, peripheral edema, weight ...

. In patients with amyloidosis, large deposits of SAP coat the affected organs, in addition to the low levels normally found in the blood stream. The injected ¹²³I-SAP localises specifically to amyloid deposits, showing up as hot spots in the image.

Procedure

The radiopharmaceutical is injected into the patient, with imaging taking place on a gamma camera 6-24 hours later. An early blood-pool image provides a baseline for comparison with the organ SAP uptake after 24 hours.

Availability

Europe

¹²³I-SAP was granted orphan designation by the

European Medicines Agency The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of medicinal products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products or Euro ...

in 2003, however this was withdrawn in 2016. SAP scanning is only carried out at two European centres; in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

from the National Amyloidosis Centre, based at the

Royal Free Hospital The Royal Free Hospital (also known simply as the Royal Free) is a major teaching hospital in the Hampstead area of the London Borough of Camden. The hospital is part of the Royal Free London NHS Foundation Trust, which also runs services at Barn ...

, and in

the Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

University Medical Center Groningen The University Medical Center Groningen (UMCG, nl, Universitair Medisch Centrum Groningen), formerly Groningen University Hospital, is the main hospital in Groningen, Netherlands. The medical centre is affiliated with the University of Groninge ...

North America

SAP scanning is not approved in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

due to its use of human blood products.

References

{{reflist Nuclear medicine procedures Amyloidosis

Procedure

Availability

Europe

North America

See also

References