By Eric Barnes, staff writer
November 13, 2013

Squeezing great images from tiny radiation doses is, of course, a central theme at this year's RSNA 2013 meeting. But it's how the researchers do it -- and how they marry dose savings to other advances in CT technology -- that are the real stars of the Chicago show.

In a week packed with scientific presentations, exhibitions, special courses, and hot topic sessions, attendees at RSNA 2013 will have plenty of opportunities to broaden their knowledge of emerging techniques such as spectral CT, perfusion imaging, iodine mapping, tissue composition analysis, automated tube current selection, flow mapping, and the intricacies of contrast dose and iterative reconstruction.

For combat training there are controversy sessions: for example, discussions about whom to screen for lung cancer, how much it costs to save a life, and what radiation risk really means in light of recent research.

Start on Sunday morning with a presentation on what happens when radiologists examine pregnant women with suspected pulmonary embolism using a shorter scan length that avoids the riskiest anatomy (11:05 a.m.-11:15 a.m., SSA05-03, Room N228).

Then there's a study on dose reduction resulting from automated tube potential selection in neck CT (Sunday, 10:45 a.m.-10:55 a.m., SSA16-01, Room N227), and another on how iterative reconstruction affects coronary plaque characterization (Sunday, 11:25 a.m.-11:35 a.m., SSA02-05, Room S502AB).

Sunday afternoon features an enlightening special exhibition on how single- and dual-source CT protocols affect organ doses to the colon and the CT dose index volume readings that your scanner produces (12:30 p.m.-1:00 p.m., LL-PHE3075-SUA, Lakeside Learning Center).

On Monday morning you can learn how radiologists performed automated analysis of their radiology reports to determine if patients needed a repeat head CT scan (10:50 a.m.-11:00 a.m., SSC12-03, Room N229).

In the afternoon, find out how reporting incidental calcifications on thoracic CT is an integral part of cutting healthcare costs in the new accountable care organizations (3:20 p.m.-3:30 p.m., SSE06-03, Room N227).

Tuesday features a hot topic session on the management of CT-detected adenocarcinomas in light of new management guidelines (7:15 a.m.-8:15 a.m., SPSH30, Room E351). Also on Tuesday, check out a dual-energy breast CT study that shows CT's potential to distinguish benign from malignant tissue far more accurately than mammography (10:40 a.m.-10:50 a.m., SSG14-02, Room S403B).

On Wednesday you can learn about the one-two punch of new CT detector circuitry combined with iterative reconstruction in the always-tricky task of stent assessment (3:50 p.m.-4:00 p.m., SSM20-06, Room S404AB). Also learn how much it really costs to follow up those extracolonic findings in CT (10:30 a.m.-10:40 a.m., SSK05-01, Room E351).

How certain are the experts regarding the uncertainties of radiation exposure and risk? Find out in a controversy session about risk and radiation that could leave you slightly more certain (Wednesday, 4:30 p.m.-6:00 p.m., SPSC42, Room N228).

Then there's lung cancer screening. How much are we willing to pay to find most of the early cases? After all, there are plenty of diseases for the finite dollars of an indebted republic to chase. In that vein, a controversy session that probes the "dollars and sense" of lung cancer screening is sure to be lively (Wednesday, 4:30 p.m.-6:00 p.m., SPSC41, Room E450A).

While we're in the lungs, the management of CT-detected nodules depends increasingly on automated volumetry to assess nodule size and growth and steer patient care. How well does volumetry work with today's ultralow doses, and how much can iterative reconstruction push that dose downward? Find out on Thursday (11:30 a.m.-11:40 a.m., SSQ04-07, Room S405AB).

Also on Thursday, you can learn how fractional flow reserve CT works in a large group of demographically diverse patients (11:30 a.m.-11:40 a.m., SSQ03-07, Room S504AB).

And you might want to end your day with a special session on spectral CT, the emerging technique that's grabbing attention for its ability to distinguish different materials at very low doses. The session wraps up with spectral imaging master Dr. Dushyant Sahani's talk on "killer apps" in spectral CT (Thursday, 3:00 p.m.-4:00 p.m., SPSH56, Room S403B).

