*5.4.1 Nuclear magnetic resonance imaging*

Nuclear magnetic resonance imaging is one of the most useful imaging techniques for the assessment of cardiac sarcoidosis. There is no pattern that can be defined as typical; however, the delayed enhancement of the gadolinium is patched (and does not follow a vascular pattern); it compromises the myocardium and the subepicardium, unlike acute myocardial infraction that compromises the subendocardium; it usually affects the basal segments of the septum and the inferolateral wall. Left ventricle involvement is more common. Transmural and right ventricle compromise is infrequent; however, these findings do not rule out the presence of the cardiac sarcoidosis. Some series report a negative predictive value up to 100% with epidemiological limitations with respect to the gold pattern. For this reason, although a negative cardiac resonance image is not common, cardiac compromise due to this pathology cannot be disregarded, especially if the probability and clinical suspicion are high [22, 23]. The superiority of the cardiac nuclear magnetic resonance imaging in the diagnosis of sarcoidosis was proven by Ichinose et al. [24]; he found sensitivity from 75 to 100% and specificity from 39 to 78%. He showed that the NMRI is superior to SPECT with thallium and gallium [25]. The increase in the T2 signal correlated in some subjects with inflammation and major adverse events; NMRI continues to be studied [20, 22]. The limitations of NMRI include patients with implanted cardiac devices (relative), chronic renal disease (stage 4/5), and claustrophobia.
