Analyzing the Cost-effectiveness of Low-dose CT

by Dr. William Shuman on March 13, 2014

We already know that low-dose CT is a valuable tool for reducing mortality rates, but now there’s evidence that it might reduce financial costs as well. A new analysis of the 2010 National Lung Screening Trial (NLST) shows that low-dose CT is a cost-effective diagnostic tool for patients at high-risk of lung cancer, according to

The Medical Imaging and Technology Alliance (MITA) released a statement saying the organization welcomes the analysis and “looks forward to ongoing collaboration with patient advocates and others in the imaging community to ensure access to this lifesaving technology.”

In my opinion, though, the key question in whether low-dose screening for lung cancer is cost effective is: what is the cost of working up the false positives? That cost needs to be subtracted from the cost benefit of the lives saved. This new analysis suggests that low-dose screening is indeed cost effective. One thing no cost analysis considers: the value of a negative exam to a very worried patient.

Further new twist: we now can do ultra-low-dose lung cancer screening using fully model-based iterative reconstruction techniques. This technique enables a 60 percent radiation dose reduction (down to the sub-0.5 mSv range) below that of even recent low-dose CT – further substantially decreasing any downside from lung cancer screening in high-risk patients.


A University of Washington study featured in the August issue of JAMA Pediatrics claims that 4 million annual pediatric CT scans of the head, spine, abdomen and pelvis are predicted to cause nearly 5,000 future cancers, according to However, the study goes on to state that the risk can be mitigated by CT dose reduction and appropriate imaging initiatives which have the potential to prevent more than half of the projected radiation-related cancers. Practices like eliminating unnecessary scans and targeting high-dose scans are called out in the study.

I believe that the best way to reduce radiation dose from CT in children is to not do studies which are inappropriate or which have a very low chance of producing impactful diagnostic information. The next best way to reduce dose is to pay close attention to all the tricks of technique: accurate patient centering in the gantry, use of radiation shields, use of 80 or 100 kVp, minimizing Z axis scan length, etc. Then newer technology will greatly further reduce dose – automated tube current modulation, iterative reconstruction – especially fully model-based iterative reconstruction. Together these can reduce radiation dose by 70-80 percent. Scanning in kids above 6-8 mSv should be a thing of the past and sub-1.0 mSv scans should be common.


Update Needed for CCTA Training Guidelines

by Dr. William Shuman on September 9, 2013

The following passage, from an article on, caught my attention:

The honeymoon has ended for coronary CT angiography (CCTA) and the seven-year itch has commenced for some radiologists and cardiologists. They do not advocate replacing the technique though. Rather, they are asking if the requirements in training guidelines need a makeover to reduce variability and better maximize CCTA’s potential to improve patients’ clinical care and outcomes.

This brings up a good point: the credentialing criteria for performing and interpreting cardiac CT are now too low. I found the learning curve was long with a gradual slope. You need to be in a training and supervised environment with a fairly good case load for at least a year. It’s challenging, but performed well and interpreted with skill, it is a very valuable test which can save the healthcare system considerable cost – especially in low- to moderate-risk chest pain patients presenting to an emergency room.


Studies Offer Hope for Future CT Protocol Comparisons

January 15, 2013

A recent study featured in the Journal of Computer Assisted Tomography touches on the perennial issue for radiology researchers studying and evaluating the effectiveness of different low-dose protocols.

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Despite Initial Challenges, ACR Dose Index Registry is a Success!

January 10, 2013

At UW, we enrolled in the DIR in May 2011 and despite initial challenges, patient CT scan data is being successfully transmitted to and analyzed by the American College of Radiology.

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A Radiologist Replies to ‘Medical Radiation Soars, With Risks Often Overlooked’

November 12, 2012

A few weeks ago, the New York Times featured an article, “Medical Radiation Soars, With Risks Often Overlooked.” The article brought up some valid points about radiation, but also requires readers to take a step back when processing some of the information given.

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Radiology on the Horizon: Can a Pill Prevent Cancer?

September 27, 2012

In last month’s Radiology, a new study was featured that suggests that a new pill can prevent DNA damage that might lead to cancer.

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Chronic Kidney Failure: Dual-Energy CTA is Best Bet!

September 24, 2012

We look at CTA and dual-energy CTA as means for coping with advanced renal failure. See which technique is the safest for patients.

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Study Offers Promising Benefits for Iterative Reconstruction

September 18, 2012

As big proponents for iterative reconstruction, new research on the benefits of the protocol is promising for the future of low-dose imaging.

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Risk Model Emerges for CT Lung Cancer Screening!

September 13, 2012

A new risk model for lung cancer has emerged and predicts the disease at a higher accuracy than smoking duration and family history.

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