@article {Xu, author = {C. Xu and Y. Zhou and R. Zhang and Z. Chen and W. Zhong and X. Gong and X. Ding and M. Lou}, title = {Metallic Hyperdensity Sign on Noncontrast CT Immediately after Mechanical Thrombectomy Predicts Parenchymal Hemorrhage in Patients with Acute Large-Artery Occlusion}, year = {2019}, doi = {10.3174/ajnr.A6008}, publisher = {American Journal of Neuroradiology}, abstract = {BACKGROUND AND PURPOSE: Parenchymal hemorrhage is a severe complication following mechanical recanalization in patients with acute ischemic stroke with large-vessel occlusion. This study aimed to assess whether the metallic hyperdensity sign on noncontrast CT performed immediately after mechanical thrombectomy can predict parenchymal hemorrhage at 24 hours.MATERIALS AND METHODS: We included consecutive patients with acute ischemic stroke with large-vessel occlusion who underwent noncontrast CT immediately after mechanical thrombectomy between January 2014 and September 2018. The metallic hyperdensity sign was defined as a nonpetechial intracerebral hyperdense lesion (diameter, >=1 cm) in the basal ganglia and a maximum CT density of \>90 HU. The sensitivity, specificity, and positive and negative predictive values of the metallic hyperdensity sign in predicting parenchymal hemorrhage were calculated.RESULTS: A total of 198 patients were included. The metallic hyperdensity sign was found in 59 (29.7\%) patients, and 51 (25.7\%) patients had parenchymal hemorrhage at 24 hours. Patients with the metallic hyperdensity sign are more likely to have parenchymal hemorrhage than those without it (76.3\% versus 4.3\%, P \< .001). The sensitivity, specificity, positive predictive value, and negative predictive value of the metallic hyperdensity sign in predicting parenchymal hemorrhage were 88.2\%, 90.5\%, 76.3\%, and 95.7\%, respectively.CONCLUSIONS: The presence of the metallic hyperdensity sign on noncontrast CT performed immediately after mechanical thrombectomy in patients with large-vessel occlusion could predict the occurrence of parenchymal hemorrhage at 24 hours, which might be helpful in postinterventional management within 24 hours after mechanical thrombectomy.HThemorrhagic transformationMTmechanical thrombectomyPHparenchymal hemorrhage}, issn = {0195-6108}, URL = {https://www.ajnr.org/content/early/2019/03/07/ajnr.A6008}, eprint = {https://www.ajnr.org/content/early/2019/03/07/ajnr.A6008.full.pdf}, journal = {American Journal of Neuroradiology} }