An elevated tricuspid regurgitant jet (TRJ) velocity is present in more than 30% of adults with sickle cell anemia (SCA) and is associated with a risk of death [1-4]. The contribution of pulmonary thrombi to an elevated TRJ velocity is not well defined. To evaluate the relationship between an elevated TRJ velocity and pulmonary thrombi, we performed 3D, contrast-enhanced magnetic resonance angiography (3D MRA) in nine adults with SCA. Of the six participants with an elevated TRJ velocity, 5 (83%) did not have thrombi in their pulmonary arteries. No individuals with a normal TRJ velocity had pulmonary thrombi. Based on this pilot study using 3D MRA images, thrombi are not present in large vessels in most individuals with a TRJ ≥ 2.5 m/sec, providing evidence thrombi may not significantly contribute to the pathogenesis of an elevated TRJ velocity in individuals with SCA.