Preliminary study of visual pathway in ocular hypertension patients using magnetic resonance diffusion tensor and 3D-OCT / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To study the microscopic changes of visual pathology in ocular hypertension(OHT)patients using magnetic resonance diffusion tensor imaging(DTI)technology and three-dimensional optical coherence tomography(3D-OCT)technology. <p>METHODS: Twenty-six patients with 52 eyes diagnosed as OHT in our hospital from January 2016 to October 2019 were included in the case group. Twenty-six healthy patients who were matched with age and gender in the same period were included in the control group. All eyes were examined for best corrected visual acuity, central corneal thickness(CCT), non-contact intraocular pressure, while all eyes were examined by optical disc 3D-OCT combined optic nerve, optic chiasma, optic tract, and optic radiation DTI. Compared the differences between the two groups. <p>RESULTS: The CCT of the OHT group was thinner than that of the normal control group; the intraocular pressure was higher than that of the normal control group, and the difference was statistically significant(all <i>P</i><0.05). The optic disc area of the OHT group was larger than that of the normal control group, while the optic cup area was increased, and the average CP-RNFL thickness and nasal CP-RNFL thickness were thinner than those of the normal control group(all <i>P</i><0.05). There was no statistic difference in the superior, inferior and temporal CP-RNFL(all <i>P</i>>0.05). The FA values of bilateral optic nerve and optic radiation decreased compared with the normal control group, and the difference was statistically significant(all <i>P</i><0.05). There was no significant difference of optic chiasma, bilateral visual tract's FA value, and bilateral visual pathway ADC value between the two groups(all <i>P</i>>0.05). <p>CONCLUSION: 3D-OCT can obtain the thickness of CP-RNFL and the parameters of optic disc, DTI can reconstruct the intracranial visual pathway and can detect the microscopic changes of optic nerve, optic chiasma, optic tract, and optic radiation at early stage. Combining 3D-OCT and DTI technology can effectively understand the microscopic changes of the visual pathway and provide new models for clinical research of ocular hypertension patients.

The relationship between fractional anisotropy value and tumor microarchitecture in late-stage rat glioma

OBJECTIVE@#To explore the magnetic resonance diffusion tensor imaging (MR-DTI) features of in the late stage of Wistar rat C6 brain glioma, and the relationship between fractional anisotropy value and tumor microarchitecture.@*METHODS@#The concentration of more than 1.0 × 10/10 μL glioma cells and complete medium were injected stereotactically into the right caudate nucleus of the experimental group (n = 35) and control group (n = 10), respectively. Conventional MRI, DTI, and enhanced T1WI scans were Performed using the GE Signa HD × 3.0T MRI scanner about 3-4 weeks after implantation for the rats. Postprocessing was done using the DTI specific software Function Tool to gain FA image. Many ROIs were drawn avoiding hemorrhage, necrosis areas in tumor parenchyma, the value of FA was recorded. Each surviving rat brain was examined histologically using HE and immunohistochemical staining for VEGF and CD34. Pearson correlation analysis was used to determine the relationships between FA values and VEGF, MVD, cell density, respectively.@*RESULTS@#A total of 35 tumor-bearing rats were confirmed the tumor formation by the subsequent MRI and pathological examination. The mean FA values of the tumor and the contralateral brain tissue were 0.17 ± 0.03 and 0.31 ± 0.05 respectively, and the difference was statistically significant (t = 12.80, P  0.05). FA value in the late stage of Wistar rat C6 brain glioma has significant positive correlation to VEGF, MVD, cell density. The correlation coefficients between FA and VEGF, MVD, and cell density were 0.67, 0.65 and 0.71 (P < 0.05), respectively.@*CONCLUSIONS@#The FA value of rat glioma tumor in the late stage can preoperatively provide an accurate, reliable and noninvasive imaging monitoring method to evaluate the microstructure of glioma (cell density, the extent of angiogenesis, fiber bundle integrity and tumor cell infiltration and so on), predict the biological behavior of the tumor and make out surgical plan.

