title: Assessment of vascular contrast and depiction of stenoses in abdominopelvic and lower extremity vasculature: comparison of dual-energy MDCT with digital subtraction angiography.
abstract: OBJECTIVE
  To assess whether dual-energy computed tomography (DECT) multidetector computed tomography (MDCT) angiography improves vascular contrast beyond MDCT angiography and digital subtraction angiography (DSA) while preserving the ability to precisely characterize stenoses, using DSA as reference standard.
  
  
  METHODS
  This prospective, Health Insurance Portability and Accountability Act-compliant, institutional review board-approved study was performed on 25 patients referred for lower extremity DECT angiography and subsequent DSA. Spectral data were postprocessed to create single-energy 120 kVp (MDCT series) and iodine-only (DECT series) datasets. The arterial tree was subdivided into 11 anatomical levels. Contrast-to-noise ratios (CNR) and corresponding coefficient -of variation (CV) of patent vessel segments were evaluated for DECT, MDCT, and DSA using analysis of variance comparisons. Degree of stenoses was determined for DECT, MDCT, and DSA and correlated with t-test, bivariate Pearson comparisons, and Bland-Altman plots.
  
  
  RESULTS
  Patent vasculature comprised 230 vessel segments. From infrarenal aorta to distal femoral arteries, DECT showed higher CNR compared to DSA and MDCT (P < .05); distal to the popliteal arteries, DSA achieved higher CNR (P < .05). Analyses of contrast homogeneity showed minimal CV above the knee for MDCT (≤9%) and for DSA below the knee (≤7%). Stenotic vasculature comprised 33 segments. Significant correlations of stenosis severity were found comparing DECT and MDCT with DSA as reference standard showing a 0.04-fold mean underestimation of stenoses on MDCT and no detectable mean variation on DECT compared with DSA.
  
  
  CONCLUSIONS
  DECT angiography improved contrast in vascular abdominopelvic and thigh distributions beyond MDCT angiography and DSA while preserving the ability to precisely assess severity of stenoses, using DSA as an accepted reference standard.
authors: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
authors: Steven Y
authors: SY
authors: Huang
authors: Rendon C
authors: RC
authors: Nelson
authors: Michael J
authors: MJ
authors: Miller
authors: Charles Y
authors: CY
authors: Kim
authors: Jeffrey H
authors: JH
authors: Lawson
authors: Daniela B
authors: DB
authors: Husarik
authors: Daniel T
authors: DT
authors: Boll
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015901:Angiography, Digital Subtraction; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014654:Vascular Patency