A focal, mildly hyperdense, lesion is noted on CT in the right centrum semiovale, with restricted diffusion and no abnormal contrast enhancement. rCBV is mildly elevated. The hyperdensity on CT is unusual, with the diffusion restriction (confirmed on the ADC map, not shown) correctly suggesting a higher-grade lesion, with the lesion appearing on other scans […] [...]

There is a large enhancing extra-axial mass lying within the 4th ventricle and extending into the foramen of Luschka on the left. Heterogeneity of the lesion with cystic and necrotic areas is characteristic, along with the previously described findings. Most patients are one to five years in age, and present – as this child – […] [...]

A hyperintense periventricular mass lesion with accompanying vasogenic edema is noted in the right occipital lobe. The mass is hyperintense on DWI, with disruption of the blood-brain barrier (enhancement) demonstrated post-contrast. The mass had restricted diffusion (reflected by the high SI on DWI), which is compatible with primary CNS lymphoma, a diagnosis confirmed at surgery. […] [...]

Pre- and post-contrast axial T1-weighted scans are illustrated. Pre-contrast, several small lesions in the frontal lobes, in particular on the left, demonstrate hyperintensity. Numerous small nodular enhancing lesions are noted post-contrast, all at the gray-white matter junction. Hemorrhagic metastases are seen in up to 15% of brain metastases. A mnemonic for the primary tumors that […] [...]

A large lytic skull lesion is noted on CT, along with benign thickening along the inner table of the frontal bone (an incidental finding). MR depicts well the soft tissue mass within the skull, which is slightly expansile and easily distinguished pre-contrast from the adjacent fatty marrow, with enhancement post-contrast. Part of the on-line supplement […] [...]

Cerebellar hemangioblastoma on MR, von Hippel Lindau syndrome. Well seen on axial T2- and sagittal post-contrast T1-weighted scans is a cystic cerebellar lesion with an enhancing mural nodule. This lesion is also illustrated on CT in an accompanying figure. A solid enhancing nodule (along the periphery of the cyst) would be the most characteristic imaging […] [...]

Cerebellar hemangioblastoma on CT, von Hippel Lindau syndrome. Post-contrast scans in all three orthogonal planes reveal a cystic cerebellar lesion, with an enhancing mural nodule, the most common imaging presentation for a hemangioblastoma. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Axial, sagittal, and coronal images reveal a round extra-axial lesion, with a broad base along the dura of the convexity, and a small associated dural tail. Additional typical findings for the diagnosis include relative isointensity to brain on the T1-weighted scan, slight hyperintensity on T2-weighted scans, and homogeneous contrast enhancement. Part of the on-line supplement […] [...]

An enhancing lesion is identified along and to the left of the falx posteriorly, with occlusion of the superior sagittal sinus (diagnosed by the lack of enhancement). A portion of the sinus and adjacent draining cortical veins are identified along the anterior margin of the lesion. The calvarium is focally involved, with expansion, osteolysis and […] [...]

In an accompanying figure, the CT findings in this case are presented. An extra-axial mass lesion is noted, adjacent to and to the left of the falx. The superior sagittal sinus is occluded. Meningiomas with restricted diffusion (hyperintensity on DWI), as in this example, tend to be malignant or highly atypical. The sagittal post-contrast exam […] [...]

The first post-contrast coronal T1-weighted scan was obtained six years prior to the second exam, with coronal FLAIR and post-contrast T1-weighted scans illustrated from the second exam. There has been interval growth of the lesion, substantial when viewed from a volume perspective. The lesion was electively removed, prior to possible involvement of the superior sagittal […] [...]

Presenting with seizure,a small intra-axial mass lesion is noted in the posterior temporal lobe in this young adult male. There is a small amount of associated vasogenic edema. Post contrast, the enhancement is predominantly rim-like in character, with likely both a solid (posteriorly) and a cystic component to the lesion. Part of the on-line supplement […] [...]

A relatively well defined intraaxial mass lesion is noted in the right temporal lobe, with low- and high signal intensity respectively on T1- and T2-weighted scans, and prominent enhancement. There is only mild accompanying vasogenic edema. Location in the temporal lobe is characteristic for this diagnosis, as was the patient’s age (13 years), with this […] [...]

A relatively well-defined enhancing mass lesion is seen, with prominent accompanying vasogenic edema. Despite the absence of gross central necrosis, the abnormal high signal intensity on FLAIR extends within the splenium of the corpus callosum, and extended (on images not presented) to the left as well. This finding is consistent with infiltration of the corpus […] [...]

A cerebellar mass lesion is seen on the axial T2-weighted scan, with mild accompanying vasogenic edema. A distinctive additional finding is the many prominent associated vascular structures (flow voids). TOF MRA performed with contrast administration reveals a highly vascular lesion, with prominent early enhancement, and tortuous feeding vessels both anteriorly and posteriorly. There is prominent […] [...]

Coronal and sagittal T1-weighted post-contrast scans are presented in a patient with a small macroadenoma, both prior to surgery (upper row) and intraoperatively (lower row). Note that the adenoma enhances less than the normal pituitary, and is located inferiorly within the sella. There is cavernous sinus invasion on the right. On the intra-operative scan, near […] [...]

A large left frontal metastasis, with prominent enhancement and surrounding vasogenic edema is noted on pre- and post-contrast T1-weighted scans. There are small areas of hemorrhage (methemoglobin) and cystic change (with low signal intensity) therein. The 4 mm coronal post-contrast T1-weighted image raises the question of a small pinpoint cerebellar metastasis on the left. Reformatting […] [...]

Multiple cerebellar hemangioblastomas on MR, perfusion imaging (ASL). Two small nodular enhancing lesions, with mild accompanying vasogenic edema, are noted within the cerebellum in this patient with von Hippel Lindau syndrome. Arterial spin labeling (ASL) is an alternative technique to first pass perfusion MR, the latter acquired during bolus gadolinium chelate administration typically using echoplanar […] [...]

Multiple cerebellar hemangioblastomas on MR, von Hippel Lindau syndrome. The highly vascular nature of hemangioblastomas is illustrated on this axial thick MIP from a contrast enhanced, 3D gradient echo, short TE, short TR T1-weighted scan. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]