Laryngeal Images Research Articles

Voice and Laryngeal Configuration of Men With Unilateral Vocal Fold Paralysis Before and After Medialization

To describe the laryngeal configuration and the voice of male patients diagnosed with unilateral vocal fold paralysis (UVFP) before and after medialization. A retrospective study involving the collection of data from medical records of 142 patients diagnosed with UVFP from January 2003 to April 2009, submitted to auditory-perceptual assessment of voices and visual perception of laryngeal images before and after medialization. The study included data from 24 male patients, with an average of 60.7 years, who underwent three surgical medialization techniques (injection of hyaluronic acid, type I thyroplasty, and injection of Teflon). Before treatment, the position of the paralyzed vocal fold was seen to have a significant influence to the passing of the healthy vocal fold beyond the midline and on the overall degree of dysphonia. After treatment, the complete glottic closure; the free margin of the linear vocal fold; paralyzed vocal fold in the median position, reduction of hoarseness, roughness and breathiness (more frequently mild), and asthenia (more frequently normal and mild); tension and instability (more frequency normal); and a decrease in the overall degree of dysphonia were found to be significant. The position of the paralyzed vocal fold influences the position of the healthy vocal fold in relation to the midline and the overall degree of dysphonia. All three treatments improved the glottic configuration and the voice of patients with UVFP.

Vocal Function Exercises for Presbylaryngis: A Multidimensional Assessment of Treatment Outcomes

Presbylaryngis, or aging of the larynx, can adversely affect vocal function and quality of life in the elderly. This preliminary investigation examined the effects of vocal function exercises, a physiologic voice therapy approach, as a primary treatment for presbylaryngis. Nine consecutive elderly patients with presbylaryngis (2 female, 7 male) underwent a 6-week course of voice therapy employing vocal function exercises. Pretherapy-versus-posttherapy comparisons were made of self-ratings of voice handicap and phonatory effort level, as well as auditory-perceptual voice assessments, acoustic analyses, and visual-perceptual evaluations of laryngeal images. After treatment, patients reported significant reductions on Voice Handicap Index scores, phonatory effort levels, and voice disorder severity. Blinded listeners rated the posttreatment voices as significantly less breathy and strained. However, comparison of pretreatment and posttreatment maximum phonation times, acoustic measures, and laryngeal images did not reveal significant changes. These preliminary data suggest that vocal function exercises produce significant functional and perceptual improvements in voice, and deserve further attention as a treatment for elderly patients with presbylaryngis.

A Brief History of Laryngeal Imaging: Informing our Current Clinical Practice

This article provides an overview of the history of laryngeal illumination as it informs current clinical practice. We argue that two pioneers, G. Paul Moore and Hans von Leden, were critical to the development of the analysis and interpretation of laryngeal images. The material presented here was originally part of a Short Course at the 2009 American Speech-Language-Hearing Association (ASHA) Convention. For readers desiring greater detail, references to key articles are provided.

Traditional Chinese Medicine for Treatment of Laryngeal Papillomatosis

The objective of this study was to assess the clinical effectiveness of Traditional Chinese Medicine (TCM) as an adjuvant therapy for recurrent respiratory papillomatosis. The design of this study was a case series. LOCATION AND SUBJECTS: Fifty-one (51) patients with laryngeal papillomatosis who were treated at Keio University Hospital between May 1981 and April 2008 were incorporated in this study. Individually formulated TCM was orally administered postsurgically to 20 patients with aggressive laryngeal papillomatosis requiring multiple laser ablations (at least biannually) because of frequent recurrence. Eight (8) patients were excluded because of discontinued visits or medication (6 patients), or malignant transformation of the lesion (2 patients). The remaining 12 patients were enrolled in this study. Retrospective chart review and review of the patients' recorded laryngeal images were performed. Clinical response to TCM was measured by the surgical necessity and Derkay's severity score for each patient, followed by statistical analyses. Surgeries were required statistically less often (p = 0.0029) after TCM administration compared with the pre-TCM period. Furthermore, Derkay's severity score was significantly lower (p = 0.022) at the patients' last visit compared with the score before TCM administration. TCM may be a useful adjuvant therapy to treat aggressive laryngeal papillomatosis. Further studies are necessary to clarify the pharmacological mechanism of TCM in the treatment of laryngeal papillomatosis.

