BPVT versus degeneration: 4D CT

(Panels A and B) Typical appearance of BPVT on 4D CT. In this patient, aortic prosthetic gradient mean increased to 42 mmHg 6 months after TAVR. Hypoattenuating leaflet thickening resulting in restricted leaflet motion was visible on 2 of the 3 cusps (arrows; panel A: short-axis view; panel B: long-axis view). Note that signal intensity is significantly lower than in the Sapien prosthetic stent.
(Panels C and D) Typical appearance of bioprosthetic degeneration on 4D CT. This patient presented with acute pulmonary embolism 19 years post-tricuspid valve replacement. The leaflets were calcified, with signal intensity similar to that of the sewing ring and bony structures (arrows). The valve is essentially immobilized in a semiclosed position, resulting in both severe stenosis and severe regurgitation. The apparent valve opening when imaged in short axis (panel C) is due to in- and out-of-plane motion; the long-axis view (panel D) shows that leaflets are completely immobile. The patient underwent successful tricuspid valve re-replacement, removal of the residual right atrial thrombus, and reduction plasty of the giant right atrium.