In this paper, first the limitations of the ray-based method and the one-way wave-field extrapolation migration (WEM) in imaging steeply dipping structures are discussed by some examples. Then a new method of the reverse time migration (RTM), used in imaging such complex structures is presented. The proposed method uses a new wave-field extrapolator called the Leapfrog-Rapid Expansion Method (L...

  Introduction: Although PET scanning using F-18[FDG] is considered the superior radiotracer for tumnor imaging, Gallium-67 is still in use for some malignancies such as lymphoma and hepatoma. One of the strategies to improve the diagnostic accuracy of Gallium is to perform SPECT which is reported to be more sensitive compared to planar imaging. In this study we compa...

Introduction: In spite of all the researches on medical imaging, this field is still hot. It is the third major area of research, conducted in the world. Unfortunately, there is no statistical evaluation available of the student theses in Iran. It does not seem like a policy is going to be established to address this issue. Providing a statistical insight to activities done in ...

Widespread studies on tumor diagnosis has led to the development of techniques with greater sensitivity and improved specificity for detection of occult and small subclinical tumors. Tumor imaging by radiolabeling of tumor-specific antibodies (Immunoscintigraphy) or tissue specific biochemical agents (Receptor imaging) and especially physiologic imaging with positron emitters (PET), have ...

Introduction: All of the Imaging modalities have advantages and disadvantages alone. So if we want to have the best and perfect image, combining these modalities produces something we desired. PET-MR images consist of morphologic and metabolic data. MRI and PET provide high spatial and contrast resolution and high sensitivity and molecular information respectively. Hybrid PET-...

introduction: interhemispheric transmission of signal is done by corpus callosum (cc) as the largest fiber tract in brain. cc comprised 5 segments of rostrum, genu, body, isthmus, and splenium. contradictory reports exist about sexual dimorphism of cc. we designed this study to assess probable sexual differences of cc and its different parts in men and women. methods: we analyzed magnetic reson...

introduction: the magnetic resonance imaging (mri) technique permits to monitor the development of the embryo in vivo without causing any developmental defects. although increasing application of mri imaging are predicted in veterinary sciences, there is little information available about mri studies of avian embryos and their eggs. the objective of the present study was to evaluate the ostrich...

introduction: the limited resolution of the imaging system causes partial volume effects (pves). these results in spreading of image counts to the neighboring pixels. this phenomenon is called spill-out effect. this study aimed at quantifying pves using imagej. methods:technetium-99m solution of concentration of 74 kbq/ml was filled into spheres a, b and c of diameters: 26 mm, 20 mm and 16 mm r...

decidualized ovarian endometrioma is a rare phenomenon in pregnancy, which can mimic ovarian malignancy in imaging and often poses a diagnostic challenge. we report a case of a large ruptured decidualized ovarian endometrioma in a 15 weeks gestation patient, and we will describe the imaging characteristics (ultrasonography and mr imaging findings) and the histopathological findings (macro- and ...

conclusion a higher magnetic field strength and a decrease in the hr resulted in an increase in body temperature during the mri procedure. results our investigation of the physiological response to rf heating indicated a link between increasing age and body temperature. a higher increase in body temperature was observed in older patients after a 3.0-t mri (r = 0.07, p = 0.29 for 1.5-t mri; r = ...