Fast isotropic banding-free bSSFP imaging using 3D dynamically phase-cycled radial bSSFP (3D DYPR-SSFP)

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• 作者：Thomas Benkert¹ ; ^{benkert@mr-bavaria.de" class="auth_mail" title="E-mail the corresponding author} ; Philipp Ehses² ; ³ ; Martin Blaimer¹ ; Peter M. Jakob¹ ; ⁴ ; Felix A. Breuer¹
• 关键词：Radial imaging ; SSFP sequences ; 3D isotropic ; banding removal
• 刊名：Zeitschrift für Medizinische Physik
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：26
• 期：1
• 页码：63-74
• 全文大小：4023 K

文摘

Dynamically phase-cycled radial balanced steady-state free precession (DYPR-SSFP) is a method for efficient banding artifact removal in bSSFP imaging. Based on a varying radiofrequency (RF) phase-increment in combination with a radial trajectory, DYPR-SSFP allows obtaining a banding-free image out of a single acquired k-space. The purpose of this work is to present an extension of this technique, enabling fast three-dimensional isotropic banding-free bSSFP imaging.

Methods

While banding artifact removal with DYPR-SSFP relies on the applied dynamic phase-cycle, this aspect can lead to artifacts, at least when the number of acquired projections lies below a certain limit. However, by using a 3D radial trajectory with quasi-random view ordering for image acquisition, this problem is intrinsically solved, enabling 3D DYPR-SSFP imaging at or even below the Nyquist criterion. The approach is validated for brain and knee imaging at 3 Tesla.

Results

Volumetric, banding-free images were obtained in clinically acceptable scan times with an isotropic resolution up to 0.56 mm.

Conclusion

The combination of DYPR-SSFP with a 3D radial trajectory allows banding-free isotropic volumetric bSSFP imaging with no expense of scan time. Therefore, this is a promising candidate for clinical applications such as imaging of cranial nerves or articular cartilage.