Aims: Cardiac sarcoidosis (CS) can be diagnosed using 18F-FDG-PET/CT (PET), cardiovascular magnetic resonance (CMR), and 123I-BMIPP/201TlCl dual myocardial SPECT. This study aims to clarify the relationships among the three modalities with respect to CS.
Methods and results: We evaluated 16 patients (male n = 11; age 55 ± 13 years) with confirmed CS who underwent PET, CMR, and dual SPECT with gated SPECT before starting steroid therapy. The left ventricular myocardium was divided into 17 segments to obtain SUVmax for PET images, defect scores from 0 to 4 (0 normal; 4 absent), and mismatch scores for dual SPECT (BMDS, TLDS, and MS) images and late gadolinium enhancement (LGE) scores (0 none; 1 partly positive; 2 homogeneous) on CMR images. Summed BMDS, TLDS, and MS were 18.6 ± 12.6, 12.9 ± 10.9, and 5.7 ± 3.1, respectively. The segmental BMDS and TLDS scores became significantly higher as the LGE scores increased. The MS scores were significantly higher in areas of LGE with a score of 1 than 0 (both, p < 0.001), but did not significantly differ between areas with LGE scores of 1 and 2. The SUVmax was significantly higher in LGE areas with a score of 1 than 0 (p < 0.025), but did not significantly differ between those with scores of 1 or 2.
Conclusion: Regions with a higher SUVmax indicating active myocardial inflammation were mainly located in areas with LGE, where BMIPP and TL mismatches were evident in patients with CS.
Keywords: Cardiac magnetic resonance; Cardiac sarcoidosis; Fatty acid metabolism; Myocardial perfusion; Positron emission tomography.