Published online before print February 27, 2004, 10.1148/radiol.2311030191
Low-Kilovoltage Multi–Detector Row Chest CT in Adults: Feasibility and Effect on Image Quality and Iodine Dose1
Anne B. Sigal-Cinqualbre, MD,
Remi Hennequin, MD,
Hicham T. Abada, MD,
Xiaoyan Chen, MD and
Jean-François Paul, MD
1 From the Department of Radiology, CT Unit, Hôpital Marie-Lannelongue, 133 Avenue de la Résistance, 92350 Le Plessis-Robinson, France (A.B.S.C., R.H., J.F.P.); Department of Interventional Radiology, Hôpital René Dubos, Cergy-Pontoise, France (H.T.A.); and Department of CT Physics and Applications, Siemens Medical Solutions, Forchheim, Germany (X.C.). From the 2002 RSNA Scientific Assembly. Received February 17, 2003; revision requested May 7; revision received June 25; accepted August 18. Address correspondence to J.F.P. (e-mail: pauljf@ccml.com).
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Figure 1. Graph of patient weight versus image noise level with the three protocols. The noise level remained below 20 HU at 120 kV (ie, with protocol C) but increased exponentially with the low-kilovoltage protocols, especially at weights greater than 60 kg (protocol A) and greater than 75 kg (protocol B).
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Figure 2a. (a) Scatterplot of patient weight versus image noise (ie, SD) with protocol A. Sixty kilograms was considered the weight limit at an image noise level of 20 HU. (b) Scatterplot of patient weight versus image noise (ie, SD) with protocol B. Seventy-five kilograms was considered the weight limit at an image noise level of 20 HU.
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Figure 2b. (a) Scatterplot of patient weight versus image noise (ie, SD) with protocol A. Sixty kilograms was considered the weight limit at an image noise level of 20 HU. (b) Scatterplot of patient weight versus image noise (ie, SD) with protocol B. Seventy-five kilograms was considered the weight limit at an image noise level of 20 HU.
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Figure 3a. Transverse CT images obtained at 80 kV and 135 mAs (protocol A) in 79-year-old man weighing 50 kg for follow-up of nontuberculous mycobacterial infection; 40 mL of contrast material was administered at 1.3 mL/sec. (a) Mediastinal window (center of 70 HU, width of 530 HU) image shows homogeneous vascular enhancement of the ascending aorta (AA), descending aorta (DA), and right pulmonary artery (RPA). The image was judged to have good diagnostic quality by the two observers. A circular region of interest was drawn over the ascending aorta; artifacts secondary to intravenous contrast material in the superior vena cava (SVC) were avoided. (b) Parenchymal window image shows well-depicted peribronchial opacities in both lung lobes.
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Figure 3b. Transverse CT images obtained at 80 kV and 135 mAs (protocol A) in 79-year-old man weighing 50 kg for follow-up of nontuberculous mycobacterial infection; 40 mL of contrast material was administered at 1.3 mL/sec. (a) Mediastinal window (center of 70 HU, width of 530 HU) image shows homogeneous vascular enhancement of the ascending aorta (AA), descending aorta (DA), and right pulmonary artery (RPA). The image was judged to have good diagnostic quality by the two observers. A circular region of interest was drawn over the ascending aorta; artifacts secondary to intravenous contrast material in the superior vena cava (SVC) were avoided. (b) Parenchymal window image shows well-depicted peribronchial opacities in both lung lobes.
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Copyright © 2004 by the Radiological Society of North America.