Finally, you can finish the week by hearing German researchers talk about voxel-to-voxel mapping of Hounsfield unit values for advanced air-trapping assessment in lung transplant patients (Friday, 10:30 a.m.-10:40 a.m., SST04-01, Room E451B).

We invite you to scroll down for more CT highlights from this year's RSNA meeting. And for a detailed list of abstracts and other presentations at this year's RSNA show, click here.

Scientific and Educational Presentations
Automated tube potential selection cuts neck dose
Sunday, December 1 | 10:45 a.m.-10:55 a.m. | SSA16-01 | Room N227
Automated tube potential selection can cut CT dose by as much as a third in patients undergoing neck CT, according to researchers from Germany, who will present their results in this RSNA 2013 session.
No harm in cutting CTPA scan length in pregnant women
Sunday, December 1 | 11:05 a.m.-11:15 a.m. | SSA05-03 | Room N228
Shorter scan lengths for CT pulmonary angiography (CTPA) do not reduce the accuracy of pulmonary embolism diagnosis, but they do cut radiation dose substantially, according to a research team from Wisconsin.
Iterative reconstruction changes plaque characterization
Sunday, December 1 | 11:25 a.m.-11:35 a.m. | SSA02-05 | Room S502AB
Does iterative reconstruction make a difference in coronary plaque characterization? Researchers from Massachusetts General Hospital think it does; they found that even the reconstruction scheme makes a difference.
Absorbed dose varies between single-, dual-source CT colonography
Sunday, December 1 | 12:30-1:00 p.m. | LL-PHE3075-SUA | Lakeside Learning Center
The dose readout on your scanner doesn't really tell you much, according to a group from Massachusetts General Hospital, who looked into dose differences between different scanners and scan modes for this education exhibit.
Natural language processing predicts need for repeat head trauma CT
Monday, December 2 | 10:50 a.m.-11:00 a.m. | SSC12-03 | Room N229
When do head trauma patients need repeat CT scans? When the report suggests the condition is worsening. However, a neuroradiologist review is time-consuming, and scans are sometimes repeated unnecessarily. By automating the process, California researchers hoped to improve CT utilization and cut radiation exposures from unneeded scans in this study to be presented on Monday morning.
Reporting calcifications would aid preventive care in ACOs
Monday, December 2 | 3:20 p.m.-3:30 p.m. | SSE06-03 | Room N227
Detecting incidental coronary artery calcifications and reporting the information can identify patients with undiagnosed coronary artery disease who may benefit from medical therapy in accountable care organizations (ACOs), concluded a study team from Brigham and Women's Hospital.
Hot topic session probes evolving concepts in lung cancer
Tuesday, December 3 | 7:15 a.m.-8:15 a.m. | SPSH30 | Room E351
This Tuesday hot topic session on lung adenocarcinoma will examine the major changes in the management of CT findings brought about by the revised lung adenocarcinoma classification scheme.
Breast DECT shows potential to predict malignancy
Tuesday, December 3 | 10:40 a.m.-10:50 a.m. | SSG14-02 | Room S403B
One of the hardest jobs in diagnostic radiology is distinguishing benign from malignant findings. So a new project that harnesses dual-energy CT (DECT) to analyze water, lipid, and protein content of breast tissue and identify malignancies with high accuracy is welcome news.
Contrast breast CT shows promise for visualizing malignant masses
Tuesday, December 3 | 3:10 p.m.-3:20 p.m. | SSJ02-02 | Room E450A
Is contrast-enhanced dedicated breast CT better than tomosynthesis and digital mammography for visualizing suspicious lesions? Researchers from the University of California, Davis Medical Center will address this question during this Tuesday scientific session.
High-resolution breast CT outperforms FFDM and tomo
Tuesday, December 3 | 3:30 p.m.-3:40 p.m. | SSJ02-04 | Room E450A
High-resolution breast CT produces 3D images that are better than full-field digital mammography (FFDM) and tomosynthesis, and it does so at acceptable dose levels for screening procedures, according to German researchers.
