Items in AFP with MESH term: Magnetic Resonance Angiography
ABSTRACT: Peripheral vascular disease of the lower extremities is an important cause of morbidity that affects up to 10 million people in the United States. The primary care physician can easily identify patients who are at risk for the disease with a questionnaire and a relatively simple test-the ankle brachial index. More than 70 percent of patients diagnosed with the disease remain stable or improve with conservative management. Those who do not improve may undergo contrast angiography or magnetic resonance angiography, which may be used in planning for surgery or percutaneous intervention. Surgical bypass is the gold standard for extensive vascular occlusive disease, but endovascular interventions, including percutaneous transluminal angioplasty and stent placement, are being used more frequently, particularly in patients with significant comorbid conditions.
ABSTRACT: Unruptured intracranial aneurysms occur in up to 6 percent of the general population. Most persons with these aneurysms remain asymptomatic and are usually unaware of their presence. Risk factors for the formation of aneurysms include a family history of aneurysm, various inherited disorders, age greater than 50 years, female gender, current cigarette smoking, and cocaine use. Because of the morbidity and mortality associated with surgical intervention, screening for aneurysms remains controversial. Two groups of patients may benefit from early detection: those with autosomal dominant polycystic kidney disease and those with a history of aneurysmal subarachnoid hemorrhage. These patients should undergo magnetic resonance angiography, followed by neurosurgical referral if an aneurysm is detected. Screening of patients who have two or more family members with intracranial aneurysms is controversial. Screening of patients who have one first-degree relative with an aneurysm does not appear to be beneficial.
ABSTRACT: More than 72 million Americans have hypertension, and the majority of these persons have essential hypertension. However, a significant subset has a secondary cause. The most common cause of secondary hypertension is renal vascular hypertension, of which renal artery stenosis is the leading pathology. Up to 5 percent of all occurrences of hypertension are caused by renal artery stenosis, equating to as many as 3.5 to 4 million occurrences in the United States. Detecting renal artery stenosis is particularly important for ensuring that this potentially curable form of hypertension is identified and treated properly. Duplex Doppler ultrasonography is a good screening test in many patients, but it has limitations in larger persons and can overlook small accessory arteries. For patients with normal renal function but a high clinical index of suspicion for renovascular disease, contrast-enhanced magnetic resonance angiography and computed tomographic angiography are the most accurate imaging tests. For patients with diminished renal function, gadolinium-enhanced contrast magnetic resonance angiography is the best imaging test. However, caution is warranted because exposure to gadolinium contrast agents is associated with nephrogenic systemic fibrosis in patients with renal failure. The American College of Radiology has developed appropriateness criteria for imaging tests related to the diagnosis of renal artery stenosis. This article is a summary of the recommendations, with the advantages and limitations of each test.
Multiple Pulmonary Nodules - Photo Quiz
ABSTRACT: Hereditary hemorrhagic telangiectasia is an uncommon autosomal dominant disease that occurs in approximately one in 5,000 to 8,000 persons. This multisystem disorder can affect the nose, skin, gastrointestinal tract, lungs, liver, and brain. Epistaxis is the most common presenting problem, occurring in 90 percent of affected patients. Approximately 15 to 30 percent of patients with hereditary hemorrhagic telangiectasia will have an arteriovenous malformation in the lungs and more than 10 percent will have one in the brain. The symptoms of hereditary hemorrhagic telangiectasia are often unrecognized. Many patients, even those with affected family members, may go undiagnosed. Hereditary hemorrhagic telangiectasia is a clinical diagnosis that is based on the presence of three of four criteria (i.e., epistaxis, telangiectasias, visceral arteriovenous malformations, or family history of the disease). Screening and treatment recommendations have been created in an attempt to limit the morbidity and mortality associated with this disease. Patients with confirmed or suspected hereditary hemorrhagic telangiectasia should be screened for brain and lung arteriovenous malformations using magnetic resonance imaging of the brain and contrast echocardiography. Pulmonary arteriovenous malformations can be treated with embolization. Patients with a history of pulmonary arteriovenous malformations or those who have not been screened should use antibiotic prophylaxis before dental treatment, endoscopy, or other procedures that could cause bacteremia because of the risk of paradoxical brain embolism or infection.
ABSTRACT: Transient ischemic attack is defined as transient neurologic symptoms without evidence of acute infarction. It is a common and important risk factor for future stroke, but is greatly underreported. Common symptoms are sudden and transient, and include unilateral paresis, speech disturbance, and monocular blindness. Correct and early diagnosis of transient ischemic attack versus mimicking conditions is important because early interventions can significantly reduce risk of future stroke. Nonspecific symptoms and gradual onset are more likely with mimics than with true transient ischemic attacks. Transient ischemic attacks are more likely with sudden onset, focal neurologic deficit, or speech disturbance. Urgent evaluation is necessary in patients with symptoms of transient ischemic attack and includes neuroimaging, cervicocephalic vasculature imaging, cardiac evaluation, blood pressure assessment, and routine laboratory testing. The ABCD2 (age, blood pressure, clinical presentation, diabetes mellitus, duration of symptoms) score should be determined during the initial evaluation and can help assess the immediate risk of repeat ischemia and stroke. Patients with higher ABCD2 scores should be treated as inpatients, whereas those with lower scores are at lower risk of future stroke and can be treated as outpatients.
ABSTRACT: Swift diagnosis and treatment are critical for good outcomes in patients with nontraumatic subarachnoid hemorrhage, which is usually caused by a ruptured aneurysm. This type of stroke often results in death or disability. Rates of misdiagnosis and treatment delays for subarachnoid hemorrhage have improved over the years, but these are still common occurrences. Subarachnoid hemorrhage can be more easily diagnosed in patients who present with severe symptoms, unconsciousness, or with thunderclap headache, which is often accompanied by vomiting. The diagnosis is more elusive in patients who present in good condition, yet these patients have the best chance for good outcome if they are correctly diagnosed at the time of presentation. Physicians should be alert for warning headaches, which are often severe, and headaches that feel different to the patient. Other symptoms may include nausea, vomiting, impaired consciousness, nuchal rigidity, orbital pain, focal neurologic deficits, dysphasia, lightheadedness, and dizziness. The most important risk factors for subarachnoid hemorrhage include cigarette smoking, hypertension, heavy alcohol use, and personal or family history of aneurysm or hemorrhagic stroke. The first step in the diagnostic workup is noncontrast computed tomography of the head. If computed tomography is negative or equivocal, a lumbar puncture should be performed. Subsequent imaging may include computed tomographic angiography, catheter angiography, and magnetic resonance angiography.