ENT - September 2020 - 544

544

Ear, Nose & Throat Journal 99(8)

impedance (MII-24 h) pH monitoring and the reflux symptom
index (RSI) scale to classify LPR patients.

Materials and Methods
Ethical Considerations
All procedures performed in studies involving human participants were in accordance with the ethical standards of the
institutional and/or national research committee and with
the 1964 Helsinki declaration and its later amendments or
comparable ethical standards. The protocol number is 20170515.

Selection/Classification of Patients
In this prospective study, 97 patients who attended the clinic
between January 2015 and February 2017 were included. The
patients were divided into 3 groups: The first was the
pH-positive group in which the patients had the RSI score
>13, and the number of proximal acid episodes was greater
than or equal to 3, proximal acid exposure time was greater
than 1%, or impedance detected proximal acid exposure was
less than 4. The second group was pH negative in which the
patients' RSI score >13, but there were fewer than 3 proximal
acid episodes, proximal acid exposure timeless was than 1%,
and impedance detected proximal acid exposure was less than
4. The third group was the control group who had no complaints about LPR (RSI < 13), but were administered laryngoscopy for routine testing before thyroid surgery. All patients
were evaluated subjectively by a RSI and a laryngoscope. With
the patients' consent, the patients with symptoms also underwent 24-hour pH probe monitoring. Laryngopharyngeal reflux
was confirmed by total acid exposure time. Laryngopharyngeal
reflux is confirmed when the proximal sensor detects pH levels
lower than 4 for more than 1% of the time, or the number of
acid episodes was at least 3 during a 24-hour monitoring
period.9,10
Laryngeal images were obtained from all patients from one
high-resolution laryngoscopy. The grouping based off of the
pH monitoring was as follows: 20 patients who were confirmed
with LPR (16 men, 4 women; age range: 18-63 years; mean
age: 42.2 years), 19 patients who were suspected to have LPR
but tested negative (10 men, 9 women; age range: 23-78 years;
mean age: 46.3 years), and 58 control patients (25 men, 33
women; age range: 20-68 years; mean age: 45.0 years). All
patients in this study were the same descent. There were no
significant differences in RSI between age groups and no significant difference in RSI between positive and negative groups
(P > .05). However, there were significant differences between
the control group and the other 2 groups (P < .05), as shown in
Figure 1.

Image Collection
Images were obtained during a laryngoscope through only one
flexible high-resolution laryngoscope (model EV-NE; XION;

Figure 1. Reflux symptom index scores between pH-positive,
pH-negative, and control groups. RSI indicates reflux symptom index.

Berlin, Germany). There was no standard nasal sidedness to the
flexible laryngoscopy; the side selected was based on accessibility or minimal level of nasal congestion. However, the selection of a particular side should not have a significant effect on
the overall classification. The images were taken near the midline of the larynx, regardless of which side was chosen. The
minor sidedness distance should not significantly change the
hue values. The white balance function was used to exclude
other potential factors that may interfere with the true image
color and to standardize the images to what was present. After
the images were saved as JPEG files, the hue values were
analyzed. Images with a noticeable blur or glare were omitted
from the study.

Data Collection
Images were deidentified and evaluated with a customized
color analysis script developed on Matlab 2013b.The color
analysis tool calculates the hue value of several manually
drawn regions of a laryngoscopic image using the algorithm
explained in Witt et al.7 For each image, specific regions of
the larynx were outlined for each area of interest. This
includes the left and right true vocal folds, left and right false
vocal folds, left and right arytenoids, and the interarytenoid
space. Using a digital sketchpad, the boundaries were manually drawn, as shown on Figure 2. In our case, processing
images using regional calculations was preferable as compared to a global calculation because hue variations may be
localized to small areas of the larynx with little variation
present in other locations. Dividing the image into manually
drawn regions would allow parts of the image to be grouped
such that the area would have similar characteristics in physical appearance. This was done to reduce variations in our
results between each individual region. The deidentification
of the images eliminated bias as the evaluator was blinded to
the group to which each image belonged.
As demonstrated in Figure 3, the red color is the reference
point of the traditional color circle, which holds a domain from
0 to 360 degrees. For each region, the hue parameter was



