|ORIGINAL CONTRIBUTION - CLINICS IN OTORHINOLARYNGOLOGY
|Year : 2017 | Volume
| Issue : 3 | Page : 159-163
Clinical Significance of High Resolution Ultrasonography vis-à -vis Laryngoscopy in Laryngeal Pathologies
Anil K Rai1, Sandeep Trehan1, MK Mittal2, Gul Motwani1
1 Department of Otorhinolaryngology, Safdarjung Hospital and Vardhman Mahavir Medical College, New Delhi, India
2 Department of Radiodiagnosis, Safdarjung Hospital and Vardhman Mahavir Medical College, New Delhi, India
|Date of Web Publication||30-Jan-2018|
Anil K Rai
Department of Otorhinolaryngology, Safdarjung Hospital and Vardhman Mahavir Medical College, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
Introduction: Larynx is a seat of a host of benign and malignant conditions. Conventionally, otolaryngologists have relied upon laryngoscopy in making a diagnosis. However, this simple doctor's office tool suffers from several limitations and flaws. In such a clinical landscape, a completely nonintrusive high-resolution ultrasonography examination can play a significant complementary role by defining the precise extent of the pathologic process. This prospective cross-sectional study, possibly the first of its kind in India, endeavours to define this synergetic relationship. Patients and Methods: A total of 60 patients with diverse undiagnosed laryngeal pathologies were taken up for the study. Those with proven laryngeal carcinoma and (or) past laryngeal surgery were excluded. Results: HRUS was found to be valuable in detecting laryngeal growth (78.57%), vocal cord polyp (66.67%), vocal cord nodule (10%), vocal cord palsy/paresis (66.67%), chronic laryngitis (17.64%), and Reinke's edema (50%). Conclusion: Compared to laryngoscopy, the role of HRUS is limited except in laryngeal lesions such as laryngeal growth and vocal cord polyp. HRUS can augment rather than replace conventional laryngoscopy in the diagnosis of laryngeal lesions.
Keywords: Laryngoscopy, high-resolution ultrasound, laryngeal lesions
|How to cite this article:|
Rai AK, Trehan S, Mittal M K, Motwani G. Clinical Significance of High Resolution Ultrasonography vis-à -vis Laryngoscopy in Laryngeal Pathologies. Astrocyte 2017;4:159-63
|How to cite this URL:|
Rai AK, Trehan S, Mittal M K, Motwani G. Clinical Significance of High Resolution Ultrasonography vis-à -vis Laryngoscopy in Laryngeal Pathologies. Astrocyte [serial online] 2017 [cited 2020 Jun 3];4:159-63. Available from: http://www.astrocyte.in/text.asp?2017/4/3/159/224201
| Introduction|| |
Till date few investigations have been carried out to evaluate various laryngeal pathologies including neoplastic involvement with ultrasound, as it was considered unsuitable for examination of air-containing structures., Modern, real-time equipment is capable of high-resolution soft tissue discrimination. During the last several years high-frequency ultrasound (HRUS) has become a new diagnostic tool with small, high-resolution ultrasound transducers. HRUS is a bedside, noninvasive, real-time, and radiation-free imaging technique. Its use is increasing and it is becoming a preferred modality, especially in patients in whom laryngoscopy has limitations. It is generally considered a “safe” imaging modality for diagnosis during pregnancy. This examination is not affected by patient movement and provides opportunity to study vocal cord mobility. It not only provides essential information about deeper structures of the neck but also helps to clinically delineate unsuspicious linear lesions.
Laryngoscopy whether indirect, direct, or fibre-optic has main role in the evaluation of the laryngeal lesions, especially glottic and supraglottic lesions. However, as mentioned above laryngoscopy alone has limitations (a) it may be insufficient to judge the extent of infiltrative processes, the exact infiltration of a tumor, and invasion of the laryngeal skeleton; (b) all patients do not tolerate rigid endoscopy, especially patients with a sensitive gag reflex, patients with neck or jaw disease, and patients suffering from stridor; and (c) it is a difficult procedure to perform in infants and children.,,,
Therefore, HRUS, computed tomography (CT), and magnetic resonance imaging (MRI) are often used to supplement laryngoscopy as additional imaging methods. CT is considered to be superior because it provides a complete detailed three-dimensional image of the organ. However, it is expensive, requires exposure to high-dose radiation, and is best avoided in pregnant women and children.
