Echocardiography in Sarcoidosis

PURPOSE OF REVIEW

Cardiac sarcoidosis (CS) is associated with significant morbidity and mortality. The diagnosis of CS is challenging and typically one that is only entertained after many other conditions have been ruled out. A high index of suspicion is necessary in order to correctly determine appropriate testing for the disease. Transthoracic echocardiography is the most readily available imaging modality available to help establish a diagnosis in a potential patient. However, no one echocardiographic feature is pathognomonic.

RECENT FINDINGS

On echocardiography, unusual wall motion abnormalities, which do not fit a classic coronary distribution, along with diastolic dysfunction may alert one to the presence of cardiac sarcoid, particularly in the right clinical context. Myocardial strain imaging on echocardiography may increase the sensitivity of identifying cardiac sarcoidosis. Alternative imaging with cardiac magnetic resonance imaging or positron emission tomography have become more frequently utilized to establish a diagnosis of CS. Cardiac sarcoidosis remains a difficult condition to diagnose. However early diagnosis is critical to decrease the associated high mortality. Endomyocardial biopsy is highly specific but lacks sensitivity due to the patchy nature of the granulomatous deposition. Thus, imaging plays a role in diagnosis as well as for follow-up. Echocardiography remains an hallmark during the workup for CS. Decreased sensitivity of echocardiography has facilitated the use of other techniques to establish the presence of CS.

Cardiovascular PET/MR imaging: Quo Vadis?

With the recent advent of PET/MRI scanners, the combination of molecular imaging with a variety of known and novel PET radiotracers, the high spatial resolution of MRI, and its potential for multi-parametric imaging are anticipated to increase the diagnostic accuracy in cardiovascular disease detection, while providing novel mechanistic insights into the initiation and progression of the disease state. For the time being, cardiac PET/MRI emerges as potential clinical tool in the identification and characterization of infiltrative cardiac diseases, such as sarcoidosis, acute or chronic myocarditis, and cardiac tumors, respectively. The application of PET/MRI in conjunction with various radiotracer probes in the identification of the vulnerable atherosclerotic plaque also holds much promise but needs further translation and validation in clinical investigations. The combination of molecular imaging and creation of multi-parametric imaging maps with PET/MRI, however, are likely to set new horizons to develop predictive parameters for myocardial recovery and treatment response in ischemic and non-ischemic cardiomyopathy patients. Molecular imaging and multi-parametric imaging in cardiovascular disease with PET/MRI at current stage are at its infancy but bear a bright future.