Steady-State Multifrequency Magnetic Resonance Elastography of the Thoracic and Abdominal Human Aorta—Validation and Reference Values

Objectives
The aim of this study was to investigate the potential of stroboscopic-wavefield-sampling-based multifrequency magnetic resonance elastography (sMRE) for quantifying the stiffness of the human thoracic and abdominal aorta in vivo.
Materials and Methods
The sMRE of the thoracic and abdominal aorta was performed at 1.5 T field strength in 20 healthy volunteers aged 27 to 77 years (3 women; median age, 33 years; interquartile range [IQR], 16 years). Compound maps of shear wave speed (SWS) were reconstructed and evaluated during the diastolic phase in 3 anatomical regions: ascending thoracic aorta (AA), descending thoracic aorta (AD), and abdominal aorta (AAb). The SWS maps were read by 2 readers. Blood pressure and pulse wave velocity were determined noninvasively before sMRE. Data are given as median (IQR) and were compared using the Kruskal-Wallis and Wilcoxon rank sum tests. Intraclass correlation was used to determine interobserver and intraobserver agreement, as well as reproducibility. Multiple linear regression analysis was performed to evaluate effects of age, sex, vessel diameter, blood pressure, pulse wave velocity, and aortic segment on measured SWS.
Results
All 20 participants underwent successful sMRE, resulting in a total of 60 aortic segments. The median SWS (IQR) of AA, AD, and AAb was 1.62 (0.16) m/s, 2.40 (0.24) m/s, and 2.48 (0.58) m/s, respectively. The SWS in AA was significantly lower (P

Source: Investigative Radiology - June 11, 2020 Category: Radiology Tags: Original Articles Source Type: research