NetForum uses cookies to ensure that we give you the best experience on our website. If you continue to use the site, we'll assume that you are happy to receive these cookies on the NetForum website. Read about our cookies.
NetForum Community
Learn. Share. Optimize.
Log in | Sign up now | Submit content | Contact

Attention valued NetForum members:

Due to evolving technology needs and global privacy regulations, we have made the hard decision to suspend the NetForum User Community platform on Friday, November 29, 2019.

After this date, the current NetForum can no longer be reached. Please click here for more information about this decision, what happens next and how to stay in touch with us about the future of the community.

Go to similar content

Feasibility of ultra-low kVp CT colonography

Abstract
Philips CT Clinical Science Philips Healthcare • USA

Effect of different iterative reconstruction algorithms on radiologists’ performance

Shin CI, Kim SH, Lee ES, Lee DH, Hwang EJ, Chung SY, Lee JM, Han JK, Choi BI.

Purpose 
To analyze the effect of a decrease in tube voltage from 100~120 kVp to 80 kVp in CT colonography (CTC) on dose, image noise, and diagnostic performance using anthropomorphic phantoms and to assess the effect of two different iterative reconstruction algorithms on radiologists’ performance.

Method and Materials
Seven colon phantoms with 68 simulated polyps = 6 mm were scanned at different kVp settings (80, 100, and 120 kVp) and 10 mAs. Images were reconstructed using filtered back projection (FBP), statistical model-based iterative reconstruction (iDose⁴), and knowledge-based iterative reconstruction algorithm (IMR). Nine datasets for each phantom according to three kVp settings and three reconstruction algorithms yielded 63 CTC datasets. Volume CT dose index (CTDIvol) and image noise were recorded and compared. Two readers blinded to kVp and reconstruction algorithm independently reviewed CTC using primary 3D method. Per-polyp sensitivity was compared among the datasets.

Results
Decreasing tube voltage from 120 and 100 to 80 kVp resulted in 70.7% and 50.5% significant reduction in CTDIvol, respectively (P=0.014). Effective radiation dose of 80 kVp CTC was 0.17 mSv. With FBP reconstruction, image noise in 80 kVp FBP significantly increased by 67.8% and 45.5%, respectively (P=0.018) and per-polyp sensitivity of both reviewers (14.7%, 7.4%) was significantly lower than those in 100 kVp FBP (57.4%, 39.7%) and 120 kVp FBP (85.3%, 83.8%)(P<0.0001). With iDose⁴, image noise in 80 kVp iDose⁴ significantly drop to 52.6% compared to that in 80 kVp FBP (P=0.018) but, per-polyp sensitivity (79.4%, 66.2%) in 80 kVp iDose⁴ was still significantly lower than those of 100 kVp iDose⁴ (95.6%, 86.8%) and 120 kVp iDose⁴ (98.5%, 89.7%)(P<0.002). With IMR, per-polyp sensitivity (98.5%, 95.6%) in 80 kVp IMR was not significantly different from those in 100 kVp IMR (100%, 95.6%) and 120 kVp IMR (100%, 95.6%) for both reviewers (P>0.05).

Conclusion
A decrease in tube voltage to 80 kVp results in a significant reduction of radiation dose to 0.17 mSv at a cost of significant deterioration in image noise and diagnostic performance. With application of knowledge-based iterative reconstruction algorithm, radiologists’ performance of 80 kVp CTC is acceptable and is on par with 100 or 120 kVp CTC.

Clinical Relevance/Application
Ultra-low kVp CT colonography with 80 kVp can be feasible with an application of knowledge-based iterative reconstruction algorithm, significantly lowering the radiation dose with sub-mSv.

Legal Note - The results described in this abstract are for this case only and do not claim to represent universal results. 


This content has been made possible by NetForum Community.
Share this on: Share your link in twitter Share your link in facebook Share your link on LinkedIn Print Rate this article: Log in to vote

 
Rating:
Votes:
0
Views:
2907
Added:
Jan 21, 2014

Rate this:
Log in to vote
 

Abstract
abdomen, Body, colon, dose, FBP reconstruction, iDose4, IMR, iterative model reconstruction, iterative reconstruction, phantom, polyps
 

Clinical News
Best Practices
Case Studies
Publications and Abstracts
White Papers
Web seminars and Presentations
ExamCards
Protocols
Application Tips and FAQ
Training
Try an Application
Business News
Case Studies
White Papers
Web Seminars and Presentations
Utilization Services
Contributing Professionals
Contributing Institutions
Become a Contributor