The air crescent sign is regarded as an important diagnostic finding in invasive @entity57 (IPA). This study examined the incidence, clinical importance, and natural history of air crescents in 25 @entity1 with @entity3052 and IPA. Twelve (50%) of the @entity1 had cavities (ten with an air crescent) that appeared an average of 15 days after the initial infiltrate. The diagnostic utility of the air crescent sign was relatively minor; cavities developed after the diagnosis was established in 50% of cases and after therapy was started in 75% of cases. In each case, the @entity55 improved at the time of cavitation. In six @entity1 (50%), the cavities resolved over 2-8 months. Three @entity1 (25%), however, experienced massive hemoptysis. Air crescent formation, previously shown to be dependent on granulocyte recovery, was associated with improved survival (67%) compared with the group without cavitation (8%). In the latter group, the @entity55 in ten (77%) of 13 @entity1 progressed to diffuse disease. In @entity1 with @entity1778 , the diagnostic value of the air crescent sign is limited by cavities that develop relatively late, as the infection improves after white blood cell recovery; cavities that do not occur in @entity1 who remain @entity1398 ; and associated @entity548 , at times life-threatening, that obscures the air crescent. The diagnosis of IPA should not await observation of air crescents in these @entity1 .

Invasive @entity57 and XXXX . Limitations in the diagnostic utility of the air crescent sign.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity57 :: ('MESH:D055732', 'Disease') :: ['pulmonary aspergillosis'] @entity548 :: ('MESH:D006470', 'Disease') :: ['hemorrhage'] @entity55 :: ('MESH:D011014', 'Disease') :: ['pneumonia'] @entity3052 :: ('MESH:D015470', 'Disease') :: ['acute leukemia'] @entity1778 :: ('MESH:D007938', 'Disease') :: ['leukemia'] @entity1398 :: ('MESH:D009503', 'Disease') :: ['neutropenic']
@entity3052 :: (MESH:D015470,Disease) :: ['acute leukemia']
