Accelerated susceptibility-based positive contrast imaging of MR compatible metallic devices based on modified fast spin echo sequences

Caiyun Shi, Guoxi Xie, Yongqin Zhang, Xiaoyong Zhang, Min Chen, Shi Su, Ying Dong, Xin Liu, Jim Ji

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

This study aims to develop an accelerated susceptibility-based positive contrast MR imaging method for visualizing MR compatible metallic devices. A modified fast spin echo sequence is used to accelerate data acquisition. Each readout gradient in the modified fast spin echo is slightly shifted by a short distance Tshift. Phase changes accumulated within Tshift are then used to calculate the susceptibility map by using a kernel deconvolution algorithm with a regularized ℓ1 minimization. To evaluate the proposed fast spin echo method, three phantom experiments were conducted and compared to a spin echo based technique and the gold standard CT for visualizing biopsy needles and brachytherapy seeds. Compared to the spin echo based technique, the data sampling speed of the proposed method was faster by 2-4 times while still being able to accurately visualize and identify the location of the biopsy needle and brachytherapy seeds. These results were confirmed by CT images of the same devices. Results also demonstrated that the proposed fast spin echo method can achieve good visualization of the brachytherapy seeds in positive contrast and in different orientations. It is also capable of correctly differentiating brachytherapy seeds from other similar structures on conventional magnitude images.

Original languageEnglish
Pages (from-to)2505-2520
Number of pages16
JournalPhysics in Medicine and Biology
Volume62
Issue number7
DOIs
Publication statusPublished - 1 Mar 2017
Externally publishedYes

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Keywords

  • magnetic resonance imaging
  • metallic devices
  • positive contrast
  • susceptibility mapping

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging

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