What are the commonly used X-ray examination methods for nose?

X-ray is a kind of electromagnetic wave with short wavelength, which is penetrating and can make photographic film "sensitive". These characteristics of X-rays can make the examined tissues produce "images". According to the changes of these images, clinicians can infer the internal changes of tissues and organs that are invisible to the naked eye. Commonly used nasal X-ray examination methods mainly include extranasal X-ray examination and paranasal sinus X-ray examination. The former is mainly suitable for nasal trauma, which is used to judge whether there is a nasal bone fracture and the position and displacement of the fracture. Lateral films are usually used. The latter is mainly suitable for judging sinus, zygomatic arch fracture, inflammation and space-occupying lesions (such as polyps, cysts, new organisms, etc.). ) in the sinus. Usually, two postures are used to take photos: the chin position, also known as water level, and the forehead position, also known as Cald (well position). The former can display maxillary sinus, ethmoid sinus, frontal sinus, nasal cavity and orbit. The latter mainly shows frontal sinus and ethmoid sinus. In addition, there are orbital oblique position and skull base position, which are mainly used to observe the lesions of posterior ethmoid sinus, optic foramen, middle cranial fossa and posterior wall of maxillary sinus. Because the sinus itself overlaps the skull, sometimes the observed images can not accurately judge the lesions. The above is the plane photography method when X-ray is used for nasal examination. In order to overcome the influence of sinus and skull overlap on the captured images, tomography can be used. At present, the widely used CT technology is the product of the combination of computer and tomography. The application of CT and other imaging methods in the examination and diagnosis of nasal diseases will be introduced respectively. For some vascular tumors, contrast media can be injected into blood vessels, and the blood supply of the lesions can be known by digital subtraction technique. Contrast media can also be injected into the sinus cavity to understand some malformations or space-occupying lesions.