LEARN NUCLEAR MEDICINE
Musculoskeletal · Case 10
Read the history, inspect the study, then reveal the teaching.
IMAGE PLACEHOLDER · Diagnostic study
Original study · Companion image placeholders
Clinical history
A 40-year-old man presents to the clinic with weakness, edema, and macroglossia. He has a 5 year history of rheumatoid arthritis, managed with methotrexate. A bone scan is provided below.
Read the images before opening the teaching panel below.
Amyloidosis
Imaging Findings
The technetium-99m MDP bone scan shows cardiac uptake of MDP.
Diferential Diagnosis
Scleroderma
Myocarditis
Essential Facts
Amyloidosis is a rare disease that causes an accumulation of insoluble, abnormal protein (amyloid) in various organs and tissues, including the heart, nervous system, liver, and digestive system.
This buildup prevents affected organs from functioning properly, and can even lead to organ failure.
Symptoms include: edema, fatigue, weakness, GI disturbances, skin changes, and arrhythmias. Risk factors include old age, male sex, and family histroy.
Scan Information
Bone scans using Tc99m-PYP tracer have proven to be helpful in identifying certain types of amyloidosis. Extraosseous uptake suggests the presence of amyloid deposits in the organs and soft tissues that take up the tracer. However, the absence of any uptake does not rule out amyloid infiltration. An endomyocardial biopsy remains the gold standard for definitive diagnosis of cardiac amyloid.
References
Little, D. (n.d.). Cardiac amyloidosis: Radiology Case. Retrieved June 17, 2020, from https://radiopaedia.org/cases/cardiac-amyloidosis-8?lang=us
https://drive.google.com/drive/folders/1Ie3LOc5F3RJvYvqD6nVyLqB49kn8J6Cz