title: Well-balanced system for coronary calcium detection and volume measurement in a low resolution intravascular ultrasound videos.
abstract: Accurate and fast quantitative assessment of calcium volume is required during the planning of percutaneous coronary interventions procedures. Low resolution in intravascular ultrasound (IVUS) coronary videos poses a threat to calcium detection causing over-estimation in volume measurement. We introduce a correction block that counter-balances the bias introduced during the calcium detection process.
  
  
  
  Nineteen patients image dataset (around 40,090 frames), IRB approved, were collected using 40MHz IVUS catheter (Atlantis® SR Pro, Boston Scientific®, pullback speed of 0.5mm/sec). A new set of 20 generalized and well-balanced systems each consisting of three stages: (i) calcium detection, (ii) calibration and (iii) measurement, while ensuring accuracy of four soft classifiers (Threshold, FCM, K-means and HMRF) and workflow speed using five multiresolution techniques (bilinear, bicubic, wavelet, Lanczos, Gaussian Pyramid) were designed. Results of the three calcium detection methods were benchmarked against the Threshold-based method.
  
  
  
  All 20 well-balanced systems with calibration block show superior performance. Using calibration block, FCM versus Threshold-based method shows the highest cross-correlation 0.99 (P<0.0001), Jaccard index 0.984±0.013 (P<0.0001), and Dice similarity 0.992±0.007 (P<0.0001). The corresponding area under the curve for four calcium detection techniques is: 1.0, 1.0, 0.97 and 0.93, respectively. The mean overall performance improvement is 38.54% and when adapting calibration block. The mean workflow speed improvement is 62.14% when adapting multiresolution paradigm. Three clinical tests shows consistency, reliability, and stability of our well-balanced system.
  
  
  
  A well-balanced system with a combination of Threshold embedded with Lanczos multiresolution was optimal and can be useable in clinical settings.
authors.affiliation: Department of Electrical Engineering, NIT Raipur, CG, India.
authors.forename: Sumit K
authors.initials: SK
authors.lastname: Banchhor
authors.affiliation: Department of Electrical Engineering, NIT Raipur, CG, India.
authors.forename: Narendra D
authors.initials: ND
authors.lastname: Londhe
authors.affiliation: Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Araki
authors.affiliation: Department of Radiology, University of Cagliari, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Saba
authors.affiliation: Department of Mathematics and Computer Science, University of Barcelona, Barcelona, Spain.
authors.forename: Petia
authors.initials: P
authors.lastname: Radeva
authors.affiliation: UC Davis Vascular Centre, University of California, Davis, CA, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Laird
authors.affiliation: Monitoring and Diagnostic Division, AtheroPoint™, Roseville 95661, CA, USA; Department of Electrical Engineering, University of Idaho (Affl.), ID, USA. Electronic address: Jasjit.Suri@atheropoint.com.
authors.forename: Jasjit S
authors.initials: JS
authors.lastname: Suri
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002138:Calibration; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D017143:Fuzzy Logic; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018084:Ultrasonography, Interventional / Q000379:methods*; D014584:User-Computer Interface; D061205:Vascular Calcification / Q000000981:diagnostic imaging*; D014741:Video Recording
keywords: Calibration; Classification; Coronary calcium volume; Low-resolution IVUS; Multiresolution; Speed