Dual-Energy Multidetector-Row Computed Tomography of the Hepatic Arterial System: Optimization of Energy and Material-Specific Reconstruction Techniques.
OBJECTIVE
To investigate the optimal dual-energy reconstruction technique for the visualization of the hepatic arterial system during dual-energy multidetector computed tomographic (MDCT) angiography of the liver.


METHODS
Twenty-nine nonconsecutive patients underwent dual-energy MDCT angiography of the liver. Synthesized monochromatic (40, 50, 60, and 80 keV) and iodine density data sets were reconstructed. Aortic attenuation, noise, and contrast-to-noise ratio (CNR) were measured. In addition, volume-rendered images were generated and qualitatively assessed by 2 independent readers, blinded to technique. The impact of body size on the readers' scores was also assessed.


RESULTS
Aortic attenuation, noise, and CNR increased progressively with decreasing keV and were significantly higher between 40 and 60 keV (P < 0.001). There was a significant improvement of readers' visualization of arterial anatomy at lower monochromatic energies (P < 0.001). Iodine density images yielded significantly higher CNR compared with all monochromatic data sets (P < 0.001). However, iodine density images were scored nondiagnostic by the 2 readers.


CONCLUSIONS
Synthesized monochromatic images between 40 and 60 keV maximize the magnitude of arterial enhancement and improve visualization of hepatic arterial anatomy at dual-energy MDCT angiography of the liver. Larger body sizes may counteract the benefits of using lower monochromatic energies.
From the Department of Radiology, Duke University Medical Center, Durham, NC.
Daniele
D
Marin
Devin T
DT
Caywood
Achille
A
Mileto
Caecilia S
CS
Reiner
Danielle M
DM
Seaman
Bhavik N
BN
Patel
Daniel T
DT
Boll
Rendon C
RC
Nelson
D000328:Adult; D000368:Aged; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging*; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011856:Radiographic Image Enhancement; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio