Sensitivity and specificity of chest imaging for sarcoidosis screening in patients with cardiac presentations

Patients with sarcoidosis can present with cardiac symptoms as the first manifestation of disease in any organ. In these patients, the use of chest imaging modalities may serve as an initial screening tool towards the diagnosis of sarcoidosis through identification of pulmonary/mediastinal involvement; however, the use of chest imaging for this purpose has not been well studied. We assessed the utility of different chest imaging modalities for initial screening for cardiac sarcoidosis (CS).

All patients were investigated with chest x-ray, chest computed tomography (CT) and/or cardiac/thorax magnetic resonance imaging (MRI). We then used the final diagnosis (CS versus no CS) and adjudicated imaging reports (normal versus abnormal) to calculate the sensitivity and specificity of individual and combinations of chest imaging modalities. We identified 44 patients (mean age 54 (±8) years, 35.4% female) and a diagnosis of CS was made in 18/44 patients (41%). The sensitivity and specificity for screening for sarcoidosis were 35% and 85% for chest x-ray, respectively (AUC 0.60; 95%CI 0.42-0.78; p value=0.27); 94% and 86% for chest CT (AUC 0.90; 95%CI 0.80-1.00; p value <0.001); 100% and 50% for cardiac/thorax MRI (AUC 0.75; 95%CI 0.56-0.94; p value=0.04).

During the initial diagnostic workup of patients with suspected CS, chest x-ray was suboptimal as a screening test. In contrast CT chest and cardiac/thorax MRI had excellent sensitivity. Chest CT has the highest specificity among imaging modalities. Cardiac/thorax MRI or chest CT could be used as an initial screening test, depending on local availability.