title: Effectiveness of a three-dimensional dual gradient echo two-point Dixon technique for the characterization of adrenal lesions at 3 Tesla.
abstract: OBJECTIVE
  To compare the sensitivity, specificity, and diagnostic accuracy of fat-only datasets reconstructed using a two-point Dixon technique, with corresponding opposed-phase (OP) and in-phase (IP) datasets for characterization of adrenal lesions at 3 Tesla (T).
  
  
  METHODS
  Fifty-nine patients (21 male, 38 female) with 66 adrenal lesions (49 adenomas, 17 nonadenomas) underwent 3D dual gradient-echo 3-T adrenal MR imaging with reconstruction of OP/IP and fat/water datasets. Sensitivity, specificity, and diagnostic accuracy were compared between OP/IP datasets, using the signal intensity index (SII), and fat/water datasets, using the fat fraction and fat ratio. Four radiologists qualitatively assessed OP/IP and fat-only datasets for reader confidence in lesion characterization and image quality.
  
  
  RESULTS
  There were significant differences between adenomas and nonadenomas with regard to mean SII, fat fraction, and fat ratio (P < 0.001). There was no significant difference in mean diagnostic accuracy among different evaluation methods using OP/IP and fat/water datasets. Mean readers' scores for lesion characterization were significantly higher for adenomas than for nonadenomas using OP/IP and fat-only datasets. There was no significant difference between the two datasets regarding mean readers' scores for image quality.
  
  
  CONCLUSIONS
  Fat-only images can readily differentiate adrenal adenomas from nonadenomas, with diagnostic accuracy comparable to OP/IP images.
authors.affiliation: Department of Radiology, Duke University Medical Center, Duke North-Room 1417, Erwin Road, Durham, NC 27710, USA.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marin
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dale
authors.forename: Mustafa R
authors.initials: MR
authors.lastname: Bashir
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Ziemlewicz
authors.forename: Kristina I
authors.initials: KI
authors.lastname: Ringe
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Boll
authors.forename: Elmar M
authors.initials: EM
authors.lastname: Merkle
mesh_terms: D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000473:pathology; D000311:Adrenal Glands / Q000473:pathology*; D018246:Adrenocortical Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult