Objective: Computed tomography (CT)-based attenuation correction (CTAC) offers the clear benefit of reliable reconstruction of single-photon emission computed tomography (SPECT) images through its ability to achieve object-specific attenuation maps, but artifacts from dense materials often deteriorate CTAC performance. Therefore, we investigate the feasibility of CTAC in the presence of dense m...

Introduction: The use of a simple tissue analog material in the fabrication of medical computed tomography (CT) imaging phantoms has great potential to help researchers. The purpose of the present study is to develop new gel tissue-equivalent materials and determine whether their CT numbers and relative electron densities vary in CT images obtained by scans at different energie...

Energy gaps, AXsar (X=E, H and G) (AX.,.,-=lia,„,,,InrX“dpka,) between single (s) and triplet (I) states werecalculated at B3LTP/6-3 I 1.HO" level of theory. Our results showed that electron donating substituents(G = -NHz, -OH. -CH), -F, -Cl and -Br) at phenyl group cause to increase and electron withdrawingsubstiluents (G -CF2. and -NO:) lead to decrease the singlet-triplet energy gaps of Ar -...

Constitutional thinness (CT) is characterized by a low and stable body mass index (BMI) without any hormonal abnormality. To understand the weight steadiness, energetic metabolism was evaluated. Seven CT, seven controls, and six anorexia nervosa (AN) young women were compared. CT and AN had a BMI <16.5 kg/m(2). Four criteria were evaluated: 1) energy balance including diet record, resting metab...

C omputed tomography (CT) has evolved into a powerful diagnostic tool, and since the advent of 64-detector row scanners, it has been demonstrated as a promising noninvasive method for coronary artery stenosis imaging (1). Although the basic physical principle of CT is unidimensional, a function of x-ray attenuation detected from multiple orientations around the imaged object, exciting new techn...

PURPOSE To compare computed tomography (CT) number measurement consistency under different beam hardening conditions in phantom experiment between dual-energy spectral CT and conventional CT imaging. MATERIALS AND METHODS A phantom with 8 cells in periphery region and 1 cell in central region were used. The 8 conditioning tubes in the periphery region were filled with 1 of the 3 iodine soluti...

Scattering of rare gas cations from C60 has been studied in a guided-beam tandem mass spectrometer. Charge transfer ~CT! is observed to be the dominant channel over the collision energy range from 0 to 100 eV, but dissociative CT and endohedral complex formation are significant at high collision energies. The threshold energies for endohedral penetration are found to be proportional to rare gas...

In this study, 22 patients (15-75 years old) were selected and transferred to CT scan for tumor ablation. For ablations, after prep and drep under the local anesthesia and mild sedation in proper position, small incision made and special needle inserted and guided by proper direction to the core of the tumor. Then, laser probe inserted through the needle and laser energy delivered. Although we ...