Background/Objective: Nowadays, radiation is widely used in the diagnosis of many diseases, but hazards of radiation are an important limitation in the use of radiation for medical purposes. Awareness of radiation doses received by patients in different radiological examinations is the main step of patients' radiation protection. The purpose of this study was to investigate the level of doctor's knowledge about radiation doses received by patients in radiological examinations. Patients and Methods: A questionnaire was compiled and the most commonly requested radiological investigations were listed. Participants were asked to identify the average dose of radiation received by patients when they underwent a posterior-anterior hand x-ray. This was then utilized to represent a single dose of radiation, and doctors were asked to estimate the equivalent doses of radiation for other radiological examinations. The correct answers were derived from other related studies and text books. The questionnaire also had some questions about dose measurement units and low exposure risk investigations. We asked a convenience sample of 155 physicians. About 77% of the participants answered the questions completely. Results: The results indicated that only 58.3% of the doctors know the units of radiation absorb dose measurement units. Most of the doctors could not correctly estimate the amount of the radiation dose received by patients in a routine radiography of the hand and were not aware of the annual maximum permissible dose for the general public. Some of the doctors did not know that sonography and MRI have no radiation dose. The majority of them under estimated the radiation dose received by patients in radiological examinations. Conclusion: It does seem that most doctors have no idea of the amount of radiation received by patients undergoing commonly requested investigations, despite the fact that they have all passed the medical physics course.

Aims: Magnetic resonance venography based on susceptibility weighted imaging (SWI) utilizes deoxygenated hemoglobin in veins as an intrinsic contrast medium. Magnetic susceptibility difference between deoxygenated hemoglobin, oxygenated hemoglobin and parenchyma lead to an excellent venous contrast. The purpose of this study was to evaluate the different magnetic resonance imaging sequences and susceptibility weighted imaging in the visualization of sinus venous thrombosis.Materials & Methods: This cross-sectional study was performed in Shafa Medical imaging Center in Isfahan City, Iran, from August 2013 to September 2014 and 12 patients with sinus venous thrombosis were analyzed using MRI, SWI, and Phase contrast-magnetic resonance venography (PC-MRV).Findings: In all patients, sub-acute superior sagittal sinus, transverse and sigmoid sinuses thrombosis was most successfully detected during the susceptibility weighted imaging. In only one case, the sub-acute left transverse and sigmoid sinuses and left jugular vein of thrombosis was discernible with T1W. In 6 patients, sinus venous thrombosis was discernible with T2W in the sub-acute stage. PC-MRV showed the acute and sub-acute sinus venous thrombosis in all patients.Conclusion: Susceptibility weighted imaging has a high diagnostic value for detecting sub-acute superior sagittal sinus, transverse and sigmoid sinuses thrombosis.

Aims: Endometrial cancer is the most common malignancy of the female reproductive tract. As the prognosis factors, the determination of exact cancer stage and the differentiation of the lymph nodes plays a role in the selection of treatment plan and the rate of patient’s survival. The aim of this study was to investigate the diagnosis accuracy of dynamic and diffusion imaging techniques in the endometrial cancer staging as well as the differentiation of metastatic and non-metastatic lymph nodes.Materials & Methods: In this prospective study, 30 patients with endometrial cancer were studied in MRI ward of the imaging center of Imam Khomeini Hospital in Tehran in 2013-14. The subjects, selected by purposeful sampling method, underwent the pelvis imaging before the surgery. T1W and T2W scenes, the dynamic technique in phases including 25, 60, 120, and 240 seconds after the injection, and the diffusion technique (b=zero and 1000 s/mm2) were used in the imaging. Data was analyzed by SPSS 22 software using kappa statistic, two-independent T test, and one-way ANOVA.Findings: The agreement rate between the results of radiology and pathology in the determination of the different cancer stages was approximately 0.8, showing a good and considerable result (p<0.001). The diagnostic authenticity rate of the dynamic and diffusion techniques was 0.83. The results of radiology and pathology were completely consistent regarding the differentiation between the metastatic and non-metastatic lymph nodes. In different cancer stages, as well as in the metastatic and non-metastatic lymph nodes, the mean age and number of fertility were not significantly different (p>0.05).Conclusion: In the differentiation between the metastatic and non-metastatic lymph nodes in patients with endometrial cancer, the diagnostic accuracy is increased by the diffusion techniques utilizing the routine scenes and the injection.