Intraaxial masses - supratentorial Flashcards
What tumors are hyperintense on T1?
Melanoma
hemorrhagic mets (RCC, Thyroid, Choriocarcinoma, Melanoma)
Dermoid, teratoma
What are the 4 main types of glial cell?
Astrocytome - support, healing
Oligodendrocyte - maintain myelin
Ependymal cells - circulates CSF
Choroid plexus - makes CSF
What age range to suspect low grade astrocytoma?
What is the MRI appearance? CT?
Key feature?
20-40
T2 hyperintense/ FLAIR hyperintense, rarely surrounding edema
20% calcify on CT
NO ENHANCEMENT!
Supratentorial parenchymal location, Nonenhancing mass, bright on T2/FLAIR, calcs on CT
20-40yo
Low grade astrocytoma
What are the MRS and perfusion differences in low grade vs anaplastic astrocytoma?
Low grade: no increase in rCBV, elevated myoinositol and choline, low NAA, no lipids/lactate
Anaplastic: Elevated rCBV, LOW myoinositol and NAA, high choline, no lipids
Supratentorial parenchymal inhomogenous mass with EDEMA, can have enhancement
40-50 yo
Anaplastic astrocytoma
What is the imaging of anaplastic astrocytoma?
Varies, can range from T2/FLAIR thickening of cortex to focal enhancing lesion mimicking GBM
White matter mass with nodular rim enhancement and surrounding T2/FLAIR signal, restrict diffusion
elderly male
GBM
Who gets GBM? What is the imaging on MRI?
Where does it spread?
> 50 (65-75), Males 3:2
Heterogeneously enhancing mass within cerebral WM with surrounding edema
INVADES white matter tracts, through CSF, and transependymally
What are the spectrum of astrocytoma?
Low grade astrocytoma, anaplastic astrocytoma, GBM
Also JPA in post fossa of kids
What is gliomatosis cerebri?
Diffuse infiltrating astrocytoma that invades 2 or more cerebral lobes
First involves white matter with widening of tracts then extends diffusely
Criteria for dx is at least 2 lobes plus extracortical involvement such as BG, CC, brainstem, cerebellum
What is the imaging of gliomatosis cerebri?
Diffue T2/FLAIR signal throughout involved brain
Shows mass effect but DOESNT enhance
Differential for diffuse T2/FLAIR signal throughout multiple cerebral lobes?
Gliomatosis cerebri
Lymphoma
PML
AIDS encephalopathy
What is a key feature of gliomatosis cerebri?
DOESNT enhance
Who gets oligodendroglioma? What is the usual symptom?
40-50 male with seizures
Where do oligodendroglioma present?
What are the variants?
What is the imaging features?
Subcortical white matter in FRONTOTEMPORAL regions (also temporal and occipital and CC)
Pure
Oligoastrocytoma - mixture with astrocytoma, can degenerate into GBM
Anaplastic oligodendroglioma - indistinguishable from GBM
CALCIFY!!!! most common calcifying intracranial tumor
Scalloping of inner table
MR: T2 Bright, enhances 50%, doesnt restrict diffusion
What is a key feature between GBM and high grade oligodendroglioma?
Oligodendroglioma DOESNT restrict diffusion, will calcify
Where do supratentorial ependymomas occur? Who gets them? What is the imaging appearance/DDx?
SUPRATENTORIALLY: frontoparietal regions, adjacent to ventricles or within ventricles
Older adults
Oligodendroglioma/Astrocytoma - indistinguishable
Partially calcified/cystic mass adjacent to ventricles with enhancement
Where is the most common location for subependymoma? Where is the second most common?
Who gets them? What are the imaging characteristics?
MC: 4th ventricle, usually enhance
Frontal horn lateral ventricles adjacent to septum pellucidum, dont enhance
40-50yo
Calcifications, can present with hemorrhage, T2/FLAIR bright
Nonenhancing mass with/without calcification with hemorrhagic propensity
Subependymoma
What is the age/presentation for ganglioglioma?
Where are they located?
What is the classic appearance?
male,
Temporal lobe cyst and enhancing mural nodule with calcification
Ganglioglioma
What are the 4 tumors with a cystic appearance and enhancing nodule?
JPA
Hemangioblastoma
PXA
Ganglioglioma
What tumors cause scalloping of calvarium?
Ganglioglioma
Oligodendroglioma
Bubbly mass attached to septum pellucidum in frontal horn of lateral ventricle with calcification and moderate-marked enhancement
What is the unique MR appearance?
Central neurocytoma
Susceptibilty artifact
Who gets central neurocytoma
young adults
What are the intraventricular tumors?
Central neurocytoma, choroid plexus, meningioma, SEGA, subependymoma
What are the 3 types of metastatic disease to the head?
Bone/epidural
Dural/leptomeningeal
Parenchymal
What are the common mets to bone/epidural?
breast, prostate, lung, kidney, myeloma
What are the common mets to dural/leptomeningeal?
breast, small cell carcinoma, melanoma, lymphoma, leukemia
What are the common mets to the parenchyma?
Lung, breast, melanoma (skin), kidney, GI
“Lots of Bad Stuff Kill Glia”
What mets are hyperintense on T1?
Melanoma, kidneys, lungs, choriocarcinoma, bowel
What are the common types of lymphoma in the brain?
Nonhodgkins and B cell
What is the imaging appearance of primary CNS lymphoma?
What are the key imaging features?
Deep grey/white matter lesions that are hyperdense on noncontrast CT, little mass effect or edema, PROMINENT ENHANCEMENT
PERIVENTRICULAR location and HIGH CELLULARITY (restricted diffusion, hyperdense on CT, hypo on T2), avidly enhance
Homogenously enhancing periventricular lesion, dark on T1
Primary CNS lymphoma
What is the main difference between immunocompetent and immunocompromised CNS lymphoma?
competent: avid enhancement
compromised: ring enhancement with central necrosis
What is the typical appearance of immunocompromised CNS lymphoma (AIDS)?
periventricular ring enhancing lesions
What is the appearance of secondary lymphoma in the CNS?
Leptomeningeal carcinomatosis/enhancement
AVIDly enhancing tumor in
Choroid plexus papilloma
What is the key feature between central neurocytoma and choroid plexus papilloma?
CPP avidly enhances
What is the associated syndrome with CPP?
VHL
Who is the patient with PXA?
Where is the most common location?
Rare tumor of childhood and adolescents, history of chronic epilepsy
Temporal lobe
Supratentorial cystic cortical mass with enhancing mural nodule in the temporal lobe?
JXA
What is the main differentiating feature between JXA and ganglioglioma?
JXA has dural thickening
Give a tumor for the following posterior fossa mass in a child
Hyperattenuating CT, restricted diffusion
Cystic mass with enhancing mural nodule
Intraventricular mass, pushes through ventricle
Cystic mass with enhancing mural nodule with flow voids
Hyperattenuating CT, restricted diffusion,
Medulloblastoma
JPA
Ependymoma
Hemangioblastoma
ATRT
Give a tumor for the following posterior fossa mass in an adult
Hx of malignancy, enhancing mass with edema
Cystic mass with enhancing mural nodule with flow voids
Minimal or little enhancement
Young adult and lateral location
Metastasis
Hemangioblastoma
Brain stem astrocytoma
Medulloblastoma