High-speed digital imaging of the neoglottis after supracricoid laryngectomy with cricohyoidoepiglottopexy

Objective To determine the utility of high-speed digital imaging (HSDI) in evaluating vocal kinetics of the neoglottis after supracricoid laryngectomy with cricohyoidoepiglottopexy (SCL-CHEP). Study Design Case series. Setting The University of Tokyo Hospital. Subjects and Methods High-speed digital recordings of laryngeal images were obtained from six patients after SCL-CHEP to clarify the vocal kinetics of the postoperative neoglottis. Simultaneous recording of electroglottograms (EGGs) were obtained and multiline kymograms were generated on the basis of the recorded images. The distribution of frequency, amplitude, and phase in the neoglottis were visualized by using gradients of colors superimposed onto the glottal and supraglottal areas of laryngeal images to produce laryngeal topograms. Furthermore, waveforms of estimated laryngeal sound source (ELSS) were obtained on the basis of glottal inverse filtering of the vocal signal to reflect vibratory motions in the neoglottis. The vibratory part of the neoglottis was determined as a possible sound source when the frequencies of the ELSS, EGG, and laryngeal topograms, as well as the waveforms of ELSS, EGG, and kymograms, were consistent with each other. Results Spaces between the arytenoid(s) and epiglottis (5 patients) or pyriform sinus mucosa (1 patient) were estimated as the major source of sound during postoperative vocalization. The possible sound source could be determined by HSDI, even in the neoglottis, with more than one vibratory position. Conclusion HSDI could be useful for evaluating the vocal kinetics of the neoglottis after SCL-CHEP.

Modifications of Vestibular Fold Shape From Respiration to Phonation in Unilateral Vocal Fold Paralysis

The diversity of vestibular fold (VeF) behavior during phonation, as well as the lack of insight regarding both the anatomy and muscle fiber composition hinder our understanding of their role during phonation. The concave shape of the free margin of VeF appears to be standard, but little is known regarding the variability of this shape. We, therefore, sought to determine the laryngoscopic features related to changes in the free margin of the VeFs during phonation in patients with unilateral vocal fold paralysis. Laryngeal images from 39 patients with unilateral paralysis associated with recurrent laryngeal nerve damage were evaluated with regard to variations in length and shape of the VeFs (concave, straight, or convex) during both respiration and phonation. The VeFs on both the paralyzed and unaffected sides were analyzed during both phonation and respiration resulting in 156 total images. During phonation, all VeFs on the nonparalyzed side were straight or convex, whereas on the paralyzed side, only 20 of the 39 were straight or convex during phonation. During respiration, significant differences in the shape of the nonparalyzed side were observed. During phonation, a nonconcave appearance on the paralyzed side usually correlated with a similar appearance during respiration. VeF length decreased during phonation in 30 nonparalyzed VeFs in contrast to only 13 paralyzed folds. When subjects switched from respiration to phonation, the VeFs were typically nonconcave on the nonparalyzed side. In contrast, on the paralyzed side, nonconcave VeFs were consistent across both tasks. In patients with unilateral vocal fold paralysis, VeF conformation is likely determined from extralaryngeal than intrinsic muscle. These findings have important theoretical considerations for laryngeal treatment.

