Scintigraphy in patients with possible inflammation after joint replacement with prosthesis

Summary

Introduction:
Three-phase bone scan together with leukocytes scan to detect inflammation after joint prosthesis could be non-specific. It is due to the fact, that leukocytes accumulate both in the site of inflammation and in the bone marrow. Bone marrow scintigraphy with labeled colloids, which accumulates only in the bone marrow, makes the diagnosis more precise.

Aim:
To inform about the principles of scintigraphic methods used for characterization of possible inflammation after joint prosthesis.

Material and methods:
Scintigraphy with Tc-99m labeled leukocytes and bone marrow scan with Tc-99m labeled nano-colloid were performed in patients after knee joint replacement with the gamma camera Infinia Hawkeye with high-resolution collimator within the interval of 2 to 5 days. We performed static planar images in the anterior and posterior views with 256x256 matrix, 600 sec/frame and tomographic images (128x128 matrix, step 6°, 20 sec/frame) together with a low-dose computed tomography. The precise position of lower extremities was achieved with a special holder. Images Registration software Volumetrix IR using computed tomography was used to subtract data from both studies.

Results:
Inflammation is characterized by leukocytes accumulation while accumulation of nano-colloid is absent. Accumulation of both leukocytes and colloid in the surrounding of knee prosthesis is typical for bone marrow, not for inflammation.

Conclusion:
Comparison of the distribution of both Tc-99m labeled leukocytes and Tc-99m labeled nano-colloid and images registration with computed tomography makes it possible to detect possible inflammation after joint surgery with higher precision.

Key Words:
joint prosthesis, inflammation, leukocyte scintigraphy, bone marrow scintigraphy with colloids