نتایج جستجو برای: megavoltage cone beam computed tomography

تعداد نتایج: 397607  

2014
Kana Motegi Ryosuke Kohno Takashi Ueda Toshiyuki Shibuya Takaki Ariji Mitsuhiko Kawashima Tetsuo Akimoto

Accurate dose delivery is essential for the success of intensity-modulated radiation therapy (IMRT) for patients with head-and-neck (HN) cancer. Reproducibility of IMRT dose delivery to HN regions can be critically influenced by treatment-related changes in body contours. Moreover, some set-up margins may not be adaptable to positional uncertainties of HN structures at every treatment. To obtai...

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2011
Hassan S. Abou-elenein Ehab M. Attalla H. Ammar Ismail Eldesoky Mohamed Farouk Mohamed S. Zaghloul

The improvement in conformal radiotherapy techniques enables us to achieve steep dose gradients around the target which allows the delivery of higher doses to a tumor volume while maintaining the sparing of surrounding normal tissue. One of the reasons for this improvement was the implementation of intensity-modulated radio therapy (IMRT) by using linear accelerators fitted with multi-leaf coll...

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2014
Wolfgang Hohenforst-Schmidt Rosemarie Banckwitz Paul Zarogoulidis Thomas Vogl Kaid Darwiche Eugene Goldberg Haidong Huang Michael Simoff Qiang Li Robert Browning Lutz Freitag J Francis Turner Patrick Le Pivert Lonny Yarmus Konstantinos Zarogoulidis Johannes Brachmann

RATIONALE Cone Beam Computed Tomography imaging has become increasingly important in many fields of interventional therapies. OBJECTIVE Lung navigation study which is an uncommon soft tissue approach. METHODS As no effective organ radiation dose levels were available for this kind of Cone Beam Computed Tomography application we simulated in our DynaCT (Siemens AG, Forchheim, Germany) suite ...

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2017
Sunil Sharma Ganesh Narayanasamy Richard Clarkson Ming Chao Eduardo G. Moros Xin Zhang Yulong Yan Marjan Boerma Nava Paudel Steven Morrill Peter Corry Robert J. Griffin

PURPOSE To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. METHOD AND MATERIALS The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6...

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Journal: :iranian journal of radiology 0
solmaz valizadeh department of oral and maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran zahra vasegh department of oral and maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran; department of oral and maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran. tel: +98-2188773550, fax: +98-2188773550 samin rezapanah department of oral and maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran yaser safi department of oral and maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran mohamad javad khaeazifard dental research institute, tehran university of medical sciences, tehran, iran

objectives this study aimed to assess the effect of object position in the field of view (fov) of cbct on detection of vrfs in teeth with intra-canal posts. materials and methods the crowns of 60 extracted premolar teeth were cut at the level of cementoenamel junction (cej). root canals were filled with gutta-percha and filling of the coronal 2/3 of the root canals was subsequently removed to f...

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ژورنال: :مجله دانشگاه علوم پزشکی شهید صدوقی یزد 0
فاطمه عزالدینی اردکانی f ezzadini ardekani school of dentistry, shahid sadoughi university of medical sciences, yazdدانشکده دندانپزشکی یزد فهیمه احرار یزدی f ahrar yazdi school of dentistry, shahid sadoughi university of medical sciences, yazdدانشکده دندانپزشکی یزد مجید کاظمی m kazemi university of medical sciences, tehran, iranدانشگاه علوم پزشکی ارتش تهران، تهران، ایران

مقدمه: عفونت های ادنتوژنیک یکی از عوامل شایع سینوزیت ماگزیلاری است. هدف از این مطالعه ارزیابی رابطه بین دندان ها با بیماری پریودنتال و افزایش ضخامت مخاط سینوس ماگزیلاری با استفاده از cbct می باشد. روش بررسی: این مطالعه از نوع گذشته نگر و مقطعی بود. اسکن های cbct97 بیمار(188 سینوس) به منظور ارزیابی وجود بیماری پریودنتال و ضایعات پری اپیکال در دندان های خلفی ماگزیلا و رابطه اش با افزایش ضخامت مخا...

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ژورنال: :مجله دانشگاه علوم پزشکی شهید صدوقی یزد 0
فاطمه عزالدینی اردکانی department of oral and maxillodacial radiology, school of dentistry, shahid sadughi university of medical sciences, yazd, iran.گروه رادیولوژی دهان و فک و صورت، دانشکده دندانپزشکی، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی شهید صدوقی یزد یاسر صافی department of oral and maxillodacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran.گروه رادیولوژی دهان و فک و صورت، دانشکده دندانپزشکی، دانشگاه علوم پزشکی شهید بهشتی تهران شیوا ایران پور department of oral and maxillodacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran.گروه رادیولوژی دهان و فک و صورت، دانشکده دندانپزشکی، دانشگاه علوم پزشکی شهید بهشتی تهران خلیل ساریخانی خرمی department of oral and maxillodacial radiology, school of dentistry, shahid sadughi university of medical sciences, yazd, iran.گروه رادیولوژی دهان و فک و صورت، دانشکده دندانپزشکی، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی شهید صدوقی یزد محمدرضا بیطرف school of dentistry, shahid sadoughi university of medical sciences, yazd, iran.دانشکده دندانپزشکی، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی شهید صدوقی یزد

مقدمه: میزان استخوان موجود از معیارهای مهم در درمان های ایمپلنت است، در این راستا نوع رادیوگرافی در تعیین کمیت استخوان باقی مانده حائز اهمیت است و cbct با دقت بالایی نشان دهنده ارتفاع و پهنای استخوان موجود می باشد. هدف از این مطالعه بررسی توزیع فراوانی انواع ریج خلفی مندیبل بدون دندان با استفاده از(cbct) cone beam computed tomography در یک جمعیت ایرانی بود. روش بررسی: در این مطالعه توصیفی مقطعی...

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Journal: :journal of dental school, shahid beheshti university of medical sciences 0
s. valizadeh dept. of oral & maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran. n. abazarian y. safi dept. of oral & maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran. z. azizi dept. of oral & maxillofacial radiology, school of dentistry, shahid beheshti university of medical sciences, tehran, iran.

objective: diagnosis of vertical root fractures (vrfs) is critical in endodontics. cone beam computed tomography (cbct)  has significantly enhanced image quality compared to digital radiography (dr) and greatly aids the diagnosis of vrfs but, metal artifacts has remained as a problem in vrf detection.  this study evaluated the effect of intra canal posts on the diagnostic accuracy of cbct and d...

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Journal: :iranian endodontic journal 0
zahra sadat madani azam haddadi sina haghanifar ali bijani

introduction: due to the importance of apical transportation during root canal preparation, the aim of the current study was to use cone-beam computed tomography (cbct) to assess the extent of apical transportation caused by protaper and mtwo files. methods and materials: forty extracted maxillary first molars with 19-22 mm length and 20-40 degrees of curvature were selected. the mesiobuccal ca...

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Journal: :iranian endodontic journal 0
jamileh ghoddusi maryam forghani assistant professor of endodontics, dental material research center, school of dentistry, mashhad university of medical sciences, mashhad,iran ali bagherpour fatemeh mahmudabadi majid sarmad

introduction : the aim of this in vitro study was to compare the effect of gates-glidden and peeso reamer drills on residual dentin thickness during post space preparation in order to discover which method has minimum root structure damage. materials and methods: thirty extracted human maxillary premolars with bifurcations at root middle were horizontally cut 15 mm coronal to the apical end aft...

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