Object Early postoperative MRI within 72 hours after @entity1313 surgery is commonly used to assess residual contrast-enhancing @entity5 . The 72-hour window is commonly accepted because previous 1.5-T MRI studies have not found confounding postoperative reactive contrast enhancement in this time frame. The sensitivity to detect contrast enhancement increases with the field strengths. Therefore, the authors aimed to assess whether the 72-hour window is also appropriate for the MRI scanner with a field strength of 3 T. Methods The authors retrospectively analyzed findings on early postsurgical MR images acquired in 46 @entity1 treated for high-grade @entity11 . They performed 3-T MRI within 7 days before surgery and within 72 hours thereafter. The appearance of enhancement was categorized as postoperative reactive enhancement or tumoral enhancement by comparison with the pattern and location of presurgical enhancing @entity5 . Results Postoperative reactive enhancement was present in 15 @entity1 (32.6%). This enhancement, not seen on presurgical MRI, had a marginal or leptomeningeal/dural pattern. In 13 @entity1 (28.3%) postsurgical enhancement was found within the first 72 postoperative hours, with the earliest seen 22:57 hours after surgery. Subsequent MR scans in @entity1 with postoperative reactive enhancement did not reveal @entity5 recurrence in these regions. Conclusions Postoperative reactive enhancement earlier than 72 hours after @entity1313 surgery can be expected in about one-third of the cases in which a 3-T scanner is used. This might be due to the higher enhancement-to-brain contrast at higher field strengths. Therefore, the time window of 72 hours does not prevent reactive enhancement, which, however, can be recognized as such comparing it with presurgical enhancing @entity5 .

Time window for postoperative reactive enhancement after resection of XXXX : less than 72 hours.

@entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity11 :: ('MESH:D005910', 'Disease') :: ['gliomas'] @entity1313 :: ('MESH:D001932', 'Disease') :: ['brain tumor']
@entity1313 :: (MESH:D001932,Disease) :: ['brain tumors']
