Can Dynamic MRI Be Used to Accurately Identify Velopharyngeal Closure Patterns?

Magnetic Resonance Imaging of the Velopharynx: Clinical Findings in Patients with Velopharyngeal Insufficiency

BACKGROUND

Magnetic resonance imaging (MRI) is the only imaging modality capable of directly visualizing the levator veli palatini (LVP) muscles: the primary muscles responsible for velopharyngeal closure during speech. MRI has been used to describe normal anatomy and physiology of the velopharynx in research studies, but there is limited experience with use of MRI in the clinical evaluation of patients with velopharyngeal insufficiency (VPI).

METHODS

MRI was used to evaluate the velopharyngeal mechanism in patients presenting for VPI management. The MRI followed a fully awake, nonsedated protocol with phonation sequences. Quantitative and qualitative measures of the velopharynx were obtained and compared with age- and sex-matched individuals with normal speech resonance.

RESULTS

MRI was completed successfully in 113 of 118 patients (96%). Compared with controls, patients with VPI after cleft palate repair had a shorter velum (P < 0.001), higher incidence of LVP discontinuity (P < 0.001), and shorter effective velar length (P < 0.001). Among patients with persistent VPI after pharyngeal flap placement, findings included a pharyngeal flap base located inferior to the palatal plane [11 of 15 (73%)], shorter velum (P < 0.001), and higher incidence of LVP discontinuity (P = 0.014). Patients presenting with noncleft VPI had a shorter (P = 0.004) and thinner velum (P < 0.001) and higher incidence of LVP discontinuity (P = 0.014).

CONCLUSIONS

MRI provides direct evidence of LVP muscle anomalies and quantitative evaluation of both velar length and velopharyngeal gap. This information is unavailable with traditional VPI imaging tools, suggesting that MRI may be a useful tool for selecting surgical procedures to address patient-specific anatomic differences.

Speech Outcomes Following Operative Management of Velopharyngeal Dysfunction (VPD) in Non-Syndromic Post-Palatoplasty Cleft Palate Patients

OBJECTIVE

Approximately 30% of patients with a history of repaired cleft palate (CP) go on to suffer from velopharyngeal dysfunction (VPD). This study discusses the operative management of VPD and postoperative speech outcomes in a cohort of CP patients.

SETTING

An academic tertiary pediatric care center.

METHODS

Retrospective cohort study.

PATIENTS

Patients with history of repaired CP (Veau I-IV) who underwent operative management of VPD between January 1st, 2010 and December 31st, 2020. Operative modalities were posterior pharyngeal flap (PPF), sphincter pharyngoplasty (SPP), Furlow palate re-repair, and buccal myomucosal flap palate lengthening (PL).

OUTCOME MEASURES

The primary outcome measure is postoperative speech improvement evaluated by the Pittsburgh Weighted Speech Scale (PWSS).

RESULTS

97 patients met inclusion criteria. 38 patients with previous straight-line primary palatoplasty underwent Furlow re-repair; these patients were significantly younger (7.62 vs 11.14, P < .001) and were more likely to have severe VPD per PWSS (OR 4.28, P < .01, 95% CI 1.46-12.56) when compared to VPD patients with previous Furlow repair. 21.1% of these patients required an additional non-revisional VPD procedure. The remaining patients underwent a non-revision procedure (26 PPF, 22 SPP, 11 PL); all experienced significant (P < .001 on paired t-test) reductions in PWSS total and subgroup VPD severity scores without difference in improvement between operation types. SPP was statistically associated with all-cause complication (OR 2.79, 95% CI 1.03-7.59, P < .05) and hyponasality (OR 3.27, 95% CI 1.112-9.630, P < .05).

CONCLUSION

Furlow re-repair reduced need for additional VPD operations. Speech outcomes between non-revisional operations are comparable, but increased complications were seen in SPP.

