Evaluating the effectiveness of a single CT method for attenuation correction in stress-rest myocardial perfusion imaging with thallium-201 chloride SPECT

Thallium Use, Toxicity, and Detoxification Therapy: An Overview

Thallium (Tl) is released into the environment, where is present at very low levels, from both natural and anthropogenic sources. Tl is considered as one of the most toxic heavy metals; it is a non-essential metal, present in low concentrations in humans. Tl toxicity causes dermatological and gastrointestinal diseases and disorders of the nervous system, and may even result in death. Many isotopes of Tl exist, with different uses. One of the isotopes of this metal (201Tl) is used in cardiovascular scintigraphy and for the diagnosis of malignant tumors such as breast or lung cancer and osteosarcoma bone cancer. Many Tl compounds are tasteless, colorless, and odorless. Due to these characteristics and their high toxicity, they have been used as poisons in suicides and murders for criminal purposes, as well as instances of accidental poisoning. Impaired glutathione metabolism, oxidative stress, and disruption of potassium-regulated homeostasis may play a role in the mechanism of Tl toxicity. Solanum nigrum L. and Callitriche cophocarpa have been suggested as promising agents for the phytoremediation of Tl. In addition, macrocyclic compounds such as crown ethers (18-crown-6) are good candidates to absorb Tl from wastewater. Through this review, we present an update to general information about the uses and toxicity of Tl. Furthermore, the attention is focused on detoxification therapies.

CT Attenuation correction and its impact on image quality of myocardial perfusion imaging in coronary artery disease: A systematic review

Myocardial perfusion imaging is a non-invasive procedure that plays an integral role in the diagnosis and management of coronary artery disease. With the routine use of computerised tomography attenuation correction (CTAC) in myocardial perfusion imaging still under debate, the aim of this review was to determine the impact of CTAC on image quality in myocardial perfusion imaging. Medline, Embase and CINAHL were searched from the earliest available time until August 2019. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies version 2. Details pertaining to image quality and diagnostic accuracy were analysed, and results summarised descriptively. Three studies with 'unclear' risk of bias and low applicability concerns (1002 participants) from a yield of 2725 articles were identified. Two studies demonstrated an increase in image quality, and one study found no difference in image quality when using CTAC compared to no attenuation correction. Benefits of CTAC for improving image quality remain unclear. Given the potential exposure risk with the addition of CTAC, patient and clinician factors should inform decision making for use of CTAC in myocardial perfusion imaging for coronary artery disease.