Objective: To determine retrospectively the distinguishing features of cardiac tamponade on conventional chest computed tomography (CT).
Materials and methods: Blinded retrospective analysis of CT scans from 14 patients (6 women, 8 men; age range, 49-93 yrs; mean age, 71 yrs) with echocardiographic evidence of tamponade and 15 controls (11 women, 4 men; age range, 37-96 yrs; mean age, 66 yrs) without tamponade was performed by 3 cardiothoracic radiologists. Computed tomographic scans were analyzed for right ventricular flattening, contrast reflux into the azygos vein, and coronary sinus compression. Inferior vena cava (IVC) and superior vena cava short-axis diameter and pericardial fluid attenuation were recorded. If the pericardium or pericardial fluid was sampled, results were noted. Case and control group variables were compared using the Fisher exact test and the t test. Results were also subjected to logistic regression analysis.
Results: Coronary sinus compression was present in 46% (6/13) patients with tamponade and in no controls (P = 0.006). Trends toward IVC dilatation and elevation of pericardial fluid attenuation in cases of tamponade did not reach statistical significance. A specific pathological diagnosis was made in 88% (7/8) of tamponade cases and 29% (2/7) of controls (P = 0.04).
Conclusions: The detection of coronary sinus compression on CT is an early specific indicator of cardiac tamponade. Dilatation of the IVC and the presence of elevated pericardial fluid attenuation are CT signs suggestive of the diagnosis.