Thoracic and abdominal aortic diameter measurement by MRI using plain axial volumetric interpolated breath-hold examination in epidemiologic research: a validation study.

RATIONALE AND
OBJECTIVES: This study evaluates the validity and reliability of measuring the diameters of the thoracic and abdominal aorta from plain volumetric interpolated breath-hold examination (VIBE) images.
MATERIALS AND METHODS: The study included 50 male subjects from the population-based Study of Health in Pomerania. They underwent imaging of the thoracic and abdominal aorta at 1.5 Tesla using a contrast-enhanced magnetic resonance angiography (CE-MRA) and plain VIBE sequence. Diameters were measured at five predefined anatomic sites from reformatted orthogonal CE-MRA images and axial plain VIBE images. The measurements were validated using Pearson correlation and Bland-Altman analysis. The Bland-Altman method was also used to assess reliability.
RESULTS: Comparison of the diameters measured from CE-MRA and VIBE images revealed strong correlation for the ascending, descending, suprarenal, and infrarenal aorta with r = 0.95 (P < .0001), r = 0.88 (P < .0001), 0.92 (P < .0001), and 0.87 (P < .0001), respectively. Measurement for the aortic arch was moderately correlated with r = 0.78 (P < .0001). Mean bias did not exceed 0.1 cm (6%). The 95% limits of agreement (LOA) were less than 0.5 cm (15%). Intra- and interobserver agreement showed a mean bias of less than 2%; the 95% LOA were less than 11%.
CONCLUSIONS: Axial measurement of the diameters of the thoracic and abdominal aorta using a plain axial VIBE sequence is highly valid and reliable, making it suitable for use in epidemiologic research.