We propose a method for the creation of an anatomically and mechanically realistic brain phantom from polyvinyl alcohol cryogel (PVA-C) for validation of image processing methods for segmentation, reconstruction, registration, and denoising. PVA-C is material widely used in medical imaging phantoms for its mechanical similarities to soft tissues. The phantom was cast in a mold designed using th...

We have developed an image quality theory for reconstruction that we apply to filtered back-projection (FBP) and statistical reconstruction (OSEM) for Single Photon Emission Computed Tomography (SPECT). Quantitative measures of reconstruction performance are given in terms of signal and noise power spectra, SPS and NPS, that we derive from phantom images. This allows evaluating the properties o...

A novel method was presented for the effective dose (ED) measurement with metal-oxide-semiconductor field-effect transistor (MOSFET) detectors in dual-energy (DE) dual-source (DS) computed tomography (CT) scanner. This study demonstrated that the mean energy of the combined spectrum in dual-source computed tomography can be used to measure the ED. For validation, the MOSFET dose at the centre c...

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...

introduction: vertical root fracture (vrf) is common in endodontically treated teeth. conventional and digital radiographies have limitations for detection of vrfs. cone-beam computed tomography (cbct) offers greater detection accuracy of vrfs in comparison with conventional radiography. this study compared the effects of metal artifacts on detection of vrfs by using two cbct systems. methods a...

background: in many cases of ild (interstitial lung disease), overlap diagnosis is considered. here, a few cases with diagnosis of a variety of ilds, where eventual open lung biopsy has been performed are selected. reference will be made to reliable sources to show that nsip can still be a variant of uip (usual interstitial pneumonia) with better treatment response and prognosis. case presentat...

introduction: cholesteatoma is traditionally diagnosed by otoscopic examination and treated by surgery. the necessity for imaging in an uncomplicated case is controversial. this study was planned to investigate the usefulness of a preoperative high-resolution computed tomography (hrct) scan in depicting the status of middle ear structures in the presence of cholesteatoma and also to compare the...

introduction in computed tomography (ct) technology, an optimal radiation dose can be achieved via changing radiation parameters such as ma, pitch factor, rotation time and tube voltage (kvp) for diagnostic images. materials and methods in this study, the brain, abdomen, and thorax scaning was performed using toshiba 16-slice scannerand standard aapm and ctdi phantoms. aapm phantom was used for...

odontogenic myxoma (om) is an infiltrative benign bone tumor that occurs almost exclusively in the facial skeleton. the radiographic characteristics of odontogenic myxoma may produce several patterns, making diagnosis difficult. cone-beam computed tomography (cbct) may prove extremely useful in clarifying the intraosseous extent of the tumor and its effects on surrounding structures. here, we r...

background and aims. at present, cone beam computed tomography (cbct) has become a substitute for computed tomography (ct) in dental procedures. the metallic materials used in dentistry can produce artifacts due to the beam hardening phenomenon. these artifacts decrease the quality of images. in the present study, the number of artifacts as a result of beam hardening in the images of dental imp...