introduction bolus is a soft and resilient material which is used for increasing skin dose or to even out the irregular patient contour. the main property of various materials used presently as bolus is the water-equivalent electron density. ethyl methacrylate is used as a soft-liner in dentistry and its physical and chemical properties are proved to be nontoxic for human body. the goal of this...

chronic rhinosinusitis (crs) is a common disease which is usually diagnosed clinically, considering the combination of natural history, physical examination and imaging studies. this study aimed to evaluate the clinical value of routine postoperative histopathologic examination (pohe) in patients with a clinical diagnosis of chronic rhinosinusitis with polyposis (crswp), or without polyposis (c...

in this study, 22 patients (15-75 years old) were selected and transferred to ct scan for tumor ablation. for ablations, after prep and drep under the local anesthesia and mild sedation in proper position, small incision made and special needle inserted and guided by proper direction to the core of the tumor. then, laser probe inserted through the needle and laser energy delivered. although we ...

This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4-dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list-mode data acquisition in 4-dimensional ...

UNLABELLED Respiratory motion can induce artifacts in cardiac PET/CT because of the misregistration of the CT attenuation map and emission data. Some solutions to the respiratory motion problem use 4-dimensional CT, but this increases patient radiation exposure. Realignment of 3-dimensional CT and PET images can remove apparent uptake defects caused by mispositioning of the PET emission data in...

Abstract Background Cerebral neoplasm arises from brain, spinal cord and meningeal cells. Not only malignant cerebral neoplasm also benign tumor could lead to death due to mass effect on vital structures. Access to these tumors is difficult, and MRI and CT scan could be helpful in determining anatomical location of tumors and distinction of malignant from benign. Objective For better and ea...

BACKGROUND Chronic otitis media (COM) can be treated with tympanoplasty with or without mastoidectomy. In patients who have undergone middle ear surgery, three-dimensional spiral computed tomography (CT) scan plays an important role in optimizing surgical planning. OBJECTIVES This study was performed to compare the findings of three-dimensional reconstructed spiral and conventional CT scan of...

a 25-year-old man was admitted in hospital due to right side hemopneumothorax secondary to car accident. a chest tube was inserted. during the hospitalization days, chest ct scan revealed a 3cmx3 cm oval-shaped density located in the right upper lobe. since he was in a good general condition, he was discharged from hospital after removal of chest tube and a follow-up chest ct-scan was recommend...

conclusions headache, seizure, and trauma are the main reasons for ct scan requests. about 12% of the brain ct scans were abnormal. being knowledgeable about the indications of imaging, unnecessary imaging can be prevented, and consequently, its risks can be minimized. patients and methods in the present case series, demographic information and ct scan reports of 167 patients referred to taba r...

Introduction: Becuase of the most radiation dose receiving by human is related to medical radiation exposures, and also Computed Tomography (CT) is a special type of radiography that is one of the main method of radiation exposure today, and it's growing increasingly. Therefore, radio technologists working in CT scan imaging centers, are at risk of radiation. Due to the high am...