Background: Prostate cancer is the third leading cause of death and is the most common cause of cancer in elderly men. Regarding to the low accuracy of screening methods such as prostate-specific antigen (PSA), Digital Rectal Examination (DRE) and trans rectal ultrasound (TRUS) in detection and localization of tumor, Magnetic Resonance Imaging (MRI) and diffusion Weighted Imaging (DWI) attracted many attentions in the past years. DWI reveals micro-molecular diffusion, which is the Brownian motion of the spins in biologic tissues. This technique can delineate pathologic lesions with high tissue contrast against generally suppressed background signal. In this paper, the value of DWI in detection of prostate cancer is studied.Methods: In this cross-sectional study, the studied population are suspicious patients to prostate cancer based on high Prostatic Specific Antigen level or abnormal Digital Rectal Examination who refered for prostate biopsy to radiology department of Hazrate- Rasoul Hospital during the year 2011. The results of DWI are compared to biopsy results for all patients.Results: Eighty five patients are selected. The DWI sensitivity in detecting of prostate cancer is 100%, specificity 97.1% and positive and negative predictive values are 89.5% and 100%, respectively. The results showed that if DWI reports the prostate cancer as negative, the result was highly reliable and if it reports as positive, although the report was not 100% reliable, but it still had high reliability, more than 90%.Conclusion: DWI had high accuracy in detecting prostate cancer for patients with cancer. Also the accuracy of this method for patients without prostate cancer was acceptable compared to the other common methods.

Background: Multiple sclerosis (MS) is a chronic disease that begins most commonly in young adults and is characterized pathologically by multiple areas of central nervous system (CNS) white matter inflammation, demyelination, and glial scarring. The most valuable aid for diagnosis is magnetic resonance imaging (MRI). New type of MRI has been developed on the basis of molecular diffusion which capable of detecting acute and active lesions. Early diagnosis and treatment is possible to stop or slowdown progression of disease. The aim of this study is to compare the findings of conventional and diffusion- weighted (DW) MRI in detection cerebral lesions of MS.Methods: Thirty patients with clinically definite MS and 30 healthy volunteers were studied in a descriptive-prospective survey over a twelve-month period of time.Conventional and DW MRI were used in both groups. Total number, morphology, location and the mean size of the intra-cerebral plaques of MS were compared between group. The sensitivity and the specificity of both imaging methods in detecting these plaques were determined.Results: Thirty patients with MS with the mean age of 32.76±8.79 years and 30 healthy individuals with the mean age of 32.75±9.23 years were enrolled. Plaque within the brain was significantly higher by the conventional method (P<0.05). Ovoid lesions were greater in number in the conventional method group. More lesions were detected by the conventional method in the areas of periventricle, centrum semiovale and corpus callosum. Regarding the size of plaque, the minimum measurement was significantly lower in the conventional method group. The sensitivity of both methods was 100%. The specificity of conventional and DW MRI was 86.6% and 96.6%, respectively.Conclusion: In our study the sensitivity of both methods was the same but the specificity of DW MRI was higher. DW MRI may detect lesions which are not detectable by the routine methods.

Introduction The staging of endometrial carcinoma is now performed based on postoperative pathological assessments. If the staging of the cancer could be possible with a preoperative non-invasive method, based on the International Federation of Gynecology and Obstetrics system, a more appropriate treatment protocol can be recommended for patients. This study was performed aimed to evaluate the diagnostic value of dynamic magnetic resonance imaging with diffusion-weighted imaging in the staging of endometrial carcinoma, based on the postoperative histopathological reference standard. Methods This prospective study was conducted in 2016-2021 on 35 patients with endometrial cancer referred to Ghaem Hospital in Mashhad. The staging of endometrial cancer was performed based on MRI findings and pathological samples. The diagnostic value of MRI was calculated to distinguish stages 1 from 2 and 1A from 1B. The lesion dimensions in the MRI and the pathological samples were compared using independent-sample t-test and the lesion dimensions between different stages using the ANOVA test by SPSS (version 17). P<0. 05 was considered statistically significant. Results According to the findings of MRI and pathology, the majority of patients (93. 3%) were in stage 1, and 2 (6. 7%) were in stage 2. The sensitivity, specificity, positive and negative predictive value in differentiating stage 1 from stage 2 was 100%, and the sensitivity, specificity, positive and negative predictive value of MRI in differentiating IA from IB was 100%. Conclusion It seems that dMRI by DWI method can be used in the staging of endometrial tumors in the initial stages (stage 1 from 2 and IA from IB) with diagnostic value.

Background: The most common primary tumors of brain are gliomas. Grading of tumor is vital for designing proper treatment plans. The gold standard choice to determine the grade of glial tumor is biopsy which is an invasive method. Objective: In this study, we try to investigate the role of fractional anisotropy (diffusion anisotropy) and linear anisotropy coefficient (its shape) with the aim of diffusion Tensor imaging (as a non-invasive method) in the grading of gliomas. Methods: A group of 20 patients with histologically glial approved was evaluated. In this study, we used a 1. 5-Tesla MR system (AVANTO; Siemens, Germany) with a standard head coil for scanning. Multi-directional diffusion weighted imaging (measured in 12 non-collinear directions) and T1 weighted non-enhanced were performed for all patients. We defined two Regions of Interest (ROIs); white matter adjacent to the tumor and the homologous fiber tracts to the first ROI in the contralateral hemisphere. Results: Linear anisotropy coefficient (CL), fractional anisotropy (FA) values and ratios of low-grade peri-tumoral fiber tracts were higher than high-grade gliomas (Pvalue CLt=0. 014, P-value CLt/n=0. 019 and P-value FAt=0. 006, P-value FAt/n=0. 024). In addition, we perform ROC curve for each parameter (CL ratio-AUC = 0. 82 and FA ratio-AUC = 0. 868). Conclusion: Our findings prove significant difference between diffusion anisotropy (FA) and diffusion shape (Cl) between low grade and high grade glioma, based on which we find this evaluation helpful in the grading of glial tumors.

This paper proposes a new approach for image noise reduction using partial diffusion equation (PDE). diffusion coefficient is an important parameter in PDE for image noise reduction. This parameter affects the noise reduction results and quality of edges in the denoised image. The existing PDE-based image denoising techniques experimentally adjust the diffusion coefficient. This paper proposes a new approach to adaptively adjust the diffusion coefficient. The proposed approach was applied on a number of standard images to evaluate its performance. The results indicate that the proposed approach outperform the existing PDE-based image denoisng techniques.

A novel meshless numerical technique to solve problems in computational mechanics is introduced. In the interest of the distinct comparison between the new technique and the prior methods, the manuscript fully explains the theory of the technique. For the one and two-dimensional diffusion and one and two-dimensional advection-diffusion examples presented in this study, the solution technique is presented in details. Being a meshless technique, the control volumes are arbitrary chosen, and they possess simple shapes which contrary to the existing control volume methods can overlap. The number of the points within each control volume, hence the degree of the interpolation can be different throughout the considered computational domain. Since the control volumes are of simple shapes, the integrals can be readily evaluated. Compared to the other methods including the exact solution, the results show to be highly accurate and very promising for a broad range of problems in computational mechanics.