Frequency and reasons for extra sequences in clinical abdominal MRI examinations

The purpose of the study was to identify the frequency and reasons for extra sequences in clinical liver MRI and MRCP examinations.

A total of 250 consecutive liver MRI and 250 consecutive MRCP examinations performed at a single institution were reviewed. Extra sequences performed in comparison with our standard institutional protocol were identified. Reasons for the extra sequences were identified. Overall trends were assessed.

In significantly greater fractions of exams (p = 0.009-0.030), MRCP had ≥1 extra sequence (40.8% vs. 29.2%) and ≥2 extra sequences (16.0% vs. 5.6%) in comparison with the institutional protocol than did liver MRI. The average number of extra sequences was significantly higher (p = 0.004) for MRCP (0.73 ± 1.2) than liver MRI (0.44 ± 0.88). Reasons for extra sequences were as follows: sequence repeated for patient motion (33.8% for liver MRI; 31.9% for MRCP); sequence repeated for anatomic coverage (24.3% for liver MRI; 19.8% for MRCP); sequence added by the radiologist (15.3% for liver MRI; 33.0% for MRCP); sequence repeated for other reason (17.1% for liver MRI; 12.6% for MRCP); and sequence added by the technologist (5.4% for liver MRI; 2.7% for MRCP). The most commonly repeated sequence due to motion was the axial fat-saturated turbo spin-echo T2-weighted sequence for both liver MRI and MRCP (54.7% and 29.3% of sequences repeated due to motion, respectively).

For liver MRI and MRCP exams, sequences were most often repeated due to motion artifact (most often occurring on TSE T2WI), and sequences were most often added by the radiologist. The findings may help guide sequence optimization, quality improvement initiatives, and standardization of operations, for improving efficiency in abdominal MRI workflow.