There is paucity of Indian literature comparing the two most common diagnostic modalities –laryngoscopy and HRUS. The aims of this study were to compare the role of laryngoscopy with high-resolution ultrasonography in various laryngeal lesions and to see whether HRUS can be used as an complementary diagnostic modality to laryngoscopy in the diagnosis of various laryngeal lesions and in defining the extent of various laryngeal lesions.
| Patients and Methods|| |
This cross-sectional study was carried out in the Department of Otorhinolaryngology in collaboration with Department of Radiodiagnosis, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi. The study included 60 patients who presented with complaints of laryngeal symptoms. Those with proven laryngeal carcinoma, postradiotherapy, and (or) history of laryngeal surgery were excluded from the study. A written bilingual informed consent was procured from the patients before enrolling them for the study. Clinical examinations were carried out before each imaging session in addition to regular patient visits. Physical examination included a complete head and neck examination. Evaluation of the larynx was done using one or both of the following: (a) indirect laryngoscopy and (or) (b) direct rigid endoscopy [using Hopkins rod rigid laryngoscope 70-degree (Carl Storz) with photo documentation] with an angled tip. HRUS was performed in all patients within 10 days of laryngoscopy. HRUS was performed using Philips IU 22 unit with linear probe of frequency 5–17 MHz. Laryngeal HRUS was carried out in 2 phases: (i) quiet breathing and (ii) during phonation by instructing the patient to say (long E). The findings of both laryngoscopy and HRUS were compared and analyzed.
| Results|| |
Out of the 60 patients included in this study, 37 were males (61.67%) and 23 females (38.33%). The mean age of the patients included in the study was 39.3 years. Majority of the patients were in the age group of 31–40 years (43.3%) and the least were in the age group greater than 60 years (5%). Patients presented with various symptoms such as hoarseness of voice 51 patients (85%), foreign body sensation 27 patients (45%), chronic cough 26 patients (43.3%), and difficulty in swallowing 17 patients (28.3%).
Laryngoscopy performed in 60 patients revealed that 17 patients had chronic laryngitis, 14 patients had laryngeal growth, 10 had vocal nodules, 9 patients had vocal cord polyp, 4 had Reinke's edema, and 6 patients had vocal cord palsy. HRUS was performed in all these patients. [Table 1] shows the distribution of these laryngeal lesions detected on laryngoscopy and HRUS in the study group.
|Table 1: Comparison between laryngoscopy and HRUS in the diagnosis of laryngeal lesions|
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Out of the 17 patients with chronic laryngitis, only 3 patients (17.64%) were detected on HRUS. All 3 patients diagnosed on HRUS had mucosal edema. Those without obvious edema could not be detected on HRUS.
Of the 14 (23.3%) patients with laryngeal growth, 6 had supraglottic growth, 2 had glottic growth, 2 had pyriform sinus bulge, and 4 had transglottic growth. HRUS correctly identified the growth in 11 patients [Figure 1]. The cases missed by HRUS included both cases of glottis carcinoma and 1 case of pyriform sinus bulge. Thyroid cartilage involvement was detected on HRUS in 6 (42.86%) out of 14 patients. Thyroid cartilage involvement was seen in 3 (37.5%) out of 6 supraglottic growth cases and in 3 (75%) out of 4 transglottic growth patients. Two of these 6 patients showed destruction (complete erosion), whereas 4 showed infiltration of cortex of the thyroid cartilage by the growth. None of the patients showed erosion of the anterior ring of the cricoid cartilage. Pre-epiglottic space involvement on HRUS was seen in 6 (42.86%) of the 14 patients. Laryngoscopy could neither detect thyroid cartilage involvement nor the involvement of the pre-epiglottic space. Thyroid cartilage calcification was seen in 5 patients. In 3 patients, thyroid calcification hindered the detection of lesions by HRUS, thus limiting its use in diagnosing laryngeal growth lesions.
|Figure 1: (a) Ultrasound of the larynx in a patient of laryngeal growth showing a large heteroechoic mass lesion involving right vocal cord, encroaching the left vocal cord with near partial occlusion of the glottic lumen. (b) Laryngoscopic image of growth involving right aryepiglottic fold, right vocal cord and right pyriform fossa.|
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The vocal cord nodules were detected in 10 patients on laryngoscopic examination size. However, it was detected in only 1 patient (10%) on HRUS. Only nodule which was which was greater than 2 mm in diameter was detected. It is likely that nodules smaller than 2 mm are missed on HRUS.
