Diagnostic Imaging Approach to a Supratentorial SOL in an Adult

Antoinette ReindersDept of Diagnostic and Interventional Radiology

University of the Free StateAug 2012

Approach

• Age• Location

• Intra vs extra axial• Anatomical compartment• Midline crossing

• Tumour spread• Characteristics on CT and MRI

• Spectroscopy• Calcification/edema/mass effect

• Enhancement• Differential diagnoses

• “Tumor mimickers”

Brain Tumours

Smithuis R, Montanera W. Brain Tumor – systematic approach. Available from URL: http://www.radiologyassistant.nl/en

Major Anatomical considerations

Intra axial

•Hemispheres (cerebrum/cerebellum)•Brainstem•Sellar/supraseller•Pineal•Ventricular

Extra axial

•Dural based•Bone tumours•Nasopharyngeal tumours

Approach

• Location– Intra-axial vs Extra-axial

Smithuis R, Montanera W. Brain Tumor – systematic approach. Available from URL: http://www.radiologyassistant.nl/en

Extra axial tumour

• Smithuis R, Montanera W. Brain Tumor – systematic approach. Available from URL: http://www.radiologyassistant.nl/en

Intra vs Extra axial

Smithuis R, Montanera W. Brain Tumor – systematic approach. Available from URL: http://www.radiologyassistant.nl/en

Approach

• Location– Grey matter

• Cortical/subcortical

– White matter– Grey/white matter interface– Dural surface

• Abut the meninges

– Ventricles• Foramen of Monroe• Trigonum of the lateral ventricles

– Pineal gland– Sella/suprasellar

Robert Wood Johnson University Hospital. Available from URL: http://www.rwjuh.edu/gamma-knife/gamma-knife-brain-tumor-treatment.aspx

Approach

• Cross midline– Glioblastoma Multiforme, Radiation necrosis,

Meningioma, Lymphoma, Epidermoid cyst, MS• Multifocal disease– Phacomatoses• NF1: Optic gliomas, astrocytomas• NF2: Meningiomas, Ependymomas, Schwannomas,

Choroid plexus papillomas• TS: Subependymal tubers, Giant cell astrocytomas• VHL: Hemangioblastomas

Approach

• Tumour spread– Subarachnoid seeding

• PNET• Ependymoma• GBM• Lymphoma• Oligodendroglioma

– WM Tracts• Astrocytoma

– Pilocytic, Fibrillary, Gemistocytic, Protoplasmic

– Foramina• Ependymoma

Tumour Spread

Ependymoma of 4th ventricle Pleomorphic xantoastrocytoma

Approach

• Characteristics– MRI

• Edema• Cystic• Mass effect• Fat containing• Spectroscopy

– CT• Calcifications• Haemorrhage• Homogenous or heterogenous appearance• Periosteal reaction

Characteristics on CT

HaemorrhageCommon haemorrhage Not common haemorrhage

Glioblastoma multiforme Germ cell tumours

Metastases•Choroid•Thyroid•Bronchus•Mamma/melanoma•Renal

Medulloblastoma

Craniopharyngioma Colloid cysts/central neurocytoma

Oligodendrogliomas

Ependymal

Giant cell astrocytomas

Chordoma

Epidermoid/dermoid

Characteristics on MRI

Characteristics on MRI

Diffusion Weighted Imaging

Abscesses, infarcts have ABNORMAL diffusion – restriction

Tumours have NORMAL diffusion – no restriction

Approach

• Enhancement– Destruction of BBB in order to enhance– Homogenous vs heterogenous enhancement– Enhancement of gliomas = higher grade of

malignancy• NB in follow up

– Diffusion weighted • Restricted diffusion in abscesses and not in tumours

Smithuis R, Montanera W. Brain Tumor – systematic approach. Available from URL: http://www.radiologyassistant.nl/en

ApproachNo Enhancement Patchy Enhancement Homogenous

EnhancementLow grade astrocytomas Metastases Metastases

Cystic non tumour lesions Oligodendroglioma Lymphoma

•Dermoid GBM Germinoma and pineal tumours

•Epidermoid Radiation necrosis Pituatary macroadenoma

•Arachnoid cyst Pilocytic astrocytoma

Hemangioblastoma

Gangliocytoma

Meningioma

Schwannoma

Common things.....

Glial40%

Non Glial40%

Metastases20%

Brain Tumours

MeningiomaSchwannomaPituitaryPinealLymphoma

BreastColonLungKidneyMelanoma

AstrocytomaOligodendroglioma

Approach

• Differential diagnoses

• Dural based – Meningioma, Dural metastases, Sarcoid, Haemangiopericytomas, pineoblastoma, lymphoma• Cortical based – Dural AV malformation, Herpes

encephalitis• Multifocal disease – Septic emboli, Abscesses and

Multiple Sclerosis• Sellar - Aneurysm

Take home points...• Age of patient• Location

– Intra vs extra axial– Crossing midline– Multifocal disease

• Tumour spread• Characteristics on CT/MRI

– Calcifications– Haemorrhage– Spectroscopy

• Enhancement pattern• Differential diagnoses

Cellphones?

Int J Cancer. 2007 Apr 15;120(8):1769-75.Mobile phone use and risk of glioma in 5 North European countries.

“Although our results overall do not indicate an increased risk of glioma in relation to mobile phone use, the possible risk in the most heavily exposed part of the brain with long-term use needs to be explored further before firm conclusions can be drawn.”

BMJ. 2012 May 1;344:e3083; author reply e3088. doi: 10.1136/bmj.e3083.Association of mobile phone use with adult brain cancer remains plausibleDavis DL, Miller AB, Philips A

BMJ. 2012 Mar 8;344:e1147. doi: 10.1136/bmj.e1147.Mobile phone use and glioma risk: comparison of epidemiological study results with incidence trends in the United States.

Raised risks of glioma with mobile phone use, as reported by one (Swedish) study forming the basis of the IARC's re-evaluation of mobile phone exposure, are not consistent with observed incidence trends in US population data, although the US data could be consistent with the modest excess risks in the Interphone study.

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• Robert Wood Johnson University Hospital. Available from URL: http://www.rwjuh.edu/gamma-knife/gamma-knife-brain-tumor-treatment.aspx

• Dahnert W. Radiology Review Manual 6th ed. Lippincott Williams & Wilkins 2007

• Weissleder et al. Primer of Diagnostic Imaging 4th ed. Mosby Elsevier 2007