Results of a prospective multicenter study for evaluation of the diagnostic duality of an open whole-body low-field MRI unit. A comparison with high-field MRI measured by the applicable gold standard

Objective: To evaluate the diagnostic quality of an open whole-body low-fie ld MRI scanner compared to high-field scanners. Materials and methods: Over a period of 3 months, 401 patients with diseases of the kidney (n = 78), t he shoulder (n = 122), the spine (n = 105) and the cerebrum (n = 96) were p rospectively evaluated in four participating centers. They all underwent cl inical evaluation, low-field and high-field MRI examination and surgical or follow-up confirmation of diagnosis. Clinical, histopathologic, high-field and low-field MRI diagnoses were recorded in standardized questionnaires t hat were centrally evaluated. Statistical evaluation comprised two parts: R OC analysis assessed accuracy of MRI and clinical diagnoses; furthermore ra tes of concordance of high- and low-field MRI diagnosis were calculated. Re sults: We found no statistically relevant difference in high-field MRI diag nosis compared to low-field MRI diagnostic accuracy measured by clinical or surgical gold standard in three of the four regions examined; in cerebral examinations there was a small yet significant advantage for the high-field systems (P = 0.01). Conclusion: We conclude that the open low-field scanne r we evaluated using clinical and surgical gold standard as reference is ab le to achieve comparable diagnostic accuracy compared to high-field scanner s at lower costs and greater patient comfort. Limitations due to field stre ngth (signal-to-noise ratio, resolution, scan time) seem to be relevant onl y in a very small number of cases that warrant high-field examination. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.