title: Optimal MR protocol for hepatic hemangiomas. Comparison of conventional spin-echo sequences with T2-weighted turbo spin-echo and serial gradient-echo (FLASH) sequences with gadolinium enhancement.
abstract: OBJECTIVE
  To compare conventional spin-echo (SE) sequences with T2-weighted turbo SE and serial gadolinium-enhanced T1-weighted FLASH sequences in the detection and characterization of hepatic hemangiomas, and to describe the enhancement characteristics of the lesions on dynamic MR imaging.
  
  
  METHODS
  Forty-two patients with 66 hemangiomas were studied at 1.0 T or 1.5 T by using conventional SE sequences (T1-weighted, T2-weighted, and heavily T2-weighted), T2-weighted turbo SE sequences, and breath-hold T1-weighted FLASH sequences acquired before, immediately after, and 1, 2, 3, 5, and 10 min after injection of a bolus of gadopentetate dimeglumine. Images were quantitatively analyzed for lesion-to-liver contrast-to-noise (C/N) ratios, and qualitatively analyzed for lesion conspicuity. The enhancement pattern and the rapidity of enhancement were analyzed in small (<15 mm), medium (15-39 mm), and large (>39 mm) hemangiomas.
  
  
  RESULTS
  In T2-weighted images, T2-weighted turbo SE and heavily T2-weighted SE images had higher C/N ratios than T2-weighted SE images (p=0.003). Lesion conspicuity was not significantly different in these 3 sequences (p=0.307). In T1-weighted images, T1-weighted FLASH images had higher C/N (p<0.001) and also better lesion conspicuity (p<0.001) than T1-weighted SE images. Immediate uniform enhancement was seen in 43% of small hemangiomas (9 of 21 lesions), and persistent central hypointensity was seen in 73% of large hemangiomas (11 of 15 lesions). Rapid enhancement was seen in 62% of small hemangiomas (13 of 21 lesions) and in 31% of medium or large hemangiomas (14 of 45 lesions).
  
  
  CONCLUSIONS
  Further clinical study is needed for evaluating the differential diagnostic advantages of turbo SE T2-weighted imaging compared to the calculation of T2-values by means of a SE T2-weighted sequence. However, the results of the present study suggest that T2-weighted turbo SE imaging and precontrast and serial gadolinium-enhanced FLASH imaging have the potential to replace conventional SE imaging in the evaluation of hepatic hemangiomas.
authors.affiliation: Department of Diagnostic Radiology, Seoul National University College of Medicine, Korea.
authors.forename: T K
authors.initials: TK
authors.lastname: Kim
authors.forename: B I
authors.initials: BI
authors.lastname: Choi
authors.forename: J K
authors.initials: JK
authors.lastname: Han
authors.forename: H J
authors.initials: HJ
authors.lastname: Jang
authors.forename: M C
authors.initials: MC
authors.lastname: Han
mesh_terms: D003287:Contrast Media; D003937:Diagnosis, Differential; D004338:Drug Combinations; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006391:Hemangioma / Q000175:diagnosis*; D006801:Humans; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA