The name “smoker’s disease” originates from the fact that a cerebral angiogram shows a fuzzy mesh-like shadow at the base of the brain due to abnormal capillary growth, which resembles a puff of smoke from smoking, hence the name smoker’s disease. Since the lesions of smog are all within the skull, whether it is a narrowing and occlusion of blood vessels or a malformation of the vascular network at the base of the skull, these are invisible to the naked eye, so how should we determine if we have smog? Do I need a DSA to consider smog with MRA? The symptoms of smog can give a general assessment of the condition. Generally, patients with ischemic type often have symptoms of headache, dizziness, nausea and vomiting, and some patients may have different degrees of impaired consciousness, decreased intelligence, sensory loss, dysphonia, aphasia, migraine, headache and brain nerve damage. Smoky disease may also trigger intracranial hemorrhage. 12% to 14% of patients may have subarachnoid hemorrhage, intraventricular hemorrhage or intracerebral hemorrhage, and some patients may even have recurrent hemorrhage. The diagnosis of the disease cannot be made by symptoms alone, and some medical screening equipment is needed at this time. MRA is a preliminary screening test for smog, and the gold standard for smog diagnosis is DSA, or cerebral angiography, which can comprehensively reflect the morphological structure of cerebral blood vessels with clear images and high resolution, providing a true three-dimensional image for observing vascular lesions and measuring the localization of blood vessel stenosis. The DSA image shows the stenosis or occlusion of the main branches of the cerebral arterial ring bilaterally in patients with smog, and the abnormal smog-like network of tiny vessels at the base of the skull, providing an accurate scientific basis for treatment.