PURPOSE To compare computed tomography (CT) number measurement consistency under different beam hardening conditions in phantom experiment between dual-energy spectral CT and conventional CT imaging. MATERIALS AND METHODS A phantom with 8 cells in periphery region and 1 cell in central region were used. The 8 conditioning tubes in the periphery region were filled with 1 of the 3 iodine soluti...

background: cone beam computed tomography (cbct) is an alternative to a computed tomography (ct) scan, which is appropriate for a wide range of craniomaxillofacial indications. the long‑term use of metallic materials in dentistry means that artifacts caused by metallic restorations in the oral cavity should be taken into account when utilizing cbct and ct scanners. the aim of this study was to ...

PURPOSE To measure the sensitivity of deformable image registration to image noise. Deformable image registration can be used to map organ contours and other treatment planning data from one CT to another. These CT studies can be acquired with either conventional fan-beam CT systems or more novel cone-beam CT techniques. However, cone-beam CT images can have higher noise levels than fan-beam CT...

BACKGROUND AND PURPOSE The development of flat panel detectors (FPDs) has made cone-beam CT feasible for practical use in a clinical setting. Our purpose was to assess the usefulness of cone-beam CT using the FPD in conjunction with conventional digital subtraction angiography (DSA) for performing superselective intra-arterial chemotherapy for head and neck tumors. MATERIALS AND METHODS Twent...

Cone beam CT, usually used in dental area, could easily obtain 3-dimensional images using cone beam shaped ionized radiation. Cone beam CT is very useful for direct percutaneous sac injection (DPSI) which needs very precise measurement to avoid puncture of inferior vena cava or vessel around sac or stent graft. Here we describe two cases of DPSI using cone beam CT. In case 1, a 79-year-old male...

Introduction: Computed tomography (CT) has numerous applications in clinical procedures but its main problem is its high radiation dose to the patients compared to other imaging modalities using x-ray. CT delivers approximately high doses to the nearby tissues due to the scattering effect, fan beam (beam divergence) and limited collimator efficiency. The radiation dose from multi-slice scanners...

Since cone-beam computed tomography (CT) has been adapted for use with a C-arm system it has brought volumetric CT capabilities in the interventional suite. Although cone-beam CT image resolution is far inferior to that generated by traditional CT scanners, the system offers the ability to place an access needle into position under tomographic guidance and use the access to immediately begin a ...

Participants Kai Niu, MS, Madison, WI (Presenter) Nothing to Disclose Pengfei Yang, Shanghai, China (Abstract Co-Author) Nothing to Disclose Beverly A. Kienitz, MD, DDS, Madison, WI (Abstract Co-Author) Nothing to Disclose Ke Li, PhD, Madison, WI (Abstract Co-Author) Nothing to Disclose Sebastian Schafer, Madison, WI (Abstract Co-Author) Consultant, Siemens AG Kevin Royalty, PhD,MBA, Hoffman Es...

background: this prospective study was conducted to evaluate and compare the efficacies of nasopharyngoscopy and ct scan in the diagnosis of local failure of external beam radiotherapy (ebrt) for nasopharyngeal carcinoma. methods: total 52 patients of histopathologically proven nasopharyngeal carcinoma treated with external beam radiotherapy (ebrt), were included in this study. for every patien...

OBJECTIVES In this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (CTAC), using the bilinear scaling method. METHODS The measured attenuation coefficient (μm) was compared to the theoretical attenuation coefficient (μt), using four different CT scanners and an RMI 467 phantom. The effective energy of CT beam X-rays was calculated, using the alumin...