Establishing a Clinical Protocol for Velopharyngeal MRI and Interpreting Imaging Findings

Traditional imaging modalities used to assess velopharyngeal insufficiency (VPI) do not allow for direct visualization of underlying velopharyngeal (VP) structures and musculature which could impact surgical planning. This limitation can be overcome via structural magnetic resonance imaging (MRI), the only current imaging tool that provides direct visualization of salient VP structures. MRI has been used extensively in research; however, it has had limited clinical use. Factors that restrict clinical use of VP MRI include limited access to optimized VP MRI protocols and uncertainty regarding how to interpret VP MRI findings. The purpose of this paper is to outline a framework for establishing a novel VP MRI scan protocol and to detail the process of interpreting scans of the velopharynx at rest and during speech tasks. Additionally, this paper includes common scan parameters needed to allow for visualization of velopharynx and techniques for the elicitation of speech during scans.

Magnetic Resonance Imaging for Assessing Velopharyngeal Function: Current Applications, Barriers, and Potential for Future Clinical Translation in the United States

OBJECTIVE

The use of magnetic resonance imaging (MRI) in the assessment process for children with cleft/craniofacial conditions remains uncommon, particularly for velopharyngeal assessments. The purpose of this study was to analyze the perceived clinical utility of MRI for cleft/craniofacial providers and identify barriers that exist for clinical translation of this imaging modality to this population of patients.

METHODS

A 38-item survey was disseminated to craniofacial team providers. Workplace context and demographics, MRI as a research and clinical tool, access and barriers for use of MRI, and needs for successfully establishing MRI protocols at clinical sites were investigated. Descriptive statistics were used to identify differences in the clinical use of MRI across disciplines. Chi-square analyses were conducted to determine how different specialties perceived potential barriers.

RESULTS

Respondents reported that MRI is likely to be beneficial for clinical assessments (93.5%) and that this imaging modality is available for use (83.8%). However, only 11.8% of providers indicated the use of MRI in their clinical assessments. This discrepancy highlights a potential disconnect between perceived use and implementation of this imaging methodology on cleft and craniofacial teams. A number of barriers were identified by providers. Challenges and opportunities for clinical translation of MRI protocols were highlighted.

CONCLUSION

Results may guide the development for improved clinical feasibility and implementation of MRI for clinical planning in this population of patients. Reported barriers highlight additional areas for translational research and the potential for the development of clinical tools related to MRI assessment and protocol implementation.

Pharyngeal flap outcomes for velopharyngeal insufficiency: Evaluation of speech, obstructive sleep apnea, and velopharyngeal anatomy

The purpose of this study was to evaluate the speech outcomes, reveal postoperative rates of obstructive sleep apnea, and characterize changes in the pharyngeal flap and velopharyngeal anatomy following pharyngeal flap surgery for velopharyngeal insufficiency. A retrospective chart was reviewed for patients with clefts who underwent pharyngeal flap surgery between November 2020 and November 2021. The data collected included age, gender, cleft palate type, age at pharyngeal flap surgery, postoperative complications, age and type of primary palatoplasty, preoperative and postoperative speech assessments, magnetic resonance imaging findings, and obstructive sleep apnea outcomes. The authors included 72 nonsyndromic patients who underwent pharyngeal flap surgery following cleft palate repair. The mean age at pharyngeal flap surgery was 10.6 ± 6.2 years. There was a significant improvement in the Pittsburgh Weighted Speech Score Hypernasality Component and the nasalance scores of oral syllables (p < 0.001). The obstructive sleep apnea rate after pharyngeal flap surgery was 6.9%. Compared to preoperatively, the velar angle was more acute (p < 0.001), the velar length was longer (p < 0.001), the distance of the velum tip to the posterior pharyngeal wall was shorter (p < 0.001), the size of velopharyngeal gap was narrower (p < 0.001), and the pharyngeal flap atrophied (p < 0.001) at 6 months postoperatively. The pharyngeal flap improved speech outcomes in patients with velopharyngeal insufficiency with a relatively low incidence of obstructive sleep apnea (6.9%). The velum is positioned more superiorly and posteriorly, and the size of the velopharyngeal gap is substantially reduced after pharyngeal flap surgery. In addition, the pharyngeal flap partially atrophied over time.

