Figure 2.

Unexpected tumor residuals reported in the studies included in this review. Studies that explicitly reported unexpected tumor residuals following maximal initial resection (Table 1) are analyzed here. The reported proportions of cases with unexpected residuals was not statistically significantly different with the strength of the magnetic field in iMRI studies (A). Similarly, no differences were found in the proportion of cases that underwent a re-exploration following intra-operative imaging (B). A statistically significant lower occurrence of unexpected residuals (p = 0.03) was reported in studies reporting an endoscopic approach compared to ones reporting a microscopic approach (C). High – high field strength magnet, 1.5 Tesla; Low – low field strength magnet, ≥ 0.5 Tesla; Ultra high ≥ 3Tesla field strength magnets.