[Magnetic resonance tomography in the diagnosis of nonorganic bulky masses of the retroperitoneal space. Part 1. Cysts, abscesses and flegmons].

The paper considers the diagnostic capacities of magnetic resonance imaging (MRI) in detecting non-organic bulky masses of the retroperitoneal space. Based on the analysis of tomographic findings in 23 patients with non-organic cysts of the retroperitoneal space and 27 patients with its abscesses and phlegmons, the first part of the paper describes the MRI semiotics of these diseases in detail and proposes methodic approaches to their identification. Comparison of the data of MRI and pathomorphological analysis of operation materials has yielded the rates of sensitivity, specificity, and accuracy of the method, which are equal to 100, 88.5, and 94.2% for non-organic cysts and 100, 87.1, and 93.5%, respectively. The authors note the lower efficiency of MRI in recognizing hydatid cysts and foreign bodies than ultrasound study and X-ray computed tomography and show it necessary to take into account clinical information in making a radiological conclusion.