We are pleased to see the interest of Volpicelli and colleagues1,2 in lung ultrasound and the BLUE protocol.3 Our observations (July 2008)3 stressed a correlation between pulmonary edema and the B profile. Volpicelli and colleagues1,2 pointed out cases of pulmonary edema without the B profile. In actual fact, we believe there is no discordance between their results and ours; rather, they are complementary. As Volpicelli and colleagues1,2 say, the severity of their patients' illness was different (patients were able to keep the supine position, and most did not require instrumental therapy1). The time at which these results were recorded, up to 48 h after hospital admission,1 is important since B lines vanish during therapy. Most of their patients had the B profile, however. Those patients with no B profile (14.8%, considering only patients examined at hospital admission2) should indeed be referred to as having the mildest cases. This hypothesis is explained by the physiopathology of pulmonary edema since fluids flow against gravity. On the other hand, in the BLUE protocol, all patients had acute respiratory failure, and pulmonary edema nearly always correlated with the B profile. Errors in the final diagnosis, which can never be fully excluded, may explain the few cases (3%) in this study and a previous one4 in which the B profile did not show. Exceptional cases of giant bullous dystrophy may alter the location of B lines.