Advances in laryngeal imaging

Imaging and image analysis became an important issue in laryngeal diagnostics. Various techniques, such as videostroboscopy, videokymography, digital kymograpgy, or ultrasonography are available and are used in research and clinical practice. This paper reviews recent advances in imaging for laryngeal diagnostics.     

Multidimensional voice analysis of reflux laryngitis patients

The aim of the study was to analyze and quantify the voice characteristics of reflux laryngitis (RL) patients and to determine the most important voice tests and voice-quality parameters in the functional diagnostics of RL. The voices of 83 RL patients and 31 persons in the control group were evaluated. Vocal function was assessed using a multidimensional set of video laryngostroboscopic, perceptual, acoustic, aerodynamic and subjective measurements according to the protocol elaborated by the Committee on Phoniatrics of the European Laryngological Society. The mean values of the hoarseness visual analogue scale assessment and voice handicap index were significantly higher (P<0.05) in the group of RL patients as compared to the controls. Objective voice assessment revealed a significant increase in mean values of jitter, shimmer and normalized noise energy (NNE), along with a significant decrease in pitch range, maximum frequency, phonetogram area (S) and maximum phonation time (MPT) in RL patients, both in the male and female subgroups. According to the results of discriminant analysis, the NNE, MPT, S and intensity range were determined as an optimum set for functional diagnostics of RL. The derived function (equation) makes it possible to assign the person to the group of RL patients with an accuracy of 86.7%. The sensitivity and specificity of eight voice parameters were found to be higher than 50%. The results of the present study demonstrate a reduction of phonation capabilities and voice quality in RL patients. Multidimensional voice evaluation makes it possible to detect significant differences in mean values of perceptual, subjective and objective voice quality parameters between RL patients and controls groups. Therefore, multidimensional voice analysis is an important tool in the functional diagnostics of RL.This study was presented at the 4th Congress of the European Laryngological Society, Brussels, 5–7 September 2002.     

Multidimensional assessment of functional outcomes of medialization thyroplasty

Medialization thyroplasty (MT) is the most widely used laryngeal framework phonosurgical procedure for managing glottic incompetence secondary to unilateral vocal fold paralysis (UVFP). The aim of the study was to evaluate the functional outcomes of MT in 32 UVFP patients, comparing multidimensional perceptual and instrumental measures of voice before and after surgery, and to evaluate how close to normal that postoperative voice measure became. Video laryngostroboscopy (VLS), auditory perceptive evaluation of voice, the patients self-evaluation of hoarseness on the Visual Analogue Scale (VAS) and calculation of the Voice Handicap Index (VHI), analysis of objective acoustic voice parameters, quantitative assessment of phonetograms and measurement of maximum phonation time were conducted. Vocal function was evaluated before the surgery and for the period from 1 month to 3 years (Mo 1.0 month; Me 2.0 months) after MT. VLS confirmed remarkable medialization of the paralyzed vocal fold. As a consequence, hoarseness and breathiness were found to be significantly decreased after MT. Pitch and intensity range and phonetogram area were significantly increased. A significant decrease of jitter, shimmer and normalized noise energy reflected improvement of the stability of acoustic signal and a more efficient pattern of phonation. Thus, the perceptual and acoustic voice parameters studied showed statistically significant differences (P<0.001) between preoperative and postoperative voices, and these objective measurements of voice changes provided accurate and documentary evidence of the results of surgical treatment. A high degree of patient satisfaction with the MT was confirmed by a significant decrease of VHI and hoarseness on VAS. Thus, results of the present investigation confirm the functionality and effectiveness of MT in patient voice rehabilitation with UVFP. However, the means of acoustic voice parameters measured in the study did not reach normal limits, probably because of the remaining underlying condition of UVFP.This study was presented at the 4th Congress of the European Laryngological Society, Brussels, 5–7 September 2002.     

