Purpose Osteoarthritis is a common cause of pain and disability. Mild to moderate knee osteoarthritis that is resistant to nonsurgical options and not severe enough to warrant joint replacement represents a challenge in its management. On the basis of the hypothesis that neovessels and accompanying nerves are possible sources of pain, previous work demonstrated that transcatheter arterial embolization for chronic painful conditions resulted in excellent pain relief. We hypothesized that transcatheter arterial embolization can relieve pain associated with knee osteoarthritis. Methods Transcatheter arterial embolization for mild to moderate knee osteoarthritis using imipenem/cilastatin sodium or 75 lm calibrated Embozene microspheres as an embolic agent has been performed in 11 and three patients, respectively. We assessed adverse events and changes in Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores. Results Abnormal neovessels were identified within soft tissue surrounding knee joint in all cases by arteriography. No major adverse events were related to the procedures. Transcatheter arterial embolization rapidly improved WOMAC pain scores from 12.2 ± 1.9 to 3.3 ± 2.1 at 1 month after the procedure, with further improvement at 4 months (1.7 ± 2.2) and WOMAC total scores from 47.3 ± 5.8 to 11.6 ± 5.4 at 1 month, and to 6.3 ± 6.0 at 4 months. These improvements were maintained in most cases at the final follow-up examination at a mean of 12 ± 5 months (range 4-19 months). Conclusion Transcatheter arterial embolization for mild to moderate knee osteoarthritis was feasible, rapidly relieved resistant pain, and restored knee function.
Under the specific conditions of this study, the limits currently applicable were respected. If a new eye lens dose limit is introduced, our results indicate it could be difficult to comply with, without introducing additional protective eyewear.
The thalami are bilateral ovoid grey matter cerebral structures bordering the third ventricle on both sides, which participate in functions such as relaying of sensory and motor signals, regulation of consciousness, and alertness. Pathologies affecting the thalami can be of neoplastic, infectious, vascular, toxic, metabolic, or congenital origin.
The purpose of this review is to provide a comprehensive approach to the thalamus focusing on its anatomy, the main pathologies affecting this structure and their radiological semiology on CT and MRI. We will also illustrate the importance of multimodal MR imaging (morphologic sequences, diffusion-weighted imaging, perfusion, spectroscopy) for the diagnosis and treatment of these conditions.
This educational paper reviews the normal anatomy of the cavernous sinus (CS) and the imaging findings of common and uncommon lesions of this region. CS lesions may arise from different components of the CS or from adjacent structures and spaces. They can be classified as tumoral, inflammatory/infectious, vascular and congenital. Tumoral lesions include benign (meningiomas, pituitary adenomas, schwannomas) and malignant neoplasms (chondrosarcomas, chordomas, nasopharyngeal carcinomas, leukemia, metastases). Inflammatory/infectious conditions comprise: Tolosa Hunt, abscess, Lemierre syndrome and thrombophlebitis. Vascular lesions include: hemangiomas, carotido-cavernous fistula, aneurysms, arteriovenous malformations. Congenital conditions include the epidermoid cyst, dermoid cyst and fatty deposits. Although imaging features of non-vascular CS diseases are most often non-specific, careful analysis of the adjacent structures suggests the correct diagnosis. In vascular pathology, characteristic MR imaging findings are observed.
Proton beam therapy (PBT) is used for the treatment of skull base tumors to precisely deliver high-doses of radiation to the tumor volume while sparing normal brain tissue and other organs at risk such as the optic apparatus, the brainstem and the pituitary gland. It offers superior dose distribution as compared to photon radiation therapy. The clinical advantage of PBT over photon techniques is the marked reduction in the integral dose to the patient due to the absence of an exit dose beyond the proton Bragg peak. Proton beam therapy has shown benefits in the treatment of skull base tumors, uveal melanoma, optic pathway gliomas, pituitary adenomas, acoustic neuromas, nasopharynx and paranasal sinus tumors and spinal cord tumors. [1][2][3][4] . A rare yet important complication following brain radiation therapy is radiation necrosis 5-7 , i.e. the appearance of a new ABSTRACT: Background: Discrimination between radiation necrosis and tumor progression after radiation therapy represents a radiologic challenge. The aim of our investigation is to identify patterns of radiation necrosis on brain magnetic resonance imaging (MRI) and positron emission tomography (PET) with Fluoroethyltyrosin (FET) after proton beam therapy (PBT) for skull base tumors.
Material and Methods:Five consecutive patients with extra-axial neoplasms were included, presenting a total of eight radiation necrosis lesions (three clival chordomas; two petroclival chondrosarcomas; two women; mean age: 49 ± 18.2 years). Radiation necrosis was defined as the appearance of abnormal enhancement on MRI after PBT decreasing over time, and additional histopathologic confirmation in one patient. MRI and PET imaging were retrospectively analyzed by two experienced radiologists in consensus. Results: All lesions were localized close to the primary tumor in the field of irradiation. Three patients showed bilateral symmetrical lesions. All lesions showed T2 hyperintensity and T1 hypointensity. Cerebral blood volume (CBV) was reduced in all available studies. None of the lesions showed a restricted diffusion. FET-PET (three patients) showed a higher uptake in four out of five lesions; three of which had a mean tumor-to-background (TBRmean) uptake lower than 1.95 and FET uptake increasing over time and were correctly classified into radiation necrosis. Conclusions: Most radiation necroses were in direct continuity with the primary tumor mimicking tumor progression. The most consistent imaging findings for PBT radiation necrosis are low CBV without restricted diffusion and FET-PET TBRmean lower than 1.95 or increasing uptake over time. Bilateral symmetric involvement may be another indicator of radiation necrosis.RÉSUMÉ: Critères radiologiques de la nécrose après protonthérapie des tumeurs de la base du crâne. Contexte : La distinction entre la nécrose due à l'irradiation et la progression de la tumeur après l'irradiation est un défi au point de vue radiologique. Le but de notre étude était d'identifier le profil radiologique de la nécrose radio-induite à l'IRM et...
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