The relationship between fractional anisotropy value and tumor microarchitecture in late-stage rat glioma

Objective To explore the magnetic resonance diffusion tensor imaging (MR-DTI) features of in the late stage of Wistar rat C6 brain glioma, and the relationship between fractional anisotropy value and tumor microarchitecture. Methods The concentration of more than 1.0 × 10

Progress in diffusion tensor imaging in the optic nerve disease / 国际眼科杂志(Guoji Yanke Zazhi)

The optic nerve disease is a kind of diseases that seriously affect the visual function. In recent years, magnetic resonance diffusion tensor imaging ( DTI ) technology has been widely applied in the field of optic nerve diseases. Compared with the ophthalmic testing, such as optical coherence tomography imaging, visual evoked potential, field of vision, this method has obvious advantages. It not only can directly show the morphology changes of the optic nerve, visual pathway and visual cortex, but also can quantitatively analyze the morphological and pathological changes of the optic nerve, visual pathway and the visual cortex. This article reviews the imaging principle of diffusion tensor imaging, the progress and development prospect of diffusion tensor imaging in the study of the optic nerve diseases.

Clinical study of magnetic resonance diffusion tensor tractography on the evaluation of prognosis in patients with cerebral infarction / 中国综合临床

Objective To investigate application of diffusion tensor tractography (DTT) on evaluating motor dysfunction degree of patients with cerebral infarction and explore the relationship between infracted focus and cortical spinal tract(CST).Methods Forty patients with cerebral infarctions in the different periods and 30 healthy volunteers were enrolled our study.They all underwent DTT check and then established CST.Meantime,all the patients were measured ADL score according to activities of daily living (ADL) on admission and two months after the onset.Results DTT image was made for both in patients and health control people.The CST was built in people in control group and its shape was like the adults'.Its shape was from the precentral gyrus down to internal capsule and continued to pontine and medulla oblongata.Each successive was form good consistency.The DTT image of patients' health side was like normal and injury corticospinal tract was affected by influence of infarction area at different level,manifested as loss of discontinuity and anatomical configuration consistency.Based on the degree of CST,there were 9 cases in grade Ⅰ,20 cases in grade Ⅱ and 11 cases at grade Ⅲ.DTT image showed that the damage level of CST had an negative relation with ADL score at 2 month after therapy (r =-0.914,P ＜ 0.05).Conclusion DTT can show the spatial positions of infarctions and CST at non-invasive lesion and analyze the influence of infarctions and corticospinal tract.Therefore,it can serve as the objective proof for judging the injury of the motor function and evaluating prognosis.

Quantitative study on MR diffusion tensor imaging at acute stage of radiation-induced brain injury / 中华放射医学与防护杂志

Objective To explore the sensibility of radiation-induced normal brain injury in different regions at acute stage after all cranial radiotherapy by MR diffusion tensor imaging (DTI).Methods A total of 44 patients with brain tumors undergoing whole cranial radiotherapy were examined with convention and enhancement magnetic resonance imaging and diffusion tensor imaging before and three weeks after radiotherapy.The apparent diffusion coefficient ( ADC ),fractional anisotropy ( FA),relative anisotropy (RA) and volume ratio(VR) of DTI in contralateral brain hemisphere after radiotherapy with the dose of 27 Gy were measured and analyzed in different regions.Results No abnormal signal intensities were revealed in convention and enhancement MRI.ADC values in superficial cerebral convolution gray matter,ADC and VR values in deep gray nucleus were increased(t =- 3.321,- 2.810,P ＜ 0.05 ),while FA and RA values in deep gray nucleus were descended( t =2.906,2.349,P ＜0.05 ).There was no statistically significant difference among DTI index in other regions.Conclusions The brain gray matter more sensitive to radiation-induced brain injury in than white matter at acute stage of radiation.DTI could be used to evaluate the functional changes at the histocytology level of radiation-induced brain injury,and to explain the early clinical reactions after radiotherapy.

MR Diffusion Tensor Imaging in Optic Atrophy / 实用放射学杂志

Objective To study the MR diffusion tensor imaging(MR-DTI) feature of optic atrophy.Methods Diffusion tensor imaging data of optic nerve were acquired in twenty patients with optic atrophy and 20 healthy subjects.Results ①Atrophic optic nerves were thin obviously on MRI,and the signal of atrophic optic nerves decreased markedly on fractional anisotropy(FA) map and directionally encoded color(DEC) map.②The FA value(0.277?0.078) and ?∥ value(1.808?0.307) of atrophic optic nerves were declined obviously,and mean diffusivity(MD) value(1.442?0.264) and ?⊥ value(1.231?0.225) increased obviously in comparison to the normal optic nerves,there were statistically significant differences between the patients and the volunteers(P