Magnetic resonance imaging applications in evaluating of gamma knife radiosurgery induced effects on optic pathways

AMAÇ: Sellar- parasellar bölgeye radyocerrahi tedavisi alan hasta grubunda optik yolaklarda gamma knife radyocerrahiye bağlı değişiklikleri difüzyon tensör parametreleri ile incelenmesi. GEREÇ ve YÖNTEM: Sellar ve parasellar kitle tanısı ile gamma knife radyocerrahi amacıyla yönlendirilen 25 hasta tedavi öncesi ve tedavi sonrası 3.-6. aylarda difüzyon tensör görüntüleme ile değerlendirildi. FA, ADC, E1, E2, E3 haritaları görsel olarak karşılastırmalı değerlendirildi. 3B T1 GRE ve b:0 görüntüler kılavuzluğunda optik sinir, optik radyasyon proksimal orta ve distali ile kontrol lokalizasyonlarında ADC, E1, E2, E3, AD, RD değerleri ölçüldü. Ölçülen değerler bağımlı gruplarda t testi ile karşılaştırılarak değerlendirildi. BULGULAR: Tedavi sonrası erken dönemde optik sinirlerde tedavi öncesi kontrol grubuna göre FA değerinde azalma, ADC, AD ve RD değerlerinde artma saptandı Optik radyasyon proksimal kesimlerindeki ölçümlerde her iki tarafta da FA azalırken, ADC artmış, solda ise ek olarak RD de artmıştır. Bilateral optik radyasyon orta, distal kesim lokalizasyonlarında difüzyon parametrelerinde tedavi öncesi ile karşılaşıldığında anlamlı düzeyde farklılık saptanmamıştır. Difüzyon parametrelerinde diğer bölgelere göre anlamlı değişiklik gösteren lokalizasyon optik sinirler olarak tespit edildi. Kitleye verilen total doz ile difüzyon parametre değişimleri arasında anlamlı bir korelasyon saptanmamıştır. SONUÇ: Difüzyon tensör görüntüleme stereotaktik radyocerrahiye bağlı optik yolak ve beyaz cevherdeki değişiklikleri erken dönemde tespit edebilen iyi bir görüntüleme yöntemdir.PURPOSE: The aim of study is to investigate radiosurgery induced effects on optic pathway by using DTI parameters in patients with underwent stereotactic radiosurgery to the sellar and parasellar region. MATERIAL AND METHOD: Twenty five patients referred to Gamma Knife stereotactic radiosurgery for sellar- parasellar tumors, were evaluated by DTI before and at 3 and 6 months following radiosurgery. FA, ADC, E1, E2, E3 maps were visually evaluated. With the reference of 3D T1 GRE and b = 0 images, ADC, E1, E2, E3, AD, RD were calculated over each optic nerve, proximal- middle and distal optic radiations and control localization. Differences values statistically compared by using paired t-test. RESULTS: At early stage of radiosurgery mean FA values of optic nerves were significantly lower, ADC, AD, RD values of optic nerve significantly higher than pre- radiosurgery values. FA values were significantly reduced, ADC significantly increased in bilateral proximal optic radiations, RD increased only in left proxial optic radiations. No significant differences were observed in the DTI parameters of bilateral optic nerves, proximal- middle and distal optic radiations within pre and post radiosurgery group. Changes in DTI parameters on optic nerves were significantly different than other localizations. No significant correlation were found between the mean tumor dose and changes in DTI parameters. CONCLUSION: Diffusion tensor imaging is a valuable method in evaluating stereotactic radiosurgery induced effects on optic nerve and white matter at early stage

Assessment of Endothelial Dysfunction With Flow-Mediated Dilatation in Myeloproliferative Disorders.

Thrombosis is the most important cardiovascular complication of classical myeloproliferative disorders (MPDs). Endothelial dysfunction (ED) is known to play a major role in the mechanism of thrombophilia in MPDs

Assessment of Endothelial Dysfunction With Flow-Mediated Dilatation in Myeloproliferative Disorders

Background: Thrombosis is the most important cardiovascular complication of classical myeloproliferative disorders (MPDs). Endothelial dysfunction (ED) is known to play a major role in the mechanism of thrombophilia in MPDs. Methods: Endothelial dysfunction and its associations with other parameters were investigated. A total of 18 patients with polycythemia vera (PV), 24 with essential thrombocytosis (ET), 7 with primary myelofibrosis (PMF), and 30 healthy patients as a control group were included in the study. To assess the ED, flow-mediated dilatation (FMD) measurements were used. Results: The FMD (\%) result showing ED was determined as 9.9 (0.0-21.6) in the patients with PV, 7.3 (0.0-30.5) in patients with ET, 7.5 (0.0-18.0) in patients with PMF, and 13.9 (6.2-26.7) in the control group. The FMD (\%) was markedly impaired in all patients with MPD compared to the control patients (7.8 {[}0.0-30.5] vs 13.9 {[}6.15-26.8], P = .02). According to the disease subtypes, FMD (\%) was significantly lower in the ET group than in the control group (P = .01). Conclusion: Endothelial function was assessed in patients with MPD having FMD and was determined to demonstrate ED. Lower FMD was associated with older age, leukocytosis, thrombocytosis, and thrombosis history