Objective: to perfect and estimate the possibilities of using a mini-invasive diagnostic procedure under magnetic resonance (MR) guidance in the complex anatomic situations in cases of pathological small pelvic changes of unknown origin.Material and methods. Ten small pelvic interventions were made under MR guidance. The indications for bone biopsy under MR guidance were poor visualization of bone changes or their absence during radiography, including computed tomography. Small pelvic organ and soft tissue biopsies were carried out in the situations of complex location of pathological changes adjacent to critical organs, large vascular and neural structures. All interventions were done using a high-field MR scanner. Freehand biopsy was performed in a stepwise fashion under axial and sagittal T2-weighted image control.Results. Informative histological material was obtained in 100% of cases. No complications were observed.Conclusions. It became possible to verify the diagnosis based on morphological findings and to timely determine management tactics only by target biopsy under MR guidance in these 10 patients with small pelvic changes of unknown origin
