title: Test-bolus injection for optimization of arterial phase imaging during contrast-enhanced hepatic MR imaging.
abstract: Contrast enhancement during the dynamic MR imaging is important for the detection and characterization of focal liver lesions. The purpose of this study was to determine whether or not a timing examination with a injection of a 1.0-mL bolus of gadopentetate dimeglumine into the antecubital vein followed by rapid dynamic scanning and measurement of signal intensity of the aorta could help to obtain proper arterial-dominant phase images for the characterization of focal hepatic lesions during subsequent multiphase dynamic MR imaging. The imaging delay to acquisition of the first gadolinium-enhanced image for multiphase dynamic MR imaging was set to equal the time to peak aortic enhancement during the test examination. The first contrast-enhanced images of 80 patients with 160 focal liver lesions (hepatocellular carcinoma, n = 79; cavernous hemangioma, n = 51; metastatic tumor, n = 30) were then retrospectively reviewed. Peak aortic enhancement occurred between 10 and 28 seconds (mean, 16.5 seconds +/- 3.1) after starting the infusion of contrast material in 80 patients during the test-examination. Depending on the findings of intrahepatic vascular enhancement on the full-scale dynamic images, hepatic arterial phase (n = 11, 14%) or sinusoid phase (n = 65, 81%) imaging was obtained during the first gadolinium-enhanced acquisition in 76 (95%) of 80 patients. Three different lesions were well characterized and easily distinguished from each other (p < .0001) on the first-phase images depending on their enhancement pattern. In the majority of patients, timing examination with test-bolus injection was helpful in obtaining qualified images for the characterization of various focal lesions.
authors.affiliation: Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Korea. yjsrad97@yumc.yonsei.ac.kr
authors.forename: J S
authors.initials: JS
authors.lastname: Yu
authors.forename: K W
authors.initials: KW
authors.lastname: Kim
authors.forename: B J
authors.initials: BJ
authors.lastname: Jo
authors.forename: M G
authors.initials: MG
authors.lastname: Jeong
authors.forename: J K
authors.initials: JK
authors.lastname: Kim
authors.forename: J K
authors.initials: JK
authors.lastname: Hahm
authors.forename: J T
authors.initials: JT
authors.lastname: Lee
authors.forename: H S
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006499:Hepatic Artery / Q000473:pathology; D006801:Humans; D007089:Image Enhancement; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013997:Time Factors