The Pediatric Neuroradiologist's Practical Guide to Capture and Evaluate Pre- and Postoperative Velopharyngeal Insufficiency

Up to 30% of children with cleft palate will develop a severe speech disorder known as velopharyngeal insufficiency. Management of velopharyngeal insufficiency typically involves structural and functional assessment of the velum and pharynx by endoscopy and/or videofluoroscopy. These methods cannot provide direct evaluation of underlying velopharyngeal musculature. MR imaging offers an ideal imaging method, providing noninvasive, high-contrast, high-resolution imaging of soft-tissue anatomy. Furthermore, focused-speech MR imaging techniques can evaluate the function of the velum and pharynx during sustained speech production, providing critical physiologic information that supplements anatomic findings. The use of MR imaging for velopharyngeal evaluation is relatively novel, with limited literature describing its use in clinical radiology. Here we provide a practical approach to perform and interpret velopharyngeal MR imaging examinations. This article discusses the velopharyngeal MR imaging protocol, methods for interpreting velopharyngeal anatomy, and examples illustrating its clinical applications. This knowledge will provide radiologists with a new, noninvasive tool to offer to referring specialists.

Diagnosing and Managing Velopharyngeal Insufficiency in Patients With Cleft Palate After Primary Palatoplasty

Velopharyngeal insufficiency (VPI) after palatoplasty is caused by improper anatomy preventing velopharyngeal closure and manifests as a hypernasal resonance, audible nasal emissions, weak pressure consonants, compensatory articulation, reduced speech loudness, and nostril or facial grimacing. A multidisciplinary team using multimodal instruments (speech analysis, nasoendoscopy, videofluoroscopy, nasometry, and magnetic resonance imaging) to evaluate velopharyngeal function should manage these patients. Careful monitoring of velopharyngeal function by a speech pathologist remains paramount for early identification of VPI and the perceptual assessment should follow a standardized protocol. The greatest methodology problem in CLP studies has been the use of highly variable speech samples making comparison of published results impossible. It is hoped that ongoing international collaborative efforts to standardize procedures for collection and analysis of perceptual data will help this issue. Speech therapy is the mainstay treatment for velopharyngeal mislearning and compensatory articulation, but it cannot improve hypernasality, nasal emissions, or weak pressure consonants, and surgery is the definitive treatment for VPI. Although many surgical methods are available, there is no conclusive data to guide procedure choice. The goal of this review article is to present a review of established diagnostic and management techniques of VPI.

Ultrasound Sonosensitizers for Tumor Sonodynamic Therapy and Imaging: A New Direction with Clinical Translation

With the rapid development of sonodynamic therapy (SDT), sonosensitizers have evolved from traditional treatments to comprehensive diagnostics and therapies. Sonosensitizers play a crucial role in the integration of ultrasound imaging (USI), X-ray computed tomography (CT), and magnetic resonance imaging (MRI) diagnostics while also playing a therapeutic role. This review was based on recent articles on multifunctional sonosensitizers that were used in SDT for the treatment of cancer and have the potential for clinical USI, CT, and MRI applications. Next, some of the shortcomings of the clinical examination and the results of sonosensitizers in animal imaging were described. Finally, this paper attempted to inform the future development of sonosensitizers in the field of integrative diagnostics and therapeutics and to point out current problems and prospects for their application.

