An analysis of the strengths and weaknesses of endoscopic and radiological investigations of velopharyngeal incompetence based on a 20 year experience of simultaneous recording

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.

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.

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.

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.

A Preliminary Study of Anatomical Changes Following the Use of a Pedicled Buccal Fat Pad Flap During Primary Palatoplasty

OBJECTIVE

The purpose of this study was to examine the surgical impact of the pedicled buccal fat pad (BFP) flap on the levator veli palatini (LVP) muscle and surrounding velopharyngeal (VP) anatomy following primary palatoplasty using magnetic resonance imaging (MRI).

DESIGN

Observational, prospective.

SETTING

MRI studies were completed at 3 different facilities. All participants with BFP flap were operated on by the same surgeon.

PARTICIPANTS

Five pediatric participants with cleft palate with or without cleft lip (CP±L) who underwent primary palatoplasty with BFP flap placement. Comparison groups consisted of 10 participants: 5 with CP±L who did not receive the BFP flap and 5 healthy controls.

INTERVENTIONS

All participants underwent nonsedated MRI 2 to 5 years postoperatively.

MAIN OUTCOMES AND MEASURES

Anatomical measures of the velopharynx and LVP among the 3 participant groups.

RESULTS

Median values were significantly different among groups for velar length (P = .042), effective velar length (P = .048), effective VP ratio (P = .046), LVP length (P = .021), extravelar LVP length (P = .009), and LVP origin-origin distance (P = .030). Post hoc analysis revealed a statistically significant difference between the BFP and traditional repair groups for effective VP ratio (P = .040), extravelar LVP length (P = .033), and LVP length (P = .022).

CONCLUSIONS

This study provides preliminary support that the BFP flap creates a longer velum, with increased distance between the posterior hard palate and the LVP, and a larger effective VP ratio compared to traditional surgical techniques. Future research is needed to determine whether this procedure provides a more favorable mechanism for VP closure.

Real-time dynamic vocal tract imaging using an accelerated spiral GRE sequence and low rank plus sparse reconstruction

PURPOSE

To develop a real-time dynamic vocal tract imaging method using an accelerated spiral GRE sequence and low rank plus sparse reconstruction.

METHODS

Spiral k-space sampling has high data acquisition efficiency and thus is suited for real-time dynamic imaging; further acceleration can be achieved by undersampling k-space and using a model-based reconstruction. Low rank plus sparse reconstruction is a promising method with fast computation and increased robustness to global signal changes and bulk motion, as the images are decomposed into low rank and sparse terms representing different dynamic components. However, the combination with spiral scanning has not been well studied. In this study an accelerated spiral GRE sequence was developed with an optimized low rank plus sparse reconstruction and compared with L1-SPIRiT and XD-GRASP methods. The off-resonance was also corrected using a Chebyshev approximation method to reduce blurring on a frame-by-frame basis.

RESULTS

The low rank plus sparse reconstruction method is sensitive to the weights of the low rank and sparse terms. The optimized reconstruction showed advantages over other methods with reduced aliasing and improved SNR. With the proposed method, spatial resolution of 1.3*1.3 mm² with 150 mm field-of-view (FOV) and temporal resolution of 30 frames-per-second (fps) was achieved with good image quality. Blurring was reduced using the Chebyshev approximation method.

CONCLUSION

This work studies low rank plus sparse reconstruction using the spiral trajectory and demonstrates a new method for dynamic vocal tract imaging which can benefit studies of speech disorders.

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.

Assessment of velopharyngeal function with dual-planar high-resolution real-time spiral dynamic MRI

PURPOSE

To develop a real-time dynamic MRI method for comprehensive evaluation of velum movement during speech.

METHODS

Dynamic MRI has been used to study velopharyngeal insufficiency (VPI) by imaging the movement of the velum during speech, because it can provide good anatomic details with no exposed radiation. To be able to comprehensively evaluate dynamic velum movement, a real-time spiral non-balanced SSFP sequence was developed with simultaneous dual-planar coverage and improved spatial and temporal resolution using a combination of parallel imaging and spatial and temporal compressed sensing to achieve 6 × acceleration. New off-resonance correction and post-processing methods were also developed to reduce blurring and slice crosstalk.

RESULTS

The method demonstrated good image quality for visualizing dynamic velum movement with reduced blurring and improved image homogeneity. Spatial resolution of 1.2*1.2 mm² with 150 mm FOV and temporal resolution of 20 frames-per-second with simultaneous dual-planar coverage was achieved.

