Patient preferences for development in MRI scanner design: a survey of claustrophobic patients in a randomized study

Abstract

Objective: To investigate which magnetic resonance imaging (MRI) scanner designs claustrophobic patients prefer.

Material/methods: We analyzed questionnaires completed by 160 patients at high risk for claustrophobia directly after a scan in either a short-bore or open panoramic scanner as part of a prospective randomized trial Enders et al (BMC Med Imaging 11:4, 2011). Scanner preferences were judged based on schematic drawings of four scanners. Information on the diagnostic performance of the depicted scanners was provided, too.

Results: A majority of patients suggested upright open (59/160, 36.9%) and open panoramic (53/160, 33.1%) before short-bore designs (26/160, 16.3%, for all p < 0.001) for future development. When asked about patients' preferred scanner choice for an upcoming examination, information about a better diagnostic performance of a short-bore scanner significantly improved its preference rates (from 6/160 to 49/160 or 3.8 to 30.5%, p < 0.001). Patients with a claustrophobic event preferred open designs significantly more often than patients without a claustrophobic event (p = 0.047). Patients scanned in a short-bore scanner in our trial preferred this design significantly more often (p = 0.003). Noise reduction (51/160, 31.9%), more space over the head (44/160, 27.5%), and overall more space (33/160, 20.6%) were the commonest suggested areas of improvement.

Conclusion: Patients at high risk for claustrophobia visually prefer open- over short-bore MRI designs for further development. Education about a better diagnostic performance of a visually less-attractive scanner can increase its acceptance. Noise and space were of most concern for claustrophobic patients. This information can guide individual referral of claustrophobic patients to scanners and future scanner development.

Key points: • Patients at high risk for claustrophobia visually favor the further development of open scanners as opposed to short- and closed-bore scanner designs. • Educating claustrophobic patients about a higher diagnostic performance of a short-bore scanner can significantly increase their acceptance of this otherwise visually less-attractive design. • A medical history of earlier claustrophobic events in a given MRI scanner type and focusing on the features "more space" and "noise reduction" can help to guide referral of patients who are at high risk for claustrophobia.

Keywords: Claustrophobia; Magnetic resonance imaging; Questionnaire.

Fig. 1

MRI scanner designs in the study questionnaire to choose from. Four different MRI scanner designs were presented to choose from when asked about their design preferences in the questionnaire. a An open panoramic scanner with a vertical magnetic field and 1-T field strength (Phillips, Panorama). b A short-bore scanner with 1.5-T field strength (Siemens, MAGNETOM Avanto). c A 0.4-T open one-column scanner. d A 0.6-T frontal and overhead open scanner in which the patient sits in an upright position. The following additional information on the diagnostic utility of the different scanner designs was given in a second step: (a) good, (b) very good, (c) moderate, and (d) adequate diagnostic utility

Fig. 2

Conduct of the trial. A total of 174 patients were initially included. Fourteen patients did not fill out the questionnaire due to severe claustrophobia or because they did not undergo the MRI examination due to medical reasons. A total of 160 patients answered questions 1–4 regarding design preferences after the MRI examination. Question 1 and 2 asked about the preferred scanner design for an imaginary future examination as judged by the drawings in the questionnaire assuming equal (question 1) versus different diagnostic utility* (question 2) of the depicted scanners. Question 3 queried about the overall preferred scanner design for future development by manufacturers. Differences in answers to question 3 depending on the occurrence of a claustrophobic event and the scanner type used in the examination preceding the questionnaire are also shown. Question 4 was an open question in which patients could make suggestions for further improvements of MRI scanners. Answers to question 4 are not shown in this presentation (for details, see Fig. 6). *Differences in diagnostic utility: a good, b very good, c moderate, and d adequate

Fig. 3

Scanner design preferences in relation to the diagnostic performance of a scanner. When patients did not have any information on the different diagnostic utilities of the scanners depicted in the questionnaire, and therefore assumed equal diagnostic utility of all scanner designs to choose from, a majority of patients preferred an upright open scanner (51.9%). The short-bore scanner was least frequently chosen in this scenario (3.8%). After having been informed about the superior diagnostic performance of the short-bore and open panoramic scanner compared with the other imagers, patients favored those scanners significantly more often (51.9% for the open panoramic scanner and 30.6% for the short-bore scanner, respectively, p < 0.001) than before information about the diagnostic utility of the individual scanners was provided. *The difference in diagnostic utility was defined as follows: open panoramic scanner: good; short-bore scanner: very good; open one-column scanner: moderate; upright open scanner: adequate

Fig. 4

Scanner preference in relation to occurrence of a claustrophobic event in the preceding MRI examination. Patients who experienced a claustrophobic event immediately before filling out the questionnaire preferred an upright open or open panoramic design significantly more often than patients without a claustrophobic event (p = 0.047). Only 6.8% of patients with an event favored a short-bore scanner design. Patients without a claustrophobic event were more likely to accept a short-bore scanner design (19.8%)

Fig. 5

Design preferences in relation to the scanner type patients were scanned in directly before filling out the questionnaire. Patients scanned in a short-bore scanner within the study protocol preferred the short-bore scanner design for future development significantly more often than patients scanned in the open panoramic scanner (27% vs. 6%). The changes in design preferences depending on the scanner type patients were scanned in were significant (p = 0.003)

Fig. 6

Suggested improvements by patients at higher risk for claustrophobia for future scanner development. Most patients suggested a reduction of noise (31.9%, 51/160), more space over their head (27.5%, 44/160), and overall more space (20.6%, 33/160). Patients could make multiple suggestions. Not shown are the following other suggestions that were mentioned only once: cooler, adjustable air conditioning, no breaks in the examination, broader gurney, sitting scanner position, open casing of the scanner, active warming of hands and feet, and opportunity to leave the scanner anytime