Rheumatoid arthritis is a chronic inflammatory disease with a multifactorial etiology and varied course, which in the majority of patients leads to partial disability or to permanent handicap. Its characteristic trait is a persistent inflammation of the synovial membrane and the formation of an invasive synovial tissue, called the pannus, which in time leads to destruction of the cartilage, subchondral bone tissue, and the soft tissue of the affected joint(s). The pathogenesis of rheumatoid arthritis is complex and involves cells of both innate and adaptive immunity, a network of various cytokines and an immunoregulatory dysfunction. An important role in the discovery of rheumatoid arthritis pathogenesis was played by magnetic resonance imaging, which showed the disease process to extend beyond the synovium into the bone marrow. Many studies have shown a strict correlation between the vascularity of the synovium (assessed through the power Doppler ultrasound and magnetic resonance examinations), bone marrow edema and the clinical, laboratory and histopathological parameters of rheumatoid arthritis. From the current understanding of rheumatoid arthritis, bone erosions could occur from two directions: from the joint cavity and from the bone marrow. With power Doppler ultrasound, as well as in magnetic resonance imaging, it is possible to visualize the well-vascularized pannus and its destructive effects on joint structures and ligaments. In addition, the magnetic resonance study shows inflammatory and destructive changes within the bone marrow (bone marrow edema, inflammatory cysts, and erosions). Bone marrow edema occurs in 68–75% of patients with early rheumatoid arthritis and is considered to be a predictor of rapid disease progression.

Early diagnosis of rheumatoid arthritis followed by early initiation of treatment, prevent the destruction of joints and progression to disability in the majority of patients. A traditional X-ray fails to capture early inflammatory changes, while late changes (e.g. erosions) appear after a significant delay, once 20–30% of bone mass has been lost. Sonography and magnetic resonance imaging studies have shown that erosions are seen in the first 3 months from the appearance of symptoms in 10–26% of patients, while in 75% they are seen in the first 2 years of the disease. Power Doppler ultrasound and dynamic magnetic resonance studies allow for qualitative, semiquantitative and quantitative monitoring of the vascularization of the synovium. In addition, magnetic resonance enables assessment of the bone marrow. The ultrasonographic examination using a state-of-the-art apparatus with a high-frequency probe allows for images with great spatial resolution and for the visualization of soft tissues and bone surfaces. However, the changes seen in ultrasonography (synovial pathologies, the presence of exudate, tendons changes, cartilage and bone lesions, pathologies of tendon attachments and ligaments – enthesopathies) are not only specific for rheumatoid arthritis and occur in other rheumatic diseases. Qualitative methods are sufficient for diagnosing the disease through ultrasound or magnetic resonance imaging. Whereas semiquantitative and quantitative scales serve to monitor the disease course – efficacy of conservative treatment and qualification for radioisotope synovectomy or surgical synovectomy – and to assess treatment efficacy.

SummaryAssessing the pathology of the synovium, its thickening and increased vascularity through ultrasound and magnetic resonance examinations (more often an ultrasound study alone) is still considered a sensitive parameter in the diagnosis of rheumatoid arthritis and in monitoring of treatment efficacy. Magnetic resonance studies showed that, aside from the joint pannus, the subchondral bone tissue constitutes an essential element in the development of rheumatoid arthritis. Bone marrow edema correlates with inflammation severity, joint destruction, clinical signs and symptoms of rheumatoid arthritis, and thus is considered a predictor of rapid radiological progression of the disease. The newest studies reveal that bone marrow edema may be a more sensitive indicator of the response to therapy than appearance of the synovium. Bone marrow edema presents with increased signal in T2-weighted images, being most visible in fat saturation or IR sequences (STIR, TIRM). On the other hand, it is hypointense and less evident in T1-weighted images. It becomes enhanced (hyperintense) after contrast administration. Histopathological studies confirmed that it is a result of bone inflammation (osteitis/osteomyelitis), i.e. replacememt of bone marrow fat by inflammatory infiltrates containing macrophages, T lymphocytes, B lymphocytes, plasma cells and osteoclasts. Bone marrow edema appears after a few weeks from occurrence of symptoms and therefore is considered an early marker of inflammation. It correlates with clinical assessment of disease activity and elevated markers of acute inflammatory phase, i.e. ESR and CRP. It is a reversible phenomenon and may become attenuated due to biological treatment. It is considered a “herald” of erosions, as the risk of their formation is 6-fold higher in sites where BME was previously noted

Most cases of periaqueductal tumours were found in children and adolescents, so treatment modalities in adults are not evaluated yet. A case of 40 years old woman with tectal and periaqueductal protoplasmatic astrocytoma grade II with history of headache and episodes of syncope is described. MRI showed triventricular hydrocephalus. After a shunt procedure she was doing well for about 15 months. Then she became somnolent, disoriented, and Parinaud syndrome appeared. The solid tumour was resected microsurgically in one stage. A part of it was removed via the supracerebellar infratentorial approach and tectal plate incision. The remainder of the tumour was removed through the fourth ventricle and the aqueduct which was filled by tumour mass. Postoperatively bilateral ptosis, vertical gaze palsy, slight horizontal gaze limitation and pupilloplegia were the main neurological sequelae. They all almost completely resolved within a year. The patient is doing well two and half years after the surgery. MRI showed patency of the aqueduct and no residual tumour. The authors suggest, that direct surgical attempt at total tumour removal should be considered in cases of periaqueductal and tectal gliomas. They also believe it is the first described case, in whom this type of tumour was totally removed by a combined transtectal and transaqueductal route.

Matching rest perfusion and function in anatomically co-registered myocardial segments in our study confirms that 3-D image co-registration of cine MRI, DE MRI and gated SPECT could be a precise method of integrated visualization of perfusion, function and viability helping in differentiating all forms of reversible and irreversible effects of myocardial ischemia.