Exercise-induced laryngeal obstructions objectively assessed using EILOMEA

We describe a diagnostic software measuring tool (EILOMEA) to objectively describe images obtained by the continuous laryngoscopic exercise (CLE) test, and assess the reproducibility and clinical applications of this tool for the diagnosis of exercise-induced laryngomalacia (EIL) and exercise-induced vocal cord dysfunction (EI-VCD). A total of 97 subjects, 14-24 years of age, were tested with a CLE test. For each laryngoscopic recording, the severity of EIL and/or EI-VCD was assessed by an expert and compared with data obtained using EILOMEA. For both EIL and EI-VCD, a separate objective factor was found describing the degree of laryngeal obstruction by measuring cross-sectional areas of the inspiratory laryngeal images. A threshold value was set giving the diagnosis of EI-VCD, with a sensitivity of 0.65, a specificity of 0.96, a positive-predictive value of 0.79, and a negative-predictive value of 0.93. The threshold set for diagnosing EIL gave sensitivity, specificity, positive and negative-predictive value of 1.00. EIL and EI-VCD show different objective findings confirming that they are two separate conditions both causing laryngeal obstruction. The use of the CLE test is mandatory, because this is the only way to differ between the two conditions and EILOMEA gives the diagnosis and the degree of obstruction objectively.

A feature selection technique for generation of classification committees and its application to categorization of laryngeal images

This paper is concerned with a two phase procedure to select salient features (variables) for classification committees. Both filter and wrapper approaches to feature selection are combined in this work. In the first phase, definitely redundant features are eliminated based on the paired t-test. The test compares the saliency of the candidate and the noise features. In the second phase, the genetic search is employed. The search integrates the steps of training, aggregation of committee members, selection of hyper-parameters, and selection of salient features into the same learning process. A small number of genetic iterations needed to find a solution is the characteristic feature of the genetic search procedure developed. The experimental tests performed on five real-world problems have shown that significant improvements in classification accuracy can be obtained in a small number of iterations if compared to the case of using all the features available.

Comparison of Pediatric Voice Outcome Survey, Reflux Symptom Index, Reflux Finding Score, and Esophageal Biopsy Results

To examine correlations between the Pediatric Voice Outcome Survey (PVOS) score, the Reflux Symptom Index (RSI) score, the Reflux Finding Score (RFS), and esophageal biopsy findings in children undergoing upper aerodigestive tract endoscopy. Retrospective review of pediatric voice quality-of-life and laryngopharyngeal reflux surveys. Blinded assessment of endoscopic laryngeal images. Tertiary care children's hospital. The study included 36 children with the primary problem of dysphonia (n = 28) or cough (n = 8) who underwent endoscopy. The PVOS and the RSI were administered to the patient's parents before surgery. The patients underwent laryngotracheobronchoscopy and esophageal biopsy. Four raters independently assigned an RFS to the laryngeal photographs. The assessment included (1) PVOS scores, RSI scores, and RFSs; (2) internal consistency of PVOS and RSI scores; (3) RFS intrarater and interrater reliability; and (4) correlations between PVOS score, RSI score, RFS, and esophageal biopsy findings. The mean (SD) age of the patients was 7.5 (2.6) years; the mean (SD) PVOS score, 71.9 (21.4); and the mean (SD) RSI score, 16.2 (9.1). The PVOS and the RSI scores demonstrated good internal consistency (Cronbach alpha = 0.79 and 0.78, respectively). The RFS exhibited good intrarater reliability (r = 0.66-0.98) and moderate interrater reliability (r = 0.32-0.70). The PVOS and RSI instruments displayed significant correlation (r = -0.30; P = .04). There were no other significant correlations between RFSs, esophageal biopsy results, PVOS scores, or RSI scores (P > .05). The RSI may be a useful parent-proxy instrument in addition to the PVOS for pediatric voice patients. The RFS is reliable in children, but its validity could not be demonstrated in this patient population.

