MR Diagnosis of Osteonecrosis in Divers of Various Qualifications

Relevance. Dysbaric osteonecrosis is a pathology of the skeletal bones that develops against the background of decompression disorders in divers, submariners, divers and caisson workers. The highest frequency of this pathology is observed in divers-fishermen (50–77%); in commercial divers it is 16–55%, in caisson workers – 25–35%, and in military divers this figure is significantly lower – 2–5%. The main pathogenetic causes of the development of dysbaric osteonecrosis are gas embolism of blood vessels of the microcirculatory bed by bubbles of free gas (nitrogen), as well as mechanical damage to the endothelium of capillaries and bone marrow, which leads to their inflammation, edema, hypercoagulation and compartment syndrome. This causes a violation of intraosseous blood flow, the development of ischemia and the initiation of necrotic processes in bone tissues. Materials and methods. The studies were conducted on high-field magnetic resonance tomographs with a magnetic field induction of 1.5 T "Ingenia" (Philips) and "Magnetom Symphony" (Siemens) according to standard protocols with obtaining T1, T2 and PD-weighted images, as well as images using the effect of signal suppression from fat tissue (FS). MRI scanning was performed of the most frequently affected, according to literary sources, anatomical areas – shoulder, hip and knee joints, covering the parts of the diaphyses adjacent to the joints. The localization, distribution and type of specific pathological changes characteristic of dysbaric osteonecrosis were assessed. A total of 54 divers were examined, who were divided into 3 groups: 1) divers performing deep-sea diving descents of more than 60 m. (having additional diving qualifications of deep-sea diver and aquanaut); 2) divers performing diving descents up to 60 m; 3) divers performing diving descents in normobaric conditions (having an additional diving qualification of hydronaut). Results. The conducted MRI studies have shown that dysbaric osteonecrosis most often affects deep-sea divers and aquanauts, and the presence of episodes of acute decompression sickness in the anamnesis increases the risk of its occurrence. The published data on the predominant localization of lesions: in the head of the humerus, metaepiphyses and diaphysis of the femur have also been confirmed. Conclusion. Based on the results of the study, it can be stated that regular MRI monitoring of the skeletal bones is indicated for divers at risk (performing deep-sea diving descents and having episodes of acute decompression sickness in the anamnesis).