Radial fast spin-echo method for T2-weighted imaging and T2 mapping of the liver

Maria I. Altbach, Eric K. Outwater, Theodore P. Trouard, Elizabeth A. Krupinski, Rebecca J. Theilmann, Alison T Stopeck, Mitsuko Kono, Arthur F. Gmitro

Research output: Contribution to journalArticle

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Abstract

Purpose: To evaluate a multishot radial fast-spin echo (RAD-FSE) method developed to improve the quality of abdominal T2-weighted imaging as well as the characterization of focal liver lesions. Materials and Methods: The RAD-FSE sequence used in this work consisted of a preparatory period followed by a short echo train (ETL = 16). A novel radial k-space trajectory was used to minimize streaking artifacts due to T2 variations and motion. Small diffusion gradients (b = 1.2 mm/s2) were used to improve flow suppression. The quality of images obtained with RAD-FSE was compared to multishot 2DFT fast spin-echo (2DFT-FSE) and half-Fourier acquisition single-shot turbo-spin-echo (HASTE) images using data from 16 patients. A postprocessing algorithm was used to generate multiple high-resolution images (at different effective TE values) as well as a T2 map from a single RAD-FSE data set. The T2 maps were used to differentiate malignant from benign lesions for a set of 33 lesions ranging from 0.8-194 cm3. Results: RAD-FSE produces high-resolution images of the liver in a breath-hold without the motion artifacts of 2DFT-FSE methods, and without the blurriness and loss of small lesion detectability of HASTE. The inclusion of diffusion weighting in RAD-FSE decreases the signal from blood in hepatic vessels, which improves lesion visualization. The T2 values obtained by postprocessing a single RAD-FSE data set can differentiate malignant from benign lesions. The mean T2 values obtained for malignancies, hemangiomas, and cysts are 108 ± 30 msec, 240 ± 14 msec, and 572 ± 334 msec, respectively. Conclusion: These results indicate that RAD-FSE produces abdominal images of higher quality than 2DFT-FSE and HASTE. In addition, lesions can be characterized using T2 maps generated from a single RAD-FSE data set.

Original languageEnglish (US)
Pages (from-to)179-189
Number of pages11
JournalJournal of Magnetic Resonance Imaging
Volume16
Issue number2
DOIs
Publication statusPublished - 2002

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Keywords

  • Diffusion weighting
  • Fast spin-echo
  • Flow suppression
  • Projection reconstruction MRI
  • Radial MRI
  • T2 measurements

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

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