title: Prospective Randomized Comparison of High-pitch CT at 80 kVp Under Free Breathing with Standard-pitch CT at 100 kVp Under Breath-Hold for Detection of Pulmonary Embolism.
abstract: To prospectively compare high-pitch computed tomography (HPCT) under free breathing (FB) with standard-pitch CT (SPCT) under breath-hold (BH) for detection of pulmonary embolism (PE).
  
  
  
  One hundred consecutive patients (47 females; mean age 58.7 ± 16.6) randomly underwent HPCT-FB (n = 50) or SPCT-BH (n = 50). Radiation doses were documented. One reader measured pulmonary artery attenuation and noise; mean signal-to-noise ratio (SNR) was calculated. Two readers assessed image quality, diagnostic confidence for detection of PE, motion artifacts, assessability of anatomical structures, and presence of transient interruption of contrast as sign of Valsalva maneuver. Inter-reader agreement was calculated.
  
  
  
  Radiation dose was significantly lower in HPCT compared to SPCT (2.68 ± 0.60 mGy vs 6.01 ± 2.26 mGy; P < .001). Mean pulmonary artery attenuation and image noise were significantly higher in HPCT (attenuation: 479 Hounsfield unit (HU) vs 343HU; P < .001; noise: 16 HU vs 10 HU; P < .001) whereas SNR was similar between groups (34 HU vs 38 HU; P = .258). HPCT had significantly higher diagnostic confidence for PE detection (P = .048), less cardiac and breathing artifacts (P < .001), better assessability of anatomical structures, and fewer cases of transient interruption of contrast (P < .001) compared to the SPCT.
  
  
  
  HPCT-FB allows for a significant reduction of breathing and motion artifacts compared to SPCT-BH. Diagnostic confidence, assessability of vascular and bronchial structures, as well as SNR are maintained.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland. Electronic address: Thomas.frauenfelder@usz.ch.
authors.forename: K
authors.initials: K
authors.lastname: Martini
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Meier
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Higashigaito
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Saltybaeva
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Alkadhi
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Frauenfelder
mesh_terms: D016477:Artifacts; D062485:Breath Holding; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D012119:Respiration; D059629:Signal-To-Noise Ratio
keywords: Pulmonary embolism; Valsalva maneuver; artifacts; imaging; multidetector computed tomography