CONCLUSIONS

This work describes a new technique for studying speech disorders using dual-planar accelerated spiral dynamic MRI.

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

BACKGROUND

Dynamic magnetic resonance imaging (MRI) has been proposed as a non-invasive, child-friendly, reproducible, and repeatable imaging method providing a 3-dimensional view of the velopharyngeal structures and function during speech. However, the value of dynamic MRI as compared to imaging methods such as nasopharyngoscopy is not well understood. The aim of this study was to compare the ability of nasopharyngoscopy and dynamic MRI to accurately identify velopharyngeal closure patterns among adults without cleft palate.

METHODS

Participants included 34 healthy adults with normal anatomy between 19 and 33 years of age (mean = 23 years; SD = 4.1 years). Participants underwent dynamic MRI and nasopharyngoscopy studies and comparisons were performed to determine the intra- and inter-rater reliability for accurately determining closure pattern. The MRI acquisition was a dynamic acquisition of a 2D plane.

RESULTS

Strong inter- (κ = .824; P < .001) and intra-rater (Rater 1: κ = 0.879, P < .001, 94% agreement between ratings; Rater 2 with 100% agreement) agreement was observed for the identification of closure pattern using nasopharyngoscopy. Inter-rater agreement for ratings using MRI demonstrated moderate agreement (κ = .489; P < .004). Examining point agreement revealed only 27 of the 33 ratings of MRI showed agreement (80%).

CONCLUSION

This demonstrates that inter-rater reliability for determining closure patterns from nasopharyngoscopy is good; however, ratings using MRI was less reliable at determining closure patterns. It is likely that future improvements in dynamic imaging with MRI to enable 3D visualizations are needed for improved diagnostic accuracy for assessing velopharyngeal closure patterns.

Velopharyngeal Structural and Functional Assessment of Speech in Young Children Using Dynamic Magnetic Resonance Imaging

OBJECTIVE

The purpose of this study was to demonstrate a novel method for examining the velopharyngeal mechanism using static and dynamic magnetic resonance imaging (MRI) at the sentence-level production in young children with normal anatomy. This study examined whether velopharyngeal events occurring in the midsagittal plane are correlated to muscle events occurring along the plane of velopharyngeal closure. Adenoid involvement in velopharyngeal function was also explored.

METHODS

A high-resolution, T2-weighted turbo-spin-echo three-dimensional anatomical scan was used to acquire static velopharyngeal data and a fast-gradient echo fast low angle shot multishot spiral technique (15.8 frames per second) was used to acquire dynamic data on 11 children between 4 and 9 years old.

RESULTS

Changes in velar knee height from rest to the bilabial /p/ production was strongly correlated with changes in the velar configuration (r = 0.680, P = .021) and levator muscle contraction (r = 0.703, P = .016). Velar configuration was highly correlated to levator muscle changes (r = 0.685, P = .020). Mean alpha angle during bilabial /p/ production was 176°, which demonstrated that subjects achieve velopharyngeal closure at or just below the palatal plane. Subjects with a larger adenoid pad used significantly less (r = -0.660, P = .027) levator muscle contraction compared with individuals with smaller adenoids.

CONCLUSIONS

This study demonstrates a potentially useful technique in dynamic MRI that does not rely on cyclic repetitions or sustained phonation. This study lends support to the clinical potential of dynamic MRI methods for cleft palate management.

Differences in Velopharyngeal Structure during Speech among Asians Revealed by 3-Tesla Magnetic Resonance Imaging Movie Mode

OBJECTIVE

Different bony structures can affect the function of the velopharyngeal muscles. Asian populations differ morphologically, including the morphologies of their bony structures. The purpose of this study was to compare the velopharyngeal structures during speech in two Asian populations: Japanese and Thai.

METHODS

Ten healthy Japanese and Thai females (five each) were evaluated with a 3-Tesla (3 T) magnetic resonance imaging (MRI) scanner while they produced vowel-consonant-vowel syllable (/asa/). A gradient-echo sequence, fast low-angle shot with segmented cine and parallel imaging technique was used to obtain sagittal images of the velopharyngeal structures.

RESULTS

MRI was carried out in real time during speech production, allowing investigations of the time-to-time changes in the velopharyngeal structures. Thai subjects had a significantly longer hard palate and produced shorter consonant than Japanese subjects. The velum of the Thai participants showed significant thickening during consonant production and their retroglossal space was significantly wider at rest, whereas the dimensional change during task performance was similar in the two populations.

