You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Premature filling of veins is a manifestation in cerebral angiography of: and explain in detail?
Diagnosis of AVM is made by conventional catheter cerebral angiography Diagnosis is based on demonstration of aeries and veins on the same conventional angiographic image, proving the high-flow shunting of blood (leading to early filling of veins) through the nidus network or fistulous vessels In the typical AVM, there is a cloudlike nidus, or network of smaller vessels, well seen on angiography Ref: Sabiston 20th edition Pgno: 1925