Introduction: Nowadays, Imaging of the myocardial perfusion (MPI) using the single photon emission tomography (SPET) in the diagnosis of coronary artery disease, especially myocardial ischemia, is of great importance. In contrast to the coronary artery angiography, MPI is non-invasive, less expensive and more physiological. Unfortunately, this image is affected by the some artifacts. Thes...

Purpose: Fiber carbon is the most common material used in treating couch as it causes less beam attenuation than other materials. Beam attenuation replaces build-up region, reduces skin-sparing effect and causes target volume under dosage. In this study, we aimed to evaluate beam attenuation and variation of build-up region in 550 TxT radiotherapy couch.Materials and Methods: In this study, we ...

currently available non-invasive clinical methods for diagnosing osteoporosis are mainly associated with ionizing radiation. ultrasonic assessment of bone disease is a more recent technology. a theoretical explanation for the relationship between ultrasonic parameters and bone structure is necessary. thus, two types of bone samples of perspex (hap) and perspex-glass beads were produced. each ty...

introduction: nowadays, imaging of the myocardial perfusion (mpi) using the single photon emission tomography (spet) in the diagnosis of coronary artery disease, especially myocardial ischemia, is of great importance. in contrast to the coronary artery angiography, mpi is non-invasive, less expensive and more physiological. unfortunately, this image is affected by the some artifacts. these arti...

S U M M A R Y The differential attenuation for upper-mantle paths beneath northern Australia has been estimated using spectral ratio methods, both in a narrow frequency band near 0.6 Hz to obtain stable estimates for subsequent inversion and also over a broad frequency band up to 3–6 Hz to look at the frequency dependence of attenuation. The frequency dependence of the differential attenuation ...

OBJECTIVE The purpose of this study was to evaluate the relation between bronchial wall attenuation on thin-section CT images and airflow limitation in persons with chronic obstructive pulmonary disease. SUBJECTS AND METHODS One hundred fourteen subjects (65 men, 49 women; age range, 56-74 years) enrolled in the National Lung Screening Trial underwent chest CT and prebronchodilation spirometr...