title: Radiation dose reduction in chest CT--review of available options.
abstract: Computed tomography currently accounts for the majority of radiation exposure related to medical imaging. Although technological improvement of CT scanners has reduced the radiation dose of individual examinations, the benefit was overshadowed by the rapid increase in the number of CT examinations. Radiation exposure from CT examination should be kept as low as reasonably possible for patient safety. Measures to avoid inappropriate CT examinations are needed. Principles and information on radiation dose reduction in chest CT are reviewed in this article. The reduction of tube current and tube potential are the mainstays of dose reduction methods. Study results indicate that routine protocols with reduced tube current are feasible with diagnostic results comparable to conventional standard dose protocols. Tube current adjustment is facilitated by the advent of automatic tube current modulation systems by setting the appropriate image quality level for the purpose of the examination. Tube potential reduction is an effective method for CT pulmonary angiography. Tube potential reduction often requires higher tube current for satisfactory image quality, but may still contribute to significant radiation dose reduction. Use of lower tube potential also has considerable advantage for smaller patients. Improvement in image production, especially the introduction of iterative reconstruction methods, is expected to lower radiation dose significantly. Radiation dose reduction in CT is a multifaceted issue. Understanding these aspects leads to an optimal solution for various indications of chest CT.
authors: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan. Electronic address: tkubo@kuhpkyoto-u.ac.jp.
authors: Takeshi
authors: T
authors: Kubo
authors: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. Electronic address: yosirad@kobe-u.ac.jp.
authors: Yoshiharu
authors: Y
authors: Ohno
authors: Diagnostic and Interventional Radiology, University Clinic Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany. Electronic address: hu.kauczor@med.uni-heidelberg.de.
authors: Hans Ulrich
authors: HU
authors: Kauczor
authors: Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, United States. Electronic address: hhatabu@partners.org.
authors: Hiroto
authors: H
authors: Hatabu
mesh_terms: D006801:Humans; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods*; D011874:Radiometry / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
keywords: CT; Radiation dose; Thoracic imaging