Reliability and Value of 3D Sequential QUantitative T₁ -T₂ -T₂ * MAppings (SQUMA) MR Multi-Parametric Imaging in...

T₁ , T₂ , and T₂ * mappings are seldom performed in a single examination, and their values in evaluating symptomatic atherosclerosis are lacking.

To perform three-dimensional (3D) quantitative T₁ , T₂ , and T₂ * mappings (SQUMA) multi-parametric imaging for carotid vessel wall and evaluate its reliability and value in assessing carotid atherosclerosis.

Prospective.

Eight healthy subjects and 20 patients with symptomatic carotid atherosclerosis.

3 T, SQUMA imaging T₁ -, T₂ -, and T₂ *-mapping, multi-contrast vessel wall imaging including T₁ - and T₂ -weighted, time-of-flight, and SNAP sequences.

SQUMA was acquired in all subjects and multi-contrast images were acquired in healthy subjects. T₁ , T₂ , and T₂ * values and lumen area (LA), wall area (WA), mean wall thickness (MeanWT), and normalized wall index (NWI) of carotid arteries were measured. SQUMA and multi-contrast measurements were compared in healthy subjects and differences in SQUMA measurements between healthy subjects and patients were assessed. The discriminative value of SQUMA measurements for symptomatic vessel was determined.

Paired t or Wilcoxon signed-rank test, independent t or Mann-Whitney U test, area under the receiver operating characteristic curve (AUC), intraclass correlation coefficients, and Bland-Altman plots. Statistically significant level, P < 0.05.

There were no significant differences in LA (P = 0.340), WA (P = 0.317), MeanWT (P = 0.088), and NWI (P = 0.091) of carotid arteries between SQUMA and multi-contrast vessel wall images. The values of T₂ (50.9 ± 2.9 msec vs. 44.5 ± 4.2 msec), T₂ * (28.2 ± 4.3 msec vs. 24.7 ± 2.6 msec), WA (23.7 ± 4.6 mm² vs. 36.2 ± 7.7 mm² ), MeanWT (0.99 ± 0.05 mm vs. 1.50 ± 0.28 mm), and NWI (40.7 ± 3.0% vs. 53.8 ± 5.4%) of carotid arteries in healthy subjects were significantly different from those in atherosclerotic patients. The combination of quantitative T₁ , T₂ , and T₂ * values and MeanWT showed greatest AUC (0.81; 95% CI: 0.65-0.92) in discriminating symptomatic vessels.

Carotid MR 3D quantitative multi-parametric imaging of SQUMA enables acquisition of T₁ , T₂ , and T₂ * maps, reliably measuring carotid morphology and discriminating carotid symptomatic atherosclerosis.

2 TECHNICAL EFFICACY: Stage 2.