Reliable? The Value of Early Postoperative Magnetic Resonance Imaging after Cerebral Cavernous Malformation Surgery

BACKGROUND: Cerebral cavernous malformations (CCM) can cause intracerebral hemorrhage. The lesions themselves are frequently associated with perifocal hemosiderin deposits caused by repetitive microhemorrhages. Main indications for a surgical treatment are recurrent symptomatic hemorrhages or cavernoma-related epilepsy. After surgical resection, follow-up magnetic resonance imaging (MRI) is usually performed to confirm 1) the complete resection of the CCM and, especially in cases of cavernoma-related epilepsy, 2) the complete resection of the hemosiderin deposits. METHODS: This prospective study evaluates the value of early postoperative MRI (within 72 hours) regarding the detection of CCM or hemosiderin remnants compared with a standard 3-6 months postoperative MRI control in 61 CCM cases. RESULTS: Sensitivity of early postoperative MRI for CCM remnant detection was 66.67% (95% confidence interval [CI], 9.43%-99.16%), specificity was 76.74% (95% CI, 61.37%-88.24%), positive predictive value was 16.67% (95% CI, 2.09%-48.41%), and negative predictive value was 97.06% (95% CI, 84.67%-99.93%). Because of the high number of patients who could not be evaluated because of imaging artifacts, sensitivity and specificity analysis was not performed for early postoperative MRI using T2*/susceptibility-weighted imaging to assess hemosiderin remnants. Sensitivity of early postoperative MRI for hemosiderin remnant detection using T2-weighted sequences was 85.71% (95% CI, 63.66%-96.95%), specificity was 66.67% (95% CI, 44.68%-84.37%), positive predictive value was 69.23% (95% CI, 55.45%-80.27%), and negative predictive value was 84.21% (95% CI, 64.31%-94.04%). CONCLUSIONS: Our data suggest that early postoperative MRI after CCM surgery is often hampered by imaging artifacts creating false-positive results and therefore ineligible for a resection control. However, reliability of a negative result on early postoperative T2-weighted MRI is relatively high regarding both CCM and hemosiderin remnants.