CONCLUSIONS

The 3 T MRI movie method can be used to investigate velopharyngeal function and diagnose velopharyngeal insufficiency. The racial differences may include differences in skeletal patterns and soft-tissue morphology that result in functional differences for the affected structures.

Evaluation of velopharyngeal closure by 4D imaging using 320-detector-row computed tomography

OBJECTIVE

Current imaging techniques for velopharyngeal closure (VPC) evaluation are two-dimensional, static, or distressing, thus necessitating multiple procedures to understand this three-dimensional and dynamic area. We validated the use of a novel four-dimensional (4D) computed tomography (CT) technique for the morphological and kinematic evaluation of VPC in cleft palate patients based on dynamic volume scanning with 320-detector-row CT.

METHODS

Five patients aged 4-10 years (40% males) with persistent velopharyngeal insufficiency post palatoplasty underwent conventional tests (cephalometry and video-nasal endoscopy) and 4D-CT. For each patient, complete multiplanar reconstruction, 4D airway CT, and 4D-CT endoscopy data for all scanning phases were compared with cephalometric and video-nasal endoscopy data. The movements of the velum and posterior pharyngeal walls were graded by each modality.

RESULTS

4D airway CT revealed higher anatomical detail than cephalometry, additionally providing dynamic images. 4D-CT endoscopy and video-nasal endoscopy were in agreement for all patients regarding the patterns of VPC, with complete visualization of VPC in five versus one patient, respectively. 4D airway CT and cephalometry showed a discrepancy in one case, wherein grading by cephalometry was overestimated. 4D-CT was also useful in determining the width and length of a proposed pharyngeal flap. The examination time (mean ± standard deviation (SD), seconds), including patient preparation time, was 224 ± 73, 492 ± 145, and 718 ± 123 for cephalometric radiographs, CT, and video-nasal endoscopy, respectively. The mean estimated radiation dose during 4D-CT was 4.44 ± 1.64 mSv.

CONCLUSIONS

4D-CT provides detailed morphological and kinematic analysis of VPC and may offer advantages over conventional procedures.

Using MRI for assessing velopharyngeal structures and function

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.

A review of the evaluation and management of velopharyngeal insufficiency in children

This article highlights the most common causes of velopharyngeal insufficiency (VPI), and discusses routine evaluation and treatment algorithms for the management of VPI in children. VPI is a multifactorial condition that occurs commonly in syndromic and non-syndromic children. The most common features of VPI are audible hypernasal speech, facial grimacing, decreased speech intelligibility, nasal regurgitation, and nasal emission from failure to produce oronasal separation. Work-up of VPI typically involves radiologic and endoscopic testing performed with the assistance of a speech-language pathologist. Management of VPI involves initial speech therapy followed by operative repair with sphincter or pharyngeal flap pharyngoplasty, if needed.

Velopharyngeal Dysfunction and 22q11.2 Deletion Syndrome: A Longitudinal Study of Functional Outcome and Preoperative Prognostic Factors

Objective

To describe the effect of time after velopharyngoplasty on outcome and to search for preoperative prognostic factors for residual hypernasality in patients with 22q11.2 deletion syndrome.

Design

Retrospective chart review.

Setting

Tertiary hospital.

Patients

Patients with 22q11.2 deletion syndrome and velopharyngeal dysfunction who underwent a primary (modified) Honig velopharyngoplasty between 1989 and 2009.

Main Outcome Measures

Clinically obtained perceptual and instrumental measurements of resonance, nasalance, and understandability before and after velopharyngoplasty.

Results

Data were available for 44 of 54 patients (81% follow-up), with a mean follow-up time of 7.0 years (range, 1.0 to 19.4 years). During follow-up, 24 (55%) patients attained normal resonance and 20 (45%) had residual hypernasality or underwent revision surgery. Mean postoperative nasalance and understandability scores were closer to the norm than mean preoperative scores were (2.0 versus 5.5 standard deviations for the normal passage, 1.3 versus 8.1 standard deviations for the nonnasal passage, and score 2.3 versus 4.1 understandability). Serial measurements revealed that hypernasality only resolved an average of 5 years after surgery, and three patients whose resonance initially normalized later relapsed to hypernasality. Gender, age at surgery, lateral pharyngeal wall adduction, velar elevation, presence of a palatal defect, previous intravelar veloplasty, nasalance, understandability, adenoidectomy, hearing loss, and IQ were not able to predict poor outcome following primary velopharyngoplasty (all p > .05).

