Current HHT guidelines recommend CT scan to detect new or recurrent PAVMs after embolotherapy. Recent studies using transthoracic contrast echocardiography (TTCE) shunt grade for PAVM screening suggest that graded TTCE can accurately predict the size of PAVMs on chest CT and their amenability to embolization. This study's purpose is to evaluate whether TTCE shunt grade can also accurately predict PAVM size and amenability to treatment in patients who are post-embolization.