Image noise-based dose adaptation in dynamic volume CT of the heart: dose and image quality optimisation in comparison with BMI-based dose adaptation

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• 作者：Devang Odedra (1)
  Joerg Blobel (2) (3)
  Saad AlHumayyd (3)
  Miranda Durand (3)
  Laura Jimenez-Juan (3)
  Narinder Paul (3)
  
• 关键词：Cardiac angiography ; Radiation dosage ; Computed ?X ; ray tomography ; Image enhancement ; Cardiac imaging techniques
• 刊名：European Radiology
• 出版年：2014
• 出版时间：January 2014
• 年：2014
• 卷：24
• 期：1
• 页码：86-94
• 全文大小：
• 作者单位：Devang Odedra (1)
  Joerg Blobel (2) (3)
  Saad AlHumayyd (3)
  Miranda Durand (3)
  Laura Jimenez-Juan (3)
  Narinder Paul (3)
  
  1. School of Medicine, Queen? University, 18 Barrie Street, Kingston, ON, K7L 3N6, Canada
  2. Toshiba Medical Systems Europe BV, Zilverstraat 1, 2718 RP, Zoetermeer, The Netherlands
  3. Division of Cardiothoracic Imaging, Department of Medical Imaging, Toronto General Hospital, University of Toronto, 585 University Ave., Toronto, ON, M5G 2N2, Canada
  
• ISSN：1432-1084

文摘

Objectives To compare the image quality and radiation dose using image-noise (IN)-based determination of X-ray tube settings compared with a body mass index (BMI)-based protocol during CT coronary angiography (CTCA). Methods Two hundred consecutive patients referred for CTCA to our institution were divided into two groups: BMI-based, 100 patients had CTCA with the X-ray tube current adjusted to the patient? BMI while maintaining a fixed tube potential of 120?kV; IN-based, 100 patients underwent imaging with the X-ray tube current and voltage adjusted to the IN measured within the mid-left ventricle on a pre-acquisition trans-axial image. Two independent cardiac radiologists performed blinded image quality assessment with quantification of the IN and signal-to-noise ratio (SNR) from the mid-LV and qualitative assessment using a three-point score. Radiation dose (CTDI and DLP) was recorded from the console. Results Results showed: IN (HU): BMI-based, 30.1??9.9; IN-based, 33.1??6.7; 32?% variation reduction (P?=?0.001); SNR: BMI-based, 18.6??7.1; IN-based, 15.4??3.7; 48?% variation reduction (P?<?0.0001). Visual scores: BMI-based, 2.3??0.6; IN-based, 2.2??0.5 (P?=?0.54). Radiation dose: CTDI (mGy), BMI-based, 22.68??8.9; IN-based, 17.16??7.6; 24.3?% reduction (P?<?0.001); DLP (mGy.cm), BMI-based, 309.3??127.5; IN-based, 230.6??105.5; 25.4?% reduction (P?<?0.001). Conclusions Image-noise-based stratification of X-ray tube parameters for CTCA results in 32?% improvement in image quality and 25?% reduction in radiation dose compared with a BMI-based protocol. Key Points ? Image quality and radiation dose are closely related in CT coronary angiography. ? So too are the image quality, radiation dose and body mass index (BMI). ? An image-noise-based CTCA protocol reduces the radiation dose by 25?%. ? It improves inter-patient image homogeneity by 32?%.