## 4 Clinical and Paralinical Diagnosis
The collected samples, after being tested via Gram staining, are cultured on two blood agar plates (one for aerobes and one for anaerobes), MacConkey agar, and Sabouraud agar, for 5 days at 37 \({}^{\circ}\)C [48]. The gold standard in the diagnosis and therapeutic management of DNM is dynamic CT. This method also identifies damage to the upper respiratory tract before the appearance of clinical symptoms (dyspnea, stridor). Computer tomography is the most used imaging modality in emergency situations. It can be used to establish the extension of the infection in the anatomical spaces adjacent to the initial necrotic process. Knowledge of radiological anatomy makes surgical approaches to deep neck infections accessible. Identifying the deep spaces of the neck involved in the infection allows the radiologist to evaluate the ways in which the infection spreads, and the probable causes of suppuration [48]. CT with a contrast substance is the first choice in emergency medical centers, being accessible, with fast image speed, and the ability to visualize the local extension of the infection. It should be noted that CT has a false positive rate of approximately 10% and a false negative rate of 13%. Retropharyngeal cellulitis can often have the CT appearance of an abscess, which leads to an increased rate of false positive results. The use of multiplane helical CT results in better resolution and a substantial reduction in scan acquisition time and display time, and this method is non-invasive. Multiplanar reconstructions via CT can be utilized to effectively distinguish fat from other tissues, and are superior to MRI in terms of evaluating bone and calcifications. Compared to MRI, CT has the advantages of being less susceptible to motion artifacts and having better temporal resolution [49]. Although CT scanning has an important role in the diagnosis of cervical mediastinal supurations, it is not 100% predictive. [PERSON] and colleagues [50] evaluated the positive predictive value of CT in deep throat infections. A total of 75% of surgically drained patients had a discrete pus collection that correlated with the CT findings; however, 25% did not. It was concluded that the decision for surgical drainage should be made based on clinical symptoms and signs, and that a negative exploration rate of 25% should be expected. [PERSON] and colleagues [51] compared CT with MRI in the evaluation of head and neck infections. Although MRI hasbeen shown to be efficient in defining spaces and identifying the source of the infection, CT has been utilized to depict the presence of gas and calcifications [46]. Swelling of the neck that extends to the sternal notch may indicate the infectious involvement of the mediastum, and a CT scan of the neck and chest should be performed in such cases [52; 53]. The advantages of MRI are represented by the avoidance of exposure to radiation, the non-use of allergenic contrast substances, and a better evaluation of the limits of infection in soft tissues than is provided by CT [54]. In the event of vascular complications (thrombosis of the internal jugular vein, or aneurysm or rupture of the carotid artery), magnetic resonance angiography is recommended [37]. Unfortunately, its increased cost and longer scan time compared to CT are disadvantages that preclude its utility in most cases [50]. X-rays may also be helpful in certain cases of deep throat infections. Even if a chest X-ray can detect complications such as mediastinitis, pneumonia, and pleural effusion, CT evaluation is preferred, as it is clearly superior for detecting mediastinal cellulitis or abscesses [35]. In the case of deep neck infections with the presence of a deep abscess, CT can be supplemented with ultrasound, which is more precise in differentiating an abscess from cellulitis, and needle aspiration can be attempted [35; 39].