Cine Magnetic Resonance Imaging With Simultaneous Audio to Evaluate Pediatric Velopharyngeal Insufficiency

The Cleft Palate Craniofacial Journal

Kuehn

et al. 2014

Objective Direct visualization of the velopharynx and, in particular, the levator muscle is particularly important in the assessment of velopharyngeal function and normal speech production. The purpose of this study is to demonstrate the development of a static and dynamic magnetic resonance imaging protocol for evaluation of velopharyngeal structures and function. Methods A high-resolution, T2-weighted turbo-spin-echo three-dimensional anatomical scan (sampling perfection with application optimized contrasts using different flip angle evolution) was used to acquire a large field of view covering the velopharyngeal anatomy. Dynamic speech assessment was obtained using a fast-gradient echo, fast low-angle shot, multi-shot spiral technique to acquire 15.8 frames per second (fps) of the sagittal and oblique coronal image planes. Results Using a three-dimensional data set, as opposed to two-dimensional data, the full contour of the levator muscle can be appreciated. Dynamic images were obtained at 15.8 fps in the sagittal and oblique coronal planes, enabling visualization of the movements of the velum, posterior pharyngeal wall, lateral pharyngeal walls, and levator muscle during speech. Conclusions A three-dimensional magnetic resonance imaging sequence, such as that used in the present study, may provide better analyses and more precise measurements. A dynamic fast low-angle shot sequence allows for visualization of the levator muscle and the velum during speech at a high image rate. This protocol could have a significant impact in improving the process of visualizing pathology and promoting clinical treatment plans for individuals born with cleft lip and palate.

Section: Discussionmentioning

confidence: 99%

Using MRI for Assessing Velopharyngeal Structures and Function

Perry

The Cleft Palate Craniofacial Journal

Kuehn

et al. 2014

“…RT-MRI has been demonstrated to be a promising alternative to current functional tests, which are either invasive (nasoendoscopy), or involve radiation (x-ray video fluoroscopy), and has been adapted in several clinical VPI studies. [13][14][15][16][17][18][19] The clinical role of RT-MRI for VPI assessment has not yet been fully established, and notable hurdles include the cost and complexity of scanning. 20,21 RT-MRI and structural MRI have also been explored for assessment of functional restoration for postsurgical assessment of cleft-palate repair.…”

mentioning

confidence: 99%

Recommendations for real-time speech MRI

Lingala

J. Magn. Reson. Imaging

Miquel

et al. 2015

127

Real-time magnetic resonance imaging (RT-MRI) is being increasingly used for speech and vocal production research studies. Several imaging protocols have emerged based on advances in RT-MRI acquisition, reconstruction, and audio-processing methods. This review summarizes the state-of-the-art, discusses technical considerations, and provides specific guidance for new groups entering this field. We provide recommendations for performing RT-MRI of the upper airway. This is a consensus statement stemming from the ISMRM-endorsed Speech MRI summit held in Los Angeles, February 2014. A major unmet need identified at the summit was the need for consensus on protocols that can be easily adapted by researchers equipped with conventional MRI systems. To this end, we provide a discussion of tradeoffs in RT-MRI in terms of acquisition requirements, a priori assumptions, artifacts, computational load, and performance for different speech tasks. We provide four recommended protocols and identify appropriate acquisition and reconstruction tools. We list pointers to open-source software that facilitate implementation. We conclude by discussing current open challenges in the methodological aspects of RT-MRI of speech.

“…Studies have examined traditional image planes including sagittal, oblique, and axial (Akgüner et al, 1998; Özgür et al, 2000; Kane et al, 2002; Beer et al, 2004; Atik et al, 2008; Kao et al, 2008; Drissi et al, 2011; Silver et al, 2011). …”

mentioning

confidence: 99%

Sexual Dimorphism of the Levator Veli Palatini Muscle: An Imaging Study

Perry

Kuehn

The Cleft Palate Craniofacial Journal

et al. 2014

Objective Magnetic resonance imaging studies of the levator veli palatini muscle have used small numbers of subjects and have not consistently controlled for sex, race, or age. The purpose of this study was to conduct a structural assessment using a large homogeneous sample to examine the sex differences in the levator muscle morphology. Methods Thirty white adult subjects (15 men and 15 women) were imaged using a 3 Tesla MRI system. A high-resolution SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolution) sequence was used to acquire images of the velopharyngeal anatomy. Levator muscle measurements were obtained. Results Men displayed significantly greater levator extravelar segment length (P = .003), levator intravelar segment muscle length (P < .001), greater distance between levator insertion points (P < .001), and greater angles of origin (P= .008) compared with women. There was no statistically significant variation between men and women in the distance between points of origin at the base of the skull. Conclusions This study provides normative data to improve understanding of levator dysmorphology such as that in cleft palate muscle anatomy. Results of the study demonstrate significant differences between white men and women across several levator muscle measures. Variations in the relative size of the cranium or height of the individual were not proportionate to the variations observed in the levator muscle.