Decreasing radiation dose in CT for COPD patients

Study concludes that ultralow-dose CT may substitute for standard-dose CT in some COPD patients

There are at least three different generations of iterative reconstruction, all of which enable substantial CT dose reductions without compromise of diagnostic power. While earlier versions of IR yielded 30% dose reductions, those with model-based IR or some blend thereof can result in 50-80% patient radiation dose reductions – with even better spatial and low contrast resolution. Access the full article on this study.

CT Lung Screening and Follow-up Protocol

Research published in this month’s American Journal of Roentgenology reported excellent results on a protocol for working up patients with nodules found in CT lung screening. Ever since the National Lung Screening Trial showed a 20% mortality reduction among high-risk patients screened for the disease, criticism has been vocalized due to the potentially large number of false-positive results following diagnostic imaging investigations. Though the possibility of finding cancer outweighs the risk of false positives, the researchers argued that false-positive results could potentially increase the risks and costs of screening, diminishing the benefit of early cancer detection.

This study, which required participants without a history of cancer to have smoked a minimum of 10 pack-years, concluded with positive results. According to the research, the algorithm produced low false-positive rates, and could make the establishment of large-scale CT screening programs more feasible.

Follow-up CT protocols in lung cancer screening – once a finding is discovered and needs to be evaluated over time or even just routinely on a schedule – is one area ripe for ultra low-dose CT technique. With this technique, we really can see doses reduced by 40 – 80% among these applications! Accepting higher noise in images, very low-dose kVp (in the 80-100 range), and aggressive application of iterative reconstruction techniques can produce diagnostic CT results at breathtakingly low doses.