Sarcoidosis is a multisystem
disease characterized by noncaseating
granulomas . Cardiac involvement is known to have poor
prognosis because it can manifest as a serious condition such as the conduction
abnormality, heart failure, ventricular
arrhythmia , or
sudden cardiac death . Although
early diagnosis and early
treatment is critical to improve
patient prognosis , the
diagnosis of CS is challenging in most cases.
Diagnosis usually relies on endomyocardial
biopsy (EMB), but its diagnostic yield is low due to the
incidence of patchy myocardial involvement. Guidelines for the
diagnosis of CS recommend a combination of clinical, electrocardiographic, and imaging findings from various modalities, if EMB cannot confirm the
diagnosis . Especially, the
role of advanced imaging such as cardiac
magnetic resonance (CMR) imaging and
positron emission tomography (
PET ), has shown to be important not only for the
diagnosis , but also for
monitoring treatment response and prognostication. CMR can evaluate cardiac function and fibrotic
scar with good
specificity . Late
gadolinium enhancement (LGE) in CMR shows a distinctive enhancement pattern for each
disease , which may be useful for
differential diagnosis of CS from other
similar diseases . Effectively, T1 or T2 mapping
techniques can be also used for early recognition of CS. In the meantime,
PET can detect and quantify metabolic activity and can be used to monitor
treatment response. Recently, the use of a
hybrid CMR-
PET has introduced to allow identify
patients with active CS with excellent co-
localization and better diagnostic accuracy than CMR or
PET alone. However, CS may show various findings with a wide spectrum, therefore,
radiologists should consider the possible
differential diagnosis of CS including
myocarditis ,
dilated cardiomyopathy (DCM),
hypertrophic cardiomyopathy ,
amyloidosis , and
arrhythmogenic right ventricular cardiomyopathy .
Radiologists should recognize the differences in various
diseases that show the characteristics of mimicking CS, and try to get an accurate
diagnosis of CS.