Table 1

Differentiating pannus from thrombus on cardiac CT

Timing of presentationUsually 12 months after surgeryOccurs at any time
LocationBelow the aortic prosthesisAbove or below the aortic prosthesis
Morphology on CTCircular mass extending from sewing ring
Contrast enhancement
Calcification may be present
Irregularly shaped mass attached to leaflet or hingepoint
No contrast enhancement
CT attenuation>145 HU<145 HU
  • HU, Hounsfield units.