PURPOSE To determine the impact of patient positioning and scan orientation on the appearance of air in the nasolacrimal drainage system on computed tomography (CT) imaging, and the repeatability of the observations. METHODS This was a retrospective analysis of CT images for 92 patients. RESULTS Air was found to be present more fully in the upright-position group as compared with the supine...

introduction: cholesteatoma is traditionally diagnosed by otoscopic examination and treated by surgery. the necessity for imaging in an uncomplicated case is controversial. this study was planned to investigate the usefulness of a preoperative high-resolution computed tomography (hrct) scan in depicting the status of middle ear structures in the presence of cholesteatoma and also to compare the...

A 50-year old woman was admitted to emergency room due to an episode of recurrent renal colic. Double-J ureteral stent has been placed several weeks earlier due to mild hydronephrosis of the left kidney. She had a history of urinary tract infections and poorly defined abdominal pain. Abdominal computed tomography (CT) scan revealed normal left kidney and normal left urinary tract without calcul...

Between 1980 and 1985, 102 patients (84 women and 18 men) who had coronal CT scans of the sella turcica for suspected prolactin adenoma underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070), and reports of the preoperative CT examinations were compared with the findings at transsphenoidal exploration. The same neurosurgeon perfo...

the presence of anatomic variations of paranasal sinuses must be noted in order to attain a full understanding and accurate diagnosis of chronic sinusitis. the frequency of anatomic variations in chronic sinusitis is different in various studies. the purpose of this study is to assess the frequency of anatomic variations in chronic sinusitis patients admitted to otolaryngology ward of shahid sa...

introduction in ct imaging, metallic implants inside the tissues cause metal artifact that reduce the quality of image for diagnosis. in order to reduce the effect of this artifact, a new method with more appropriate results has been presented in this research work. materials and methods the presented method comprised of following steps: a) image enhancement and metal areas extraction, b) sinog...

introduction: pulmonary embolism (pe) is a common lethal disease that its clinical symptoms may be seen in many other diseases. computed tomography pulmonary angiography (ctpa) is a valuable diagnostic modality for detection of pe. in addition, it can accurately detect the other diseases with clinical symptoms similar to pe. the aim of this study is to evaluate the frequency of pe and nonemboli...

introduction: 99mtc-mibi has been proposed for use as an imaging agent for various tumors, including breast cancer, lung cancer, lymphomas, melanomas and brain neoplastic lesions. brain tumors are very common and radiotherapy being major part of treatment following surgery. after radiotherapy, deteriorating clinical status can be due to either radiation necrosis or recurrent tumor. computed tom...