In nuclear medicine, studies of important tissues such as cardiac, the emitted photons from the cardiac before reaching the gamma detectors are attenuated and scattered by other tissues inside the thorax. Therefore, the quality and contrast of the image will be reduced. In this research, to improve the quality of cardiac images by SPECT system, the most convenient algorithms for attenuation correction were studied and assessed in the first step. Then the best method using the line source in Transmission Attenuation Correction (TAC) method was modified and the experimental data wase obtained by using this new and modified method, cardiac phantom, Dual Head SPECT system and a line source of 201Tl with the activity of about 0.5 mCi. The data was collected and obtained in two steps: (1) Scanning the cardiac phantom and line source which was beside the cardiac phantom this step involves using emission and transmission simultaneously. (2) Scanning the cardiac phantom in the absence of line source which means using emission data. Next, the suggested attenuation correction formula was used and the calculated attenuation coefficient for each pixel was calculated and applied to each pixel. Our results showed a nice improvement in contrast and visibility of the images by this simple and in imporoved expensive method. The advantages of this method include simplicity, the available radionuclide, improved accuracy, quality and contrast of the final image, and finally, cost – effectiveness. These advantages may help the nuclear medicine centers to improve their ability to detect the physiological and functional defects of the cardiac, especially in the elder and women patients.

Ahmad ibn Ali ibn Ahmad ibn Abbas Najashi proficient at rijal science and the author of the first and most important Shiite rijal work namely Fihrist Asmai Musannaf al-Shiah (or al-Najashi's rijal).Although the author's aim was to list Shiite works and books, however there are useful information about the compilers of books, their classes, their race and genealogies and finally their academic status and authenticity of their works. Studying and evaluating the method used by Najashi, the author of this paper tries to display his efforts in providing general information about compilers and his method in presenting them.

Background & Aims: Nowadays, imaging of the blood supply of the heart muscle by single photon emission computed tomography (SPECT: Single Photon Emission Computed Tomography) due to its non-invasive nature and providing information with physiological value and low cost compared to the valuable angiography method. It is highly diagnostic. But these images undergo changes and artifacts under the influence of factors, the result of which is the reduction of the diagnostic accuracy of the images and false positive cases. During the detection process, several physical effects such as attenuation, scattering, and collimator response function affect the frequency of emitted photons,this leads to the destruction of the contrast and as a result of reducing the quantitative and qualitative accuracy of the images. Attenuation, as the most destructive factor of SPECT images, reduces the quality of SPECT images of heart blood supply and reduces the sensitivity of tests related to the diagnosis of coronary artery diseases, and for non-uniform environments, especially in nuclear imaging of chest areas. And the heart is necessary to produce a map of patient attenuation coefficients. The existence of scattered photons is also one of the main factors of error in quantization,the detection of scattered events affects the contrast of the lesions and causes the lack of image resolution and signal-to-noise ratio. Therefore, to correct the attenuation and scattering of the rays in the heart images quantitatively and qualitatively, patterns are needed in SPECT systems. Due to the importance of the topic, various research groups around the world have presented their research and results on correcting the effect of scattering of rays and also correcting the effect of weakening the rays. If there was no limitation of energy resolution, it was easily possible to identify the scattered rays and prevent them from being recorded in the image. Because we know that scattered rays lose energy. Because gamma rays are single energy and their energy amount is completely known. Therefore, each photon with less energy will represent scattered rays, but due to the limited energy resolution of the gamma camera, a range is usually considered on the sides of the main energy, which is called the energy window. It is assumed that the photons recorded in this energy range are primary photons, but in fact, many photons scattered in the body are also recorded in this window. These scattered rays do not carry correct spatial information and lead to a decrease in image resolution and contrast and quantization errors in the image. In nuclear medicine, instead of researching and examining the patient or processing the image of the patient, simulated images can be examined. Simulators can provide information about each of the image destruction factors. The purpose of this research is to propose a new method for scattering correction, in this research, a combination of Monte Carlo and modeling is used for the rapid production of scattered views, and in the proposed method, the two-matrix method is used, this method At the stage of generating mathematical views, dispersion is added and this problem leads to the removal of scattered rays. As a result, an image is reconstructed that is free from the effects of attenuation and non-ideal dispersion and leads to an increase in contrast and improvement of power. Detecting waste, increasing the signal-to-noise ratio, and increasing the accuracy of quantification. Methods: In this study, the effect of applying attenuation and dispersion correction using two energy windows (DEW) and three energy windows (TEW) methods in cardiac aspect imaging was investigated and evaluated, and to simulate cardiac aspect imaging, a special code similar to SAR Monte Carlo GATE was used as the SPECT imaging system and XCAT digital phantom with activity distribution and realistic attenuation map was used to model the human trunk. Results: Comparison of image contrast improvement in different modes of attenuation and dispersion correction shows that the highest image contrast is obtained from the (TEW1+AC) method with an average increase of 25% and MSE in different modes of attenuation correction. And the dispersion compared to the reference image was reduced from 51. 5% to 54. 5%. Compared to the reference image, MSE decreased from 1. 4 in Un_Cor to 1. 15, 1. 13, 1. 12, and 1. 14 in AC+TEW1, AC+DEW, AC, and AC+TEW2, respectively, and the signal-to-noise ratio (SNR) increased up to 71% in all methods of applying dispersion correction along with attenuation correction compared to applying attenuation correction (AC). Conclusion: In this study, the effect of attenuation and dispersion correction in 5 non-correction modes, with attenuation correction, attenuation, and dispersion correction using two-window and three-window methods with triangular approximation and three-window with trapezoidal approximation on We evaluated XCAT phantom simulated images and heart muscle perfusion images by SPECT method and 4 different parameters were used to compare and evaluate the images, including profile, contrast, mean squared error (MSE) and signal to noise. According to the results of the quantification of reconstructed images, it is possible to apply dispersion correction along with attenuation correction.

