Tag: medical imaging

Lung Screening Narrows Disparities

Posted on by Brian Casey

New research confirms that not only does low-dose CT screening reduce lung cancer mortality, it can also narrow health disparities. Researchers found that screening’s beneficial impact was greater at lower socioeconomic levels in a new study published in Lancet Regional Health – Europe.

As we mentioned in our last issue, CT lung cancer screening is gaining momentum globally; at the same time, researchers have documented greater mortality and morbidity for a variety of diseases among racial minorities and at lower socioeconomic levels.

  • This difference can be especially profound when it comes to lung disease, given higher smoking rates among some minority groups and economically disadvantaged populations.

In the original UK Lung Cancer Screening Trial (UKLS) in 2021, researchers found that a single CT screening round produced a 16% lung cancer mortality reduction. 

  • The new study is a secondary analysis of UKLS to investigate whether CT lung screening’s impact differed by socioeconomic status, which is important given that smoking occurs in England at higher rates in the most deprived neighborhoods compared to wealthier ones (24% vs. 6.8%).

UKLS researchers compared lung cancer mortality rates in 4k individuals in different groups classified by a widely used socioeconomic barometer. They found that … 

  • CT lung screening had the same lung cancer mortality benefit in both low and high socioeconomic groups (-19% vs. -20%)
  • But there was a bigger reduction in death from COPD in lower socioeconomic groups (-34% vs. +4%)
  • And fewer deaths from other lung diseases (-32% vs. +10%)
  • While cardiovascular mortality was also lower (-30% vs. -13%)
  • All-cause mortality was lower in lower socioeconomic groups – a benefit not seen at higher levels

Lung screening’s reduction in all-cause mortality is particularly intriguing, as this is an accomplishment that has eluded most other cancer screening tests – a point that has been repeatedly hammered home by screening skeptics.

The Takeaway

The new findings highlight how – to a greater degree than other major cancer screening tests – CT lung screening has the potential to address ongoing racial and socioeconomic healthcare disparities. It’s yet another reason to press for broader adoption of lung screening.

CT Lung Screening Shows Progress at ATS 2024

Posted on by Brian Casey

Making CT lung cancer screening more effective has been a hot topic at the American Thoracic Society meeting, which convened this weekend in San Diego. Presentations at ATS 2024 have ranged from improving screening compliance rates to eliminating racial disparities in screening attendance.

After years of fits and starts, low-dose CT lung cancer screening appears to be finally making progress. 

  • While the US still struggles with overly restrictive screening criteria and convoluted reimbursement rules, the rest of the world – including Australia, Germany, and Taiwan – is moving ahead with population-based screening programs designed to counter the tobacco epidemic’s deadly scourge.

At ATS 2024, investigators are presenting research to ensure that the benefits of CT lung cancer screening are delivered to those who need it, with the following highlights …

  • Researchers at the University of Minnesota saw a 7.2% completion rate for screening-specific low-dose CT among 91k eligible individuals – an indication of “overall poor uptake of screening” 
  • To improve uptake, another group implemented a centralized nurse coordinator for lung screening, resulting in a 23-day reduction in time from initial consultation to report delivery as well as better adherence to eligibility criteria
  • Patients who self-identify as Black are more likely to miss a scheduled CT screening appointment (OR=2.05), while Hispanic patients also have high miss rates (OR=1.92) as do those with limited English proficiency (OR=1.72). The numbers highlight the need for patient conversations to boost completion rates
  • Incidence rates of lung and bronchus cancer dropped from 2007-2019 compared to 1999-2006, underscoring the importance of smoking cessation and supporting current USPSTF age criteria for lung screening
  • Pulmonary physicians significantly overestimated their patients’ lung screening completion rates, with almost half thinking the rate was higher than 60% when it was actually 17%. Researchers suggested interventions for improving completion rates

The Takeaway

The fact that ATS 2024 has seen so many presentations on CT lung cancer screening – the vast majority presented by US authors – indicates that low screening rates haven’t discouraged American researchers and clinicians. The presentations underscore the progress being made toward making the benefits of lung screening available to Americans who would benefit from it.

