For head computed tomography (CT), non-helical scanning has been recommended even in the widely used multi-slice CT (MSCT). Also, an acute stroke imaging standardization group has recommended the non-helical mode in Japan. However, no detailed comparison has been reported for current MSCT with more than 16 slices. In this study, we compared the non-helical and helical modes for head CT, focusin...

Introduction: Variable resolution x-ray (VRX) CT is a new type of CT that can image objects at various spatial resolutions. In a VRX CT scanner, the spatial resolution increases at the cost of reduction in the field of view (FOV). An important factor that limits the spatial resolution of the VRX CT is the effect of focal spot size. Also, the optimum magnification is different at each incident a...

The new NCRP Report No. 147 includes methodology to determine x-ray protective shielding for CT scanner rooms. This methodology assumes fixed values of the scatter fraction per centimeter (kappa) for the peripheral axis of the head and body CT phantoms. An investigation was performed to determine kappa for different makes and models of CT scanner and examine the consequences of the differences ...

background the present data show a global increase in the rate of cardiovascular disease. cardiac ct angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. conclusions the total mean radiation dose to the thyroid and gonads was 0.36 msv, and 96.5 μsv, respectively for the subjects. these values were high for ...

In 2008, there were more than 5,000 motorcycle crash fatalities in the United States. Many states have motorcycle helmet laws that are meant to protect riders during a crash. After recruiting motorcycle occupants injured in crashes, a protocol was established to scan three different types of motorcycle helmets commonly worn (cap, ¾ shield, and full face shield) using a computed tomography (CT) ...

OBJECTIVE To determine whether micro-computed tomography (micro-CT) could be used to reconstruct ancient dental anatomy accurately and differentiate the enamel from the dentin, as well as to verify whether micro-CT could detect tooth disorders such as attrition or caries accurately. METHODS Micro-CT imaging was performed, using a cone-beam micro-CT specimen scanner, on a 500-year-old human to...

segmentation and three‑dimensional (3d) visualization of teeth in dental computerized tomography (ct) images are of dentists’ requirements for both abnormalities diagnosis and the treatments such as dental implant and orthodontic planning. on the other hand, dental ct image segmentation is a difficult process because of the specific characteristics of the tooth’s structure. this paper presents ...

Pulmonary sequestration is a focal area of nonfunctioning, dysplastic lung parenchyma that lacks communication with the normal tracheobronchial tree. It is supplied by the systemic arterial circulation and has two types, intralobar and extralobar, that can be differentiated from each other by the pleural covering and the venous drainage. Their coexistence is extremely rare. We report the imagin...