Intestinal obstruction (click on images to magnify).

Reference

Multiple sclerosis.(Please click on the slide to magnify)

Please click on the slide to magnify

Dawson's fingers: MS plaques extending up through corpus callosum.

Sagittal T1 C+

Multiple T2 hyperintense lesions most prominent at C4 level, with enhancing plaque at C2/3.

Multiple scattered supra and infratentorial white matter plaques, most of them are seen at the periventricular region perpendicular to the lateral ventricles giving the appearance of Dawson fingers, other plaques involve the subcortical U fibers, juxta cortical and brainstem. Most of the lesions show T2 shine through effect on DWI/ADC. Characteristically they display low signal on T1 WIs.

Juxta cortical lesion along U fiber.

Reference

D.D.

Tumefactive multiple sclerosis is a term used to describe patients with established multiple sclerosis who develop large aggressive demyelinating lesions, similar/identical in appearance to those seen in sporadic tumefactive demyelinating lesions (TDL). TDL is now considered to be a separate entity, lying on a spectrum between multiple sclerosis and postinfectious demyelination / acute disseminated encephalomyelitis (ADEM)

Marburg's variant of multiple sclerosis, also known as acute, fulminant, or malignant multiple sclerosis, is characterised by extensive and fulminant acute demyelination, often resulting in death within one year after the onset of clinical signs.

Schilder's disease, (also known as diffuse myelinoclastic sclerosis, or diffuse cerebral sclerosis) is considered a variant of multiple sclerosis (MS), and represents an extremely rare progressive demyelinating process that begins in childhood 

Balo concentric sclerosis (BCS) is a rare and severe monophasic demyelinating disease, considered a subtype of multiple sclerosis, appearing as a rounded lesion with alternating layers of hyper and hypoattenuation giving it a characteristic 'bullseye' or 'onion bulb' appearance 

Reference

Vascular territories

The supratentorial vascular territories of the major cerebral arteries are demonstrated superimposed on axial (left) and coronal (right) T2-weighted images through the level of the basal ganglia and thalami. The middle cerebral artery (MCA; red) supplies the lateral aspects of the hemispheres, including the lateral frontal, parietal and anterior temporal lobes, insula, and basal ganglia. The anterior cerebral artery (ACA; blue) supplies the medial frontal and parietal lobes. The posterior cerebral artery (PCA; green) supplies the thalami and occipital and inferior temporal lobes. The anterior choroidal artery (yellow) supplies the posterior limb of the internal capsule and part of the hippocampus extending to the anterior and superior surface of the occipital horn of the lateral ventricle.

Reference

PCA.branches

Frontal projection from a right vertebral artery angiogram illustrates the posterior circulation. The vertebral arteries join to form the basilar artery. The posterior inferior cerebellar arteries (PICA) arise from the distal vertebral arteries. The anterior inferior cerebellar arteries (AICA) arise from the proximal basilar artery. The superior cerebellar arteries (SICA) arise distally from the basilar artery prior to its bifurcation into the posterior cerebral arteries.

Reference

MCA& ACA branches.

Frontal view of a cerebral angiogram with selective injection of the left internal carotid artery illustrates the anterior circulation. The anterior cerebral artery consists of the A1 segment proximal to the anterior communicating artery with the A2 segment distal to it. The MCA can be divided into 4 segments: the M1 (horizontal segment) extends to the limen insulae and gives off lateral lenticulostriate branches, the M2 (insular segment), M3 (opercular branches) and M4 (distal cortical branches on the lateral hemispheric convexities).

Lateral view of a cerebral angiogram illustrates the branches of the anterior cerebral artery and Sylvian triangle. The pericallosal artery has been described to arise distal to the anterior communicating artery or distal to the the origin of the callosomarginal branch of the anterior cerebral artery (ACA). The segmental anatomy of the ACA has been described as follows: the A1 segment extends from the internal carotid artery (ICA) bifurcation to the anterior communicating artery; A2 extends to the junction of the rostrum and genu of the corpus callosum; A3 extends into the bend of the genu of the corpus callosum; A4 and A5 extend posteriorly above the callosal body and superior portion of the splenium. The Sylvian triangle overlies the opercular branches of the middle cerebral artery (MCA), with the apex representing the Sylvian point.