A Comparative Study of Ultrasound Versus CT Measurement of Tongue and Oral Cavity Size

Study Overview
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Brief Summary
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Difficulty in managing the airway is the single most important cause of major anesthesia-related morbidity and mortality. The currently used clinical method of predicting airway difficulty used by anesthetists is limited and not very highly sensitive or specific. Any additional bedside method that increases its specificity and sensitivity would be valuable. This project is designed to study and measure the tongue thickness and oral cavity height by using an ultrasound scan and comparing them with the same measurements obtained by CT scan. These will also be compared to a more complicated measurements used in previous studies to investigate any correlation with the currently used clinical methods. This information will help us decide if ultrasound may help Anesthesiologists assess difficulties in airway management in a more accurate, precise and reliable simpler method.

Official Title
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A Comparative Study of Ultrasound Versus CT Measurement of Tongue and Oral Cavity Size: Validation of Sonographic Technique

Conditions
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Ultrasound Airway Imaging in Determining the Oral Cavity and Tongue Size

Intervention / Treatment
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* Other: Ultrasound scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18 to 80 Years Gender: Both males and females are eligible for the study ASA I-III Scheduled for CT-scan of the head and neck as part of medical investigation (for test validation part) Exclusion Criteria: Volunteer/ patient refusal Language Barrier Known oropharyngeal, laryngeal or head and neck disease or cancers Multiple amalgam fillings of the teeth Past history of oral or head and neck surgical procedures Past history of burns or radiotherapy of the head and neck region Presence of any scars, sinuses, infection, swelling, cysts in the head and neck region

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| High resolution CT Scan of the head and neck<br>Patients scheduled for high resolution computerized tomography (CT scan) of the head and neck as part of their medical investigation of thyroid or laryngeal disorders will be recruited for this study. | Other: Ultrasound scan<br>* Ultrasound scanning examinations will be performed twice (pre-CT scan and post CT-scan). Each examination will be performed by two observers who are blinded to each other's measured values.Patients will be asked to place a small sip of water (20 mL)in their mouth and keep the mouth open during the imaging. A second ultrasound examination of each patient by the two observers will be performed after the CT-scan.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Validity of the assumption that ratio of tongue thickness/oral cavity height is a good estimate of the ratio tongue volume/oral cavity volume as measured by CT scan. |  | 2012-2013 | 
| Validity of ultrasound measurement of the two airway parameters (tongue thickness and height of oral cavity) against CT measurements of the same parameters. |  | 2012-2013 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reproducibility of the ultrasound measurements |  | 2012-2013 | 
| Correlating ultrasound measured values with Mallampati scores |  | 2012-2013 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ultrasound, Computed Tomography, Oral cavity size, The Mallampati classification