Incorporating Velopharyngeal MRI into the Clinical Decision-Making Process for a Patient Presenting with Velopharyngeal Dysfunction Following a Failed Palatoplasty

This clinical report describes the implementation of magnetic resonance imaging (MRI) to evaluate a patient with long-standing velopharyngeal dysfunction. She was referred to the craniofacial clinic at age 10 with no prior surgical history and subsequently completed a Furlow palatoplasty due to a suspected submucous cleft palate. However, results were unfavorable with minimal improvement in speech or resonance. The clinical presentation, treatment, outcomes, and contributions from MRI for secondary surgical planning are described. Addition of MRI into the clinical workflow provided insights into the anatomy and physiology of the velopharyngeal mechanism that were unable to be obtained from nasendoscopy and speech evaluation alone.

Nonsedated Magnetic Resonance Imaging for Visualization of the Velopharynx in the Pediatric Population

BACKGROUND

Non-sedated MRI is gaining traction in clinical settings for visualization of the velopharynx in children with velopharyngeal insufficiency. However, the behavioral adaptation and training aspects that are essential for successful pediatric MRI have received limited attention.

SOLUTION

We outline a program of behavioral modifications combined with patient education and provider training that has led to high success rates for non-sedated velopharyngeal MRI in children.

Videofluoroscopy Versus Nasopharyngoscopy of Lateral Pharyngeal Wall Movement for Assessment of Velopharyngeal Insufficiency

BACKGROUND

Competent speech requires closure of the velopharyngeal sphincter by dynamic apposition of the velum and posterior and lateral pharyngeal walls. An accurate estimation of lateral pharyngeal wall motion is an important determinant in the planning and the outcome of any operation to correct velopharyngeal insufficiency (VPI). The purpose was to compare the assessment of lateral pharyngeal wall movement by videofluoroscopy (VP) versus nasopharyngoscopy (NP).

METHODS

The authors retrospectively reviewed the charts of 269 consecutive patients in our cleft lip/palate clinic from 1982 to 2008 and culled those treated with a pharyngeal flap for VPI. The authors included patients who were evaluated preoperatively by both VP and NP, and had studies of suitable quality. Percentage of lateral pharyngeal wall motion was estimated with each technique and compared for each patient.

RESULTS

The authors identified 25 patients who underwent both VP and NP at the same median age (4.7 years). The estimated percentage of lateral pharyngeal wall motion between the 2 techniques was significantly different ( P <0.001). Average lateral pharyngeal wall motion was estimated to be 59±25% (range: 5%-90%) by VP and only 40%±25% (range: 0%-95%) during NP.

CONCLUSIONS

VP and NP are complementary, but assessment of lateral pharyngeal wall motion can vary between the 2 methods. The surgeon should be aware of the difference in estimated lateral pharyngeal wall movement when planning a procedure to correct VPI.

Recent development of contrast agents for magnetic resonance and multimodal imaging of glioblastoma

Glioblastoma (GBM) as the most common primary malignant brain tumor exhibits a high incidence and degree of malignancy as well as poor prognosis. Due to the existence of formidable blood–brain barrier (BBB) and the aggressive growth and infiltrating nature of GBM, timely diagnosis and treatment of GBM is still very challenging. Among different imaging modalities, magnetic resonance imaging (MRI) with merits including high soft tissue resolution, non-invasiveness and non-limited penetration depth has become the preferred tool for GBM diagnosis. Furthermore, multimodal imaging with combination of MRI and other imaging modalities would not only synergistically integrate the pros, but also overcome the certain limitation in each imaging modality, offering more accurate morphological and pathophysiological information of brain tumors. Since contrast agents contribute to amplify imaging signal output for unambiguous pin-pointing of tumors, tremendous efforts have been devoted to advances of contrast agents for MRI and multimodal imaging. Herein, we put special focus on summary of the most recent advances of not only MRI contrast agents including iron oxide-, manganese (Mn)-, gadolinium (Gd)-, ¹⁹F- and copper (Cu)-incorporated nanoplatforms for GBM imaging, but also dual-modal or triple-modal nanoprobes. Furthermore, potential obstacles and perspectives for future research and clinical translation of these contrast agents are discussed. We hope this review provides insights for scientists and students with interest in this area.

