China 
Africa 
Explore chapters and articles related to this topic
Contrast enhancement agents and radiopharmaceuticals
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Barium sulphate is an inorganic compound with the chemical formula BaSO4. It occurs in the mineral barite which, when mined, is the commercial source of barium (Fig. 2.18a). Preparations are available either as colloidal barium sulphate, which comprises a suspension of fine barium particles that stay evenly distributed, or more commonly as high-density barium sulphate, which comprises microscopically fine particles of varying size. It is frequently used as a radiocontrast material in medical imaging due to its very high atomic mass and its ability to attenuate X-ray photons. It is most commonly used in imaging of the GI tract (Fig. 2.18b) and can either be administered orally as barium meals and barium swallows, or rectally via rectal catheters for barium enema examinations.
Designing Safer Chemicals
Published in Aidé Sáenz-Galindo, Adali Oliva Castañeda-Facio, Raúl Rodríguez-Herrera, Green Chemistry and Applications, 2020
Cesar Garcias Morales, Armando Ariza Castolo, Mario Alejandro Rodriguez
An example is the use of iodine X-ray contrast media during radiography. Because it requires high doses to obtain a good radiocontrast, the administration is intravenous. Iodine is a stable compound with extremely low toxicity, it is not surprising that due to compound stability it has a low biodegradability, so this it accumulates and is detectable in microgram levels in wastewater effluents and certain bodies of water, contributing to the loading of easily absorbed halogenated organic compounds (Steger-Hartmann et al., 1999; 2002). In an effort to reduce the risk of bioaccumulation, iodine compounds derived from sugars have been investigated as candidates for X-ray contrast media with low toxicity and are easily degradable (Crawford et al., 2017).
Overview of the application of inorganic nanomaterials in breast cancer diagnosis
Published in Inorganic and Nano-Metal Chemistry, 2022
Asghar Ashrafi Hafez, Ahmad Salimi, Zhaleh Jamali, Mohammad Shabani, Hiva Sheikhghaderi
Computed tomography scan (CT scan) is a medical imaging method that its earlier name was CAT scan or computed axial tomography. Further, this medical imaging technique is one of the noninvasively methods to achieve images of the body in details as a diagnostic purpose. Additionally, radiology technologists or radiographers perform CT scans. The above versatile imaging technique has developed since 1970s and used in diagnostic medicine. Finally, Allan M. Cormack and Godfrey N. Hounsfield for the development of computer-assisted tomography was awarded jointly the 1979 Nobel Prize in Physiology and Medicine.[58] To compare with other 2D imaging techniques, the X-ray CT technique has three major superiorities. First, the X-ray CT obliterates all of images related to the structures outside the body from internal organs of the body in the desired area. Next, the X-ray CT can diagnose differences among the tissues that differ in physical density by less than 1% because this technique has both high contrast and resolution. The last technique is a multiplanar reformatted imaging and can procure images by multiple contiguous or one helical scan,[59,60] whereas one of the disadvantage of this technique is to use the X-ray beam, which leads to damage the body cell including DNA molecules and this phenomenon might be the cause of cancer in the patient.[61,62] Markedly, allergic reactions and kidney failure to the contrast agents as injected radiocontrast (iodine) intravenous are one of the tricks in these techniques, while the replacement of barium sulfate suspension as oral is a suitable agent to prevent allergic reaction and kidney failure but cannot be used in the patients with suspected bowel perforation or suspected bowel injury.[63]