Intraventricular metastases from lung carcinoma. Axial enhanced Tl-weighted images demonstrate an enhancing mass within the atrium and occipital horn of the right lateral ventricle. Note attachment to the pedicle of the choroid plexus (arrow). (Click to magnify figure)

http://yassermetwally.wordpress.com/brain-tumors/adult-brain-tumors/

Metastatic breast carcinoma. A, Axial FLAIR images demonstrate a solitary mass with extensive surrounding edema in the left subinsular region. B, Axial and coronal enhanced Tl -weighted images show ring enhancement. Although the differential for a solitary mass lesion includes primary neoplasms and infectious etiologies, the peripheral location of this lesion, and the disproportionate amount of edema incited by the mass suggest metastatic disease. (Click to magnify figure)

http://yassermetwally.wordpress.com/brain-tumors/adult-brain-tumors/

Berry Aneurysm

Types of aneurysm

Sites

Complications

Subarachnoid hemorrhage

Subarachnoid hemorrhage

Subarachnoid hemorrhage

Colloid Cyst

A, Coronal T2-weighted sequence shows a very low-signal colloid cyst of the third ventricle, with obstruction of Monro's foramen.
B, High signal intensity can be seen on the T1-weighted sequence. Aspiration during the endoscopic procedure was difficult. The cyst's contents were evacuated after opening the cyst's wall by using larger aspirating probes.
Baseline CT and CT studies obtained during present admission.
A, Baseline noncontrast axial 5-mm section shows hyperdense colloid cyst (arrow) in the rostral aspect of the third ventricle. There is moderate dilatation of the lateral ventricles and cerebral atrophy secondary to AIDS. In this view, the colloid cyst is round in appearance.
B, CT scan obtained immediately after acute neurologic deterioration shows marked hydrocephalus and hypodensity in the white matter of the frontal lobes. The etiology of the presumed punctate hemorrhage in the right frontal lobe is not known.
C, CT obtained immediately after the initial ventriculostomy shows a right-sided catheter that has decompressed the lateral ventricle. The left lateral ventricle remains enlarged and there is mild midline shift to the right. A small amount of blood is present in the right lateral ventricle secondary to catheter insertion.
D, CT done after insertion of left-side ventriculostomy shows decreased hydrocephalus, compared with B, and no midline shift.

Postmortem MR imaging. A, Coronal T1-weighted image (560/15/1 [TR/TE/excitations]) of the fixed brain shows that the colloid cyst is centrally of higher signal intensity [c] and its rim is relatively hypointense. The lesion is oval-shaped in this projection. The linear hyperintensities in the left basal ganglia are related to a hemorrhagic infarction (see fig 3A).
B, Corresponding proton density–weighted image (4500/15/1) shows the lesion to be homogeneous and of similar signal intensity to white matter.
C, Corresponding T2-weighted image (4500/105/1) shows the central portion of the cyst to be hypointense and its rim to be slightly hyperintense. Cortical sulci dilatation is well seen in this sequence.

In vivo MR imaging of a colloid cyst (different patient).
A, Axial noncontrast T1-weighted image shows oval-shaped, hyperintense colloid cyst [c].
B, Corresponding T2-weighted image shows the cyst to be markedly hypointense. There is no hydrocephalus in this patient.

Tuberous Sclerosis

Giant Cell Astrocytoma

27-year-old woman with bilateral renal angiomyolipoma in tuberous sclerosis. Axial unenhanced CT scan of brain shows numerous calcified subependymal nodules.

Image 2

Image 3

Image 1

Findings:

Image #1 is an axial (T1 weighted scan demonstrating multiple cystic appearing lesions within the white matter. In addition, there is a small subependymal nodule within the anterior horn of the right lateral ventricle.
Image #2 demonstrates a region of decreased signal intensity located within the left frontal cortex consistent with a cortical tuber. In addition, subependymal nodules are identified within the lateral ventricles.
Image #3 demonstrates enhancement of a right lateral ventricle subependymal nodule.
Diagnosis: Tuberous sclerosis.

CT - Cerebellar atrophy: The non-contrasted CT scan in the above demonstrates marked cerebellar atrophy with enlargement of the cisterna magna and the more anteriorly located vallecula between the cerebellar tonsils. In the panel on the down, note the prominent pattern of cerebellar folia. Although the brain stem is mildly atrophic the remaining structures appear normal.

Brain Metastases

Multiple Metastasis To The Brain From Breast Primary
40-year old lady with a history of breast carcinoma diagnosed 6 years ago, presented with headache and ataxia.
Findings: Shower of at least 30 metastatic enhancing lesions are seen closely packed together within both cerebellar hemispheres (yellow arrows), and few lesions also seen within both posterior fronto-parietal lobes (red arrows).

Acoustic Neuroma

Acoustic Neuroma

Brain scan of a patient with a Large Acoustic Neuroma

Confirmation of Presence of Acoustic Neuroma
Auditory tests can reveal loss of speech discrimination and hearing loss.
Magnetic resonance imaging (MR) scans done after injecting a contract medium into the patient will show the presence of acoustic neuromas, even those that are still confined to the internal auditory canal.