This article is more than 5 years old. Information may no longer be current.
New CT scanner yielded better images with less radiation
A next-generation CT scanner produced higher-quality images, with as much as 95% less radiation exposure, compared with currently used machines, according to results of a study.
Marcus Y. Chen, MD, a clinician in the NHLBI’s Advanced Cardiovascular Imaging Laboratory, and colleagues analyzed data from 107 patients (mean age, 55.4 years; 53.3% men) who underwent coronary CT angiography with a new second-generation CT scanner. They then compared radiation exposure and image quality with 100 patients who underwent CT imaging with the previous first-generation scanner.
The researchers used a tube potential of 100 kV in 97 patients, single-volume acquisition in 104 patients and prospective electrocardiographic gating in 106 patients. Mean heart rate was 57.1 beats per minute, and 100 patients were able to have single-heartbeat scans.
With the second-generation scanner, median radiation dose was 0.93 mSv vs. 2.67 mSv with the first-generation unit (P<.0001). Additionally, median size-specific dose estimate was 6 mGy with the second-generation scanner compared with 13.2 mGy with the first-generation scanner (P<.0001). Among the 107 patients examined, median radiation exposure was less than 0.5 mSv for 21.5%, less than 1 mSv for 54.2% and less than 4 mSv for 96.3%, according to the researchers.
“All studies were of diagnostic quality, with most having excellent image quality. Three of four image quality indexes were significantly better with the second-generation unit compared with the first-generation unit,” the researchers wrote.
The new scanner has more detector rows than most current CT scanners — 320 vs. 64 — and has a shorter gantry rotation time of 275 ms.
“These multiple advancements work together to allow us to image the entire heart within one heartbeat about 93% of the time,” Chen said in a press release. “These improvements could help clinicians identify problems in even the smallest blood vessels or enable them to conduct complicated tests like measuring blood flow in the heart while limiting radiation exposure.”
Disclosure: This study was supported by the NIH.