title: Detection of parathyroid adenomas using a monophasic dual-energy computed tomography acquisition: diagnostic performance and potential radiation dose reduction.
abstract: BACKGROUND
  The aims of the study were to compare the diagnostic performance of a combination of virtual non-contrast (VNC) images and arterial images obtained from a single-phase dual-energy CT (DECT) acquisition and standard non-contrast and arterial images from a biphasic protocol and to study the potential radiation dose reduction of the former approach.
  
  
  METHODS
  All DECT examinations performed for evaluation of parathyroid adenomas during a 13-month period were retrospectively reviewed. An initial single-energy unenhanced acquisition was followed by a dual-energy arterial phase acquisition. "Virtual non-contrast images" were generated from the dual-energy acquisition. Two independent and blinded radiologists evaluated three different sets of images during three reading sessions: single arterial phase, single-phase DECT (virtual non-contrast and arterial phase), and standard biphasic protocol (true non-contrast and arterial phase). The accuracy of interpretation in lateralizing an adenoma to the side of the neck and localizing it to a quadrant in the neck was evaluated.
  
  
  RESULTS
  Sixty patients (mean age, 65.5 years; age range, 38-87 years) were included in the study. The lateralization and localization accuracy, sensitivity, and positive predicted value (PPV) and negative predicted value (NPV) of the different image datasets were comparable. The combination of VNC and arterial images was more specific than arterial images alone to lateralize a parathyroid lesion (OR = 1.93, p = 0.043). The use of the single-phase protocol resulted in a calculated radiation exposure reduction of 52.8 %.
  
  
  CONCLUSIONS
  Virtual non-contrast and arterial images from a single DECT acquisition showed similar diagnostic accuracy than a biphasic protocol, providing a significant dose reduction.
authors: Department of Radiology, Division of Neuroradiology, University of Virginia, 1215 Lee Street-New Hospital, Charlottesville, VA, 22908, USA.
authors: Carlos
authors: C
authors: Leiva-Salinas
authors: Department of Radiology, Division of Neuroradiology, University of Virginia, 1215 Lee Street-New Hospital, Charlottesville, VA, 22908, USA.
authors: Lucia
authors: L
authors: Flors
authors: Department of Radiology, Division of Neuroradiology, University of Virginia, 1215 Lee Street-New Hospital, Charlottesville, VA, 22908, USA.
authors: Christopher R
authors: CR
authors: Durst
authors: Department of Radiology, Division of Neuroradiology, University of Virginia, 1215 Lee Street-New Hospital, Charlottesville, VA, 22908, USA.
authors: Qinghua
authors: Q
authors: Hou
authors: Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA.
authors: James T
authors: JT
authors: Patrie
authors: Department of Radiology, Stanford University, Palo Alto, CA, USA.
authors: Max
authors: M
authors: Wintermark
authors: Department of Radiology, Division of Neuroradiology, University of Virginia, 1215 Lee Street-New Hospital, Charlottesville, VA, 22908, USA. Sm5qd@virginia.edu.
authors: Sugoto
authors: http://orcid.org/0000-0001-6031-2557
authors: S
authors: Mukherjee
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Computed tomography; Dual energy; Hypercalcemia; Parathyroid adenoma; Radiation dose