abstract   background: the x-ray machines used for radiodiagnosis should meet certain quality assurance (qa) programmes . these are necessary to have good quality radiographs at reasonably low exposure to patients.   materials and methods: dose reduction methods in abdomen x-ray examination were carried out in 10 hospitals in tehran. this paper presents the work, which was implemented on 200 pa...

SPEAR3 has two diagnostic beam lines: an x-ray pinhole camera and a visible/UV beam line. The pinhole camera images ~8 keV dipole synchrotron radiation (SR) incident on a phosphor screen. The visible beam line delivers conventional optical radiation to an array of cameras and diagnostic elements on a 1x3m optical bench. This paper briefly reviews the pinhole camera system while concentrating mo...

background: increasing the x-ray focus to film distance (ffd) has been advocated as an effective method to reduce the patients’ radiation dose. the aim of this study was to investigate the efficacy of this technique in patients' dose and image quality in pediatric chest x-ray.material and methods: sixty pediatric patients were x-ray imaged at ffds of 100 and 130 cm. dose measurements were ...

Background: Exposure to ionizing radiation is known to have various effects on hematological parameters of biological sample. This study was aimed at evaluating the effect of ionizing radiation on some hematological parameters in guinea pigs. Materials and Methods: Thirty-six (36) apparently healthy adult guinea pigs of both sexes weighing between 700g – 1200...

The availability of computed radiography has opened the possibility of using reduced dosage for radiographs in clinical settings and reducing the retake rate. A prospective controlled study was carried out over a period of four months comparing conventional X-rays and computed radiography. The aim was to assess if computed radiography at 50% normal dosage would result in films of adequate quali...

The chest X-ray (CXR) is an important diagnostic tool in diagnosing and monitoring a spectrum of diseases. Despite our universal reliance on the CXR, our ability to confidently diagnose and accurately document our findings can be unreliable. We sought to assess the diagnostic accuracy and certainty of making a diagnosis based on 10 short clinical histories with one CXR each. We conclude from ou...

Cone beam computed tomography (CBCT, also referred to as C-arm computed tomography [CT], cone beam volume CT, or flat panel CT) is a medical imaging technique of X-ray CT where the X-rays are divergent, forming a cone.[1] CBCT systems have been designed for imaging hard tissues of the maxillofacial region. CBCT is capable of providing sub-millimeter resolution in images of high diagnostic quali...

The techniques of treatment of carcinoma of the bronchus using 8 million volt x rays are described. In a group of inoperable cases of carcinoma of the bronchus a three-year survival rate of 10% was obtained with squamous lesions, and in anaplastic and oat-cell lesions the three-year survival rate was 4%. The factors affecting the prognosis are described and also the palliation achieved. The imm...

background: medical x-rays are the largest man-made source of public exposure to ionizing radiation. it is important to avoid conditions where the amount of radiation used is more than that needed for the procedure. materials and methods: the entrance skin exposure (ese) measurement was conducted for quality control of x-ray machines and survey of operator’s experimental techniques. the eses we...

The purpose is to review in a 4-part series: (i) the basic principles of x-ray production, (ii) x-ray interactions and data capture/conversion, (iii) acquisition/creation of the CT image, and (iv) operational details of a modern multislice CT scanner integrated with a PET scanner. Advances in PET technology have lead to widespread applications in diagnostic imaging and oncologic staging of dise...