Non-hemorrhagic cerebellar contrast enhancement on intraoperative MRI during a supratentorial glioma resection: Concerning finding of no significance

Abstract

Intraoperative magnetic resonance imaging (iMRI) is a powerful tool used to verify maximal safe resection of gliomas. However, unsuspected new or incidental findings can present difficult clinical scenarios. Here we present a case of a large supratentorial glioma resection where new, incidental bilateral cerebellar hemispheric enhancement was noted on iMRI. A 52-year-old male with a large intra-axial mass spanning the right temporal and parietal lobes underwent a craniotomy for tumor resection utilizing iMRI. Imaging displayed new, remote, bilateral cerebellar enhancement. Upon completion of surgery, the patient was extubated and was at his neurological baseline. An immediate CT scan showed no abnormalities in the cerebellum, and the duration of his hospital stay was unaffected by this finding. An MRI 24 hours after the procedure demonstrated complete resolution of the enhancement. New, remote contrast enhancement in the cerebellum raises concerns for the potentially emergent, well-defined pathology known as remote cerebellar hemorrhage (RCH). However, here we describe a case where these findings turned out to be clinically insignificant, CT-negative, and self-limiting. Therefore, here we call this finding remote non-hemorrhagic cerebellar contrast enhancement (RNHCCE) to differentiate it from RCE, and we discuss nuances and management considerations for differentiating the two.

Keywords: Brain tumor; Craniotomy; High grade glioma; Intracranial surgery; Oligodendroglioma.

Fig. 1

Preoperative MRI. (A) Axial T1 pre-contrast scan demonstrates relatively iso to slightly hypo-intense lesion on the right temporal-parietal region. (B) Axial T1 post-contrast demonstrates the large heterogenous mass infiltrating the right temporal-parietal region with scattered foci of enhancement, (C) Axial FLAIR sequence demonstrates significant expansile FLAIR signal. (D and E) Coronal T2 sequences demonstrates multiple flow voids within the tumor, as well as trans-tentorial herniation of the tumor with midbrain compression. (F) Sagittal T2 sequence demonstrating the lesion with multiple flow voids within the mass.

Fig. 2

Intraoperative photographs. (A) Surgical exposure of the skull demonstrating visibility of cranial contents through bone and dura, highlighted by the yellow square, which is enlarged on (B). The circled portions are holes in which cranial contents are visible through defects in the skull. (C) Surgical exposure of the brain demonstrating the intrinsic pink/red tumor.

Fig. 3

Intra-operative MRI. (A) Axial T1 post-contrast, (B) Axial FLAIR, and (C) sagittal FLAIR sequences demonstrate a gross total resection with skeletonized mesial pial borders and blood products.

Fig. 4

Intra-operative MRI demonstrating active contrast extravasation. First row demonstrates pre-operative MRI non-contrast (first 2 axial images on the left) with their post-contrast T1 sequences (equivalent axial sections) on the right half. Second row demonstrates intra-operative MRI pre- and post-contrast T1 sequences with evidence of contrast extravasation on 2 separate axial slices within the cerebellum bilaterally encircled in yellow. Third row demonstrates 2 equivalent axial sections susceptibility weighted image (SWI) without evidence of signal, suggesting no evidence of blood products at the location of contrast extravasation.

Fig. 5

Postoperative imaging. Top left demonstrating intra-operative FLAIR signal correlating with the same location as the contrast enhancement. Top right demonstrating 4-month post-operative FLAIR sequences which no longer have signal in those regions. Center of the figure is immediate post-operative CT scan without contrast which does not demonstrate any hyper-densities in the regions of enhancement. Bottom row demonstrates T1 pre- and post-contrast MRI 24-hours postoperatively with resolution of the areas of enhancement.