Does the Type of MRI Sequence Influence Perceived Quality and Measurement Consistency in Investigations of the Anatomy of the Velopharynx?

PURPOSE

The purpose of this study was to evaluate perceived image quality, confidence in identifying key velopharyngeal landmarks, and reliability of making velopharyngeal measures between 3-dimensional (3-D) and 2-D magnetic resonance imaging (MRI) methods and between T1-, T2-, and proton density (PD)-weighted sequences.

METHODS

Twelve healthy participants completed an MRI study. Three raters assessed overall image quality and their ability to identify key anatomic features within the images. A single rater evaluated the reliability of making measures between imaging methods and sequence types to determine if image type (2-D and 3-D) or image sequence (T1, T2, PD weighted) resulted in different values for key velopharyngeal landmarks.

RESULTS

An analysis of variance test revealed image quality was rated significantly different based on the scan type (P < .001) and the sequence used (P = .015). Image quality was rated higher among 2-D MR images compared to 3-D, and higher among T2 sequences compared to T1- and PD-weighted imaging methods. In contrast, raters favored 3-D sequences over 2-D sequences for identifying velopharyngeal landmarks. Measures of reliability revealed scan type significantly impacted 2 of the 6 variables but to a minimal degree; however, sequence type had no impact on measures of reliability across all variables.

CONCLUSION

Results of the study suggest the scan type and sequence used are factors that likely do not impact the reliability of measures. Based on image quality, the recommended technique for velopharyngeal imaging would be using a 2-D T2-weighted technique. However, based on the ability to identify key landmarks, a 3-D T1- or PD-weighted technique was favored.

Realistic Dynamic Numerical Phantom for MRI of the Upper Vocal Tract

Dynamic and real-time MRI (rtMRI) of human speech is an active field of research, with interest from both the linguistics and clinical communities. At present, different research groups are investigating a range of rtMRI acquisition and reconstruction approaches to visualise the speech organs. Similar to other moving organs, it is difficult to create a physical phantom of the speech organs to optimise these approaches; therefore, the optimisation requires extensive scanner access and imaging of volunteers. As previously demonstrated in cardiac imaging, realistic numerical phantoms can be useful tools for optimising rtMRI approaches and reduce reliance on scanner access and imaging volunteers. However, currently, no such speech rtMRI phantom exists. In this work, a numerical phantom for optimising speech rtMRI approaches was developed and tested on different reconstruction schemes. The novel phantom comprised a dynamic image series and corresponding k-space data of a single mid-sagittal slice with a temporal resolution of 30 frames per second (fps). The phantom was developed based on images of a volunteer acquired at a frame rate of 10 fps. The creation of the numerical phantom involved the following steps: image acquisition, image enhancement, segmentation, mask optimisation, through-time and spatial interpolation and finally the derived k-space phantom. The phantom was used to: (1) test different k-space sampling schemes (Cartesian, radial and spiral); (2) create lower frame rate acquisitions by simulating segmented k-space acquisitions; (3) simulate parallel imaging reconstructions (SENSE and GRAPPA). This demonstrated how such a numerical phantom could be used to optimise images and test multiple sampling strategies without extensive scanner access.

Comparison of contrast-enhanced videofluoroscopy to unenhanced dynamic MRI in minor patients following surgical correction of velopharyngeal dysfunction

OBJECTIVES

To compare dynamic magnetic resonance imaging (MRI) with videofluoroscopy (VFS) regarding image quality and assessment of gap size between soft palate (SP) and posterior pharyngeal wall (PPW) in children and adolescents following surgical correction of velopharyngeal dysfunction (VPD).