S192 – 3D Diagnosis of Vocalizing Larynx Using Cone Beam CT

Objectives Cone beam computed tomography (CBCT) was developed for the office-based quick and precise 3D visualization of maxillofacial region. CBCT requires scanning time of less than 10 seconds and provides isotropic 3D image with high resolution. In this study, we examined the potential role of CBCT as a tool for 3-dimensional evaluation of the glottal insufficiency. Methods CBCT was performed in 2 normal controls and in 14 patients with unilateral vocal fold paralysis (13 cases) or paresis (1 case). Laryngeal CBCT images were taken in the resting state and during phonation. Furthermore, preoperative and postoperative images were evaluated to assess the impact of phonosurgeries in 5 cases. Results CBCT of the vocalizing vocal fold was successfully performed in all the cases, producing clear coronal images. During phonation, no remarkable differences in levels between the paralyzed and normal vocal folds were observed in 10 cases, proving the 2-dimensional glottal gap (2D cases). On the other hand, the levels of paralyzed vocal folds stayed higher during phonation compared to the normal side in 4 cases, proving the 3-dimensional glottal gap (3D cases). 4 of the 2D cases had injection laryngoplasty and 1 of the 3D cases had arytenoid adduction procedure to correct their glottal gaps. Postoperative CBCT images verified the successful correction of these gaps. Conclusions Our study proved the feasibility of CBCT for 3D evaluation of vocalizing larynx. This quick and easy system may have an informative role to suggest the proper phonosurgical procedure for glottic insufficiency.

Segmentation of the glottal space from laryngeal images using the watershed transform

The present work describes a new method for the automatic detection of the glottal space from laryngeal images obtained either with high speed or with conventional video cameras attached to a laryngoscope. The detection is based on the combination of several relevant techniques in the field of digital image processing. The image is segmented with a watershed transform followed by a region merging, while the final decision is taken using a simple linear predictor. This scheme has successfully segmented the glottal space in all the test images used. The method presented can be considered a generalist approach for the segmentation of the glottal space because, in contrast with other methods found in literature, this approach does not need either initialization or finding strict environmental conditions extracted from the images to be processed. Therefore, the main advantage is that the user does not have to outline the region of interest with a mouse click. In any case, some a priori knowledge about the glottal space is needed, but this a priori knowledge can be considered weak compared to the environmental conditions fixed in former works.

Calibration of laryngeal endoscopic high-speed image sequences by an automated detection of parallel laser line projections

High-speed laryngeal endoscopic systems record vocal fold vibrations during phonation in real-time. For a quantitative analysis of vocal fold dynamics a metrical scale is required to get absolute laryngeal dimensions of the recorded image sequence. For the clinical use there is no automated and stable calibration procedure up to now. A calibration method is presented that consists of a laser projection device and the corresponding image processing for the automated detection of the laser calibration marks. The laser projection device is clipped to the endoscope and projects two parallel laser lines with a known distance to each other as calibration information onto the vocal folds. Image processing methods automatically identify the pixels belonging to the projected laser lines in the image data. The line detection bases on a Radon transform approach and is a two-stage process, which successively uses temporal and spatial characteristics of the projected laser lines in the high-speed image sequence. The robustness and the applicability are demonstrated with clinical endoscopic image sequences. The combination of the laser projection device and the image processing enables the calibration of laryngeal endoscopic images within the vocal fold plane and thus provides quantitative metrical data of vocal fold dynamics.

A kernel-based approach to categorizing laryngeal images

This paper is concerned with an approach to automated analysis of vocal fold images aiming to categorize laryngeal diseases. Colour, texture, and geometrical features are used to extract relevant information. A committee of support vector machines is then employed for performing the categorization of vocal fold images into healthy, diffuse, and nodular classes. The discrimination power of both, the original and the space obtained based on the kernel principal component analysis is investigated. A correct classification rate of over 92% was obtained when testing the system on 785 vocal fold images. Bearing in mind the high similarity of the decision classes, the correct classification rate obtained is rather encouraging.

A full digital, high definition video system (1080i) for laryngoscopy and stroboscopy

This study aimed to estimate the effectiveness of a full digital, high definition video system for laryngeal observations. A newly available, full digital, high definition video camera and high definition video monitor were used. With an endoscopic adaptor and rigid telescope, laryngoscopy and stroboscopy were performed on patients with various kinds of laryngeal lesions. All laryngeal lesions were observed and recorded by the full digital, high definition video camera without incident. The image quality for laryngoscopy and stroboscopy was far superior to that of a conventional video system, including video-endoscopy. Even tiny structures or lesions could clearly be visualised on the monitor. The still image obtained from the full digital, high definition video camera was 1920 x 1080 pixels and was comparable to that obtained from a still camera. Full digital, high definition video cameras are now commonplace products and can easily be applied to patients with laryngeal disorders. They provide superior laryngeal images, compared with conventional video systems. Furthermore, high definition video systems are cheaper than proprietary medical video systems. We consider our system to represent an accessible technique of gaining superior laryngeal observation in otolaryngological clinics.

