Radiology
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To evaluate the accuracy of the size and location of the ablation zone produced by volumetric magnetic resonance (MR) imaging-guided high-intensity focused ultrasound ablation of uterine fibroids on the basis of MR thermometric analysis and to assess the effects of a feedback control technique. ⋯ Sonication accuracy of volumetric MR imaging-guided high-intensity focused ultrasound ablation of uterine fibroids appears clinically acceptable and may be further improved by feedback control to produce more consistent ablation zones.
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Controlled Clinical Trial
Hyperpolarized 3He and 129Xe MR imaging in healthy volunteers and patients with chronic obstructive pulmonary disease.
To quantitatively compare hyperpolarized helium 3 (3He) and xenon 129 (129Xe) magnetic resonance (MR) images obtained within 5 minutes in healthy volunteers and patients with chronic obstructive pulmonary disease (COPD) and to evaluate the correlations between 3He and 129Xe MR imaging measurements and those from spirometry and plethysmography. ⋯ In patients with COPD, the VDP obtained with hyperpolarized 29Xe MR imaging was significantly greater than that with 3He MR imaging, suggesting incomplete or delayed filling of lung regions that may be related to the different properties of 129Xe gas and physiologic and/or anatomic abnormalities in COPD.
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Randomized Controlled Trial
Pulmonary perifissural nodules on CT scans: rapid growth is not a predictor of malignancy.
To assess the prevalence, natural course, and malignancy rate of perifissural nodules (PFNs) in smokers participating in a lung cancer screening trial. ⋯ PFNs are frequently found at CT scans for lung cancer. They can show growth rates in the range of malignant nodules, but none of the PFNs in the present study turned out to be malignant. Recognition of PFNs can reduce the number of follow-up examinations required for the workup of suspicious nodules.
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This article summarizes the proceedings of a portion of the Radiation Dose Summit, which was organized by the National Institute of Biomedical Imaging and Bioengineering and held in Bethesda, Maryland, in February 2011. The current understandings of ways to optimize the benefit-risk ratio of computed tomography (CT) examinations are summarized and recommendations are made for priority areas of research to close existing gaps in our knowledge. The prospects of achieving a submillisievert effective dose CT examination routinely are assessed.