Effectiveness of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for reducing motion artifacts caused by mandibular movements on fat-suppressed T2-weighted magnetic resonance (MR) images.

PURPOSE: To compare a fat-suppressed T2-weighted periodically rotated overlapping parallel lines with enhanced reconstruction (T2W-PROPELLER) sequence with a fat-suppressed T2-weighted fast spin-echo (T2W-FSE) sequence in the oral and maxillofacial regions for the evaluation of the presence of motion artifacts caused by mandibular movements.

METHODS: Fifty-six healthy adult volunteers were examined in a closed mouth position and then with three different rhythmical mandibular movements throughout MR scanning: open-close movement (movement 1), lateral movement (movement 2) and open-close and lateral movement (movement 3). All subjects were scanned first with fat-suppressed T2W-FSE and then with fat-suppressed T2W-PROPELLER while performing the same movements. Motion artifacts, including ghosting or pulsation artifacts, streak artifacts, susceptibility artifacts and the overall image quality were independently evaluated by two oral and maxillofacial radiologists using a five-point scale. The score graded by the two observers was averaged.

RESULTS: The inter-observer agreement was almost perfect for all evaluated items (κ ≥ 0.81). The T2W-PROPELLER images showed significantly fewer ghosting artifacts than T2W-FSE images in subjects performing the mandibular movements throughout MR scanning (P < .001). T2W-PROPELLER images also showed significantly fewer pulsation artifacts than T2W-FSE images, regardless of the performance of a movement, throughout MR scanning (P < .001). Finally, the T2W-PROPELLER images showed a significantly better overall image quality than T2W-FSE images in subjects performing movements 2 or 3 throughout MR scanning (P < .001).

CONCLUSION: The PROPELLER technique was found to be effective in reducing the motion artifacts caused by mandibular movements on fat-suppressed T2W MR images in the oral and maxillofacial regions.