Costs remain low in workup of extracolonic findings
Wednesday, December 4 | 10:30 a.m.-10:40 a.m. | SSK05-01 | Room E351
In this scientific session, Italian investigators will discuss their conclusion that it's not expensive to work up patients with potentially serious extracolonic findings, especially considering the benefits of finding serious conditions early.
Iterative reconstruction permits sub-mSv CT colonography
Wednesday, December 4 | 11:20 a.m.-11:30 a.m. | SSK05-06 | Room E351
Researchers dialed their CT radiation dose way down -- to 1 mSv per CT colonography exam -- and reconstructed the images using two different iterative reconstruction algorithms in this study from Korea.
Iterative reconstruction plus new detector circuitry aids stent assessment
Wednesday, December 4 | 3:50 p.m.-4:00 p.m. | SSM20-06 | Room S404AB
CT with iterative reconstruction is racking up points throughout the body for high-resolution imaging at low doses, but improved detector technology also is an important part of the picture in boosting the quality of low-dose imaging, according to German researchers.
Session probes 'dollars and sense' of lung cancer screening
Wednesday, December 4 | 4:30 p.m.-6:00 p.m. | SPSC41 | Room E450A
The debate over CT lung cancer screening isn't just about safety, it's about dollars. This special controversy session takes on the issue with National Lung Screening Trial data, addressing what the information shows, along with the limitations and cost-effectiveness of screening.
Controversy session probes CT radiation and risk
Wednesday, December 4 | 4:30 p.m.-6:00 p.m. | SPSC42 | Room N228
This session will take a new look at the data used to evaluate the association between radiation exposure and cancer risk. The participants will examine how those data have been used to quantify risk and assess the uncertainties inherent in those estimates.
Tumor shrinkage post-treatment confers excellent prognosis in kidneys
Thursday, December 5 | 10:40 a.m.-10:50 a.m. | SSQ10-02 | Room E450B
Shrinkage of 10% or more on CT post-treatment is highly predictive of good outcomes in renal cell carcinoma, according to a new study from Boston.
Advanced iterative reconstruction enhances cranial CT
Thursday, December 5 | 11:00 a.m.-11:10 a.m. | SSQ14-04 | Room N228
Using a commercially available iterative reconstruction protocol both reduces noise and improves image quality in cranial CT images, according to researchers from University Medical Center Mannheim in Germany.
Advanced iterative reconstruction enables ultralow-dose chest CT
Thursday, December 5 | 11:20 a.m.-11: 30 a.m. | SSQ04-06 | Room S405AB
Low-dose images reconstructed using advanced iterative reconstruction beat standard-dose chest CT images using a first-generation iterative reconstruction scheme, according to this study by German radiologists.
FFR-CT after cardiac CT found accurate across demographic spectrum
Thursday, December 5 | 11:30 a.m.-11:40 a.m. | SSQ03-07 | Room S504AB
This scientific session will discuss a study in which fractional flow reserve CT (FFR-CT) yielded similar discrimination and accuracy to invasive FFR for diagnosing lesion-specific ischemia across a variety of patients.
Iterative reconstruction boosts lung nodule volumetry, too
Thursday, December 5 | 11:30 a.m.-11:40 a.m. | SSQ04-07 | Room S405AB
What are the low-dose limits? Researchers from Kobe University in Japan wanted to know how low they could go in phantom studies of lung nodules using advanced iterative reconstruction.
Hot topic session covers 'killer apps' for spectral CT
Thursday, December 5 | 3:00 p.m.-4:00 p.m. | SPSH56 | Room S403B
Spectral CT is emerging as a powerful way to get more image from less dose -- with some added tricks that other CT techniques simply can't provide. This special session is dedicated to spectral imaging's growing list of uses.
Coregistration, mapping maximize accuracy of CT air-trapping evaluation
Friday, December 6 | 10:30 a.m.-10:40 a.m. | SST04-01 | Room E451B
Coregistering inspiration and expiration CT datasets and voxel-by-voxel mapping of Hounsfield unit values boost the accuracy of air-trapping assessment, according to researchers in Germany.