Nine patients were diagnosed to have vocal cord polyp on laryngoscopy. Six (66.67%) out of the 9 patients were detected on laryngeal HRUS. Vocal cord polyps were either sessile 7 patients (77.7%) or pedunculated 2 patients (22.3%). All lesions missed on HRUS were sessile in nature with wide base [Figure 2].
|Figure 2: (a) Ultrasonography of the larynx showing a well-defined, small, pedunculated hypoechoic lesion (white arrow) present at the junction of the anterior one-third and posterior two-third of the left vocal cord. (b) Laryngoscopic image of the polyp at the junction of the anterior one-third and posterior two-third of the left vocal cord.|
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The vocal cord palsy was seen in 4 patients and vocal cord paresis in 2 patients on endoscopic laryngoscopy. Four (66.67%) out of these 6 patients were diagnosed on HRUS. In 1 out of the 2 patients not diagnosed on HRUS, there was absence of opposition of bilateral vocal cords with flickering movement of bilateral vocal cord in one patient [Figure 3].
|Figure 3: Ultrasound of the larynx in a patient complaining of hoarseness showing both the vocal cords in the normal abducted position (a). On dynamic real-time evaluation, the right vocal cord (white arrows) shows normal movement. However, there is restricted mobility of the left vocal cord (red arrows). Imaging features suggested a diagnosis of left vocal cord paresis (b).|
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In this study, 4 patients (6.67%) were diagnosed with Reinke's edema on endoscopic laryngoscopy. Of these only 2 (50%) were diagnosed correctly on HRUS in the form of vocal cord thickening and fluid filled areas. While one could not be assessed due to thyroid cartilage calcification and the other showed normal vocal cord morphology on HRUS.
| Discussion|| |
The significance of lesions of the larynx lies in the contribution of the voice to one's individuality and the importance of its function in speaking. These can present with hoarseness, foreign body sensation in throat, chronic cough, dysphagia, odynophagia, or life-threatening symptom as stridor. Laryngeal lesions constitute an interesting array of diseases including benign lesions (nodules, cysts, polyps, granulomas, papilloma, laryngocele, epiglottis enlargement, Reinke's edema, laryngeal tumor) and malignant carcinomas of supraglottis, glottis, and subglottic region.
The prevalence of laryngeal lesions is rising. This has been attributed to improved understanding of the anatomy and better diagnostic modalities. The techniques for performing this examination have evolved over time and presently, the airway specialist has a number of choices that can be tailored to a specific situation. Rigid endoscopy of the larynx, which is considered as the gold standard with its advantage of larger, brighter, and clear image, has been used widely in otolaryngology outpatient clinics for endolaryngeal evaluation. Unfortunately, all patients cannot tolerate endoscopic laryngeal examinations due to various reasons. Sometimes direct laryngoscopy has to be performed under general anesthesia.
Several diagnostic modalities are currently under evaluation for their role in various laryngeal lesions. One of the promising diagnostic modality is the HRUS of the larynx. Ultrasonography has become a very important diagnostic tool for the diagnosis of various head and neck diseases. It is considered a safe imaging modality, without exposing patients to the unnecessary harmful effects of ionizing radiation of CT, and thus, considered safe even in children and pregnant females. However, the role of ultrasonography in the diagnosis/detection of laryngeal lesion has not been studied much. This study dwelt upon identifying the role of HRUS in diagnosing and defining the extent of laryngeal lesions vis-à -vis laryngoscopy.
