4 results
DNA breaks induced by iodine-containing contrast medium in radiodiagnostics: a problem of tungsten?
Eur Radiol Exp. 2018 Aug 15;2:21. doi: 10.1186/s41747-018-0050-9. eCollection 2018 Dec.
PMID: 30148253
Free PMC article.
Iodine-containing contrast media
(ICM) are extensively used to improve image quality and information
content in x-ray-based examinations, particularly in computed tomography
(CT). ...Why has iodine been preferred to any other heavy elements to e …
Why has iodine been preferred to any other heavy elements to enhance
contrast in radiodiagnostics? How to understand such DNA breaks effect?
We searched for the answers in the early times of x-ray medical use. It
appeared that the maximal ratio between the relative iodine and water
mass energy absorption coefficients is reached in the range of 40-60
keV, which defines the energy range in which the dose is preferentially
absorbed by ICM. This range does not correspond to the K-edge of iodine
but to that of tungsten, the major component of the x-ray tube anode of
CT scanners. At such energy, radiolysis of the ICM produces sodium or
potassium iodide that prevents a normal DNA breaks repair and influences
the individual response to x-ray low-dose. Both contrast enhancement
and DNA breaks effect may therefore be caused by tungsten of the anodes
of x-ray
Oral CT Contrast Agents: What's New and Why, From the AJR Special Series on Contrast Media.
AJR Am J Roentgenol. 2023 Oct 25. doi: 10.2214/AJR.23.29970. Online ahead of print.
PMID: 37877595
Review.
Current CT oral contrast agents improve the conspicuity and confidence
for bowel and peritoneal findings in many clinical scenarios,
particularly for outpatient and oncologic abdominopelvic imaging. Yet,
existing positive and neutral oral contrast agents may diminish the
detectability of certain radiologic findings, frequently in the same
scans in which the oral contrast agent improves the detectability of
other findings. With ongoing improvements in CT technology, particularly
multi-energy CT, opportunities are opening for new types of oral
contrast agents to further improve anatomic delineation and disease
detection using CT. The CT signal of new dark oral contrast agents and
of new high-Z oral contrast agents promise to combine the strengths of
both positive and neutral oral CT contrast agents by providing distinct
CT appearances in comparison with bodily tissues, iodinated IV contrast
agents, and other classes of new CT contrast agents. High-Z oral
contrast agents will unlock previously inaccessible capabilities of
multi-energy CT, particularly photon-counting detector CT, for
differentiating simultaneously administered IV and oral contrast agents;
this technique will allow generation of rich 3D, intuitive, perfectly
co-registered, high-resolution image sets with individual contrast-agent
"colors" that provide compelling clarity for intertwined intraabdominal
anatomy and disease processes.
Separating High-Z Oral Contrast From Intravascular Iodine Contrast in an Animal Model Using Dual-Layer Spectral CT.
Acad Radiol. 2019 Sep;26(9):1237-1244. doi: 10.1016/j.acra.2018.09.012. Epub 2018 Oct 9.
PMID: 30314734
RESULTS: The iodine and barium contrast appeared only in the iodine equivalent images and could not be differentiated from each other. However, the tantalum, tungsten, and rhenium contrast only appeared in the water equivalent images. This allowed i …
Clin Imaging. 2022 Oct;90:32-38. doi: 10.1016/j.clinimag.2022.06.015. Epub 2022 Jun 29.
PMID: 35914341
Review.
There are many cases of abdominal pain in the ED with
delayed diagnosis and management secondary to a combination of
institutional policies and knowledge deficits in current imaging
guidelines. Inappropriate use of abdominal radiographs, use of oral contrast for CT …
. 2023 Jul 1;58(7):515-522.
doi: 10.1097/RLI.0000000000000978.
Epub 2023 Apr 11.
New Contrast Media for K-Edge Imaging With Photon-Counting Detector CT
Affiliations
- PMID: 37068840
- PMCID: PMC10259215
- DOI: 10.1097/RLI.0000000000000978
The recent technological developments in photon-counting detector
computed tomography (PCD-CT) and the introduction of the first
commercially available clinical PCD-CT unit open up new exciting
opportunities for contrast media research. With PCD-CT, the efficacy of
available iodine-based contrast media improves, allowing for a reduction
of iodine dosage or, on the other hand, an improvement of image quality
in low contrast indications. Virtual monoenergetic image
reconstructions are routinely available and enable the virtual
monoenergetic image energy to be adapted to the diagnostic task.
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