Siemens Medical Solutions of Hoffman Estates, Ill., has received clearance from the FDA to begin clinical trials on an imaging biomarker for Alzheimer’s diagnosis. The company will conduct the Phase I safety study in conjunction with the University of California, Los Angeles, to determine the biomarker’s effectiveness in detecting amyloid plaques and tangles in patients’ brains.Siemens also has received FDA 510(k) clearance for the first six of many planned dual-energy applications for its Somatom Definition dual-source computed tomography system. The applications will allow the system — whose temporal resolution enables it to capture images independent of heart rate and without beta blockers — to perform functions such as CT angiography.