Factors affecting MRI scanner efficiency in an academic center

To determine which patient characteristics influence MRI scan time and how.

A database search of outpatient MRI liver examinations on 1.5T and 3T scanners from 1/1/2019 to 4/4/2019 was performed using an in-house developed software tool. Mean and median scan times were calculated. Patients who had difficulty following breathing instructions or completing breath-hold sequences were identified. Twenty-one additional patient characteristics were obtained from an Electronic Medical Record (EMR) search.

Scan times were significantly increased for patients with breath-holding issues during the exam (N = 43, median = 23.98 min) versus not (N = 179, median = 17.5 min, p < 0.001). Among patients who had difficulty following breathing instructions/completing breath-hold sequences, a significant number were non-native English speakers (23/43, 53%) compared to those whose first language was English (48/179, 27%, p < 0.001). Breath-holding issues were also significantly more frequent for patients requiring a translator during the exam (15/43, 35%) versus those who did not (24/179, 13%, p < 0.001). No other patient characteristics showed a significance difference between those with breathing issues and those without. Patient characteristics that caused a significant number of scan times to be one standard deviation or more above the median were as follows: Breath-holding issues during exam (21/43 ≥ one SD above, 51%, versus 22/189 < one SD above, 12%, p < 0.001); and first language not English (16/71 ≥ one SD above, 23%, versus 55/189 < one SD above, 29%, p = 0.03).

The ability to follow breathing instructions and complete breath-hold sequences had a significant impact on patient scan time. Patients who were not native English speakers had more frequent breathing issues during scans and significantly longer scans times compared native English speakers.