ENT ultrasonography refers to various ultrasound examinations of the anatomical structures located in the ear, nose and throat (ENT) area. As a noninvasive procedure without radiation exposure, ENT sonography is one of the established diagnostic procedures in ENT and is highly valued. ENT sonography is used in cases of suspected various diseases, as it is a fast and very informative diagnostic procedure. The majority of ultrasound examinations involve the examination and evaluation of the soft tissues of the neck. The starting point for the indication for an ultrasound examination in this case is swelling of the neck, swallowing difficulties, preoperative and follow-up examinations in the context of malignant head and neck diseases, and surgical planning of surgical interventions in this area.
Indications (areas of application)
- Evaluation of cervical lymph node status in tumor disease in this area.
- Assessment of the swallowing act – e.g., in case of dysphagia.
- Diseases of the submandibular gland (submandibular salivary gland) such as tumors or salivary stones.
- Changes in the oral cavity such as tumors
- Diseases of the pharynx (throat)
- Changes in the parotid gland (parotid gland) such as parotitis (parotitis).
- Changes in the soft tissues of the neck such as inflammation with enlargement of the lymph nodes.
- Examination of the sinuses and maxillary sinuses
- Examination of the masticatory muscles (primarily in the field of orthodontics or oral surgery).
Application in surgical planning:
- Assessment of the location of veins, arteries and nerves to avoid injury to these structures.
- Three-dimensional measurement, for example, of a tumor or change, as well as sizing of the same.
- Assessment of the adhesion of tumors with anatomical neighboring structures.
Contraindications
Due to the sound waves used, ENT sonography is absolutely free of side effects and harmless and can be repeated as often as desired. Only an intact skin surface must be ensured in order not to cause pain or contamination of larger wounds.
Before therapy
No special measures are necessary before sonography is performed; the patient lies down on an examination couch and the examining physician applies a transparent gel containing water to the skin to optimize the conduction of ultrasound waves into the tissue and back again.
The procedure
ENT sonography is performed using ultrasound waves, which differ from normal sound in that they have a different frequency of vibration. High-resolution broadband linear probes with a frequency of 5.5-20.0 MHz are used. The ultrasound waves are reflected differently at the borders of different body tissues and visualized on a screen. The procedure is called B-scan sonography (B-mode; B for brightness modulation; B-scan sonography), in which the gray tones are reproduced as a two-dimensional image. In addition, a color Doppler is usually used. This can perform flow measurements of the blood flow in the blood vessels, providing information about the vascular richness and thus the dignity of a tumor (biological behavior of tumors; i.e., whether they are benign (benign) or malignant (malignant)). The vascularity of a tumor is thereby reproduced as a color-coded signal. The transducer is moved with light pressure over the area to be examined. The advantages of sonography are that it can be performed quickly and at short notice, there is no radiation exposure, and there is no need for contrast media as is often the case with radiological examinations. Sonography is preceded by a detailed medical history (recording of the patient’s medical history) and a physical examination. The soft tissues of the throat as well as soft tissues of the face are very accessible to ENT sonography. Tumors of the larynx and tumors of the pharynx can often be precisely visualized and measured. Spatial lesions of the soft tissues of the lips and cheeks are also readily accessible to sonographic examination.B-scan ultrasonography, shown above, is particularly useful for visualizing malignant (malignant) space-occupying lesions of the paranasal sinuses (if localized in the maxillary sinus), but computed tomographic examination is mandatory for accurate size measurement. Another area of ENT sonography is the visualization of changes in the thyroid gland and tongue. Furthermore, the determination of the adjacency of the anatomical structures, which is relevant for a surgical therapy, is another important component or reason for a sonographic examination, in order to enable a precise surgical planning. Tumors of the parotid gland and submandibular gland can be visualized in detail by color Doppler sonography and B-scan sonography. A special procedural technique for the evaluation of the salivary glands is the possibility of enoral (“in the mouth“) sonography: here, with the help of a special transducer, the extent of tumorous processes can be determined via the oral mucosa. The maxillary and frontal sinuses can also be examined using so-called A-scan sonography (A-mode; A stands for amplitude modulation). Fluid accumulation, mucosal swelling, or inhomogeneous sinus contents, for example, can be diagnosed.
After therapy
No special measures need to be taken following ENT ultrasonography.
Possible complication
No complications are expected during ENT sonography.