A total of 60 patients presenting with laryngeal symptoms, excepting those with moderate to severe airway obstruction were taken up for evaluation. Of the 60, 37 (61.67%) were males and 23 (38.33%) were females. The age group in laryngeal growth (53.43 ± 9.14 years) was much more than with other laryngeal lesions (mean of 39.3 ± 10.66 years). Percentage of patients presenting with various symptoms was similar to previous studies. In the study carried out by Nasr et al., hoarseness of voice was present in 100% of the patients, chronic cough in 27.8%, difficulty in swallowing in 22.2%, choking attack in 18.5%, and stridor in 16.7%. In the study carried out by El-Sherif and El-Sherif, hoarseness of voice was present in 97.5% of the patients, chronic cough in 28%, choking attack in 20.5%, stridor in 6.4%, difficulty in swallowing in 6.4%, discomfort sensation in 5%, and aphonia in 2.6%. However, in the study by Gomaa et al., hoarseness of voice was present in 100% of the patients, chronic cough in 45.5%, choking attack in 12.1%, stridor in 9.1%, and difficulty in swallowing in 15.2%.
In the present study, chronic laryngitis was the most common lesion seen in 17 patients (28.3%), followed by laryngeal growth comprising 14 patients (23.3%), vocal cord nodules in 10 patients (16.6%), vocal cord polyp in 9 patients (15%), vocal cord palsy/paresis in 6 patients (10%) and Reinke's edema in 4 patients (6.6%). In the study by Nasr et al., the most common laryngeal lesion was laryngeal growth and vocal cord polyp seen in 14 patients (25.9%) each, followed by nodules (20.4%), cyst (11.1%), Reinke's edema (9.3%), and chronic laryngitis (7.4%). In the study by El-Sherif and El-Sharif, vocal nodule was the most common lesion seen in 27% of patients, vocal cord polyp (24%), laryngeal growth (27%), Reinke's edema (13%), leucoplakia (5%), cyst (4%), vocal cord palsy/paresis (19%). In a study by Gomma et al., chronic laryngitis was the most common lesion seen in 19 patients out of 66 patients (28.78%), followed by laryngeal polyp (25.7%), vocal cord nodule (15.15%), subglottic scleroma (15.2%), mass lesion (9.1%), laryngeal cyst (4.5%), and laryngocoele (1.5%).
In this study, out of the 17 patients with chronic laryngitis, only 3 (17.64%) were detected with HRUS. All had mucosal edema. In the study by Nasr et al., four patients were diagnosed with chronic laryngitis, but none were diagnosed on ultrasonography; however, a thickened cord was detected in 2 patients (50%) on the CT scan. In the study by Gomma et al., 28.8% (19 patients) were diagnosed to have chronic laryngitis, however, no case was detected by ultrasonography. Thus, HRUS appears to be a poor modality in diagnosing chronic laryngitis compared to laryngoscopy and may not add anything to diagnosis in these patients.
In this study, out of 14 (23.3%) patients with laryngeal growth, 6 had supraglottic growth, 2 had glottic growth, 2 had pyriform sinus bulge, and 4 had transglottic growth. HRUS correctly identified growth in 11 patients. Out of the 3 patients missed on HRUS, 2 had glottis carcinoma and 1 had pyriform sinus bulge. Thyroid cartilage involvement was detected on HRUS in 6 patients (42.86%) of the 14 patients. Laryngoscopy could not detect thyroid cartilage involvement as well as involvement of the pre-epiglottic space. Thyroid cartilage calcification was seen in 5 patients. In 3 patients, thyroid calcification hindered the detection of lesion by HRUS, thus limiting the use of HRUS for the diagnosis of laryngeal growth lesions. In the study by Nasr et al., 14 patients had laryngeal masses out of which 3 had supraglottic mass, 5 had glottic mass, and 6 had transglottic mass. The visibility of the laryngeal mass on ultrasonography depended on the size of the mass, which ranged approximately 4–24 mm, with a mean of 14 mm. The laryngeal mass was visible in 11 out of 14 patients (78.6%) on ultrasonography. In the study by El-Sherif and El-Sherif, 21 patients (24.7%) had laryngeal growth, 9 patients had glottic, 8 patients had supraglottic, and 4 patients had subglottic growth. All patients were detected by ultrasonography. Ultrasonography also detected adjacent lymph node involvement in 3 patients and thyroid lobe nodule in 1 case. In the study by Gomma et al., all the 6 (9.1%) patients with laryngeal growth were diagnosed ultrasonography. Thus, HRUS could detect involvement of the thyroid gland and extent of soft tissue infiltration by the tumors. It is comparable to laryngoscopy for supraglottic and subglottic mass detection. However, the role of HRUS appears to be limited in detection of growth in glottic or pyriform sinus bulge and in patients with thyroid cartilage calcification.