ENT - September 2020

Table of Contents for the Digital Edition of ENT - September 2020

The Creation of a Sustainable Otolaryngology Department in Malawi Nathan Douglas Vandjelovic, Eric Masao Sugihara, Wakisa Mulwafu, and David Nathan Madgy
Hazardous Grilling Due to Wire Brushes Nima A. Vahidi, Brenna A. Keane, Paul J. Whalen, and Anita Jeyakumar
Guns n’ Noses: Endoscopic Removal of an Air-Gun Pellet Retained in the Frontal Sinus Dylan A. Levy, Andrew Y. Lee, Waleed M. Abuzeid, and Nadeem A. Akbar
Vitamin D Status in Egyptian Children With Allergic Rhinitis Khaled Saad, Abobakr Abdelmoghny, Mohamed Diab Aboul-Khair, Yasser Farouk Abdel-Raheem, Eman Fathalla Gad, Ahmed El-Sayed Hammour, Bahaa Hawary, Asmaa M. Zahran, Mohamd A. Alblihed, and Amira Elhoufey
Pediatric Epistaxis and Its Correlation Between Air Pollutants in Beijing From 2014 to 2017 Ying-Xia Lu, Jie-Qiong Liang, Qing-Long Gu, Chong Pang, and Chun-Lei Huang
Otomycosis With Tympanic Membrane Perforation: A Review of the Literature Petros Koltsidopoulos and Charalampos Skoulakis
Simultaneous Bilateral Same-Day Endoscopic Myringoplasty Using Tragal Cartilage From One Ear Baklaci Deniz, Kuzucu Ihsan, Guler Ismail, Kum Rauf Oguzhan, and Ozcan Muge
A Preliminary Report on the Investigation of Prestin as a Biomarker for Idiopathic Sudden Sensorineural Hearing Loss Changling Sun, Xiaolin Xuan, Zhi Zhou, Yuan Yuan, and Fei Xue
A Retrospective Study to Identify the Relationship Between the Dimension of Osseous External Auditory Canal and Chronic Otitis Media Yi-Fang Lee, Pei-Yin Wei, Chia-Huei Chu, Wen-Huei Liao, An-Suey Shiao, and Mao-Che Wang
Investigation of the Effectiveness of Surgical Treatment on Respiratory Functions in Patients With Obstructive Sleep Apnea Syndrome Burak Kersin, Murat Karaman, Engin Aynacı, and Ahmet Keles
Changing Trends of Color of Different Laryngeal Regions in Laryngopharyngeal Reflux Disease Chen Du, Paige Thayer, Yan Yan, Qingsong Liu, Li Wang, and Jack Jiang
ENT - September 2020 - Intro
ENT - September 2020 - Cover1
ENT - September 2020 - Cover2
ENT - September 2020 - 489
ENT - September 2020 - 490
ENT - September 2020 - 491
ENT - September 2020 - 492
ENT - September 2020 - 493
ENT - September 2020 - 494
ENT - September 2020 - 495
ENT - September 2020 - 496
ENT - September 2020 - 497
ENT - September 2020 - 498
ENT - September 2020 - 499
ENT - September 2020 - 500
ENT - September 2020 - The Creation of a Sustainable Otolaryngology Department in Malawi Nathan Douglas Vandjelovic, Eric Masao Sugihara, Wakisa Mulwafu, and David Nathan Madgy
ENT - September 2020 - 502
ENT - September 2020 - Hazardous Grilling Due to Wire Brushes Nima A. Vahidi, Brenna A. Keane, Paul J. Whalen, and Anita Jeyakumar
ENT - September 2020 - 504
ENT - September 2020 - Guns n’ Noses: Endoscopic Removal of an Air-Gun Pellet Retained in the Frontal Sinus Dylan A. Levy, Andrew Y. Lee, Waleed M. Abuzeid, and Nadeem A. Akbar
ENT - September 2020 - 506
ENT - September 2020 - 507
ENT - September 2020 - Vitamin D Status in Egyptian Children With Allergic Rhinitis Khaled Saad, Abobakr Abdelmoghny, Mohamed Diab Aboul-Khair, Yasser Farouk Abdel-Raheem, Eman Fathalla Gad, Ahmed El-Sayed Hammour, Bahaa Hawary, Asmaa M. Zahran, Mohamd A. Alblihed, and Amira Elhoufey
ENT - September 2020 - 509
ENT - September 2020 - 510
ENT - September 2020 - 511
ENT - September 2020 - 512
ENT - September 2020 - Pediatric Epistaxis and Its Correlation Between Air Pollutants in Beijing From 2014 to 2017 Ying-Xia Lu, Jie-Qiong Liang, Qing-Long Gu, Chong Pang, and Chun-Lei Huang
ENT - September 2020 - 514
ENT - September 2020 - 515
ENT - September 2020 - 516
ENT - September 2020 - 517
ENT - September 2020 - Otomycosis With Tympanic Membrane Perforation: A Review of the Literature Petros Koltsidopoulos and Charalampos Skoulakis
ENT - September 2020 - 519
ENT - September 2020 - 520
ENT - September 2020 - 521
ENT - September 2020 - Simultaneous Bilateral Same-Day Endoscopic Myringoplasty Using Tragal Cartilage From One Ear Baklaci Deniz, Kuzucu Ihsan, Guler Ismail, Kum Rauf Oguzhan, and Ozcan Muge
ENT - September 2020 - 523
ENT - September 2020 - 524
ENT - September 2020 - 525
ENT - September 2020 - 526
ENT - September 2020 - 527
ENT - September 2020 - A Preliminary Report on the Investigation of Prestin as a Biomarker for Idiopathic Sudden Sensorineural Hearing Loss Changling Sun, Xiaolin Xuan, Zhi Zhou, Yuan Yuan, and Fei Xue
ENT - September 2020 - 529
ENT - September 2020 - 530
ENT - September 2020 - 531
ENT - September 2020 - A Retrospective Study to Identify the Relationship Between the Dimension of Osseous External Auditory Canal and Chronic Otitis Media Yi-Fang Lee, Pei-Yin Wei, Chia-Huei Chu, Wen-Huei Liao, An-Suey Shiao, and Mao-Che Wang
ENT - September 2020 - 533
ENT - September 2020 - 534
ENT - September 2020 - 535
ENT - September 2020 - 536
ENT - September 2020 - Investigation of the Effectiveness of Surgical Treatment on Respiratory Functions in Patients With Obstructive Sleep Apnea Syndrome Burak Kersin, Murat Karaman, Engin Aynacı, and Ahmet Keles
ENT - September 2020 - 538
ENT - September 2020 - 539
ENT - September 2020 - 540
ENT - September 2020 - 541
ENT - September 2020 - 542
ENT - September 2020 - Changing Trends of Color of Different Laryngeal Regions in Laryngopharyngeal Reflux Disease Chen Du, Paige Thayer, Yan Yan, Qingsong Liu, Li Wang, and Jack Jiang
ENT - September 2020 - 544
ENT - September 2020 - 545
ENT - September 2020 - 546
ENT - September 2020 - 547
ENT - September 2020 - 548
ENT - September 2020 - 549
ENT - September 2020 - 550
ENT - September 2020 - 551
ENT - September 2020 - 552
ENT - September 2020 - Cover3
ENT - September 2020 - Cover4
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