Surgical treatment of exercise-induced laryngeal dysfunction

A method for combined ergo-spirometry and continuous laryngeal inspection during exercise, entitled continuous laryngoscopy exercise test (CLE-test) has been developed in order to study airway obstruction at the laryngeal level during exercise. The aim of the study was to apply the CLE-test on patients experiencing respiratory distress during exercise in order to reveal the usefulness of the CLE-test both as a diagnostic tool in the selection of patients for surgery and in evaluation of treatment effects postoperatively. Until now, 81 patients with a history of exercise-induced stridor have undergone the CLE-test. Ten of these patients were selected for surgical treatment based on the severity of symptoms and their motivation for treatment. All ten patients underwent endoscopic supraglottoplasty (ES), with laser incision in both aryepiglottic folds anterior to the cuneiform cartilages and removal of the mucosa around the top of the tubercles. Each patient was examined by the CLE-test before and 3 months after surgery. Eight patients felt subjectively that their breathing capacity during exercise was improved. When pre- and postoperative ergo-spirometry evaluations were compared, increased peak oxygen consumption was observed in four out of ten patients and better maximal minute ventilation in seven out of ten. Postoperative evaluation of the laryngeal images showed less prominent aryepiglottic folds. The typical adduction of the supraglottic structures concomitant with inspiratory stridor found preoperatively was not present in any of the patients during exercise postoperatively. The ES procedure is an efficient surgical treatment for exercise-induced laryngeal supraglottic obstruction and the CLE-test eases the selection of patients for surgery and facilitates the evaluation of treatment effects.

Multiple feature sets based categorization of laryngeal images

This paper is concerned with an automated analysis of laryngeal images aiming to categorize the images into three decision classes, namely healthy, nodular, and diffuse. The problem is treated as an image analysis and classification task. Aiming to obtain a comprehensive description of laryngeal images, multiple feature sets exploiting information on image colour, texture, geometry, image intensity gradient direction, and frequency content are extracted. A separate support vector machine (SVM) is used to categorize features of each type into the decision classes. The final image categorization is then obtained based on the decisions provided by a committee of support vector machines. Bearing in mind a high similarity of the decision classes, the correct classification rate of over 94% obtained when testing the system on 785 laryngeal images recorded at the Department of Otolaryngology, Kaunas University of Medicine is rather promising.

INTEGRATING GLOBAL AND LOCAL ANALYSIS OF COLOR, TEXTURE AND GEOMETRICAL INFORMATION FOR CATEGORIZING LARYNGEAL IMAGES

An approach to integrating the global and local kernel-based automated analysis of vocal fold images aiming to categorize laryngeal diseases is presented in this paper. The problem is treated as an image analysis and recognition task. A committee of support vector machines is employed for performing the categorization of vocal fold images into healthy, diffuse and nodular classes. Analysis of image color distribution, Gabor filtering, cooccurrence matrices, analysis of color edges, image segmentation into homogeneous regions from the image color, texture and geometry view point, analysis of the soft membership of the regions in the decision classes, the kernel principal components based feature extraction are the techniques employed for the global and local analysis of laryngeal images. Bearing in mind the high similarity of the decision classes, the correct classification rate of over 94% obtained when testing the system on 785 vocal fold images is rather encouraging.

