title: Adoption of Splenic Enhancement to Time and Trigger the Late Hepatic Arterial Phase During MDCT of the Liver: Proof of Concept and Clinical Feasibility.
abstract: OBJECTIVE
  The purpose of this study was to prospectively investigate the clinical feasibility of adopting splenic enhancement for timing and triggering the acquisition of late hepatic arterial phase images during multiphasic liver MDCT for assessment of hypervascular tumors.
  
  
  METHODS
  Forty-eight patients (33 men, 15 women; median age, 59 years; chronic liver disease, 23 patients; portal venous hypertension, 17 patients) with a total of 81 hypervascular liver tumors underwent liver MDCT by random assignment to one of two scanning protocols. Scanning delay for the late hepatic arterial phase was determined by assessment of time-to-peak splenic enhancement (splenic-triggering protocol) or aortic enhancement (aortic-triggering protocol). Acquisition timing, vascular attenuation, liver attenuation and homogeneity, signal-to-noise ratio, tumor-to-liver contrast, and tumor-to-liver contrast-to-noise ratio were compared. Two blinded independent observers used Likert scales to score timing adequacy (3-point scale), diagnostic confidence (5-point scale), and per lesion conspicuity (4-point scale) for hypervascular tumor detection.
  
  
  RESULTS
  The splenic- and aortic-triggering protocols had significant differences in mean late hepatic arterial phase imaging timing (splenic, 36 ± 6 seconds; aortic, 32 ± 3 seconds; p = 0.010). Images obtained with the splenic-triggering protocol had significantly better observer-based judgment of adequacy (splenic, 2.04; aortic, 1.58; p = 0.002). Mean attenuation and signal-to-noise ratios from liver and portal vein were significantly higher with the splenic- than with the aortic-triggering protocol (p < 0.0001). The splenic-triggering protocol was associated with significant improvement in homogeneity of liver attenuation (p < 0.0001). Although the splenic-triggering protocol was associated with significantly higher lesion conspicuity than was the aortic-triggering protocol (p = 0.022), there was no significant difference in tumor detection rate.
  
  
  CONCLUSIONS
  Our results provide a clinical foundation for and proof of principle that the adoption of splenic enhancement renders an optimal temporal window for late hepatic arterial phase imaging during MDCT of the liver for assessment of hypervascular tumors.
authors.affiliation: 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, Durham, NC 27710.
authors.forename: Achille
authors.initials: A
authors.lastname: Mileto
authors.affiliation: 2 Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Daniela B
authors.initials: DB
authors.lastname: Husarik
authors.affiliation: 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, Durham, NC 27710.|3 Present address: Department of Radiological Sciences, Oncology and Pathology, "Sapienza" University of Rome ICOT Hospital, Latina, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Bellini
authors.affiliation: 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, Durham, NC 27710.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marin
authors.affiliation: 2 Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Caecilia S
authors.initials: CS
authors.lastname: Reiner
authors.affiliation: 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, Durham, NC 27710.
authors.forename: Rendon C
authors.initials: RC
authors.lastname: Nelson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D013154:Spleen / Q000000981:diagnostic imaging*
keywords: MDCT; late hepatic arterial phase; liver; proof of concept; splenic enhancement