Purpose: The purpose of this work was to determine the technical feasibility and value of dynamic subtraction (postcontrast-precontrast) magnetic resonance (MR) imaging for the assessment of hyperintense lesions on precontrast T1-weighted images in the cirrhotic liver.
Methods: One hundred four hyperintense lesions on T1-weighted precontrast and arterial phase postcontrast images were subjected to analysis of their subtraction qualities depending on the lesion size, location and/or the degree of misregistration between the source images in 27 different MR imaging sets.
Results: The quality of subtraction images was always diagnostic for lesions larger than 2 cm in diameter (n = 8) but not diagnostic for 73% (40 of 55 lesions) of small subcentimetric lesions. Thirty-one subcapsular lesions always showed a variable degree of coregistration artifact. Only 3 of 35 lesions with a slice misregistration of 3 mm or more gave rise to subtraction images of diagnostic quality. For determining the contrast enhancement, the area under the receiver operating characteristic curve of 30 verified lesions was significantly larger (P < 0.001) for subtraction images than for conventional arterial phase images.
Conclusion: Depending on the lesion size and/or location or the degree of misregistration between the source images, dynamic subtraction MR imaging can be useful for the characterization of hyperintense lesions on precontrast T1-weighted imaging.
From the *Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; †Department of Diagnostic Radiology, YongDong Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea; and ‡Department of Radiology, University of Massachusetts Memorial University Campus, North Worcester, MA.
Received for publication November 4, 2004; accepted November 30, 2004.
Reprints: Jeong-Sik Yu, Department of Diagnostic Radiology, YongDong Severance Hospital, Yonsei University College of Medicine, 146-92 Dogok-Dong, Gangnam-Gu, Seoul 135-720, South Korea (e-mail: email@example.com).