Is Radiology’s AI Edge Fading?

Posted on by Brian Casey

Is radiology’s AI edge fading, at least when it comes to its share of AI-enabled medical devices being granted regulatory authorization by the FDA? The latest year-to-date figures from the agency suggest that radiology’s AI dominance could be declining. 

Radiology was one of the first medical specialties to go digital, and software developers have targeted the field for AI applications like image analysis and data reconstruction.

  • Indeed, FDA data from recent years shows that radiology makes up the vast majority of agency authorizations for AI- and machine learning-enabled medical devices, ranging from 86% in 2020 and 2022 to 79% in 2023. 

But in the new data, radiology devices made up only 73% of authorizations from January-March 2024. Other data points indicate that the FDA …

  • Authorized 151 new devices since August 2023
  • Reclassified as AI/ML-enabled 40 devices that were previously authorized 
  • Authorized a total of 882 devices since it began tracking the field 

      In an interesting wrinkle, many of the devices on the updated list are big-iron scanners that the FDA has decided to classify as AI/ML-enabled devices. 

      • These include CT and MRI scanners from Siemens Healthineers, ultrasound scanners from Philips and Canon Medical Systems, an MRI scanner from United Imaging, and the recently launched Butterfly iQ3 POCUS scanner. 

      The additions could be a sign that imaging OEMs increasingly are baking AI functionality into their products at a basic level, blurring the line between hardware and software. 

      The Takeaway

      It should be no cause for panic that radiology’s share of AI/ML authorizations is declining as other medical specialties catch up to the discipline’s head start. The good news is that the FDA’s latest figures show how AI is becoming an integral part of medicine, in ways that clinicians may not even notice.

      Slashing CT Radiation Dose

      Posted on by Brian Casey

      Cutting CT radiation dose should be the goal of every medical imaging facility. A new paper in European Radiology offers a promising technique that slashed CT dose to one-tenth of conventional CT – and just twice that of a standard chest X-ray.

      CT’s wide availability, excellent image quality, and relatively low cost make it an invaluable modality for many clinical applications.

      • CT proved particularly useful during the COVID-19 pandemic for diagnosing lung pathology caused by the virus, and it continues to be used to track cases of long COVID.

      But patient monitoring can involve multiple CT scans, leading to cumulative radiation exposure that can be concerning, especially for younger people.

      • Researchers in Austria wanted to see if they could use commercially available tools to produce ultra-low-dose CT scans, and then assess how they compared to conventional CT for tracking patients with long COVID.

      Using Siemens Healthineers’ Somatom Drive third-generation dual-source CT scanner, they adjusted the parameters on the system’s CAREDose automated exposure control and ADMIRE iterative reconstruction to drive down dose as much as possible.

      • Other ultra-low-dose CT settings versus conventional CT included fixed tube voltage (100 kVp vs. 110 kVp), tin filtration (enabled vs. disabled), and CAREDose tube current modulation (enabled – weak vs. enabled – normal). 

      They then tested the settings in a group of 153 patients with long COVID seen from 2020 to 2021; both ultra-low-dose and conventional CT scans were compared by radiologists, finding … 

      • Mean entrance-dose radiation levels with ultra-low-dose CT were less than one-tenth those of conventional CT in (0.21 mSv vs. 2.24 mSv); a two-view chest X-ray is 0.1 mSv
      • Image quality was rated 40% lower on a five-point scale (3.0 vs. 5.0)
      • But all ultra-low-dose scans were rated as diagnostic quality
      • Intra-reader agreement between the two techniques was “excellent,” at 93%

      The findings led the researchers to conclude that ultra-low-dose CT could be a good option for tracking long COVID, such as in younger patients. 

      The Takeaway

      The study demonstrates that CT radiation dose can be driven down dramatically through existing commercially available tools. While this study covers just one niche clinical application, such tools could be applied to a wider range of uses, ensuring that the benefits of CT will continue to be made available at lower radiation doses than ever.

