Multimodality Imaging of Pericardial Diseases

Abstract

Pericardial diseases have changed their epidemiology in the past few years. With the aging population and decreasing incidence of communicable diseases, the causes of pericardial diseases have significantly changed from infectious and malignant to postradiation and cardiac surgery causes. Despite that, pericardial diseases remain difficult to diagnose. The accurate and timely diagnosis of these diseases is essential to avoid the late sequela of pericardial constriction and pericardial cirrhosis. Echocardiography remains the first test of choice for the assessment of patients with suspected pericardial diseases. Most patients with acute pericarditis have a self-limiting course and do not need further imaging. However, in the era of multimodality imaging, other modalities, namely, computed tomography (CT) and magnetic resonance imaging (CMR), are often utilized in complex cases. These two modalities provide a wide-open view of the pericardium and adjacent structures. They have high resolution to assess pericardial calcification, a hallmark of many diseases especially tuberculous constrictive pericarditis. CMR is also unique in its ability to assess pericardial late gadolinium enhancement (LGE) and edema. These have been recently suggested to be very important in the progression from acute pericarditis to constrictive pericarditis. In addition, they provide prognostic value to assess which patients are at high risk of developing heart failure and resource utilization. Thus, in the current era, patients with suspected complex pericardial diseases will need a multimodality approach rather than a single modality approach.

Management of acute pericarditis

“…Initial use cases include those with suspicion for myocardial involvement [5,10]. The stage of inflammation can be determined by combined evaluation of pericardial inflammation with late gadolinium enhancement (LGE) and pericardial edema in T2-weighted sequences performed by CMR [11]. There is a well established correlation between LGE and histological markers of inflammation, and as a result, LGE measurement may help identify patients who are at higher risk of developing complications [12].…”

CMR in Pericardial Diseases - an Update

“…On PSIR reconstruction the fluid has negative amplitude (it is total black) rendering it easily distinguishable from any other tissue. 4) CMR myocardial tagging sequences and CMR real-time phase contrast (RT-PC) flow measurement technique are two techniques which add information about specific entities like constrictive pericarditis [14,15].…”

“…Further supportive signs are an increased thickness of the pericardium to more than 4 mm in cine bSSFP imaging and pericardial effusion, which is apparent in less than 40% of patients [21]. PSIR-LGE imaging is able to detect even minute amounts of fluid not visible by echocardiography [14].CMR is able to detect pericarditis in >20% of patients with chest pain and exclusion of ischemia. The above further supports the notion of providing CMR to patients with chest pain but no ischemia to uncover the underlying pathophysiology of their chest pain [22].…”

“…CMR tissue characterization may indicate loculated pericardial effusion or pericardial masses with or without signs of malignancy [28]. Due to the fact that transudates, exudates, hemorrhagic, and proteinaceous pericardial effusions, have different native T1 and T2 relaxation times, we are able to discriminate them by using mapping techniques [14]. It is demonstrated that T1 mapping of the pericardial fluid can be used to provide information about its composition.…”

Hemorrhagic Pericardial Cyst Complicated with Constrictive Pericarditis

“…They are mostly asymptomatic and are detected incidentally (1). The initial diagnosis is generally established using chest radiography, and a further evaluation with echocardiography, computed tomography (CT), or magnetic resonance imaging is often performed for a definitive diagnosis (2). Treatment is generally not required in patients without symptoms or complications.…”