Conclusions

In this chart review of patients with 22q11.2 deletion syndrome and velopharyngeal dysfunction, residual hypernasality persisted in many patients after velopharyngoplasty. None of the preoperative factors that were studied had prognostic value for the outcome.

Magnetic resonance imaging assessment of the velopharyngeal mechanism at rest and during speech in Chinese adults and children

PURPOSE

Recent applications of the magnetic resonance imaging (MRI) technique introduced accurate 3-dimensional measurements of the velopharyngeal mechanism. Further standardization of the data acquisition and analysis protocol was successfully applied to imaging adults at rest and during phonation. This study was designed to test and modify a noninvasive protocol for evaluating young children without using general anesthesia. In addition, the velopharyngeal structures and their maximal motion were compared between adults and children.

METHOD

MRI data were acquired in 12 young adults and 9 children at rest and during speech production. Multiple measurements were made on the velopharyngeal and craniofacial structures as well as on the levator veli palatini muscle.

RESULTS

Most of the ratio measurements of structural shape and maximal motion in the velopharyngeal and craniofacial regions were not significantly different between the adults and the children, despite the fact that the children had much smaller structures than the adults.

CONCLUSION

The proportion of the velopharyngeal mechanism remains stable in young children and adults so that the motions of the velum and pharyngeal walls are adequate to close the velopharyngeal port completely.

Effects of Velopharyngeal Dysfunction on Middle Ear of Repaired Cleft Palate Patients

Objective

Cleft palates are strongly associated with the development of otitis media due to the anatomic and functional defect of the soft palate musculature and the associated alterations of velopharyngeal muscle insertion on tubal cartilage, or even intrinsic alterations of the cartilage, which affects eustachian tube function. This study will assess velopharyngeal muscle adequacy after palatoplasty through videonasoendoscopy and verify if there is a correlation with otologic status.

Design

Transversal study.

Setting

Otorhinolaryngology and cleft palate outpatient service of the Hospital de Clinicas de Porto Alegre (HCPA), Porto Alegre, Brazil.

Patients

Seventy-three patients with cleft palate or cleft lip and palate between the ages of 6 and 12 years who had already undergone palatoplasty.

Interventions

Videonasoendoscopy for evaluation of velopharyngeal function and videotoscopy to assess middle ear status.

Main Outcome Measures

Severity scale for videonasoendoscopic and videotoscopic findings.

Results

There was no significant correlation between the videonasoendoscopic and the videotoscopic scores in the population studied.

Discussion and Conclusions

Intrinsic defects of the eustachian tube cartilage and of the insertion of the velopharyngeal muscles seem to contribute to the evolution of otitis media in patients with cleft palate, in addition to the actual defect of the soft palate. There was no correlation between the severity of the otoscopic findings and the degree of velopharyngeal dysfunction.

Identification and characterization of an arginine kinase as a major allergen from silkworm (Bombyx mori) larvae

BACKGROUND

The silkworm, Bombyx mori, is an important insect in the textile industry and its pupa are used in Chinese cuisine and traditional Chinese medicine. The silk, urine and dander of silkworms is often the cause of allergies in sericulture workers and the pupa has been found to be a food allergen in China. Recent studies have focused on reporting cases of silkworm allergies, but only a few studies have addressed the specific allergens present in the B. mori silkworm.

METHODS

We collected sera from 10 patients with a positive skin prick test to silkworm crude extract (SCE) and analyzed these samples by Western blot and ELISA. The cDNA of arginine kinase from the B. mori silkworm was also cloned and expressed in high yield in Escherichia coli. Allergenicity and cross-allergenicity of the recombinant B. mori arginine kinase (rBmAK) were investigated by ELISA inhibition assay.

RESULTS

Collected sera all reacted to a 42-kDa protein in a Western blot with SCE as the antigen. Preincubation of sera with rBmAK eliminated the reactivity of the patients' sera to this 42-kDa band. All patient sera also exhibited positive reactivity to SCE in an ELISA assay. BmAK also demonstrated cross-reactivity with a recombinant AK from cockroach.

CONCLUSION

Arginine kinase from the B. mori silkworm is a major allergen and crossreacts with cockroach AK.