METHODS

Twenty-one patients undergoing unenhanced 3-T MRI and contrast-enhanced VFS were included in this IRB-approved prospective study. The MRI scan protocol comprised refocused gradient-echo sequences in transverse and sagittal planes during speech, with TE 1.97 ms, TR 3.95 ms, flip angle 8°, matrix size 128 × 128, and 5-mm slice thickness. Radial k-space sampling and sliding window reconstruction were used to achieve an image acquisition rate of 28 frames per second (fps). VFS with 30 fps was similarly performed in both planes. Closure of the velopharyngeal port during phonation was evaluated by two experienced radiologists.

RESULTS

Eleven (52.4%) patients displayed a complete closure, whereas ten (47.6%) patients showed a post-operative gap during speech. VFS and MRI equally identified the cases with persistent or recurrent VPD. Differences in SP-PPW distance between VFS (3.9 ± 1.6 mm) and MRI (4.1 ± 1.5 mm) were not statistically significant (p = 0.5). The subjective overall image quality of MRI was rated inferior (p < 0.001) compared with VFS, with almost perfect inter-rater agreement (κ = 0.90). The presence of susceptibility artifacts did not limit anatomical measurements.

CONCLUSION

Dynamic MRI is equally reliable as VFS to assess persistent or recurrent inadequate velum closure in patients following surgical treatment of VPD.

KEY POINTS

• Unenhanced 3-T dynamic MRI and contrast-enhanced videofluoroscopy are equally useful for the identification of patients with incomplete velopharyngeal closure during speech. • MRI using refocused gradient-echo acquisition with radial k-space sampling and sliding window reconstruction generates diagnostic images with 28 frames per second. • MRI can offer a radiation-free alternative to currently established videofluoroscopy for young patients.

Velopharyngeal closure analysis using four-dimensional computed tomography: a pilot study of healthy volunteers and adult patients with cleft palate

Background

Nasopharyngoscopy is a common method to evaluate velopharyngeal closure in patients with cleft palate. However, insertion of a fiberoptic nasopharyngoscope causes discomfort in patients. The aim of this study was to estimate the reliability of short-time exposure images obtained using 320-row area detector computed tomography (320-ADCT) as a novel evaluation method for the assessment of velopharyngeal function.

Methods

We evaluated five healthy adult volunteers and five postoperative adult patients with cleft palate. During a 3.3-s imaging exposure, the participants were asked to perform two tasks: nasal inspiration and subsequent oral expiration through a catheter into a water-filled cup. The movement of the velopharyngeal structures was recorded during each examination, and the presence of velopharyngeal insufficiency (VPI) and velopharyngeal closure (VPC) patterns were estimated. If VPI was detected, the cross-sectional area was also calculated. Cohen’s kappa and weighted kappa coefficients were used to evaluate the concordance of nasopharyngoscopy and 320-ADCT evaluation.

Results

Speech pathology evaluation did not reveal hypernasality in any study participant. Micro-VPI was detected by nasopharyngoscopy in one healthy volunteer and two patients. 320-ADCT detected micro-VPI in two more patients. The cross-sectional area of the VPI in these subjects ranged from 2.53 to 16.28 mm². Nasopharyngoscopy and 320-ADCT were concordant in detecting VPI in eight participants (κ = 0.6) and in assessing VPC patterns in nine (κ = 0.82). Moreover, images obtained using 320-ADCT allowed for reduced dead angle and, thus, easy detection of micro-VPI and Passavant’s ridges.

Conclusion

Although the radiation exposure cannot be ignored, our novel evaluation method using 320-ADCT enables more detailed evaluation of VPC than nasopharyngoscopy. Future studies should investigate the relationship between 320-ADCT findings and speech pathology evaluations.

Electronic supplementary material

The online version of this article (10.1186/s12880-019-0350-4) contains supplementary material, which is available to authorized users.

