The purpose of bowtie filters in CT scanners is to homogenize the x-ray intensity measured by the detectors in order to improve the image quality and at the same time to reduce the dose to the patient because of the preferential filtering near the periphery of the fan beam. For CT dosimetry, especially for Monte Carlo calculations of organ and tissue absorbed doses to patients, it is important ...

INTRODUCTION Computer-aided surgery (CAS) systems integrate endoscopic visualization with real-time localization based on preoperative imaging. One short-coming of the current systems is the lack of real-time, radiographic assessment of surgical changes. We describe the potential applications of xCAT, a new intraoperative mobile volume CT scanner and its utility in providing surgical navigation...

The recently developed 64-slice CT scanner together with the use of 2-D and 3-D reconstructions can aid the cardiovascular surgeon and interventional radiologist in visualizing exact geometric relationships to plan and execute complex procedures via minimally invasive or standard approaches. Cardiac 64-slice CT considerably benefits from the high temporal and spatial resolution allowing the rel...

In modern neurosurgical practice, CT is a well established, important examination for planning surgery and perioperative care. Recently, CT scanners have been used for intraoperative imaging during craniotomy [1-6]. In this paper, we report a newly developed mobile CT scanner gantry with a modified fork-lift gantry carrier. This system enables the radiologist to obtain CT images during surgery ...

In this paper, a new adaptive bolus-chasing control scheme is proposed to synchronize the bolus peak in a patient's vascular system and the imaging aperture of a computed tomography (CT) scanner. The proposed control scheme is theoretically evaluated and experimentally tested on a modified Siemens SOMATOM Volume Zoom CT scanner. The first set of experimental results are reported on bolus-chasin...

The purpose is to review in a 4-part series: (i) the basic principles of x-ray production, (ii) x-ray interactions and data capture/conversion, (iii) acquisition/creation of the CT image, and (iv) operational details of a modern multislice CT scanner integrated with a PET scanner. In part 1, the production and characteristics of x-rays were reviewed. In this article, the principles of x-ray int...

The computer algorithm used to reconstruct CT scanner images is very computationally intensive, which forces medical equipment manufacturers to strike a balance among image resolution, image generation time, and system cost when designing a new CT scanner. Cost-effective performance acceleration for image reconstruction would allow manufacturers to generate higher resolution CT images while mai...

The CT scanner-displayed radiation dose information is based on CT dose index (CTDI) over an integration length of 100 mm (CTDI(100)), which is lower than the CTDI over an infinite integration length (CTDI(∞)). In an adult or a pediatric body CT scan, the limiting equilibrium dose can be established near the central scan plane, and CTDI(∞) more closely indicates the accumulated dose than CTDI(1...

BACKGROUND AND PURPOSE It is difficult to evaluate glenoid component periprosthetic radiolucencies in total shoulder arthroplasties (TSAs) using plain radiographs. This study was performed to evaluate whether computed tomography (CT) using a specific patient position in the CT scanner provides a better method for assessing radiolucencies in TSA. METHODS Following TSA, 11 patients were CT scan...