Evaluation of Transcatheter Pulmonary Valve Endocarditis by Dual-Energy Computed Tomography

Abstract

Transcatheter pulmonary valve implantation (TPVI) is now an established alternative to surgery in patients with congenital heart disease and dysfunctional right ventricular outflow tract (RVOT) conduit. However, there is recognition of a higher incidence of infective endocarditis in the patients after TPVI. Transthoracic and transesophageal echocardiography is limited in the evaluation of prosthetic pulmonary valve endocarditis secondary to a metallic artifact and degenerative calcified conduit. Additionally, the anterior position of RVOT also limits evaluation by echocardiography. Conventional single-energy CTA can also be suboptimal in evaluating prosthetic pulmonary valve stent frame due to streak artifacts from the metallic cage and poor contrast to noise ratio if higher kV is used for single-energy CTA to avoid metallic artifacts. Dual-energy CTA can overcome these limitations using reconstructed virtual monoenergetic and iodine-only images for metal artifact reduction and improve intrastent luminal visualization. Reconstructed iodine perfusion maps may also help differentiate vegetation from a thrombus. In this case report, we discuss the diagnostic utility of dual-energy cardiac CT in the evaluation of endocarditis after TPVI and discuss the imaging protocol.

Dual-Energy Heart CT: Beyond Better Angiography—Review

“…Visualizing vegetation on the surface of electrodes or parts of artificial valves can be hard due to beam hardening, blooming and photon starvation artifacts. These artifacts can completely obscure small vegetations, which makes it had to detect them using SECT [ 13 , 67 ]. It has been proven that DECT can significantly reduce metal-related artifacts originating from artificial valves or electrodes ( Figure 8 A–D) [ 68 ].…”