title: New image-processing and noise-reduction software reduces radiation dose during complex endovascular procedures.
abstract: BACKGROUND
  A new proprietary image-processing system known as AlluraClarity, developed by Philips Healthcare (Best, The Netherlands) for radiation-based interventional procedures, claims to lower radiation dose while preserving image quality using noise-reduction algorithms. This study determined whether the surgeon and patient radiation dose during complex endovascular procedures (CEPs) is decreased after the implementation of this new operating system.
  
  
  METHODS
  Radiation dose to operators, procedure type, reference air kerma, kerma area product, and patient body mass index were recorded during CEPs on two Philips Allura FD 20 fluoroscopy systems with and without Clarity. Operator dose during CEPs was measured using optically stimulable, luminescent nanoDot (Landauer Inc, Glenwood, Ill) detectors placed outside the lead apron at the left upper chest position. nanoDots were read using a microStar ii (Landauer Inc) medical dosimetry system. For the CEPs in the Clarity group, the radiation dose to surgeons was also measured by the DoseAware (Philips Healthcare) personal dosimetry system. Side-by-side measurements of DoseAware and nanoDots allowed for cross-calibration between systems. Operator effective dose was determined using a modified Niklason algorithm. To control for patient size and case complexity, the average fluoroscopy dose rate and the dose per radiographic frame were adjusted for body mass index differences and then compared between the groups with and without Clarity by procedure. Additional factors, for example, physician practice patterns, that may have affected operator dose were inferred by comparing the ratio of the operator dose to procedural kerma area product with and without Clarity. A one-sided Wilcoxon rank sum test was used to compare groups for radiation doses, reference air kermas, and operating practices for each procedure type.
  
  
  RESULTS
  The analysis included 234 CEPs; 95 performed without Clarity and 139 with Clarity. Practice patterns of operators during procedures with and without Clarity were not significantly different. For all cases, procedure radiation dose to the patient and the primary and assistant operators were significantly decreased in the Clarity group by 60% compared with the non-Clarity group. By procedure type, fluorography dose rates decreased from 44% for fenestrated endovascular repair and up to 70% with lower extremity interventions. Fluoroscopy dose rates also significantly decreased, from about 37% to 47%, depending on procedure type.
  
  
  CONCLUSIONS
  The AlluraClarity system reduces the patient and primary operator's radiation dose by more than half during CEPs. This feature appears to be an effective tool in lowering the radiation dose while maintaining image quality.
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex. Electronic address: melissa.kirkwood@utsouthwestern.edu.
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Kirkwood
authors.affiliation: Division of Medical Physics, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Guild
authors.affiliation: Division of Medical Physics, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Arbique
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Shirling
authors.initials: S
authors.lastname: Tsai
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: J Gregory
authors.initials: JG
authors.lastname: Modrall
authors.affiliation: Division of Medical Physics, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Jon A
authors.initials: JA
authors.lastname: Anderson
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: John
authors.initials: J
authors.lastname: Rectenwald
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Carlos
authors.initials: C
authors.lastname: Timaran
mesh_terms: D000465:Algorithms; D057510:Endovascular Procedures / Q000009:adverse effects; D005471:Fluoroscopy; D006801:Humans; D016273:Occupational Exposure / Q000009:adverse effects / Q000517:prevention & control*; D016272:Occupational Health; D010818:Practice Patterns, Physicians'; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D000072232:Radiation Dosimeters; D000069079:Radiation Exposure / Q000009:adverse effects / Q000517:prevention & control*; D011834:Radiation Monitoring / Q000295:instrumentation; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015641:Radiography, Interventional / Q000009:adverse effects; D012307:Risk Factors; D012984:Software; D066231:Surgeons; D013781:Texas