Diffusion-weighted magnetic resonance imaging of the oral and maxillofacial region: optimal fat suppression method.

Objective: To compare 3 fat suppression methods-water excitation (WE), chemical shift selective (CHESS), and short T1 inversion recovery (STIR)-for optimal image quality and apparent diffusion coefficient (ADC) values with magnetic resonance imaging (MRI) using diffusion-weighted imaging (DWI) of the oral and maxillofacial region.

Study Design: In total, 53 patients with 73 lesions were enrolled in this study. MRI using DWI protocols with the 3 fat suppression methods were performed in addition to a conventional MRI protocol.

T2 relaxation times of the retrodiscal tissue in patients with temporomandibular joint disorders and in healthy volunteers: a comparative study.

Objective: The aims of this study were to compare the temporomandibular joint (TMJ) retrodiscal tissue T2 relaxation times between patients with temporomandibular disorders (TMDs) and asymptomatic volunteers and to assess the diagnostic potential of this approach.

Study Design: Patients with TMD (n = 173) and asymptomatic volunteers (n = 17) were examined by using a 1.5-T magnetic resonance scanner.

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.

Accuracy and precision of manual segmentation of the maxillary sinus in MR images-a method study.

Objective: To assess the accuracy and precision of segmentation of the maxillary sinus in MR images to evaluate the potential usefulness of this modality in longitudinal studies of sinus development.

Methods: A total of 15 healthy subjects who had been both craniofacial CT and MR scanned were included and the 30 maxillary sinus volumes were evaluated using segmentation. Two of the authors did segmentation of MRI and one of these authors did double segmentation.