Diagnosis and management of pericardial abscess in trauma patients

Methicillin-Resistant Staphylococcus aureus (MRSA)-Positive Pericardial Abscess Presenting in a Hemodialysis Patient

Purulent pericarditis is an uncommon infection of the pericardial space that can very rarely present as a pericardial abscess. Infection by hematogenous spread in dialysis patients is among the predisposing risk factors that can lead to purulent pericarditis. Herein, we present a pericardial abscess case due to methicillin-resistant Staphylococcus aureus (MRSA) infection in a male patient with end-stage renal disease (ESRD) on hemodialysis. The patient has a past surgical history of two prior pericardial effusions due to uremic pericarditis.

Imaging the pericardium: appearances on ECG-gated 64-detector row cardiac computed tomography

Multidetector row computed tomography (MDCT) with its high spatial and temporal resolution has now become an established and complementary method for cardiac imaging. It can now be used reliably to exclude significant coronary artery disease and delineate complex coronary artery anomalies, and has become a valuable problem-solving tool. Our experience with MDCT imaging suggests that it is clinically useful for imaging the pericardium. It is important to be aware of the normal anatomy of the pericardium and not mistake normal variations for pathology. The pericardial recesses are visible in up to 44% of non-electrocardiogram (ECG)-gated MDCT images. Abnormalities of the pericardium can now be identified with increasing certainty on 64-detector row CT; they may be the key to diagnosis and therefore must not be overlooked. This educational review of the pericardium will cover different imaging techniques, with a significant emphasis on MDCT. We have a large research and clinical experience of ECG-gated cardiac CT and will demonstrate examples of pericardial recesses, their variations and a wide variety of pericardial abnormalities and systemic conditions affecting the pericardium. We give a brief relevant background of the conditions and reinforce the key imaging features. We aim to provide a pictorial demonstration of the wide variety of abnormalities of the pericardium and the pitfalls in the diagnosis of pericardial disease.

Pericardial abscess occurring after tuberculous pericarditis: image morphology on computed tomography and magnetic resonance imaging

AIM

To study the image morphology on computed tomography (CT) and magnetic resonance imaging (MRI) of pericardial abscess, an uncommon complication of tuberculous pericarditis.

MATERIAL AND METHODS

In a 9-year period, 120 patients with clinical and imaging features of constrictive pericarditis were retrospectively reviewed. Of them, 13 patients (age range, 1-51 years; seven females, six males), who had a pericardial mass on echocardiography, and were subjected to CT (11 patients) and MRI (7 patients), were included as subjects of the present study. Five patients underwent both the investigations. The intra-lesional morphology, location, extent, mass effect on adjacent cardiac chambers, secondary effects on the atria and venae cavae, and pericardial thickness were studied. Histopathological confirmation of tubercular infection was available in nine patients. In the remaining four patients, the diagnosis was based on typical extra-cardiac manifestations of tuberculosis.

RESULTS

A total of 15 abscesses were detected. CT showed a lesion with a hypodense core and an enhancing rim in all patients. On spin-echo T1-weighted MRI, 57% of the paients had a lesion with a hyperintense core, suggesting an exudative process. Seventy-one percent of patients showed a lesion with a hyperintense core on T2-weighted MRI, while one lesion was hypointense. Post-gadolinium MRI was performed in two patients and showed an enhancing rim in both, with enhancing septa in one. The predominant site of involvement was in the right atrioventricular (AV) groove (77%). Localized tamponade, suggested by the presence of mass effect on an adjacent cardiac chamber, was noted in nine (69%) cases, with proximal atrial dilatation in 78% of them. Four other patients (31%) had atrial dilatation without a localized mass effect.

CONCLUSION

Pericardial abscess is an uncommon complication of constrictive pericarditis. Tuberculosis was responsible for abscess formation in all cases in this study. The majority of the lesions are located in the right AV groove with imaging features suggestive of localized tamponade. The presence of a hypointense core on T2-weighted MRI may suggest a tubercular aetiology.