European radiology
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Comparative Study
Fractional anisotropy and mean diffusivity measurements on normal human brain: comparison between low-and high-resolution diffusion tensor imaging sequences.
Non-invasive in vivo visualization of white matter fiber tracts is currently feasible by means of diffusion tensor imaging (DTI) techniques. DTI-derived metrics, like fractional anisotropy (FA) and mean diffusivity (MD), have the potential to improve tissue characterization. ⋯ Voxel-based statistical analysis revealed regions with significantly different FA and MD values between the two sequences, while the same type of analysis was performed to illustrate regions with significantly different signal-to-noise ratio. In conclusion, optimized DTI sequences may be applied routinely in clinical practice with a standard MR scanner, while accurate quantification of FA and MD may improve lesion characterization.
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Lung cancer screening with CT remains controversial. Lung cancer is the leading cause of cancer death. To date, no screening test has been demonstrated to reduce mortality. ⋯ The innumerable small nodules detected with screening CT, and diagnostic chest CT in general, present a daily clinical challenge, and result in extensive medical resource utilization and additional radiation exposure. Algorithms for how and when to follow small nodules detected on CT are in evolution. Ongoing studies are designed to determine if lung cancer screening with CT reduces lung cancer mortality.
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Computed tomographic (CT) cancer screening has seen a steady increase in interest with the introduction of multislice scanners. While the potential benefits of screening are obvious, radiation dose may pose a long-term risk for the screened individual. This article will discuss the basis for radiation risk estimation and give an overview of the current dose controversy surrounding CT screening. ⋯ For both indications substantial dose reduction up to factors of 5-10 may be possible. Full-body screening remains critical when performed at regular intervals because of the large doses required and the direct exposure of the lungs. If performed in a dose-conscious fashion, individual risks with lung and colon cancer screening are very small, but estimated population risks are non-negligible.
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Comparative Study
Importance of extracolonic findings at IV contrast medium-enhanced CT colonography versus those at non-enhanced CT colonography.
To compare the clinical importance of extracolonic findings at intravenous (IV) contrast-enhanced CT colonography versus those at non-enhanced CT colonography. IV contrast medium-enhanced (n=72) and non-enhanced (n=30) multidetector CT colonography was performed in 102 symptomatic patients followed by conventional colonoscopy on the same day. The impact of extracolonic findings on further work up and treatment was assessed by a review of patient records. ⋯ The percentage of extracolonic findings leading to further work up or having an impact on therapy was higher for IV contrast-enhanced (31%; 22/72) than for non-enhanced (13%; 4/30) CT scans (P=0.12). IV contrast-enhanced CT colonography produced more extracolonic findings than non-enhanced CT colonography. A substantially greater proportion of findings on IV contrast-enhanced CT colonography led to further work up and treatment than did non-enhanced CT colonography.