A local diagnostic reference level for velopharyngeal investigations

The purpose of this study was to derive an initial local diagnostic reference level for velopharyngeal investigations carried out as standard radiological practice in the Medical Imaging Department, Queen Victoria Hospital, East Grinstead. This is a specialist video-fluoroscopic radiological technique used to evaluate velopharyngeal dysfunction, especially for paediatric patients. A retrospective analysis over a period of 7 months involving 50 examinations yielded dose-area product values ranging from 0.04 Gy cm(2) (minimum) to 0.37 Gy cm(2) (maximum) with a mean value of 0.11 Gy cm(2) and 3rd quartile value of 0.12 Gy cm(2). The maximum effective dose was estimated as 0.016 mGy. An initial local diagnostic reference level of 0.12 Gy cm(2) has been levied.

Videonasopharyngoscopy is useful for identifying children with Pierre Robin sequence and severe obstructive sleep apnea

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) commonly appears in patients with Pierre Robin sequence (PR). Polysomnography (PS) is the gold standard for the diagnosis of OSAS. Videonasopharyngoscopy (VNP) is the best diagnostic tool for visualizing the vocal tract and detecting structural abnormalities which can be associated with OSAS.

OBJECTIVE

The purpose of this paper is to study whether VNP can be useful for identifying severe OSAS in a population of children with PR.

MATERIALS AND METHODS

Fifty-two children with PR who were present with sleep-disordered breathing were studied. All the parents completed a questionnaire concerning the children's sleeping habits and sleep complaints before consultation. Each child underwent a general pediatric examination and an evaluation of craniofacial features and upper airway permeability. In all children, a PS was performed. Also, all children underwent a VNP.

RESULTS

The diagnosis of OSAS was confirmed by PS in 31 patients. VNP showed 87% sensitivity and 100% specificity for the detection of OSAS. VNP findings showed a significant correlation with apnea-hypopnea index, arousal index, snoring time, percentage of sleep time spent at saturation of oxygen <90% and a significant inverse correlation with total sleep time, sleep efficiency and the mean saturation of oxygen during sleep.

CONCLUSION

This study shows that in children with PR, airway obstruction as detected by VNP seems to be a risk factor for OSAS. VNP appears to be a safe and reliable tool for the evaluation of sleep-disordered breathing in children with PR.

Velopharyngeal insufficiency

PURPOSE OF REVIEW

Velopharyngeal insufficiency is a niche within our specialty, but patients with hypernasality present who have never been diagnosed previously. Otolaryngologists should be familiar with current trends in diagnosis and treatment of hypernasality.

RECENT FINDINGS

Velopharyngeal insufficiency has been associated with genetic conditions and identifiable syndromes. Multiple surgical techniques are available for the treatment of this condition, the results of which vary widely in the literature. There is difficulty in interpreting the success of surgical outcomes on speech intelligibility and resonance because of the heterogeneity of the patient population and the subjective nature of assessing results. More studies are now available for the evaluation of associations of comorbid conditions and their impact on speech results.

SUMMARY

Velopharyngeal insufficiency must be diagnosed properly. Syndromes and comorbid conditions must be identified. No single specialty can care appropriately for these patients. A team approach is the ideal method of evaluating and managing patients with velopharyngeal insufficiency. Specialists with a particular interest and training in the management of patients with clefts of the palate and velopharyngeal insufficiency must collaborate to obtain the maximal functional outcome for these patients.

Colour texture analysis for quantitative laryngoscopy

OBJECTIVE

Whilst considerable progress has been made in enhancing the quality of indirect laryngoscopy and image processing, the evaluation of clinical findings is still based on the clinician's judgement. The aim of this paper was to examine the feasibility of an objective computer-based method for evaluating laryngeal disease.

MATERIAL AND METHODS

Digitally recorded images obtained by 90 degree- and 70 degree-angled indirect rod laryngoscopy using standardized white balance values were made of 16 patients and 19 healthy subjects. The digital images were evaluated manually by the clinician based on a standardized questionnaire, and suspect lesions were marked and classified on the image. Following colour separation, normal vocal cord areas as well as suspect lesions were analyzed automatically using co-occurrence matrices, which compare colour differences between neighbouring pixels over a predefined distance.

RESULTS

Whilst colour histograms did not provide sufficient information for distinguishing between healthy and diseased tissues, consideration of the blue content of neighbouring pixels enabled a correct classification in 81.4% of cases. If all colour channels (red, green and blue) were regarded simultaneously, the best classification correctness obtained was 77.1%.

CONCLUSIONS

Although only a very basic classification differentiating between healthy and diseased tissue was attempted, the results showed progress compared to grey-scale histograms, which have been evaluated before. The results document a first step towards an objective, machine-based classification of laryngeal images, which could provide the basis for further development of an expert system for use in indirect laryngoscopy.