Cerebellar and brainstem ectopia express Math1.

<p>(A, C, E) Immunofluorescent staining for Pax6 in (A) wild type cerebellum, (C) GFAP:Hi-Otx2 cerebellum, and (E) GFAP:Hi-Otx2 brainstem. (B) MATH1-GFP reporter expression in the cerebellum of <i>MATH1-GFP</i> transgenic mice. (D, F) MATH1-GFP reporter expression in the (D) cerebellum and (F) brainstem of GFAP:Hi-Otx2, <i>MATH1-GFP</i> mice. 20× mag. Arrows indicate ectopia.</p

Otx2 expression is induced in various cell types in GFAP:Hi-Otx2 mice.

<p>Sections from P7 wild type (A, C–D) or GFAP:Hi-Otx2 (B, E–J) mice were immunostained with the indicated antibodies. For (A) and (B), anterior expression threshold is designated with a red arrow. (A, B) are shown at 4× magnification (mag), all others 20× mag. sc, superior colliculus; egl, external granule layer; igl, internal granule layer. White arrows indicate overlapping expression of the indicated markers in individual cells.</p

Cerebellar hyperplasias in GFAP:Hi-Otx2 mice are spatially distinct from dysplasia/hyperplasia observed in <i>ND2:SmoA1</i>^+/− mice.

<p>Images of H & E stained sections (20× mag) from (A) wild type mice, (B) GFAP:Hi-Otx2 mice, and (C) <i>ND2:SmoA1^+/−</i> mice. Scale bar: 100 µm. (D) Location of ectopia at P7 in GFAP:Hi-Otx2 mice relative to location of hyperplasia/dysplasia in P7 ND2:SmoA1^+/− mice. Arrows indicate regions of hyperplasia.</p

Origin and fate of cerebellar ectopia.

<p>(A) Rare ectopia continuous with the EGL, H & E staining. (B) Image of rare Math1⁺ ectopia continuous with the EGL in GFAP:Hi-Otx2, <i>MATH1-GFP</i> mice. (C–D, F–M) Images of GFAP:Hi-Otx2 brain sections stained with the indicated antibodies. (C–D) Sections immunostained with Ki67 and Zic1 of (C) rare ectopia continuous with the EGL and (D) representative ectopia located just deep to the IGL. (E) Localization of histologically-apparent ectopia of GFAP:Hi-Otx2 mice at P3 and P7 (distance in µm). (F, G) Expression of differentiation markers in cerebellar ectopia at (F) P7 and (G) P21. (H–K) Location of partially- to fully-differentiated neurons in (H, I) cerebellum or (J, K) brainstem as evidenced by Zic1 and Ki67 staining shown at 10× mag in (H, J) wild type mice or (I, K) GFAP:Hi-Otx2 mice. (L, M) Cleaved caspase-3 staining of ectopia in the (L) cerebellum and (M) brainstem. All images except (H–K) shown at 20× mag. CB, cerebellum; BS, brainstem. Asterisk indicates <i>p</i>≤0.05 relative to P3, student's t-test. Arrows indicate ectopia. Boxes indicate location of cropped and zoomed image.</p

GFAP:Hi-Otx2 mice develop focal hyperplasias in the cerebellar white matter and the brainstem.

<p>(A–F) H & E stained sections from P7 hindbrains of (A, C, E) wild type and (B, D, F) GFAP:Hi-Otx2 mice. Fields shown are as follows: (A, B) whole cerebella at 4× magnification (mag), (C, D) cerebellar white matter at 10× mag, (E, F) dorsal brainstem at 10× mag. (G) reference illustration of fields shown in C–F indicated by grey boxes. (H, I) Immunofluorescent staining for Ki67 in (H) cerebellar ectopia and (I) brainstem ectopia in GFAP:Hi-Otx2 mice (20× mag). (J) Prevalence of ectopia in GFAP:Hi-Otx2 mice over time. CB, cerebellum; BS/bs, brainstem; egl, external granule layer; igl, internal granule layer; wm, white matter; IV, fourth ventricle; mvn, medial vestibular nuclei; D, dorsal; V, ventral; A, anterior; P, posterior. Black or white arrows indicate ectopia.</p

Effect of Different Enhancement Thresholds.

<p>A) Axial T1-weighted post-contrast image after volumetric analysis has been performed which shows in green the detected enhancing tumor volume using a 25% threshold level. B) Detected enhancing tumor volume using a 40% threshold level. C) While increasing the threshold decreases the calculated tumor volume, the volumes across different threshold levels are highly correlated.</p

Detection of Enhancing Tumor Volume Despite Resection Cavity Collapse.

<p>A) T1-weighted post-contrast axial image showing a resection cavity with rim enhancement. RECIST measurement would be A and Macdonald measurement would be “A * B”. B) T1-weighted post-contrast axial image showing the same patient 3 months postoperatively who had collapse of his resection cavity. RECIST measurement would be “a” and Macdonald measurement would be “a * b”, both of which would be smaller than the measurements from the initial scan above, but this change would be describing only the resection cavity configuration and not the underlying tumor burden.</p

Detection of Enhancement that is Obscured by Blood Products.

<p>A) Uncontrasted T1-weighted axial image showing resection cavity blood products (bright on T1). B) T1-weighted post-contrast axial image showing the difficulty in determining residual enhancing tumor. C) Our volumetric analysis is able to detect the obscured enhancing tumor tissue (shown in green). D) T1-weighted post-contrast axial image at 2.5 months later after the blood has resolved verifying the underlying enhancing tumor volume.</p

Traditional Non-Volumetric Measurements do not Adequately Describe Residual Enhancement in Surgical Resection Cavities.

<p>A) This schematic resection cavity has residual rim enhancement in gray. RECIST criteria measurement ‘A’ or ‘a’ or ‘b’ or Macdonald criteria measurement ‘A*B’ or ‘a*b’ would not adequately describe residual tumor volume and additional tumor growth around the rim or collapse of the resection cavity may be over- or under-interpreted. B) Differences in axial slice acquisition also impact measurements made by traditional criteria more than volumentric measurements. One scan could obtain axial slice ‘c’ with enhancing tumor measurement ‘x’ but a subsequent scan in the same patient could obtain axial slice ‘d’, causing an incorrect assessment of tumor response.</p

Automated Assessment of Enhancing Tumor Volume.

<p>A) T1-weighted post-contrast axial images are automatically fused with the pre-contrast sequences. B) The tumor region of interest (blue area) and nearby normal brain (purple area) are outlined roughly by hand. C) The enhancing nasal mucosa region is automatically detected with a built-in anatomic atlas (red area) and serves as a threshold for enhancement. D) Tissue that is present on the post-contrast images but not the pre-contrast that is above the enhancement threshold appears in yellow. This includes enhancing tissue such as vasculature, tumor, and superficial structures. Enhancing tumor volume is defined as the green area within the manually-defined blue tumor region of interest.</p