Tuberculous Pericarditis

Clinical History: An 18-year-old Nigerian male with a history of previous exposure to tuberculosis, presented to our department for a mild, subcontinuous, fever and dyspnea.

Figure 1. Short Axis Cardiac MRI shows moderate pericardial effusion (transparent arrow) mainly along the posterior and anterior walls, with thickened appearance of the pericardial layers (white arrow).

Figure 2. Four chambers cardiac MRI allows good differentiation between the pericardial fluid (transparent arrow) and pericardial layers (white arrows).

Figure 3. Short axis cardiac MRI shows strong enhancement of the thickened pericardial layers (white arrows).Tuberculous Pericarditis

A transthoracic echocardiography demonstrated a diffuse hypokinesia of the right and the left
ventricle. A moderate pericardial effusion was also noted. Mantoux reaction was positive.
MRI was requested for further assessment of global ventricular performance and to evaluate the pericardium.

Cardiac Involvement is rare in tuberculosis (0.5 percent of cases of extrapulmonary tuberculosis). Most of the cases are represented by immune compromised patients or subjects coming from regions with a high prevalence of tubercular disease.

Pericardial involvement accounts for most of the manifestations of cardiac tuberculosis. The pericardium can be primitively interested in the miliary diffusion of the disease or by the spreading of the infection from a tubercular focus from the mediastinal lymp nodes. In the majority of cases, the pericardium is thickened of more than 3 mm, showing an irregular shape and less often patchy or diffuse calcifications. Pericardial effusion may also be associated.

The suspect of tuberculous pericarditis is usually clinical and anamnestic. Imaging methods are needed to confirm the diagnosis, to evaluate the status of the pericardium, and how the disease affects the cardiac performance. The most common non-invasive methods used to confirm the diagnosis are trans-thoracic or trans-esophageal echocardiography, CT or MR.

Trans-thoracic echocardiography is the preferred imaging modality allowing to establish a correct diagnosis in most of the cases with a rapid, widely available and relatively economic diagnostic tool. Most patients have distention of the inferior vena cava to a diameter exceeding 3 cm, meaning impaired diastolic filling.

Weaknesses of echocardiography include detection of small focal effusions and the assessment of patients with unfavorable acoustic window; furthermore, pericardial thickness is usually non-assessable with ultrasound with obvious limited accuracy in presence of suspicious overlapping inflammation.

Second line imaging with CT MR is usually required to rule out underlying secondary causes of effusion (e.g. neoplastic lesions) or when a complex inhomogeneously echoic exudate is observed at echocardiography.

MR features of tuberculous pericarditis include presence of a diffuse edematous imbibition of
visceral layers which can be recognized using T2-weighted sequences and is usually associate with a variable amount of effusion and irregular thickening of the membrane. Active inflammation is also characterized by a variable degree of pericardial enhancement.

The inflammatory process appears on CT as a diffuse and irregular thickening of pericardial line In addition, CT allows a precise individuation of calcifications.

Management of the pericardial tuberculosis is complex. The final diagnosis is usually made by pericardiocentesis. Pericardiectomy must be practiced as soon as possible before receiving pharmacological treatment with triple drug therapy and steroids.

References:
Hyae et al. :Thoracic Sequelae and Complications of Tuberculosis, RadioGraphics (2001); 21:839–860
Burril et al. Tuberculosis: A Radiologic Review, RadioGraphics (2007); 27:1255–1273
Troughton et al: Pericarditis, Lancet (2004); 363:717-727
Sida-Diaz et al.: Tuberculous pericarditis. A case reported and a brief review
Rev Med Inst Mex Seguro Soc. (2011); 49(1):75-8.

Riccardo Rosati, MD; Ilaria Iampieri, MD; Bettina Conti, MD; Marco Francone, PhD
Department of Radiological Sciences, Sapienza University of Rome, Italy