title: Diagnostic accuracy of a modified subtraction coronary CT angiography method with short breath-holding time: a feasibility study.
abstract: OBJECTIVE
  To explore the feasibility and diagnostic accuracy of modified subtraction coronary CT angiography (CCTA) with short breath-holding time in patients who have limited breath-hold capability and severe coronary artery calcification.
  
  
  METHODS
  11 patients with a coronary calcium score >400 underwent CCTA using a modified subtraction protocol. All patients were unable to hold their breath for more than 20 s. Subjective image quality using a four-point scale and the presence of significant (>50%) luminal stenosis were assessed for each calcified or stented segment on both conventional CCTA and modified subtraction CCTA images and compared with invasive coronary angiography (ICA) as the gold standard.
  
  
  RESULTS
  The mean breath-holding time was 13.0 ± 0.9 s. A total of 35 calcified or stented coronary segments were evaluated. The average image quality was increased from 2.1 ± 0.9 with conventional CCTA to 3.1 ± 0.7 with subtraction CCTA (p < 0.001). The segment-based diagnostic accuracy for detecting significant stenosis according to ICA revealed an area under the receiver-operating characteristic curve of 0.722 for conventional CCTA and 0.892 for subtraction CCTA (p = 0.036).
  
  
  CONCLUSIONS
  Modified subtraction CCTA allows the breath-holding time to be shortened to <15 s. As compared with conventional CCTA, modified subtraction CCTA showed improvement in image quality and diagnostic accuracy in patients with limited breath-hold capability and severe calcification.
  
  
  CONCLUSIONS
  Modified subtraction CCTA can improve the diagnostic accuracy in patients with a high calcium score and patients who are unable to perform long breath-holds.
authors.affiliation: 1 Division of Cardiovascular Radiology, Department of Radiology, Iwate Medical University, Morioka, Japan.
authors.forename: Kunihiro
authors.identifier: http://orcid.org/0000-0002-0100-042X
authors.initials: K
authors.lastname: Yoshioka
authors.affiliation: 1 Division of Cardiovascular Radiology, Department of Radiology, Iwate Medical University, Morioka, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Tanaka
authors.affiliation: 1 Division of Cardiovascular Radiology, Department of Radiology, Iwate Medical University, Morioka, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Takagi
authors.affiliation: 2 Division of Cardiology, Department of Internal Medicine, Iwate Medical University, Morioka, Japan.
authors.forename: Kyouhei
authors.initials: K
authors.lastname: Nagata
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Chiba
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Kouta
authors.initials: K
authors.lastname: Takeda
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Ueda
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sugawara
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Sasaki
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Ueyama
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: 3 Center for Radiological Science, Iwate Medical University Hospital, Morioka, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D016477:Artifacts; D062485:Breath Holding; D000072226:Computed Tomography Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D061205:Vascular Calcification / Q000000981:diagnostic imaging*