Gold standard Investigation of choice of Cerebral A-V malformation is
(D) Cerebral Angiography # An AVM diagnosis is established by neuroimaging studies after a complete neurological and physical examination. Three main techniques are used to visualize the brain and search for AVM: Computed tomography (CT) Magnetic resonance imaging (MRI) Cerebral angiography> A CT scan of the head is usually performed first when the subject is symptomatic. It can suggest the approximate site of the bleed.> MRI is more sensitive than CT in the diagnosis of AVMs and provides better information about the exact location of the malformation> More detailed pictures of the tangle of blood vessels that compose an AVM can be obtained by using radioactive agents injected into the blood stream.> If a CT is used in conjunctiangiogram, this is called a computerized tomography angiogram; while, if MRI is used it is called magnetic resonance angiogram.> Best images of an AVM are obtained through cerebral angiography.> This procedure involves using a catheter, threaded through an artery up to the head, to deliver a contrast agent into the AVM.> As the contrast agent flows through the AVM structure, a sequence of X-ray images are obtained.> Radiographic features of A-V Malformation# CT: Diagnosis can be difficult on non-contrast CT. The nidus is blood density and therefore usually somewhat hyperdense compared to adjacent brain. Enlarged draining veins may be seen. Although they might be very large in size, they do not cause any mass effect unless they bleed. Following contrast administration, and especially with CTA the diagnosis is usually self evident with feeding arteries, nidus and draining veins visible in the so-called "bag of worm" appearance. The exact anatomy of feeding vessels and draining veins can be difficult to delineate, and thus, angiography remains necessary.# MRI: Fast flow generates flow voids easily seen on T2 weighted images. Complications including previous haemorrhage and adjacent oedema may be evident.# MRA: phase contrast MR angiography is often useful to subtract the haematoma components when an AVM complicated by an acute haemorrhage needs to be imaged# Angiography (DSA) Remains the gold standard, able to exquisitely delineate the location and number of feeding vessels and the pattern of drainage. Ideally, angiography is performed in a bi-plane system with a high rate of acquisition, as the shunts can be very rapid. On angiogram, AVM appears as a tightly packed mass of enlarged feeding arteries that supply central nidus. One or more dilated veins drain the nidus and there is abnormal opacification of veins occurs in arterial phase (early venous drainage), represents shunting.
DWI MRI scan
CT scan
MRI scan
Cerebral Angiography
Miscellaneous