Pelvimetry and patient acceptability compared between open 0.5-T and closed 1.5-T MR systems

Abstract

time was double in the open system (7:52±1:47 vs 3:12±1:20 min). Poor image quality in the open system prevented assessment of interspinous and intertuberous diameters in one woman and all measurements in another, both pregnant, with abdominal circumferences >120 cm. The open system was much more acceptable in terms of claustrophobia and confinement (both p<0.01). Claustrophobia interrupted one closed examination. Thirty-three percent of pregnant women in both systems reported fear of fetal harm. Sixty percent of all women preferred the open system, 7% the closed system, and 33% had no preference. Limits of agreement of 3-5% from the mean for all diameters confirmed good pelvimetric reproducibility. Women's preference for open-system MR pelvimetry is feasible with abdominal circumferences ≤120 cm. AbstractOur objective was to compare maternal pelvimetry and patient acceptability between open low-field (0.5-T) and closed 1.5-T MR systems. Thirty women referred for pelvimetry (pregnant: n=15) were scanned twice in the supine position, once in the vertical open system and once in the closed system. Each patient completed a comfort and acceptability questionnaire. Pelvimetric and questionnaire data were compared between systems. Total scan

High-Field Open versus Short-Bore Magnetic Resonance Imaging of the Spine: A Randomized Controlled Comparison of Image Quality

“…Others have compared high-field closed with low-field open MR scanners. Michel et al found poor image quality in MR pelvimetry with a low-field open MR scanner [11]. Calabrese et al concluded that open low-field contrast-enhanced MR imaging of the breast yielded good diagnostic performance in claustrophobic or oversized patients [31].…”

“…Mehdizade et al found that diffusion-weighted MR imaging performed with a low-field open MR scanner was reliable for the evaluation of acute stroke [32]. Regarding the restrictions of conventional MR imaging, horizontal open MR scanners have shown potential for facilitating imaging of patients with claustrophobia or extreme obesity [5], [7], [8], and a better patient acceptance is assumed for open MR scanners [5], [10], [11]. Reduced claustrophobia rates have also been found with recent short-bore MR scanners [2], [9].…”

“…Most notable differences were found in overall image quality, mean SNR values, and quantitative contour sharpness. Previous studies have shown an advantage of open MR scanners regarding patient acceptance and imaging of claustrophobic or obese patients [5], [6], [7], [10], [11]. However, high claustrophobia rates have recently been found in patients at risk for both open and short-bore MR imaging [8].…”

“…Modern MR scanners with these configurations have already shown a potential for reducing claustrophobia and allowing imaging of extremely obese patients [2], [5], [6], [7], [8], [9]. Previous studies have also demonstrated improved patient acceptability of open-configuration MR scanners [5], [10], [11]. Besides patient preference, diagnostic performance and thus image quality is crucial for a comparison of different MR systems.…”

“…An open scanner configuration might impair image quality due to a potentially larger inhomogeneity of a vertical magnetic field. Moreover, until recently, such systems operated at rather low field strengths [11], [12], [13]. However, there is no study directly comparing the image quality of horizontal and vertical magnetic field MR systems.…”