Philips Healthcare released a novel metal artifact reduction algorithm for large orthopedic implants (O-MAR). Little information was available about its CT number accuracy. Since CT numbers are used for tissue heterogeneity corrections in external beam radiotherapy treatment planning, we performed a phantom study to assess the CT number accuracy of O-MAR. Two situations were simulated: a patien...

PURPOSE To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. MATERIALS AND METHODS Tubes containing solutions with different concentrations of K2HPO4 were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT...

Computed Tomography (CT) scanner technology has progressed rapidly throughout the past decade, with major advances in CT x-ray detection, system speed, and image reconstruction that have resulted in a stillincreasing number of novel CT clinical applications. Concomitant to this increase in clinical applications, CT technology has also experienced innovation to support the realization of high CT...

PURPOSE To investigate effects of metal artifacts on the dose calculation accuracy of three dose calculation algorithms on CT and cone-beam CT images. METHODS A phantom with and without metal objects was scanned using CT simulator and on-board kV CBCT. Conformal 5-field treatment plans with identical physical and dosimetric parameters were created in the Eclipse™ treatment planning system for...

Introduction: Accurate evaluation of femoral and tibial torsion is essential for children or adult with legs deformity, becuse incorrect legs morphogenesis can lead to pathological situation. CT scan is commonly used for the measurement of skeletal bone parameters. But, disability in imaging from standing and sitting posture and absorb dose of patients are deficits of this meth...

OBJECTIVES Deep-inspiration breath-hold (DIBH) PET/CT with short-time acquisition and respiratory-gated (RG) PET/CT are performed for pulmonary lesions to reduce the respiratory motion artifacts, and to obtain more accurate standardized uptake value (SUV). DIBH PET/CT demonstrates significant advantages in terms of rapid examination, good quality of CT images and low radiation exposure. On the ...

The purpose of this study was to show that the nominal peak tube voltage potential (kVp) and measured half-value layer (HVL) can be used to generate energy spectra and fluence profiles for characterizing a computed tomography (CT) X-ray source, and to validate the source model and an in-house kV X-ray dose computation algorithm (kVDoseCalc) for computing machine- and patient-specific CT dose. S...

We present a new method of intraoperative, image-based surgical instrument guidance. The method has the potential to significantly improve visualization of intraoperative procedures that currently depend on fluoroscopic images for navigation. 3D information from preoperative computed tomography (CT) is fused with images of the instrument taken intraoperatively. Our approach employs synthesized ...