When a vascular disease is suspected, the focus is usually on morphologic features seen at contrast material-enhanced multidetector computed tomography (CT). However, unenhanced CT also plays an important role in revealing so-called hyperattenuating signs, which represent a slight increase in the focal attenuation of a vessel. Hyperattenuating signs are occasionally observed when an acute clot has formed in a vessel and can be seen in various vascular diseases, including acute arterial occlusion, acute arterial dissection, aneurysm rupture, and acute venous thrombosis. The attenuation of these signs tends to increase because the concentration of hemoglobin increases as water content decreases. Hyperattenuating signs are a transient phenomenon, as the attenuation gradually decreases. Therefore, they can serve as unique findings indicating an acute state. Although hyperattenuating signs are not well understood, recognition of these signs is important because they can help reveal serious acute vascular diseases even at unenhanced CT.
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http://dx.doi.org/10.1148/rg.301095052 | DOI Listing |
Objectives The primary objective of this study is to describe and evaluate the diagnostic performance of the hyperdense right hemidiaphragm sign (HRHS) as a novel radiological indicator for diffuse fatty infiltration of the liver on non-enhanced CT (NECT) scans. This includes assessing its sensitivity, specificity, positive predictive value, and negative predictive value, and comparing these metrics with other established NECT signs. Methods This cross-sectional multicenter retrospective study included all patients over 12 years of age who underwent both abdominal MRI and NECT scans of the abdomen within a period not exceeding six months at two tertiary hospitals (The Royal Hospital and Armed Forces Hospital, Muscat, Sultanate of Oman) between January 2010 and December 2022.
View Article and Find Full Text PDFVet Radiol Ultrasound
January 2025
Davies Veterinary Specialists, Higham Gobion, Hertfordshire, UK.
Br J Radiol
November 2024
Department of Radiology, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
Invest Radiol
February 2025
From the Institute of Radiation Physics, University Hospital Lausanne (CHUV), University of Lausanne, Lausanne, Switzerland (D.R., L.G.M., A.V.); Department of Radiology, Kantonsspital Baden, Affiliated Hospital for Research and Teaching of the Faculty of Medicine of the University of Zurich, Baden, Switzerland (T.N., R.A.K.-H., A.E.); Department of Biomedical Imaging and Image-Guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Vienna, Austria (B.N.); and Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland (H.A., T.F.).
Objectives: The aim of this study was to evaluate the potential use of simulated radiation doses from a dual-split CT scan for dose optimization by comparing their lesion detectability to dose-matched single-energy CT acquisitions at different radiation dose levels using a mathematical model observer.
Materials And Methods: An anthropomorphic abdominal phantom with liver lesions (5-10 mm, both hyperattenuating and hypoattenuating) was imaged using a third-generation dual-source CT in single-energy dual-source mode at 100 kVp and 3 radiation doses (5, 2.5, 1.
Eur Radiol
January 2025
Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
Objectives: To compare the diagnostic performance of conventional non-contrast CT, dual-energy spectral CT, and chemical-shift MRI (CS-MRI) in discriminating lipid-poor adenomas (> 10-HU on non-contrast CT) from non-adenomas.
Methods: A total of 110 patients (69 men; 41 women; mean age 66.5 ± 13.
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