Pulmonary thrombi are not detected by 3D magnetic resonance angiography in adults with sickle cell anemia and an elevated triscuspid regurgitant jet velocity

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.