Differentiation of hypointense nodules on gadoxetic acid-enhanced hepatobiliary-phase MRI using T 2 enhanced spin-echo imaging with the time-reversed gradient echo sequence: An initial experience

Eur J Radiol. 2017 Oct;95:325-331. doi: 10.1016/j.ejrad.2017.08.025. Epub 2017 Aug 30.

Abstract

Purpose: To optimize the flip angle (FA) of the T2 enhanced spin-echo imaging using the time reversed gradient echo (T2FFE) and evaluate its utility for differentiating hypointensity nodules in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced (Gd-EOB) MRI.

Materials and methods: First, FA optimization of the T2FFE in the HBP was investigated by comparing signal-to-noise ratio (SNR) among different FAs using phantoms. The liver-to-muscle contrast ratios (CRLiver-Muscle) and image quality among three FAs (20°, 50° and 80°) were compared using images of 10 patients. Next, the utility of the T2FFE with an optimized FA for differentiating hypointensity nodules in the HBP was assessed by comparing the lesion-to-liver contrast ratio (CRLesion-Liver) among cysts, hemangiomas, hepatocellular carcinomas, and metastatic tumors in 32 patients.

Results: SNR increased as FA increased, but leveled off at FAs of 50° and greater. The FA of 50° showed significantly better image quality scores than that of 80° (p<0.05). After employing an FA of 50°, the CRLesion-Liver value indicated that the T2FFE depicted benign lesions as hyperintense and most malignant lesions as hypointense in relation with the liver parenchyma (p<0.05).

Conclusion: The T2FFE in the HBP of Gd-EOB-MRI is useful for differentiating benign and malignant liver lesions.

Keywords: Gadoxetic acid; Gd-EOB-MRI; Liver; T(2) enhanced time reversed gradient echo sequence; T2FFE.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Contrast Media*
  • Diagnosis, Differential
  • Feasibility Studies
  • Female
  • Gadolinium DTPA*
  • Humans
  • Image Enhancement / methods*
  • Liver / diagnostic imaging
  • Liver Neoplasms / diagnostic imaging*
  • Liver Neoplasms / pathology
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Prospective Studies
  • Reproducibility of Results
  • Signal-To-Noise Ratio

Substances

  • Contrast Media
  • gadolinium ethoxybenzyl DTPA
  • Gadolinium DTPA