Perfusion Analysis Using Rubidium in Cardiac Sarcoidosis

The presence of cardiac involvement is a serious complication of sarcoidosis. Early diagnosis is challenging since it relies on an array of clinical, biological and imaging abnormalities. Myocardial perfusion imaging with sestamibi is currently a major feature of the diagnosis, since it allows to evidence both microcirculatory impairments and scar. However, some technical limitations are inherent to SPECT, mainly poor spatial resolution and lack of attenuation correction, resulting in the absence of flow quantification. Rubidium-82 (Rb) PET proved to be more sensitive and specific than sestamibi SPECT in the diagnosis of coronary artery disease. Furthermore, it allows noninvasive measurement of coronary flow reserve. Finally, it exposes patients to lower radiation dose than SPECT. Therefore, Rb PET may help to better identify cardiac involvement of sarcoidosis, and hence to better select those patients who require high-dose steroids.