title: Potential of combining iterative reconstruction with noise efficient detector design: aggressive dose reduction in head CT.
abstract: OBJECTIVE
  With further increase of CT numbers and their dominant contribution to medical exposure, there is a recent quest for more effective dose control. While reintroduction of iterative reconstruction (IR) has proved its potential in many applications, a novel focus is placed on more noise efficient detectors. Our purpose was to assess the potential of IR in combination with an integrated circuit detector (ICD) for aggressive dose reduction in head CT.
  
  
  METHODS
  Non-contrast low-dose head CT [190 mAs; weighted volume CT dose index (CTDIvol), 33.2 mGy] was performed in 50 consecutive patients, using a new noise efficient detector and IR. Images were assessed in terms of quantitative and qualitative image quality and compared with standard dose acquisitions (320 mAs; CTDIvol, 59.7 mGy) using a conventional detector and filtered back projection.
  
  
  RESULTS
  By combining ICD and IR in low-dose examinations, the signal to noise was improved by about 13% above the baseline level in the standard-dose control group. Both, contrast-to-noise ratio (2.02 ± 0.6 vs 1.88 ± 0.4; p = 0.18) and objective measurements of image sharpness (695 ± 84 vs 705 ± 151 change in Hounsfield units per pixel; p = 0.79) were fully preserved in the low-dose group. Likewise, there was no significant difference in the grading of several subjective image quality parameters when both noise-reducing strategies were used in low-dose examinations.
  
  
  CONCLUSIONS
  Combination of noise efficient detector with IR allows for meaningful dose reduction in head CT without compromise of standard image quality.
  
  
  CONCLUSIONS
  Our study demonstrates the feasibility of almost 50% dose reduction in head CT dose (1.1 mSv per scan) through combination of novel dose-reducing strategies.
authors.affiliation: 1 Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Brodoefel
authors.forename: B
authors.initials: B
authors.lastname: Bender
authors.forename: C
authors.initials: C
authors.lastname: Schabel
authors.forename: M
authors.initials: M
authors.lastname: Fenchel
authors.forename: U
authors.initials: U
authors.lastname: Ernemann
authors.forename: A
authors.initials: A
authors.lastname: Korn
mesh_terms: D000368:Aged; D004867:Equipment Design; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*
references.citation: Neuroradiology. 2014 Mar;56(3):187-93
references.pmid: 24384672
references.citation: Invest Radiol. 2013 Jan;48(1):32-40
references.pmid: 23192163
references.citation: J Comput Assist Tomogr. 2014 May-Jun;38(3):398-403
references.pmid: 24651744
references.citation: Acad Radiol. 2014 Dec;21(12):1506-11
references.pmid: 25201378
references.citation: Ann ICRP. 2000;30(4):7-45
references.pmid: 11711158
references.citation: BMJ. 2004 Jan 3;328(7430):19
references.pmid: 14703539
references.citation: Eur Radiol. 2013 Sep;23(9):2612-21
references.pmid: 23645331
references.citation: AJR Am J Roentgenol. 2013 Oct;201(4):W626-32
references.pmid: 24059402
references.citation: JACC Cardiovasc Imaging. 2013 Dec;6(12):1239-49
references.pmid: 24269265
references.citation: AJR Am J Roentgenol. 2014 Feb;202(2):368-74
references.pmid: 24450679
references.citation: Clin Neuroradiol. 2014 Mar;24(1):23-8
references.pmid: 24482000
references.citation: Lancet. 2004 Jan 31;363(9406):345-51
references.pmid: 15070562
references.citation: AJNR Am J Neuroradiol. 2013 Jan;34(1):205-11
references.pmid: 22627796
references.citation: Acad Radiol. 2013 Feb;20(2):165-72
references.pmid: 23099242
references.citation: J Appl Clin Med Phys. 2013;14(4):4347
references.pmid: 23835395
references.citation: Eur J Radiol. 2013 Sep;82(9):1431-5
references.pmid: 23587902
references.citation: Phys Med Biol. 1998 Apr;43(4):729-37
references.pmid: 9572499
references.citation: Br J Radiol. 2006 Dec;79(948):968-80
references.pmid: 17213302
references.citation: N Engl J Med. 2007 Nov 29;357(22):2277-84
references.pmid: 18046031
references.citation: Med Phys. 2007 Nov;34(11):4526-44
references.pmid: 18072519
references.citation: Radiat Res. 2010 Dec;174(6):809-15
references.pmid: 20731591
references.citation: AJNR Am J Neuroradiol. 2011 Oct;32(9):1578-82
references.pmid: 21835946
references.citation: AJNR Am J Neuroradiol. 2012 Feb;33(2):218-24
references.pmid: 22033719
references.citation: Invest Radiol. 2012 Mar;47(3):202-7
references.pmid: 22293512
references.citation: AJNR Am J Neuroradiol. 2012 Apr;33(4):609-15
references.pmid: 22207302
references.citation: Eur Radiol. 2012 Dec;22(12):2597-606
references.pmid: 22699873
references.citation: Invest Radiol. 2014 Apr;49(4):209-16
references.pmid: 24368613