Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Changes in hardware or image-processing settings are a common issue for large multicenter studies. To pool MRI data acquired under these changed conditions, it is necessary to demonstrate that the changes do not affect MRI-based measurements. In these circumstances, classical inference testing is inappropriate because it is designed to detect differences, not prove similarity. ⋯ Power analysis of simulated and automated hippocampal volume data demonstrated that the equivalence margin affects the number of subjects required for well-powered equivalence tests. We have presented a statistical method for determining if morphometric measures obtained under variable conditions can be pooled. The equivalence testing technique is applicable for analyses in which experimental conditions vary over the course of the study.
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Atherosclerosis and osteoporosis are two major public health problems. It is still uncertain whether an abnormal carotid ultrasonography, either increased intima-media thickness (IMT) or plaque thickness, is associated with osteoporosis in acute ischemic stroke patients. To investigate the possible relationships between osteoporosis and carotid atherosclerosis, we evaluated the correlation between carotid IMT/plaque thickness and bone mineral density (BMD) in acute ischemic stroke patients. ⋯ This study showed that carotid IMT/plaque thickness was inversely related to the BMD in female but not in male patients with acute ischemic stroke.
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Whole brain atrophy is a putative outcome measure in monitoring relapsing-remitting multiple sclerosis (RRMS). With the ongoing MRI transformation from 1.5T to 3T, there is an unmet need to calibrate this change. We evaluated brain parenchymal volumes (BPVs) from 1.5T versus 3T in MS and normal controls (NC). ⋯ Field strength may impact whole brain volume measurements in patients with MS though the differences are not too divergent between 1.5T and 3T.
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Headache after cerebral angiography is frequent but has received little attention. The purpose of this study was to evaluate the incidence and risk factors of headache after cerebral angiography. This study also addressed the predisposing factors that facilitate headache recovery. ⋯ The incidence of headache after DSA was 55.6%. Patients with a previous history of headaches, cerebrovascular disease, or a college education may have a higher risk of developing post-DSA headaches than do those without such history. Headache recovery may be associated with a patient history of diabetes or cerebrovascular disease.
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Computed tomography (CT) is an invaluable tool in the diagnosis of many clinical conditions. Several advancements in biomedical engineering have achieved increase in speed, improvements in low-contrast detectability and image quality, and lower radiation. Portable or mobile CT constituted one such important advancement. ⋯ MSU also improved the triage of patients to appropriate and specialized hospitals. Although multiple issues remain yet unanswered with the MSU concept including clinical outcome and cost-effectiveness, the MSU venture is visionary and enables delivery of life-saving and enhancing treatment for ischemic and hemorrhagic stroke. In this review, we discuss the development of mobile CT and its applications, with specific focus on its use in MSUs along with our institution's MSU experience.