Radiologic Assessment of Nose and Paranasal Sinuses

Abstract

Each new imaging modality developed within the last 30 years in sinonasal imaging has reduced the functionality of the previous one and provided comparatively more valuable guidance for clinicians. Presently, x-rays, which were used for a wide range of applications in the past, have been largely replaced by computed tomography (CT). CT has become an easily accessible, an easily and quickly applicable, and a widely used diagnostic tool for nose and paranasal sinus pathologies. Paranasal sinus CT presents very useful information for the evaluation of obstructive structural problems, trauma, inflammatory pathologies, and, especially, detailed imaging of bony structures. CT has been widely used for preoperative imaging, perioperative image-guided surgery, and guidance for surgical planning using preoperative multiplanar reconstructions. Magnetic resonance imaging (MRI) provides more detailed information through its advanced resolution for soft tissues in the evaluation of extra-sinus, soft tissue involvement of inflammatory diseases, sinonasal tumors, and sinonasal fungal diseases. In this section, we discuss the current information on sinonasal imaging, extending from conventional radiographies to advanced imaging techniques, using common diseases and examples. Currently, tomography is the first choice and most widely used diagnostic tool for nasal and paranasal sinus imaging because of its high resolution, ability to define the bony structures clearly, and preoperative guidance. With paranasal sinus CT, thin-sliced axial sections, parallel to the orbitomeatal unit or hard palate, are usually obtained, and coronal and sagittal reformattings are reconstructed to better define the sinonasal anatomy. In particular, the coronal sections are more important for preoperative evaluation because they provide more similar images with an endoscopic view. This chapter discusses radiologic assessment of nose and paranasal sinuses.