Objectives: To assess the degree of correction in superior oblique over action in A pattern strabismus, atypical Brown's syndrome, and monocular elevation deficiency syndrome by the graduated superior oblique recession.Methods: This interventional case series comprised 10 patients (12 eyes) with an indication for superior oblique weakening. According to the grade of muscle over action, forced duction test result, A-pattern and in torsion, and via a superior temporal approach the superior oblique tendon was transposed 10-12 mm posterior to the limbos and 1-4 mm medial to the insertion of the superior rectos. The patients were followed up for at least 6 weeks post operation. Results: Ten patients aged 6-22 years (6 females and 4 males) underwent the operation. The A-pattern was corrected 94%. The over action, vertical deviation and the forced duction test were reduced by less than half in cases of atypical Brown's and monocular elevation deficiency syndromes. The improvement was significant in the 2 cases of DVD with an overacting superior oblique. Conclusion: The graduated recession of the superior oblique is an appropriate procedure for weakening the muscle and is adjustable to the grade of muscle over action, A-pattern and in torsion.

Interacting with hadiths, authenticating and weakening of narrators, and describing some hadith terms such as ṣ aḥ ī ḥ , ḥ asan, shā dh, mursal, muwqū f, etc. Hakim Nayshā bū rī differs from others: He verifies some hadiths that are not authentic according to other traditionists, and even according to his own bases in his other books such as ma'rifat ‘ Ulū m al-Hadith. Accordingly, he was accused of being mutasā hil (lenient in hadith). This paper, based on descriptive-analytical method, attempts to firstly reveal his opinions on hadiths of Ṣ aḥ ī ḥ , Ḥ asan, Ḍ a'ī f, Mawqū f, Mursal, Shā dh, Zī yā dā t al-Thiqah, citing from a heretic narrator, report of sanad and text of narrations, Jarḥ and Ta'dī l. Secondly, it compares Hakim’ s views and method to other traditionists. Thirdly, it shows how much Hakim, in his al-Mustadrak, adhered to his bases. It is intended to reveal his bases and views, as well as his own adherence to them. As such, the basic features of Hakim’ s hadith school would be detected. Based on the reviews and comparisons, it can be said that it is not acceptable to ascribe tasā hul to Hakim’ s method in verifying hadiths of Mustadrak, justified by some evidences including his old age, memory weakness, lack of time to edit his book. Also, it is notable that to use his hadiths in Mustadrak, one must review both sanad and text.

Introduction: Nowadays, Imaging of the myocardial perfusion (MPI) using the single photon emission tomography (SPET) in the diagnosis of coronary artery disease, especially myocardial ischemia, is of great importance. In contrast to the coronary artery angiography, MPI is non-invasive, less expensive and more physiological. Unfortunately, this image is affected by the some artifacts. These artifacts lead to decrease image diagnostic accuracy and increase false positive cases. One of the most important effective artifacts is due to attenuation. These attenuation artifacts are caused by the left breast tissue in women, diaphragm in men and the chest wall in both sexes. Because of the inherent non- uniform attenuation map in the thorax region, this problem is very complex. Methods: The aim of this study is to correct attenuation artifact with a simple method that is available and very easy to use. In this study we used transmission scanning by 99mTc in the sequential views and an attenuation map was created.After attenuation correction of the original images with attenuation map, non corrected and corrected images were compared with angiography results to apply attenuation correction based on functional findings. Results: Results show that new artifacts are created and experiences of physicians in the impression of the images is critical. Finally, the sensitivity of images increased from 86.20% to 96.42%, the specificity decreased from 85.71% to 54.54% and the diagnostic accuracy decreased from 86% to 78%. Conclusion: Attenuation correction can produce new artifacts, which can influence the way scans are interpreted. It seems that attenuation correction of the images, need special experience. Lack of enough experience in attenuation correction techniques, can comprise the diagnostic accuracy of images.