Rapid flow assessment of congenital heart disease with high-spatiotemporal-resolution gated spiral phase-contrast MR imaging

Abstract

Purpose: To validate a prospectively triggered spiral phase-contrast magnetic resonance (MR) sequence accelerated with sensitivity encoding (SENSE) in a population of children and adults with congenital heart disease.

Materials and methods: The local research ethics committee approved this study, and written consent was obtained from all patients or guardians. Stroke volumes were quantified in 40 patients (mean age ± standard deviation: 21.4 years ± 13.8, age range: 3.0-61.3 years; 22 male patients aged 3.0-38.0 years [mean age, 17.2 years ± 10.5], 18 female patients aged 4.7-61.3 years [mean age, 26.6 years ± 15.9]) with congenital heart disease in the aorta (n = 40), main pulmonary artery (n = 38), right pulmonary artery (n = 22), and left pulmonary artery (n = 24). Stroke volumes were obtained with (a) breath-hold spiral phase-contrast MR imaging with SENSE, (b) conventional breath-hold cartesian phase-contrast MR imaging, and (c) reference free-breathing phase-contrast MR imaging. Stroke volumes were compared by using repeated-measures analysis of variance, Bland-Altman analysis, and correlation coefficients.

Results: Imaging time with the breath-hold spiral phase-contrast MR sequence was significantly lower than that with the conventional breath-hold phase-contrast MR sequence (~5 seconds vs ~16 seconds, respectively; P < .0001). There was excellent agreement in stroke volumes in all vessels between the reference free-breathing sequence (mean volume, 60.3 mL ± 27.3) and the two breath-hold sequences-spiral SENSE phase-contrast MR imaging (mean volume, 59.5 mL ± 27.1; P < .001) and conventional cartesian phase-contrast MR imaging (mean volume, 59.8 mL ± 27.6; P = .268). The limits of agreement were smaller with the spiral breath-hold sequence than with the conventional breath-hold sequence (-4.4 mL, 2.9 mL vs -10.3 mL, 9.3 mL, respectively); correlation was similar (r = 0.998 vs r = 0.984, respectively).

Conclusion: Flow volumes can be accurately and reliably quantified by using a spiral SENSE phase-contrast MR sequence, with high spatiotemporal resolution obtained in a short breath hold.

Figure 1:

Comparison of flow profiles obtained with all three sequences in the ascending aorta of one patient. PCMR = phase-contrast MR imaging.

Figure 2:

Comparisons of stroke volumes obtained in all vessels with free-breathing phase-contrast MR imaging (FB-PCMR) versus conventional breath-hold phase-contrast MR imaging (BH-PCMR) (top) and with free-breathing phase-contrast MR imaging versus spiral breath-hold phase-contrast MR imaging (SP-PCMR) (bottom). Scatterplots are shown on left, and corresponding Bland-Altman plots are on right. SD = standard deviation.

Figure 3:

Examples of image quality obtained with the three sequences in the ascending aorta (AAO) and main pulmonary artery (MPA). PCMR = phase-contrast MR imaging.