Background: Photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of SPECT images and results to errors in accuracy of quantitative measurements. This can be corrected via different physical or mathematical approaches. As the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘Piece ...

INTRODUCTION A physical 3-dimensional phantom that simulates PET/SPECT images of static regional cerebral blood flow in grey matter with a realistic head contour has been developed. This study examined the feasibility of using this phantom for evaluating PET/SPECT images. METHODS The phantom was constructed using a transparent, hydrophobic photo-curable polymer with a laser-modelling techniqu...

An investigation of the radiation from 5 different phones next to two head phantoms proposed for radiation measurements has been carried out and the radiation has been evaluated thru the Total Radiated Power, the Total Receiver Sensitivity and the Mean Effective Gain. The investigation is based on measurements of the farfield patterns measured in an anechoic room using a system tester to avoid ...

Target audience: Radiofrequency (RF) engineers, anyone interested in high field RF coils, parallel transmit or high field brain imaging. Introduction: Electric dipole antennas are seeing increasing use for 7T MR imaging. They differ from conventional surface coil loops in many ways. With 8 elements surrounding a body sized tissue equivalent phantom and array of dipole antennas can achieve highe...

A straightforward method is presented to estimate peak skin doses (PSDs) delivered by computed tomography (CT) scanners. The measured PSD values are related to the well-known volume CT dose index (CTDI(vol)), displayed on the console of CT scanners. PSD measurement estimates were obtained, in four CT units, by placing radiochromic film on the surface of a CTDI head phantom. Six different X-ray ...

AMPUTATED LIMBS persist as "phantoms" in their owners' consciousness. Temporary or permanent severance of afferent pathways may also give rise to subjective experiences in which the position of the phantom limb is different from that of the real one. Attempts have been made to explain phantom phenomena as expressions of a "body image" or "body schema" subserving a preconscious neurophysiologica...

A proposed method to obtain the dose for Computed Tomography was evaluated on long a phantom, made of polyethylene. This phantom is 600 mm large. Adopting an empirical characterized function , tendency asymptotical grow by increase scanning length can estimate in infinite single axial rotation x-ray tube. The curve estimated different clinical protocols: tension, pitch, head/body, and center/pe...

The purpose of this study was to develop coils for MR imaging of the head and neck region, with the aim of improving sensitivity and coverage. A head and neck phased array coil was constructed and compared with volume and temporomandibular joint surface coils for sensitivity and coverage in phantom studies. An algorithm was implemented to correct for the nonuniformity in the surface coil recept...

Kilovoltage (kV) cone beam computed tomography (CBCT) images suffer from a substantial scatter contribution. In this study, Monte Carlo (MC) simulations are used to evaluate the scattered radiation present in projection images. These predicted scatter distributions are also used as a scatter correction technique. Images were acquired using a kV CBCT bench top system. The EGSnrc MC code was used...

The Elekta Synergy is a radiotherapy treatment machine with integrated kilovoltage (kV) X-ray imaging system capable of producing cone beam CT (CBCT) images of the patient in the treatment position. The aim of this study is to assess the additional imaging dose. Cone beam CT dose index (CBDI) is introduced and measured inside standard CTDI phantoms for several sites (head: 100 kV, 38 mAs, lung:...