Morphological and Functional Aspects of the Senile Larynx

Objective: To analyze the senile larynx, considering morphological aspects during respiration and functional aspects during phonation, comparing it to the young adult larynx. Patients and Methods: A retrospective study was conducted of 100 laryngeal images of adults without vocal complaints, 50 laryngeal images of young adults aged 20–45 years and 50 laryngeal images of elderly individuals aged 65–85 years, of both genders. Images were produced by means of a rigid endoscope and stroboscopy. The morphological aspects analyzed were: laryngeal symmetry, vocal fold bowing, prominence of the vocal process and glottic proportion. The functional aspects analyzed were glottic closure, laryngeal vestibule behavior, phase (timing of closure) and amplitude symmetry of mucosal wave and tremor of laryngeal structures. Results: Significant differences between the young adult larynx and the geriatric larynx were found for the following parameters: vocal fold bowing, prominence of the vocal process, glottic proportion, phase and amplitude symmetry of mucosal wave and tremor of laryngeal structures. Conclusion: The data suggests that the geriatric larynx differs from the young adult larynx in many characteristic aspects.

Blinded Evaluation of the Effects of High Definition and Magnification on Perceived Image Quality in Laryngeal Imaging

Advances in commercial video technology have improved office-based laryngeal imaging. This study investigates the perceived image quality of a true high-definition (HD) video camera and the effect of magnification on laryngeal videostroboscopy. We performed a prospective, dual-armed, single-blinded analysis of a standard laryngeal videostroboscopic examination comparing 3 separate add-on camera systems: a 1-chip charge-coupled device (CCD) camera, a 3-chip CCD camera, and a true 720p (progressive scan) HD camera. Displayed images were controlled for magnification and image size (20-inch [50-cm] display, red-green-blue, and S-video cable for 1-chip and 3-chip cameras; digital visual interface cable and HD monitor for HD camera). Ten blinded observers were then asked to rate the following 5 items on a 0-to-100 visual analog scale: resolution, color, ability to see vocal fold vibration, sense of depth perception, and clarity of blood vessels. Eight unblinded observers were then asked to rate the difference in perceived resolution and clarity of laryngeal examination images when displayed on a 10-inch (25-cm) monitor versus a 42-inch (105-cm) monitor. A visual analog scale was used. These monitors were controlled for actual resolution capacity. For each item evaluated, randomized block design analysis demonstrated that the 3-chip camera scored significantly better than the 1-chip camera (p < .05). For the categories of color and blood vessel discrimination, the 3-chip camera scored significantly better than the HD camera (p < .05). For magnification alone, observers rated the 42-inch monitor statistically better than the 10-inch monitor. The expense of new medical technology must be judged against its added value. This study suggests that HD laryngeal imaging may not add significant value over currently available video systems, in perceived image quality, when a small monitor is used. Although differences in clarity between standard and HD cameras may not be readily apparent on small displays, a large display size coupled with HD technology may impart improved diagnosis of subtle vocal fold lesions and vibratory anomalies.

Vestibular folds configuration in vocal nodule

Vocal nodules are among the most common laryngopathies that cause vocal functional disorders. The voice production mechanism is complex and demand interaction of different systems of the human body. The physiological role of the vocal folds as the glottic sound source is evident, however, there is no consensus regarding the vestibular folds' participation/influence in phonation. To verify if there is difference in the bidimensional configuration of the vestibular folds between two distinct groups of women, one with the diagnosis of vocal nodules and the other without vocal complaints and vocal fold lesions. Clinical with transversal cohort. Ninety-six laryngeal images were evaluated, 48 from individuals without vocal complaints and 48 from patients with the diagnosis of vocal nodules. Angles were obtained and bilaterally measured in single frames of the vestibular folds during sustained phonation and those structures were morphologically classified as concave, linear or convex. Among the 96 vestibular folds evaluated in each group, there was predominance of the concave form, followed by the linear and the convex ones. In the control group, there was a single convex vestibular fold, 27 were linear and 68 were concave folds. In the group of vocal nodules, 8 were convex, 15 were linear and 73 were concave folds. However, the differences among groups were not statistically significant as well as those among the angles, whose average measures were proven quite similar. In the female gender, the vestibular folds presented similar behavior regarding the morphology in both patients with vocal nodules and women without vocal complaints.