      Headwinds Slow AI Funding

      Posted on by Brian Casey

      Venture capital funding of medical imaging AI developers continues to slow. A new report from Signify Research shows that funding declined 19% in 2023, and is off to a slow start in 2024 as well. 

      Signify tracks VC funding on an annual basis, and previous reports from the UK firm showed that AI investment peaked in 2021 and has been declining ever since. 

      • The report’s author, Signify analyst Ellie Baker, sees a variety of factors behind the decline, chief among them macroeconomic headwinds such as tighter access to capital due to higher interest rates. 

      Total Funding Value Drops – Total funding for 2023 came in at $627M, down 19% from $771M in 2022. Funding hit a peak in 2021 at $1.1B.

      Deal Volume Declines – The number of deals in 2023 fell to 35, down 30% from 50 the year before. Deal volume peaked in 2021 at 63. And 2024 isn’t off to a great start, with only five deals recorded in the first quarter. 

      Deals Are Getting Bigger – Despite the declines, the average deal size grew last year, to $19M, up 23% versus $15M in 2022. 

      HeartFlow Rules the Roost – HeartFlow raised the most in 2023, fueled by a massive $215M funding round in April 2023, while Cleerly held the crown in 2022.

      US Funding Dominates – On a geographic basis, funding is shifting away from Europe (-46%) and Asia-Pacific (no 2023 deals) and back to the Americas, which generated over 70% of the funding raised last year. This may be due to the US providing faster technology uptake and more routes to reimbursement.

      Early Bird Gets the Worm – Unlike past years in which later-stage funding dominated, 2024 has seen a shift to early-stage deals with seed funding and Series A rounds, such as AZmed’s $16M deal in February 2024. 

      $100M Club Admits New Members – Signify’s exclusive “$100M Club” of AI developers has expanded to include Elucid and RapidAI. 

      The Takeaway

      Despite the funding drop, Signify still sees a healthy funding environment for AI developers ($627M is definitely a lot of money). That said, AI software developers are going to have to make a stronger case to investors regarding revenue potential and a path to ROI. 

      USPSTF’s Mammography Letdown?

      Posted on by Brian Casey

      Last year’s relief that the USPSTF would lower its recommended starting age for breast screening to 40 gave way to frustration this week that the group did not go farther in its final decision on mammography recommendations. 

      In a series of papers in JAMA journals this week, the USPSTF tackled a range of breast screening issues, from the age at which screening should start to whether modalities like ultrasound and MRI should be used to supplement conventional mammography.

      That was the good news. The bad news is that breast screening advocates mostly got shut out on a variety of other issues, with the USPSTF … 

      • Advising that breast screening be conducted biennially (every two years), rather than annually as most women’s imaging advocates would prefer
      • Declining to raise the recommended upper limit for screening from 74 to 79
      • Declining to recommend supplemental screening with MRI or ultrasound for women with dense breast tissue, even as women express frustration with the lack of reimbursement for these exams

      On the positive side, the USPSTF finally weighed in on DBT, stating that the 3D mammography technology is equivalent to digital mammography for breast screening. 

      • But in another disappointment, the group said it couldn’t find any studies stating that DBT was better than 2D digital mammography. 

      Given the fierce battles that have been fought over screening guidelines in the last 15 years, what made the USPSTF change its mind on mammography’s starting age? 

      • One big factor is the 2% annual rise in breast cancer incidence in women in their 40s from 2015 to 2019; the higher mortality rates among Black women was another issue (see story below in The Wire).

      The Takeaway

      The USPSTF’s move to lower its recommended starting age for screening mammography is a welcome – if overdue – change for women, who for 15 years have borne the brunt of the group’s conservative approach to guideline formation. The question remains, is the USPSTF making the same mistake all over again when it comes to supplemental imaging and annual screening? And how long will women have to wait this time until it sees the light?

