Optimal timing and diagnostic adequacy of hepatocyte phase imaging with gadoxetate-enhanced liver MRI.
OBJECTIVE
To evaluate clinical and imaging features associated with adequacy of the hepatocyte phase (HP) in gadoxetate disodium-enhanced liver magnetic resonance imaging (MRI) in patients without chronic liver disease (CLD).


METHODS
This was a retrospective institutional review board-approved study of 97 patients who underwent liver MRI examinations with gadoxetate disodium and had no history of CLD. Available late dynamic and HP sequences (3-20 minutes postinjection) were independently analyzed by four radiologists for perceived image adequacy and level of biliary enhancement. Signal intensity ratios (SIRs) of liver/inferior vena cava (IVC), liver/spleen, and liver/muscle were measured. The Spearman ρ and receiver operating characteristic analyses were performed correlating various factors with HP adequacy. A rule for predicting HP adequacy was also derived and tested to determine whether overall examination time could be shortened.


RESULTS
A visually adequate HP was observed in 12% of subjects by 10 minutes, 80% by 15 minutes, and 93% by 20 minutes. An SIRliver/IVC > 1.8 was the imaging feature that had the strongest correlation with an adequate HP (ρ = 0.813, P < .001), and was more predictive of adequacy of the HP than the time postinjection (ρ = 0.5, P < .001). The time at which an adequate HP was first observed did not correlate with any tested demographic or laboratory values. Stopping imaging when an SIRliver/IVC > 1.8 would have successfully reduced mean postcontrast time to 15:39 ± 4:02 from 20:00 (P < .001), although maintaining HP adequacy.


CONCLUSIONS
Most patients without CLD undergoing gadoxetate-enhanced liver MRI achieve adequate HP at 20 minutes. However, a shorter postcontrast stopping time can be used in most patients.
Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710. Electronic address: mustafa.bashir@duke.edu.
Mustafa R
MR
Bashir
Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710.
Steven R
SR
Breault
Department of Radiology, Rush University Medical Center, Chicago, IL 60612.
Ryan
R
Braun
Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065.
Richard K
RK
Do
Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710.
Rendon C
RC
Nelson
Department of Radiology, University of Wisconsin, Madison, WI 53792; Department of Medical Physics, University of Wisconsin, Madison, WI 53792; Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53792; Department of Medicine, University of Wisconsin, Madison, WI 53792.
Scott B
SB
Reeder
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D022781:Hepatocytes / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies
D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
Gadoxetate disodium; gadoxetic acid; hepatobiliary; hepatocyte phase