Characteristics of Expression of Matrix Metalloproteinases (MMP-2 and MMP-9) in Glottic Squamous Cell Carcinoma and Benign Vocal Fold Lesions

ObjectivesThe aim of this study was to investigate expression profile of matrix metalloproteinases (MMP-2 and MMP-9) in glottic squamous cell carcinoma (SCC) and benign vocal fold lesions (BVFLs) and to correlate it with clinical and pathological features.MethodsThe immunohistochemical expression of MMP-2 and MMP-9 was investigated in specimens taken from 217 patients group, including vocal fold polyps (n=39), recurrent respiratory papillomatosis (n=30), laryngeal keratosis (n=36), glottic SCC (n=112), and the normal tissue of vocal fold (n=12, control group). The expression of MMP-2 and MMP-9, both in epithelium and stroma cells, was graded on a semiquantitative scale, ranging from 0 (no expression) to 18 points (high expression).ResultsExpressions of both, MMP-2 and MMP-9 were significantly higher in the glottic SCC group comparing with BVFL group. Significant higher expression of parenchymal MMP-2 (P<0.001) and stromal MMP-9 (P=0.01) was revealed in the group of moderate/poorly differentiated glottic SCC comparing with well differentiated glottic SCC group. Expression of stroma MMP-2 was found to be correlated with nodal metastasis (P=0.030). Expressions of both, MMP-2 and MMP-9 were not correlated with clinical stage, tumor T value, smoking, alcohol use, age in the glottic SSC patients group. The MMP-2 stroma value of 11.2 points was determined as the optimum point (limiting value) for separating BVFL and glottic SCC patient groups.ConclusionOur results suggest that expressions of both MMP-2 and MMP-9 are up-regulated already in the development of BVFL, the next determinant step is concerned with occurrence of malignization. Limiting value of stroma MMP-2 demonstrates prognostic importance of MMP-2 in glottic SCC carcinogenesis.     

Laryngeal examination is superior to endoscopy in the diagnosis of the laryngopharyngeal form of gastroesophageal reflux disease

Objective. The laryngopharyngeal form of gastroesophageal reflux disease (LF GERD) is a frequent manifestation of supraesophageal GERD. Diagnosis of LF GERD is difficult: most of the common diagnostic methods of GERD have insufficient accuracy in establishing LF GERD. The purpose of this study was to evaluate the role of endoscopic and laryngologic examination in the diagnosis of LF GERD and to create a laryngoscopic reflux index (LRI). Material and methods. A total of 108 LF GERD patients and 90 controls were investigated. The criteria for LF GERD were: complaints, reflux-laryngitis, and esophagitis (endoscopically or histologically proven). Lesions in four laryngeal regions were evaluated: arytenoids (A), intraarytenoid notch (IAN), vestibular folds (VF), and vocal cords (VC). Three types of mucosal lesions were evaluated on a points basis: alterations of the epithelium, erythema, and edema. Total LRI was calculated by summing-up the indices in the separate laryngeal areas. Results. The LRI mean value (11.48±3.78 points) of LF GERD patients was statistically significantly greater than that (1.64±1.93 points) of the controls. The most significant laryngoscopic changes of LF GERD were: mucosal lesions of IAN, mucosal lesions of VC, and edema of VC. A combination of these three findings reliably distinguishes the LF GERD patients from controls in 95.9% of cases. The mucosal lesions of IAN have the greatest importance in diagnosing LF GERD: the odds ratio to LF GERD – 21.32, p<0.001. Endoscopic esophagitis was established in 36 (33.3%) cases. The severity of esophagitis did not correlate with the severity of the laryngeal findings. Conclusions. Laryngoscopy is superior to endoscopy in diagnosing LF GERD. Endoscopy has limited value in the diagnosis of LF GERD. Establishing the LRI could be helpful in the differential diagnosis of the disease in the everyday clinical practice.     

Towards a computer-aided diagnosis system for vocal cord diseases

OBJECTIVE: The objective of this work is to investigate a possibility of creating a computer-aided decision support system for an automated analysis of vocal cord images aiming to categorize diseases of vocal cords. METHODOLOGY: The problem is treated as a pattern recognition task. To obtain a concise and informative representation of a vocal cord image, colour, texture, and geometrical features are used. The representation is further analyzed by a pattern classifier categorizing the image into healthy, diffuse, and nodular classes. RESULTS: The approach developed was tested on 785 vocal cord images collected at the Department of Otolaryngology, Kaunas University of Medicine, Lithuania. A correct classification rate of over 87% was obtained when categorizing a set of unseen images into the aforementioned three classes. CONCLUSION: Bearing in mind the high similarity of the decision classes, the results obtained are rather encouraging and the developed tools could be very helpful for assuring objective analysis of the images of laryngeal diseases.