Tools include:
Digital    subtraction   catheter    cerebral angiography and reformatted cross-sectional views when appropriate is recommended in the pre-treatment assessment of cerebral AVMs . Aim of endovascular treatment are:

Embolization of brain AVMs before surgical resection
Primary curative embolization
Targeted embolization of high-risk features of ruptured AVMs to reduce the risk for recurrent hemorrhage 3- Palliative embolization may be useful to treat symptomatic AVMs
Embolization as an adjunct to In an acutely ruptured AVM, endovascular treatment can occlude intra-nidal or flow- related aneurysms when determined to be the likely source of bleeding, especially when correlated with the pattern of hemorrhage on

cross-sectional imaging. Transvenous embolization more recently, (high complete occlusion rates and reasonably low complication rates). Proposed indications for this approach include a small (diameter <3 cm) and compact AVM nidus, deep or eloquent AVM location, hemorrhagic presentation, single draining vein, inaccessible arterial pedicles, exclusive arterial supply by perforators, or en passage feeding arteries Imaging follow-up after apparent cure of brain AVMs is recommended to assess for recurrence. Although non-invasive imaging may be used for longitudinal follow-up, DSA remains the gold standard