Imaging and cerebrospinal fluid (CSF) biomarkers can improve prediction of conversion from mild cognitive impairment (MCI) to Alzheimer disease (AD) compared with predictions based on clinical parameters, according to new research.
Jennifer L. Shaffer, M.D., of Duke University Medical Center, Durham, N.C., and colleagues examined 97 patients with MCI from the Alzheimer Disease Neuroimaging Initiative (ADNI), a national multicenter biomarker study in which patients are followed serially to track disease progression. MR imaging-derived gray matter probability maps and FDG PET images were analyzed by using independent component analysis, an unbiased data-driven method to extract independent sources of information from whole-brain data.
Combining MR imaging, FDG PET, and CSF data with routine clinical tests significantly increased the accuracy of predicting conversion to AD compared with clinical testing alone. The misclassification rate decreased from 41.3 percent to 28.4 percent, results showed.
“Among these three imaging and molecular biomarkers, FDG PET appears to be the primary contributor, with misclassification rates for FDG PET, MR imaging, and CSF compared with clinical variables alone of 27.2 percent (P = .00001), 39.2 percent (P = .08), and 39.6 percent (P = .32), respectively,” the authors concluded.
Intraarterial revascularization with stents was an effective and safe treatment option in patients with acute middle cerebral artery (MCA) occlusion with contraindication to intravenous thrombolysis (IVT) or after IVT failure, according to the results of a controlled trial.
Martin Roubec, M.D., Ph.D., of Ostrava University and University Hospital Ostrava, examined 131 patients (74 men and 57 women) with acute ischemic stroke (AIS) due to MCA occlusion; 75 underwent IVT. No further recanalization therapy was performed in 26 (35 percent) of IVT-treated patients with MCA recanalization. Patients with IVT failure after 60 minutes were allocated to endovascular treatment or no further therapy. Patients with contraindication to IVT were allocated to endovascular treatment within eight hours of AIS onset or to no recanalization therapy. Neurologic deficit at admission, MCA recanalization, symptomatic intracerebral hemorrhage and three-month clinical outcome were evaluated.
Results showed intraarterial revascularization with the use of stents is an effective and safe therapeutic method for patients with AIS, with a 92.6 percent recanalization rate; it had a favorable clinical outcome for 43.5 percent of those with IVT failure and for 45.2 percent with contraindication to IVT, with a 4 percent risk of symptomatic intracerebral hemorrhage.
“Cerebral PTA with stent placement seems to be a safe endovascular therapeutic method for patients with acute ischemic stroke and might be effective both in patients with MCA occlusion after IVT failure and in patients with contraindication to IVT,” the authors write. “Nevertheless, the safety and efficacy of cerebral PTA with stent placement, as endovascular method, needs to be compared directly with IVT and/or other conservative treatment within the same time window by a prospective randomized trial.”
Lifetime radiation risk estimates, when used for decision making, may overemphasize radiation-induced cancer risks relative to short-term health risks, new research shows.
Pari V. Pandharipande, M.D., M.P.H., of the Massachusetts General Hospital Institute for Technology Assessment, and colleagues developed a Markov model to project outcomes in patients with testicular cancer undergoing CT surveillance in the decade after orchiectomy. To quantify effects of early versus delayed risks, life expectancy losses and lifetime mortality risks due to testicular cancer were compared with life expectancy losses and lifetime mortality risks due to radiation-induced cancers from CT. Projections of life expectancy loss—unlike lifetime risk estimates—account for the timing of risks over the course of a lifetime, which enabled evaluation of the described limitation of lifetime risk estimates.
Researchers projected that 33-year-old men with early-stage cancer who undergo CT surveillance incur a slightly higher lifetime mortality risk from testicular cancer (598 per 100,000; 95 percent uncertainty interval [UI]: 302, 894) than from radiation-induced cancers (505 per 100,000; 95 percent UI: 280, 730). However, life expectancy loss attributable to testicular cancer (83 days; 95 percent UI: 42, 124) was more than three times greater than life expectancy loss attributable to radiation-induced cancers (24 days; 95 percent UI: 13, 35).
“Lifetime risk metrics do not account for the delayed timing of radiation-induced cancers over the course of a patient’s lifetime; as a result, radiation-induced cancer risks may be overemphasized relative to more immediate health risks in many clinical settings,” the authors write.
RadiologyInfo.org, the RSNA/American College of Radiology public information website, recently launched its Patient Safety in Imaging app for tablet devices and iPhones. The app offers information related to numerous safety topics including radiation dose, radiation safety for pediatric patients and CT/MR during pregnancy. The app contains 18 videos to help illustrate content.
Download the easy-to-navigate app for iPad, iPhone and Android tablets at:
Visit RadiologyInfo.org, RSNA and ACR’s jointly-sponsored public information website, today to read the latest procedure description posted on the site: Abnormal Vaginal Bleeding.
In November, media outlets carried 603 RSNA-related news stories. These stories reached an estimated 391 million people.
Print coverage included Chicago Tribune, The Florida Times-Union, The Star-Ledger (Newark, N.J.) and The Bellingham Herald (Wash.). Broadcast coverage included WGN-AM (Chicago), WWJ-TV (Detroit), WFSB-TV (Hartford, Conn.), KWTV-TV (Oklahoma City, Okla.) and KIMT-TV (Rochester, Minn.). Online coverage included Yahoo! News, TIME, Reuters, Boston Globe, Houston Chronicle, Boston Herald, Denver Post, San Francisco Chronicle and Examiner.com.
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In February, RSNA is distributing the “60-Second Checkup” audio program to nearly 100 radio stations across the U.S. The segments focus on how coronary CTA could benefit patients who present with chest pains in the emergency department.
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