Items in AFP with MESH term: Tomography, X-Ray Computed
ABSTRACT: Colorectal cancer causes significant morbidity and mortality in the United States. The incidence of colorectal cancer can be reduced with increasing efforts directed at mass screening of average-risk adults 50 years and older. Currently, fecal occult blood test and flexible sigmoidoscopy have the highest levels of evidence to support their use for colorectal cancer screening. Colonoscopy does not have a proven colorectal cancer mortality benefit, but it does have the greatest single-test accuracy, and it is the final test in the pathway to evaluate and treat patients with other abnormal screening tests. Double-contrast barium enema has sparse data of effectiveness. Computed tomographic colonography, fecal DNA testing, and Pillcam Colon are promising tests that need further study before they can be recommended for widespread screening. Routine screening should continue until 75 years of age. There is good evidence that fiber and antioxidants are not effective for primary prevention of colorectal cancer; they should not be recommended for chemoprevention. There is good evidence that aspirin, nonsteroidal antiinflammatory drugs, and cyclooxygenase-2 inhibitors are effective for decreasing the risk of colorectal cancer and adenomatous polyps, but increased risks, such as gastrointestinal bleeding, limit their usefulness. There is fair evidence that obesity is associated with colorectal cancer. Additional studies are needed on decreased fat intake and red meat consumption, and the use of calcium, vitamin D, and statins before these can be recommended for primary prevention of colorectal cancer.
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.
Acute Stroke Diagnosis - Article
ABSTRACT: Stroke can be categorized as ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. Awakening with or experiencing the abrupt onset of focal neurologic deficits is the hallmark of ischemic stroke diagnosis. The most common presenting symptoms for ischemic stroke are difficulty with speech and weakness on one half of the body. Many stroke mimics exist; two of the most common are a postictal seizure and hypoglycemia. Taking a detailed history and performing ancillary testing will usually exclude stroke mimics. Neuroimaging is required to differentiate ischemic stroke from intracerebral hemorrhage, as well as to diagnose entities other than stroke. The choice of neuroimaging depends on its availability, eligibility for acute stroke interventions, and the presence of patient contraindications. Subarachnoid hemorrhage presents most commonly with severe headache and may require analysis of cerebrospinal fluid when neuroimaging is not definitive. Public education of common presenting stroke symptoms is needed for patients to activate emergency medical services as soon as possible after the onset of stroke.
ABSTRACT: The population of adults with congenital heart disease is increasing in North America. Radiologic imaging is critical for the initial assessment and for surveillance in this population. Chest radiography and echocardiography are valuable first-line tools for evaluation. However, magnetic resonance imaging and computed tomography are often necessary, particularly for assessment of extracardiac anatomy or specific vascular connections or relationships, which may be complex in postoperative patients. Although magnetic resonance imaging and computed tomography can provide volumetric data for more comprehensive evaluation of cardiac anatomy and function, magnetic resonance imaging does not require patient exposure to ionizing radiation or nephrotoxic iodinated contrast media. Magnetic resonance imaging also can measure blood flow for quantification of left-to-right shunts, regurgitant fractions, and pressure gradients. Although noninvasive imaging techniques have limitations, they can evaluate most lesions and preclude the need for cardiac catheterization. Noninvasive imaging is particularly useful for serial evaluation of patients with surgically corrected congenital heart disease, because nearly one half of these patients will require two or more surgeries.
Multiple Pulmonary Nodules - Photo Quiz
A Major Medical Error - Curbside Consultation
A Widened Mediastinum - Photo Quiz
AAP Issues Recommendations for the Management of Sinusitis in Children - Practice Guidelines
Swollen Tonsil - Photo Quiz
Headache - Photo Quiz