The larynx is an organ of our body that performs many important functions in our daily functioning. These range from the fact that it has mechanisms to prevent liquids and food from entering the lower respiratory tract, through the very important respiratory functions, to the production of the voice, i.e. the phonation function.

Methods for examining the larynx

There are a number of examination methods to determine the presence of possible lesions. One method of examination is to view the larynx from the outside, which is called laryngoscopy. This examination can be performed with a mirror or by using specialised equipment such as endoscopes.

Microlaryngoscopy is a method of examination that allows a very accurate assessment of the larynx, but is performed under general anaesthesia after the patient has been intubated. The accuracy of this examination is very important, especially in cases where surgery on the vocal folds is required.

Palpation examination, or examination by touch, is necessary with regard to the assessment of abnormalities of laryngeal mobility. During this examination, it is easy to determine the consistency of the laryngeal tissues as well as to assess the condition of neighbouring organs such as the thyroid gland or lymph nodes.

Imaging methods for laryngeal lesions

For events such as fractures or breaks in cartilaginous tissues, stenosis, tumours within the larynx, foreign bodies or displacements, it is necessary to image the laryngeal region and the resulting lesions. [1]

For diagnostic purposes, the larynx is divided into certain areas. The upper floor encompasses the supraglottic region, the middle floor the glottal region, while the lower floor refers to the subglottic region. The boundaries between these areas are defined by conventional lines adopted by clinicians. [3]

X-ray images

X-rays are categorised as electromagnetic radiation operating according to the wave theory (the rays propagate through space as waves) and the quantum theory (they react in contact with matter, just like particles). X-rays are created in a vacuum bubble equipped with two electrodes, hence X-rays are taken using special apparatuses equipped with a wall and a vertical table with a tripod and X-ray tube. [2]

X-rays can have different projections. One of these is the lateral projection, through which the soft tissues within the larynx are visualised. The laryngeal cavity can also be visualised in this way and its normal structure assessed. The more calcified the cartilaginous tissues are, the better they are visualised. X-rays are also taken in the posterior-anterior projection, which allows laryngeal structures such as the laryngeal pocket folds, Morgagni's diverticulum and vocal folds to be visualised.

Laryngealradiographs, which make up the radiological documentation, are taken when it is necessary to assess the extent of tumours and lesions that are present within the larynx and are useful in the evaluation of strictures. They also allow the elimination of distortions due to the presence of the spine in the area of the image taken. [1] Layered functional radi ographs provide the opportunity to observe glottal behaviour during vowel phonation and free breathing. [3]

photo: panthermedia

CT

Another type of imaging of laryngeal lesions is CT scanning. This examination is particularly useful when a cancerous lesion is present within the larynx. Thanks to its high resolution, the image obtained shows the tumour area, its location and size very accurately. CT scanning is also useful for imaging laryngeal lesions such as the presence of cysts or cartilage fractures, as well as for diagnosing strictures.

Laryngography

In order to better visualise the laryngeal cavity, an examination called laryngography is used. It involves the injection of a shadowing agent into the structures of the larynx to give a clearer outline of the laryngeal cavity, allowing changes and abnormalities in its shape or structure to be accurately identified. [1] Currently, this examination is performed quite rarely, the reason being its high labour intensity as well as the fact that it is an examination that is uncomfortable and unpleasant for the patient himself. [3]

MR

One imaging technique is nuclear magnetic resonance imaging, which is based on the magnetic properties of hydrogen atom nuclei. The cells of the body, when placed in a magnetic field, undergo a slight induced magnetisation, which allows, as a result of determining the level of magnetisation of individual tissues, an image of the area under examination to be obtained. [4]

MR imaging is an examination used to image structures throughout the body. It has also found its application in ENT, as with this examination, the soft structures of the body are visualised very accurately and a large number of details can be extracted.

Medical US

Ultrasound plays the same role in ultrasonography as X-rays do in radiology. Thanks to ultrasound, it is possible to visualise tissues without the need to inject contrast into the examination. It is a non-invasive examination based on the action of the pulse-echo technique. Ultrasound, in a dose that is safe for the patient, is transmitted deep into the patient's body, from where the vibration echoes of individual organs and organs are received, giving an image of the tissues, depending on their properties. [5]

Echolaryngography (ultrasonography), is an examination by which an image can be obtained of the vocal folds area and the pocket folds. It is a method that allows an easy assessment of these areas and the identification of any abnormalities or pathological changes. Medical US examination can also be performed from the inside, which allows two-dimensional images of the examined structures to be obtained, which is useful in the assessment of metastases in cancer and allows these areas to be monitored during the treatment process. [1]