      Doctors Work Harder for Less

      Posted on by Brian Casey

      Medicare reimbursement to physicians per beneficiary has declined over the last 16 years, with radiologists among the biggest losers. That’s according to a new study by the ACR’s Harvey L. Neiman Health Policy Institute, which confirms what many physicians already knew: they are working harder for less money.

      It’s no secret that the US government has been struggling to rein in healthcare costs for decades. 

      CMS has a number of tools at its disposal for controlling Medicare and Medicaid costs, one of which is the relative value unit (RVU) scale. 

      • RVUs – when multiplied by monetary conversion factors – basically set the amount of money the agency pays physicians per unit of work, with CMS typically reducing the conversion factor when it needs to cut Medicare spending. 

      In the new study in the journal Inquiry, Neiman HPI researchers analyzed trends in RVU and conversion factor levels per Medicare beneficiary from 2005 to 2021, analyzing changes to calculate how much work providers have to do to deliver a unit of care. Findings included …

      • Reimbursement per Medicare beneficiary after inflation adjustment fell 2.3% for physicians as a whole
      • Radiology saw one of the biggest declines in MPFS reimbursement per beneficiary, ranking 31st on a list of 39 medical specialties, with a 25% decrease
      • Reimbursement has risen 207% for non-physician practitioners

      What’s driving the declines? The Neiman HPI researchers identified the federal government’s budget neutrality rules for Medicare, which stipulate that increases in one area have to be offset by declines elsewhere.

      The Takeaway

      The new findings confirm what many physicians have suspected – they are not only working harder for less, but non-physician practitioners seem to be getting a bigger piece of the pie. Combined with a recent report showing that radiologist salaries didn’t keep pace with inflation in 2023, it’s not a pretty picture. 

      Nuclear Medicine’s AI Uptake

      Posted on by Brian Casey

      Nuclear medicine is one of the more venerable medical imaging technologies. Artificial intelligence is one of the newest. How are the two getting on? That question is explored in new point-counterpoint articles in AJR. 

      Nuclear medicine was an early adopter of computerized image processing, for tasks like image analysis, quantification, and segmentation, giving rise to a cottage industry of niche software developers.

      • But this early momentum hasn’t carried over into the AI age: on the FDA’s list of 694 cleared AI medical applications through July 2023, 76% of the listed devices are classified as radiology, while just four address nuclear medicine and PET.

      In the AJR articles, the position that AI in nuclear medicine is more hype than reality is taken by Eliot Siegel, MD, and Michael Morris, MD, who note that software has already been developed for most of the image analysis tasks that nuclear medicine physicians need. 

      • At the same time, Siegel and Morris say the development of AI-type algorithms like convolutional neural networks and transformers has been “relatively slow” in nuclear medicine. 

      Why the slow uptake? One big reason is the lack of publicly available nuclear medicine databases for algorithm training. 

      • Also, nuclear medicine’s emphasis on function rather than anatomical changes means fewer tasks requiring detection of subtle changes.

      On the other side of the coin, Babak Saboury, MD, and Munir Ghesani, MD, take a more optimistic view of AI in nuclear medicine, particularly thanks to the booming growth in theranostics. 

      • New commercial AI applications to guide the therapeutic use of radiopharmaceuticals are being developed, and some have received FDA clearance. 

      As for the data shortage, groups like SNMMI are collaborating with agencies and institutions to create registries – such as for theranostics – to help train algorithms. 

      • They note that advances are already underway for AI-enhanced applications such as improving image quality, decreasing radiation dose, reducing imaging time, quantifying disease, and aiding radiation therapy planning. 

      The Takeaway
      The AJR articles offer a fascinating perspective on an area of medical imaging that’s often overlooked. While nuclear medicine may never have the broad impact of anatomical-based modalities like MRI and CT, growth in exciting areas like theranostics suggest that it will attract AI developers to create solutions for delivering better patient care.

