The goal is to perform geometric studies on cone-beam CT scanning along a three-dimensional (3D) spiral of variable radius. First, the background for variable radius spiral cone-beam scanning is given in the context of electron-beam CT/micro-CT. Then, necessary and sufficient conditions are proved for existence and uniqueness of PI lines inside the variable radius 3D spiral. These results are n...

a 36-year-old woman with right upper quadrant abdominal pain since three months previously and no other significant medical history was referred for evaluation of an abdominal mass. upon clinical examination, a large palpable mass in the mid -upper abdominal area was noted. abdominal ultrasound and spiral ct-scan showed a large hepatic mass in the left liver lobe. the patient was referred for t...

A good knowledge of clinical presentation and of risk factors for pulmonary embolism is mandatory to improve adequate clinical suspicion. Some recent improvements in diagnostic strategy have to be emphasized. A low D-dimer level has a good negative predictive value to rule out pulmonary embolism. Ventilation-perfusion lung scan is the most often used imaging technique. In case of non diagnostic...

hepatic inflammatory pseudotumor (ipt) is a rare non-neoplastic process of unknown etiology, generally following a benign inflammatory condition. it is often mistaken as an either primary or metastatic malignancy in imaging studies. we report a 48 year-old female with numerous target lesions (2-4 cm) seen on high resolution ultrasound, spiral ct scan, and mri in all liver lobes compatible with ...

The introduction in 1998 of multi-detector row computed tomography (CT) by the major CT vendors was a milestone with regard to increased scan speed, improved z-axis spatial resolution, and better utilization of the available x-ray power. In this review, the general technical principles of multi-detector row CT are reviewed as they apply to the established four- and eight-section systems, the mo...

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BACKGROUND Multiple basilar skull fracture and cerebrospinal leak are common complications of traumatic brain injury, which required a surgical repair. But due to the complexity of basilar skull fracture after severe trauma, preoperatively an exact radiological location is always difficult. Multi-row spiral CT and MRI are currently widely applied in the clinical diagnosis. The present study was...

Background: Prospectively electrocardiography (ECG)-triggered high-pitch spiral coronary computed tomography angiography (CCTA) is a unique scan mode for dual-source CT (DSCT). Our reports aim to compare image quality and radiation dose of CCTA using high-pitch spiral or sequential acquisition mode in patients with low and stable heart rates. Materials and Methods: Patients with low and stable ...

BACKGROUND Much controversy exists as to the value of computed tomography (CT) in the preoperative staging of gastric cancer, because of its limited ability to identify correctly lymph node (LN) metastases, invasion of adjacent organs, or hepatic and peritoneal metastases. Spiral CT scanners have a number of potential advantages over conventional scanners, including the absence of respiratory m...

BACKGROUND The aim of this study was to evaluate the amount of radiation doses absorbed by soft tissues (entrance skin dose) with a low-dose spiral computed tomography (CT) protocol compared to conventional X-ray techniques commonly used in orthodontics. METHODS The amount of skin dose has been evaluated using a tissue-equivalent head-neck radiotherapy humanoid phantom with thermoluminescent ...