Objective To evaluate the fiber altering and clinical relationship in patients with occipital and temporal lobe cerebral infarction with DTI.Methods Fifty patients suffering from cerebral stroke were analyzed with conventional MRI,DWI and DTI. The fibers of visual pathway were depicted ,and their fractional anisotropy (FA),apparent diffusion coefficient (ADC),isotropic im-age (Iso)and T2-weighted trace were measured and analyzed.Results Regions of interest (ROIs)were placed in infarction and nor-mal contralateral tissue for tracking the visual pathways.The different parameters were measured.FA is useful to differentiate hy-per-acute stroke from acute and sub-acute stroke.FA values increased slightly in hyper-acute and decreased in acute,sub-acute and chronic phase.The values of ADC in infarction regions in hyper-acute,acute and sub-acute phases were lower than those of the con-tralateral tissue.Iso and T2-weighted trace increased in acute phase and decreased in chronic phase.DTT was used to show the way and chang of visual pathway.Conclusion DTI could track the fiber of visual pathway,and depict the fiber of infarction zone.DTT could be used in evaluating the prognosis of patients.

Edge detection is an absolutely necessary step in medical image processing, and the use of differential operators to detect edge is one of the most common and effective methods. In this paper are analyzed the frequency features of the Roberts operator, Prewitt operator, Sobel operator and Laplacian operator from the viewpoint of frequency domain, and it is proposed that the frequency features of the differential operators should be considered when differential operator is being used and/or constructed. Because edge detection operator is sensitive to the edge type, the appropriate operator should be adopted in different edge type detection. Finally, the importance and necessity of selecting edge detection operator are validated in the MRI image edge processing.
Algorithms ; Brain ; pathology ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; methods ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; Pattern Recognition, Automated ; methods

Objective:To compare the diagnostic efficacy of 18F-prostate specific membrane antigen (PSMA)-1007 PET/CT, 18F-FDG PET/CT and multi-parameter MRI (mpMRI) in prostate cancer (PCa). Methods:Retrospective analysis was conducted on data from 22 patients ((72.6±6.2) years) with pathologically confirmed PCa in the Affiliated Taizhou People′s Hospital of Nanjing Medical University between April 2021 and September 2022. All patients underwent 18F-PSMA-1007 PET/CT, 18F-FDG PET/CT, and mpMRI examination within 30 d, and the imaging parameters were collected, including PSMA-SUV max, FDG-SUV max, minimum apparent diffusion coefficient (ADC min), mean apparent diffusion coefficient (ADC mean), PSMA-SUV max/ADC min, PSMA-SUV max/ADC mean, FDG-SUV max/ADC min, FDG-SUV max/ADC mean. Patients were divided into groups based on the International Society of Urological Pathology (ISUP) grading (≤3 vs >3) and serum total prostate specific antigen (TPSA; ≤20 μg/L vs >20 μg/L), and differences of imaging parameters between groups were compared (Mann-Whitney U test or independent-sample t test). ROC curves were generated to evaluate the diagnostic ability of each parameter for different levels of PCa. χ2 test and ROC curve analysis were used to compare the detection rate and diagnostic efficiency of three imaging methods for primary focus, lymph node metastasis, and bone metastasis in PCa. Results:Differences were found between ISUP≤3 ( n=6) and >3 ( n=16) groups in PSMA-SUV max/ADC min, PSMA-SUV max/ADC mean, PSMA-SUV max, and ADC min ( z values: from -2.65 to -2.36, t=3.60, P values: 0.002-0.018). But there was no significant difference found between TPSA≤20 μg/L ( n=5) and >20 μg/L ( n=17) groups in all indices ( z values: from -1.76 to -1.45, t values: -1.19 and 1.28, all P>0.05). The optimal cut-off value for PSMA-SUV max/ADC min in differentiating high-grade and low-grade PCa was determined to be 22.628×10 3. In the patient-based analysis, no statistical difference was found in the detection rate of PCa primary tumors among 18F-PSMA-1007 PET/CT, 18F-FDG PET/CT, and mpMRI ( χ2=1.91, P=0.767). However, the detection rates of lymph node and bone metastasis among three imaging methods were significantly different (72.73%(16/22), 59.09%(13/22), 36.36%(8/22) and 81.82%(18/22), 63.64%(14/22), 45.45%(10/22); χ2 values: 6.03, 6.29; P values: 0.049, 0.043). 18F-PSMA-1007 PET/CT resulted in a 36.36%(8/22) increase in N stage and the 40.91%(9/22) increase in M stage compared to mpMRI. Conclusions:PSMA-SUV max/ADC min is a valuable parameter for differentiating high-grade and low-grade PCa. 18F-PSMA-1007 PET/CT demonstrates superior detection rate of PCa lymph node and bone metastasis compared to 18F-FDG PET/CT and mpMRI, and exhibits higher diagnostic efficiency, so it can be recommended for NM staging in patients with PCa.