      CT Changes Headache Workup

      Posted on by Brian Casey

      Recent studies have raised concerns about whether CT is overused in the emergency setting for patients with symptoms like headache, but a new study in JAMA Network Open suggests that higher CT utilization could be contributing to a decline in more invasive procedures like lumbar puncture. 

      Earlier this month, we covered a study documenting the rapid rise of emergency head CT for patients presenting with acute-onset headache – which could be an indication of subarachnoid hemorrhage or other serious issues. 

      • Researchers theorized that higher CTA utilization could be a sign of overuse because the rate of positive findings over time fell 38%.

      But the new study suggests that the growth in cerebral CTA use could have beneficial effects, by reducing the use of more invasive procedures and by detecting unruptured intracranial aneurysm. 

      • Some 5% of acute-onset headaches in emergency patients are caused by subarachnoid hemorrhage; these cases have a 50% risk of death or serious disability at one year, making accurate detection and workup a serious issue.

      Researchers from Kaiser Permanente in Northern California analyzed 198k encounters for patients with headache at 21 community EDs from 2015 to 2021. 

      • They compared multiple workup protocols, ranging from CT only to others in which CT was used first, with nondiagnostic cases sent to either lumbar puncture or cerebral CTA. 

      Dramatic changes occurred in headache workup over the study period, including … 

      • Overall use of CT grew at an average annual percent change of 5.4%
      • Cerebral CTA use grew 19% annually
      • Lumbar puncture use fell 11% annually
      • Detection of unruptured intracranial aneurysms grew 33%
      • The ratio of unruptured aneurysms to subarachnoid hemorrhage grew

      The authors noted that the findings show clinicians are shifting away from a headache workup protocol that includes lumbar puncture to one that relies more on cerebral CTA.

      • The researchers were equivocal on the increase in detection of unruptured aneurysms; on the one hand, the absolute risk of rupture is low, but on the other, the consequences of rupture are severe.  

      The Takeaway

      The new study offers a more nuanced – and perhaps more positive – view of growing cerebral CTA use in the ED. In the end, it’s possible that two conflicting statements can be true: CT indeed may be overused in the emergency department, but its growing use is also having a beneficial impact on patient care.

      Breast Screening Goes Green

      Posted on by Brian Casey

      Earth Day will be celebrated on April 22, and the event is a good opportunity to step back and take a look at medical imaging’s (not insignificant) contribution to climate change. Fortunately, a new paper in Health Policy details how one imaging service – breast screening – can be made more environmentally friendly. 

      Previous studies have documented that medical imaging is a substantial contributor to greenhouse gas emissions, given the massive energy consumption required to keep all that big iron humming. 

      • Researchers have recommended a variety of solutions to reduce radiology’s environmental footprint, from powering equipment down overnight to switching to alternative energy sources to power medical facilities. 

      The new study gets even more specific, analyzing the greenhouse emissions inherent in cancer screening – in particular patient travel – and offering ways to make it more planet-friendly. 

      • Researchers reviewed cancer screening programs in the Italian region of Tuscany, quantifying the CO2 emissions for different screening services. 

      Greenhouse gas emissions could be cut dramatically by switching from a provider-centric model that requires patients to travel to centralized screening facilities to one in which mobile vans were sent into the field. Using model calculations for mammography screening, they found that in one district alone …

      • Breast screening was the most polluting cancer screening service, mostly because it had the highest number of invitees (3.4k women) traveling for screening
      • Institution-based breast screening generated CO2 emissions of 35,870 kgCO2-eq/km annually
      • Mobile breast screening had emissions of 805 kgCO2-eq/km – just 2.2% of emissions from site-based screening

      The study is unique in that it views sustainability and environmental pollution as a healthcare issue that’s fully within the purview of providers to address. 

      The Takeaway

      The new study outlines a holistic approach to healthcare services that – right now – many US providers might believe is outside the scope of their operations. But as Earth Day approaches, it’s worth at least considering how in years to come healthcare could be delivered within a broader context of social and environmental stewardship.

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