title: Noise-optimized virtual monoenergetic images and iodine maps for the detection of venous thrombosis in second-generation dual-energy CT (DECT): an ex vivo phantom study.
abstract: OBJECTIVE
  Deep venous thrombosis (DVT) can be difficult to detect using CT due to poor and heterogeneous contrast. Dual-energy CT (DECT) allows iodine contrast optimization using noise-optimized monoenergetic extrapolations (MEIs) and iodine maps (IMs). Our aim was to assess whether MEI and IM could improve the delineation of thrombotic material within iodine-enhanced blood compared to single-energy CT (SECT).
  
  
  METHODS
  Six vessel phantoms, including human thrombus and contrast media-enhanced blood and one phantom without contrast, were placed in an attenuation phantom and scanned with DECT 100/140 kV and SECT 120 kV. IM, virtual non-contrast images (VNC), mixed images, and MEI were calculated. Attenuation of thrombi and blood were measured. Contrast and contrast-to-noise-ratios (CNRs) were calculated and compared among IM, VNC, mixed images, MEI, and SECT using paired t tests.
  
  
  RESULTS
  MEI40keV and IM showed significantly higher contrast and CNR than SE120kV from high to intermediate iodine concentrations (contrast:pMEI40keV < 0.002,pIM < 0.005;CNR:pMEI40keV < 0.002,pIM < 0.004). At low iodine concentrations, MEI190keV and VNC images showed significantly higher contrast and CNR than SE120kV with inverted contrasts (contrast:pMEI190keV < 0.008,pVNC < 0.002;CNR:pMEI190keV < 0.003,pVNC < 0.002).
  
  
  CONCLUSIONS
  Noise-optimized MEI and IM provide significantly higher contrast and CNR in the delineation of thrombosis compared to SECT, which may facilitate the detection of DVT in difficult cases.
  
  
  CONCLUSIONS
  • Poor contrast makes it difficult to detect thrombosis in CT. • Dual-energy-CT allows contrast optimization using monoenergetic extrapolations (MEI) and iodine maps (IM). • Noise-optimized-MEI and IM are significantly superior to single-energy-CT in delineation of thrombosis. • Noise-optimized-MEI and IM may facilitate the detection of deep vein thrombosis.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany.
authors.forename: Malte N
authors.initials: MN
authors.lastname: Bongers
authors.forename: Christoph
authors.initials: C
authors.lastname: Schabel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Krauss
authors.forename: Ilias
authors.initials: I
authors.lastname: Tsiflikas
authors.forename: Dominik
authors.initials: D
authors.lastname: Ketelsen
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mangold
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.forename: Christoph
authors.initials: C
authors.lastname: Thomas
mesh_terms: D006801:Humans; D007455:Iodine / Q000008:administration & dosage*; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*; D020246:Venous Thrombosis / Q000000981:diagnostic imaging*
chemical_list: D007455:Iodine