title: Dynamic subtraction magnetic resonance imaging of cirrhotic liver: assessment of high signal intensity lesions on nonenhanced T1-weighted images.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. yjsrad97@yumc.yonsei.ac.kr
authors.forename: Jeong-Sik
authors.initials: JS
authors.lastname: Yu
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Kim
authors.forename: Neil M
authors.initials: NM
authors.lastname: Rofsky
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D019694:Hepatitis B, Chronic / Q000150:complications; D019698:Hepatitis C, Chronic / Q000150:complications; D006519:Hepatitis, Alcoholic / Q000150:complications; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D013382:Subtraction Technique
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA