one of the debates concerning concepts of “medial motion” and “traversal motion” is the question of which of these two concepts of motion corresponds to motion in the corporeal world. in the present article we intend to employ the language of mathematics to present a model for each of these two concepts to study the above mentioned problem. as a result, medial motion represents a covering funct...

Intensity-modulated radiation therapy can be conveniently delivered with a multileaf collimator. With this method, the entire field is not delivered at once, but rather it is composed of many subfields defined by the leaf positions as a function of beam on time. At any given instant, only these subfields are delivered. During treatment, if the organ moves, part of the volume may move in or out ...

PURPOSE Applicability of the AlignRT surface imaging system was extensively investigated for real-time motion tracking in radiation therapy of lung cancer. METHODS A 4D computer-controlled motion phantom was employed to simulate a human breathing motion. An anthropomorphic thoracic phantom (a coronal cross-sectional area: ∼1,200 cm2 ) was monitored during the 4D motion tracking. A breathing c...

background: foundry workers are occupationally exposed to hazardous substances such as silica dusts and toxic gases. the aim of this study was to examine the effects of simultaneous exposure to complex mixtures of silica dust, formaldehyde, and triethylamine on lung function parameters. study design: a cross-sectional study. methods: this study was conducted on 55 male workers of core making un...

obesity as a common health risk is increasing all over the world. the aim of this study was evaluation of standing and sitting positions on spirometric values in obese asthmatic patients, in comparison with normal obese subjects. the study included 49 obese asthmatic patients with mean age of 42.63 years and body mass index of 36.06 kg/m 2 , and 51 control obese normal subjects with mean age of...

PURPOSE It is aim to test the hypothesis that a dynamic keyhole MRI reconstruction technique using external/internal respiratory surrogate position reduces acquisition time while retaining image quality for real-time tumor monitoring, compared to the conventional keyhole technique. METHODS 46 thoracic MRI studies with 13 healthy human subjects have been acquired using a 3T GE MRI. Acquired MR...