Accelerated, free-breathing, noncontrast, electrocardiograph-triggered, thoracic MR angiography with stack-of-stars k-space sampling and GRASP reconstruction

Hassan Haji-Valizadeh, Jeremy D. Collins, Pascale J. Aouad, Ali M. Serhal, Marc D. Lindley, Jianing Pang, Nivedita K. Naresh, James C. Carr, Daniel Kim*

*Corresponding author for this work

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

Purpose: To develop an accelerated, free-breathing, noncontrast, electrocardiograph-triggered, thoracic MR angiography (NC-MRA) pulse sequence capable of achieving high spatial resolution at clinically acceptable scan time and test whether it produces clinically acceptable image quality in patients with suspected aortic disease. Methods: We modified a “coronary” MRA pulse sequence to use a stack-of-stars k-space sampling pattern and combined it with golden-angle radial sparse parallel (GRASP reconstruction to enable self-navigation of respiratory motion and high data acceleration. The performance of the proposed NC-MRA was evaluated in 13 patients, where clinical standard contrast-enhanced MRA (CE-MRA) was used as control. For visual analysis, two readers graded the conspicuity of vessel lumen, artifacts, and noise level on a 5-point scale (overall score index = sum of three scores). The aortic diameters were measured at seven standardized locations. The mean visual scores, inter-observer variability, and vessel diameters were compared using appropriate statistical tests. Results: The overall mean visual score index (12.1 ± 1.7 for CE-MRA versus 12.1 ± 1.0 for NC-MRA) scores were not significantly different (P > 0.16). The two readers’ scores were significantly different for CE-MRA (P = 0.01) but not for NC-MRA (P = 0.21). The mean vessel diameters were not significantly different, except at the proximal aortic arch (P < 0.03). The mean diameters were strongly correlated (R 2 ≥ 0.96) and in good agreement (absolute mean difference ≤ 0.01 cm and 95% confidence interval ≤ 0.62 cm). Conclusion: This study shows that the proposed NC-MRA produces clinically acceptable image quality in patients at high spatial resolution (1.5 mm × 1.5 mm × 1.5 mm) and clinically acceptable scan time (~6 min).

Original languageEnglish (US)
Pages (from-to)524-532
Number of pages9
JournalMagnetic resonance in medicine
Volume81
Issue number1
DOIs
StatePublished - Jan 2019

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Keywords

  • GRASP
  • MRI
  • aortic disease
  • compressed sensing (CS)
  • noncontrast MRA

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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