Dilution method of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI).
OBJECTIVE
To elucidate whether a contrast agent dilution method (dilution method), in which gadoxetate disodium (Gd-EOB-DTPA) is diluted with saline, is useful for good-quality arterial-phase images.


METHODS
In this study we observed 494 hypervascular hepatocellular carcinomas (HCCs) in 327 patients with chronic liver disease. Three Gd-EOB-DTPA injection methods were adopted for comparison: 1) test injection method (undiluted Gd-EOB-DTPA and modified scan delay), in which a test dose of 0.5 mL of Gd-EOB-DTPA was injected to determine scan delay; 2) conventional method (undiluted Gd-EOB-DTPA and fixed scan delay); and (3) dilution method (diluted Gd-EOB-DTPA and fixed scan delay), in which Gd-EOB-DTPA was diluted to 20 mL with saline. Lesion-liver contrast was calculated. Image quality and lesion detectability were evaluated by two radiologists blinded to the injection methods.


RESULTS
The lesion-liver contrast of the dilution method was significantly higher than that of the other two methods. Lesion detectability of the conventional method (64%) was significantly lower than that of the other two methods (contrast agent dilution method, 95%; test injection method, 93%). The image quality of the contrast agent dilution method was significantly better than that of the other two methods.


CONCLUSIONS
The dilution method contributed to improved image quality, high lesion-liver contrast, and high lesion detectability in the arterial-phase images of GD-EOB-DTPA-enhanced MRI.
Department of Radiology, University of Yamanashi, Japan. utaroh-motosugi@nifty.com
Utaroh
U
Motosugi
Tomoaki
T
Ichikawa
Hironobu
H
Sou
Katsuhiro
K
Sano
Shintaro
S
Ichikawa
Licht
L
Tominaga
Tsutomu
T
Araki
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003287:Contrast Media / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012965:Sodium Chloride
D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D012965:Sodium Chloride; D019786:Gadolinium DTPA