Introduction: The basis of image formation in Computed Tomography (CT) lies in the x-ray linear attenuation coefficient of the scanned material. Compton scattering and photoelectric effect are the dominant interactions of the x-ray photons with the subject, in the range of diagnostic radiology. These two coefficients are important in tissue characterization by Dual-Energy CT (D...

Radiologic Procedure Rating Comments RRL* CT abdomen and pelvis without and with IV contrast 2 ☢ ☢ ☢ ☢ X-ray abdomen 2 ☢ ☢ CT abdomen and pelvis without IV contrast 2 ☢ ☢ ☢ ☢ CT abdomen and pelvis with IV contrast 2 ☢ ☢ ☢ ☢ X-ray IV contrast enema 2 ☢ ☢ ☢ X-ray cystography 2 ☢ ☢ ☢ MRI pelvis without and with IV contrast 2 MRI may be indicated if urethral diverticulum is suspected. O MRI pelvis ...

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...

Most CT reconstruction system x-ray computed tomography (CT) is a well established visualization technique in medicine and nondestructive testing. However, since CT scanning requires sampling of radiographic projections from different viewing angles, common CT systems with mechanically moving parts are too slow for dynamic imaging, for instance of multiphase flows or live animals. A large numbe...

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...

AIM To evaluate the diagnostic sensitivity and accuracy and the cost-effectiveness of this technique in the detection of gastroenteropancreatic carcinoid tumors and their metastases in comparison with conventional imaging methods. METHODS Somatostatin receptor scintigraphy (SRS) was performed in 24 patients with confirmed carcinoids and 7 under investigation. The results were compared with th...

clavicular bone tumors occur in less than 0.5 percent of bone tumors. primary chondrosarcoma is very rare even among clavicle tumors. the main symptom is a touchable mass in 69 % of patients. dedicated centers using fna and cytology can reach a correct diagnosis in 94% of cases. treatment planning is done using simple x-ray, ct-scan, shoulder mri, chest ct-scan, and whole body technetium scan. ...

X-ray computed tomography (CT) has recently been experiencing remarkable growth as a result of technological advances and new clinical applications. This paper reviews the essential physics of X-ray CT and its major components. Also reviewed are recent promising applications of CT, ie, CT-guided procedures, CT-based thermometry, photon-counting technology, hybrid PET-CT, use of ultrafast-high p...

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...