PMC6694614_01
Pre-operative MRI brain demonstrating a heterogeneous, enhancing posterior fossa lesion with surrounding edema (blue arrow). 1a: Axial T2-weighted; 1b: Axial FLAIR; 1c: Axial T1-weighted pre-contrast; 1d: Axial T1-weighted post-contrast; 1e: Sagittal T1-weighted post-contrast; 1f: Coronal T1-weighted post-contrast
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Fig1
Tomography (CT) brain, which revealed an avidly enhancing posterior fossa mass in the cerebellar midline and a small additional lesion in the right superior frontal gyrus. The subsequent Magnetic Resonance Imaging (MRI) brain showed a 22 mm by 31 mm by 25 mm intra-axial mass lesion centrally within the vermis with surrounding edema, extending more prominently into the right cerebellar hemisphere; with no features of hydrocephalus (Fig. 1). 
a axial T2-weighted, b axial FLAIR, c axial T1-weighted pre-contrast and d axial T2-weighted post contrast imaging demonstrate resection cavity with some blood degradation products and early post-operative enhancement; edema surrounding the resection cavity; contusion and edema left tonsil; and pseudomeningocele (blue arrows)
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Fig2
The post-operative MRI (Fig. 2) showed no enhancing residual tumor in the posterior fossa.
99 m Tc- HMPAO Perfusion SPECT scan showing focally increased perfusion at the level of the anterior cingulate (visualized on the last row, blue arrow). The blue arrow in the first row shows absent perfusion in the posterior fossa, as expected post-surgical finding
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Fig3
In addition, there was focal hyperperfusion in the anterior cingulate (Fig. 3).
RBANS part a, visual summary of the patient's performance. The patient's scores are plotted in the standard assessment chart showing low score across the board (grey area highlights the percentile rank below 1  percentile) with relative strength in attention skills (forth column from the left). RBANS = Repeatable Battery for the Assessment of Neuropsychological Status. The columns numbered 1 to 5 represents the areas of assessment in RBANS part a. Columns from left to right: 1 = Immediate Memory; 2 = Visuospatial / Constructional; 3 = Language; 4 = Attention; 5 = Delayed Memory.
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Fig4
Sagittal FLAIR (a) showing (blue arrows) high signal affecting inferior olivary nuclei, and gliosis and malacia at the surgical bed with presumed damage to central tegmental tract and dentate nuclei. Axial T2-weighted (b) showing high signal medulla bilaterally, at the level of the inferior olivary nuclei. Post-operative pseudomeningocoele is also evident. Coronal T2-weighted (c) further highlights post-operative damage to cerebellum involving central tegmental tract and dentate nuclei with gliosis and hemosiderin deposition
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Fig5
Language fMRI with word, noun-verb and stories paradigms was performed for language localization and lateralization. The underlying BOLD technique is susceptible to the artifact arising from the shunt. This demonstrated normal left hemispheric language activation in the frontal lobe, Broca's area, and the superior temporal gyrus, Wernicke's area
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Fig6
Diffusion tensor imaging was performed. A fractional anisotropy map was obtained and tracts were manually seeded. There was some degradation secondary to the shunt, however overall tracts, especially the corticospinal tract, remain intact. Coronal (a) and sagittal (b) views
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Fig7
Diffusion Tensor Imaging (DTI) (Fig. 7) was also performed, with fractional anisotropy map obtained and tracts seeded for tractography (Fig. 7).