Anatomical Significance of the Spatial Distribution of the Palatopharyngeus With Regard to Velopharyngeal Closure

OBJECTIVE

Coordination of the various soft palate and pharyngeal muscles should be considered while evaluating velopharyngeal closure. However, it remains unclear whether different muscle bundles have specific functions during velopharyngeal closure. We macroscopically and microscopically examined these muscles in detail and particularly clarified the morphology of the palatopharyngeus (PP) in velopharyngeal closure.

DESIGN

Forty halves of 21 heads from Japanese cadavers (average: 83.9 years) were used for analysis; 37 halves of 19 heads were macroscopically examined and 3 halves of 2 heads were histologically examined.

RESULTS

The PP consisted of muscle bundles originating from the superior and inferior surfaces of the palatine aponeurosis. The most superior part of the superior constrictor (SC) and most lateral part of PP on the palatine aponeurosis initially ran in parallel and subsequently, in superoposterior and inferoposterior directions, respectively. The PP appeared as a single continuous sheet that was radially spread as a whole. Its medial margins, located superior and inferior to the aponeurosis, formed a fold that established the palatopharyngeal arch. The stylopharyngeus (StP) adjoined the base of this arch.

CONCLUSIONS

Since PP consisted of muscle bundles running in various directions, various functions of these bundles should be considered during velopharyngeal closure. The PP can function as a sphincter with SC and as an elevator with StP. In addition, PP forms the medial protrusion in collaboration with StP and SC. Thus, PP plays an important role in velopharyngeal closure with the coordination of various muscles.

Effect of motor-based speech intervention on articulatory placement in the treatment of a posterior nasal fricative: a preliminary MRI study on a single subject

BACKGROUND

Posterior nasal fricatives are a learned compensatory articulation error and commonly substituted for oral fricatives. Treatment of such articulation errors requires the modification or teaching of skilled movements. A motor-based approach is designed to teach the complex motor skill movement sequences required in the production of sounds. Although motor learning research is well established, little has been done to determine how the approach changes the underlying physiology of articulatory movements. While the underlying anatomical configuration of the posterior nasal fricative has been described, no studies have quantified anatomic and physiological changes pre- and post-treatment.

AIMS

To use magnetic resonance imaging (MRI) to visualize and quantify the results of motor-based speech-intervention approach on articulatory placement for the treatment of the posterior nasal fricative.

METHODS & PROCEDURES

A 6-year-old male with a history of ear infections and posterior nasal fricative substitution for /s/ underwent six 1-h sessions of a motor-based treatment approach over the course of 2 weeks. Pre- and post-treatment evaluation included perceptual and instrumental assessment of speech and resonance. Perceptual resonance was rated by two speech-language therapists and articulation was assessed at the single-word level. Instrumental assessment included the See-Scape, Nasometer II and MRI during the sustained phonation of /s/. Amira v5.6 Visualization and Volume modelling software used the midsagittal and oblique coronal plane to measure dimensions of the articulatory anatomy.

OUTCOMES & RESULTS

Interrater reliability was assessed using a Pearson product moment correlation (α = .05) and ranged from r = .91 to .95. Intra-rater reliability was assessed using the intra-class correlation coefficient (.976) demonstrating a high degree of reliability with a 95% confidence interval. Articulation improved from 0% accuracy for /s/ in isolation at baseline to 100% for /s/ at the word level and 95% accuracy during conversational speech by session 6. Post-treatment results from this study revealed a greater shortening of the levator veli palatini (levator) muscle length during articulatory movements, more pronounced velar knee and dimple, decreased velar thickness, increased velar length and altered tongue position.

CONCLUSIONS & IMPLICATIONS

This study demonstrated the use of pre- and post-treatment imaging methodology to quantify articulatory changes following an intensive motor-based treatment approach. MRI demonstrated quantifiable changes in articulatory placement. Individuals who exhibit non-developmental and phoneme-specific articulation errors, such as the posterior nasal fricative, may be excellent candidates for short-term, intensive and frequent speech therapy sessions to remediate the production of the posterior nasal fricative.