Sinus imaging for diagnosis of chronic rhinosinusitis in children.

Chronic rhinosinusitis (CRS) is a relatively common disease in children but is often overlooked because at times the clinical symptoms are subtle and nonspecific. This makes imaging very important in the diagnosis. Among the different techniques, plain radiography has limited utility,whereas CT scan and MRI have a major role in evaluating the modifications caused by the disease. In particular, a CT scan provides higher resolution of bone and soft tissue and removes the overlapping structures that are present in conventional radiography. CT is recommended in isolated sphenoid sinusitis, is essential in diagnosing fungal sinusitis, and is the technique of choice when orbital complications are suspected. MRI allows investigation of not only the morphology of structures, but their intrinsic biophysical and biochemical properties, such as water content, cellular density, lipid or blood product deposits, and fibrosis. MRI allows better soft tissue differentiation and high spatial resolution images depicting fine details. When indicated, MRI with contrast gadolinium-based agents may better characterize the local disease extension or its diffusion beyond paranasal and nasal cavities and has excellent contrast resolution. A combination of CT and MRI is useful in cases of diagnostic difficulties,especially when complications are involved.