In this study, the vocal cord nodules were detected in 10 patients on laryngoscopic examination. However, it was detected in only 1 patient (10%) on HRUS. In the study by Nasr et al., of the total 11 patients (20.4%) with vocal cord nodule, only 3 (27.3%) were detected by ultrasonography. In the study by El-Sherif and El-Sherif, 21 patients (27%) had vocal nodules with size between 1 and 3 mm, out of which 6 (29%) were detected by ultrasonography. All the 6 nodules ranged from 2 to 3 mm in diameter. Nodules smaller than 2 mm were not detected. In the study by Gomma et al., of the total of 10 patients (19.6%) with vocal cord nodule, none was detected on ultrasonography. It appears that vocal cord nodules greater than 2 mm in diameter are detected by HRUS. Thus, laryngoscopy appears to be superior to HRUS in the diagnosis of vocal cord nodules.
Out of the 9 patients who were diagnosed to have vocal cord polyp on laryngoscopy in this study, 6 patients (66.67%) could be diagnosed on laryngeal HRUS. All the lesions missed on HRUS were sessile in nature. In the study by Nasr et al., all patients with polyp (25.9%) were detected by ultrasonography. In the study by El-Sherif and El-Sherif, all patients with polyp (24%) were detected by ultrasonography. In the study by Gomma et al., of the 17 patients (25.7%) with polyp, 8 patients (52.9%) were detected by ultrasonography while 7 patients (47.1%) were missed. Thus, laryngoscopy is better than HRUS in the diagnosis of polyp, besides the sensitivity of HRUS decreases when the polyp is sessile rather than pedunculated in nature.
In this study, 6 patients were diagnosed to have vocal cord palsy/paresis on endoscopic laryngoscopy. It was correctly diagnosed in 4 patients (66.67%) on HRUS. In the study by El-Sherif and El-Sherif, 16% of the patients had vocal cord paresis while 3% had vocal cord palsy. All patients were detected by HRUS. Role of HRUS in the diagnosis of vocal cord palsy/paresis remains limited in contrast to laryngoscopy.
In this study, 4 patients (6.67%) were diagnosed with Reinke's edema on endoscopic laryngoscopy. In the study by Nasr et al., Reinke's edema was diagnosed in 5 (9.3%) patients out of which 3 (60%) were diagnosed on ultrasound. Further, Reinke's edema was present in 10 patients (12.8%). All these cases appeared as diffuse cord thickening on ultrasonography. Thus, the role of HRUS in detection of Reinke's edema is appears to be limited since these appear as diffuse cord thickening on HRUS, and requiring histological diagnosis.
The sensitivity of HRUS varies in the diagnosis of various laryngeal lesions. In this study, it was maximum for laryngeal growth (i.e. 78.57%) followed by vocal cord polyp (66.67%). The sensitivity was least for vocal cord nodule (10%) and chronic laryngitis (17.64%), while sensitivity for Reinke's edema was intermediate (50%).
| Conclusion|| |
The role of HRUS is limited compared to laryngoscopy. HRUS is more sensitive for detection of some laryngeal lesions such as laryngeal growth and vocal cord polyp. However, its sensitivity decreases when used for other lesions such as vocal cord nodule and chronic laryngitis, while in Reinke's edema detection it is of intermediate sensitivity.
HRUS has some advantages over laryngoscopy in being noninvasive, bedside, and a cheap modality that can visualize soft tissue and thyroid invasion from the laryngeal lesions. HRUS has some limitations that limits its use for certain laryngeal pathologies. These limitations can be overcome by conventional laryngoscopy. Thus, it can be concluded that HRUS, though being less sensitive than laryngoscopy, has several advantages of its own. HRUS, therefore, may be used to augment rather than replace conventional laryngoscopy for the diagnosis of laryngeal lesions.
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[Figure 1], [Figure 2], [Figure 3]