Advanced

Impact on image quality and radiation exposure in coronary CT angiography: 100 kVp versus 120 kVp

Ripsweden, Jonaz; Brismar, Torkel B.; Holm, Jon; Melinder, Annika; Mir-Akbari, Habib; Nilsson, Tage; Nyman, Ulf LU ; Rasmussen, Elsbeth; Ruck, Andreas and Cederlund, Kerstin (2010) In Acta Radiologica 51(8). p.903-909
Abstract
Background: The risk of radiation-induced cancer has become a major concern with the increasing use of computed tomography (CT). Purpose: To compare image quality and radiation doses when decreasing X-ray tube peak kilovoltage (kVp) from 120 to 100 kVp in patients undergoing coronary CT angiography (CCTA). Material and Methods: Patients referred for evaluation of suspected coronary artery disease (CAD) underwent 64-channel detector CCTA using a tube voltage of either 120 kVp (n = 46) or 100 kVp (n = 82). The individual volume CT dose index (CTDIvol) and dose length product (DLP) were recorded and effective radiation dose was estimated on the basis of DLP. Subjective image quality was assessed by two radiologists on per-patient based... (More)
Background: The risk of radiation-induced cancer has become a major concern with the increasing use of computed tomography (CT). Purpose: To compare image quality and radiation doses when decreasing X-ray tube peak kilovoltage (kVp) from 120 to 100 kVp in patients undergoing coronary CT angiography (CCTA). Material and Methods: Patients referred for evaluation of suspected coronary artery disease (CAD) underwent 64-channel detector CCTA using a tube voltage of either 120 kVp (n = 46) or 100 kVp (n = 82). The individual volume CT dose index (CTDIvol) and dose length product (DLP) were recorded and effective radiation dose was estimated on the basis of DLP. Subjective image quality was assessed by two radiologists on per-patient based consensus. Vascular density and image noise were quantified in the left main coronary artery (LMCA) and proximal ascending aorta (AA). Mean density in the adjacent perivascular tissue was also quantified. Contrast-to-noise ratio (CNR) was calculated. Corresponding invasive coronary angiography (ICA) was performed, which constituted the gold standard. Results: Mean values in the 100120 kVp cohorts regarding CNR in the LMCA were 12.716.0 (P < 0.0001)) and in the AA 13.217.2 (P < 0.0001), CTDIvol 34.457.4 mGy (a 40% reduction, P < 0.0001), DLP 5781125 mGy X cm (P < 0.0001), and estimated effective dose 9.620.2 mSv (P < 0.0001). There was no statistically significant difference in subjective image quality between the two cohorts. The sensitivity to detect significant coronary stenoses was 88% (120 kVp) and 84% (100 kVp) and the specificity was 71% (120 kVp) and 74% (100 kVp), respectively. Conclusion: By reduction of tube voltage from 120 to 100 kVp at CCTA, while keeping all other scanning parameters unchanged, the radiation dose to the patient can be almost halved while keeping the diagnostic image quality at a clinically acceptable level. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
radiation dose, signal-to-noise ratio, contrast-to-noise ratio, coronary arteries, Angiography, heart
in
Acta Radiologica
volume
51
issue
8
pages
903 - 909
publisher
John Wiley & Sons
external identifiers
  • wos:000281771700010
  • scopus:77956520348
ISSN
1600-0455
DOI
10.3109/02841851.2010.504740
language
English
LU publication?
yes
id
873ffc1e-c6d6-48b9-8234-0b3c2f4f72f6 (old id 1728191)
date added to LUP
2010-11-22 12:41:30
date last changed
2018-05-29 11:50:40
@article{873ffc1e-c6d6-48b9-8234-0b3c2f4f72f6,
  abstract     = {Background: The risk of radiation-induced cancer has become a major concern with the increasing use of computed tomography (CT). Purpose: To compare image quality and radiation doses when decreasing X-ray tube peak kilovoltage (kVp) from 120 to 100 kVp in patients undergoing coronary CT angiography (CCTA). Material and Methods: Patients referred for evaluation of suspected coronary artery disease (CAD) underwent 64-channel detector CCTA using a tube voltage of either 120 kVp (n = 46) or 100 kVp (n = 82). The individual volume CT dose index (CTDIvol) and dose length product (DLP) were recorded and effective radiation dose was estimated on the basis of DLP. Subjective image quality was assessed by two radiologists on per-patient based consensus. Vascular density and image noise were quantified in the left main coronary artery (LMCA) and proximal ascending aorta (AA). Mean density in the adjacent perivascular tissue was also quantified. Contrast-to-noise ratio (CNR) was calculated. Corresponding invasive coronary angiography (ICA) was performed, which constituted the gold standard. Results: Mean values in the 100120 kVp cohorts regarding CNR in the LMCA were 12.716.0 (P &lt; 0.0001)) and in the AA 13.217.2 (P &lt; 0.0001), CTDIvol 34.457.4 mGy (a 40% reduction, P &lt; 0.0001), DLP 5781125 mGy X cm (P &lt; 0.0001), and estimated effective dose 9.620.2 mSv (P &lt; 0.0001). There was no statistically significant difference in subjective image quality between the two cohorts. The sensitivity to detect significant coronary stenoses was 88% (120 kVp) and 84% (100 kVp) and the specificity was 71% (120 kVp) and 74% (100 kVp), respectively. Conclusion: By reduction of tube voltage from 120 to 100 kVp at CCTA, while keeping all other scanning parameters unchanged, the radiation dose to the patient can be almost halved while keeping the diagnostic image quality at a clinically acceptable level.},
  author       = {Ripsweden, Jonaz and Brismar, Torkel B. and Holm, Jon and Melinder, Annika and Mir-Akbari, Habib and Nilsson, Tage and Nyman, Ulf and Rasmussen, Elsbeth and Ruck, Andreas and Cederlund, Kerstin},
  issn         = {1600-0455},
  keyword      = {radiation dose,signal-to-noise ratio,contrast-to-noise ratio,coronary arteries,Angiography,heart},
  language     = {eng},
  number       = {8},
  pages        = {903--909},
  publisher    = {John Wiley & Sons},
  series       = {Acta Radiologica},
  title        = {Impact on image quality and radiation exposure in coronary CT angiography: 100 kVp versus 120 kVp},
  url          = {http://dx.doi.org/10.3109/02841851.2010.504740},
  volume       = {51},
  year         = {2010},
}