Imaging in the diagnosis of rare diseases

A disease is considered rare if it affects no more than 5 in 10,000 people. More than six thousand rare diseases have been detected so far and they affect 6-8% of the population which equals 2.3-3 million people in Poland. Some of the rare diseases are already diagnosed in utero, e.g. skeletal dysplasias on ultrasonography or central nervous system diseases on magnetic resonance imaging (MRI). Many cases are finally diagnosed after radiologist's suggestion in a radiological report. Although diagnostic imaging cannot be considered as a basis for diagnosis of most of rare diseases, these studies represent an important element in the diagnostic chain. The complicated and long process of diagnosis may be significantly shortened by suggestions of the radiologist, based on the observation of these elements of radiological appearance of the lesions that are characteristic for a particular group of diseases, or even for a particular disease entity. However, the absolute condition for success is the close clinical-radiological cooperation, with clinicians providing the radiologists with their knowledge of patient's history, clinical manifestations, and the results of other investigations.