Well-timed evaluation of changes in kidneys at acute pyelonephritis (AP) is still a pressing issue. Experience of nephrologists, urinologists and other clinicians, including experience in handling of visualizing diagnostics methods, does not always prevents severe clinical course of a disease with development of local purulent-destructive changes against the background of urosepsis down to lethal outcome. As majority of experts note, nothing, except clear and well-timed conclusion about serous or purulent-destructive stage of AP, can be a basis for choosing between conservative or surgical tactics in case management. However, in practice clinicians in majority of cases have no reliable and safe methods to reveal renal changes at various forms of AP and identify speed of their development and spreading. Existing diagnostic methods, such as x-ray, radioisotope scanning, thermography in majority of cases are inapplicable for highly informative and dynamic evaluation of extraperitoneal structures at AP. The reasons were complexity and expensiveness of these methods with, at the same time, subjectiveness of acquired data evaluation or impossibility to apply them due to needs in limitations to radiation exposure.

Reliable (constant) signs were defined by dynamic morphological stereotype of a disease, that is why they are characterized by staging manifestation in accordance with acute pyelonephritis pathomorphogenesis stages: infiltrative, purulent-exudative (pre-destructive), destructive (tissular lysis) and reparative. NLS-graphic manifestation of these stages determines NLS semiotics of acute pyelonephritis. NLS evaluation with bioplasm machine of intrarenal changes dynamics with consideration of given semiotics allows to acquire well-timed information about presence, stage, spreading and development of inflammatory process, that may be a basis for treatment tactics choosing.