Reduction of claustrophobia during magnetic resonance imaging: methods and design of the "CLAUSTRO" randomized controlled trial

We propose to analyze the rate of claustrophobic reactions, clinical utility, image quality, patient acceptance, and cost-effectiveness of an open MR scanner in a randomized comparison with a recently designed short-bore but closed scanner with 97% noise reduction. The primary aim of this study is thus to determine whether an open MR scanner can reduce claustrophobic reactions, thereby enabling more examinations of claustrophobic patients without incurring the safety issues associated with conscious sedation. In this manuscript we detail the methods and design of the prospective "CLAUSTRO" trial.This randomized controlled trial will be the first direct comparison of open vertical and closed short-bore MR systems in regards to claustrophobia and image quality as well as diagnostic utility.ClinicalTrials.gov: NCT00715806Magnetic resonance (MR) imaging has been described as the most important medical innovation in the last 25 years [1]. There has been an enormous increase in the use of this modality in the clinical setting. Over 80 million MR procedures are now performed each year worldwide. For an MR scan, patients typically have to be placed in a long, narrow tube [2]. Thus, claustrophobia preventing MR imaging is a common problem. Between 1% and 15% of all patients scheduled for MR imaging suffer from claustrophobia and cannot be imaged, or they require sedation to complete the scan (mean: 2.3%; 95% confidence interval: 2.0% to 2.5%) [3]. Thus it can be estimated that worldwide approximately 2,000,000 MR procedures cannot be performed or are prematurely terminated due to claustrophobia. At an average cost of € 500 per MR imaging, this is equal to a loss of productivity of € 1 billion, which is an important financial loss for the health care system. Therefore, claustrophobia is not only a common problem that prevents many patients from benefiting from the findings obtained with MR imaging but also represents an important socioeconomic issue for the health care system