AI Investment Shift

VC investment in the AI medical imaging sector has shifted notably in the last couple years, says a new report from UK market intelligence firm Signify Research. The report offers a fascinating look at an industry where almost $5B has been raised since 2015. 

VC investment in the AI medical imaging sector has shifted in the last couple years, with money moving to later-stage companies.

Total Funding Value Drops – Both investors and AI independent software vendors (ISVs) have noticed reduced funding activity, and that’s reflected in the Signify numbers. VC funding of imaging AI firms fell 32% in 2022, to $750.4M, down from a peak of $1.1B in 2021.

Deal Volume Declines – The number of deals getting done has also fallen, to 42 deals in 2022, off 30% compared to 60 in 2021. In imaging AI’s peak year, 2020, 95 funding deals were completed. 

VC Appetite Remains Strong – Despite the declines, VCs still have a strong appetite for radiology AI, but funding has shifted from smaller early-stage deals to larger, late-stage investments. 

HeartFlow Deal Tips Scales – The average deal size has spiked this year to date, to $27.6M, compared to $17.9M in 2022, $18M in 2021, and $7.9M in 2020. Much of the higher 2023 number is driven by HeartFlow’s huge $215M funding round in April; Signify analyst Sanjay Parekh, PhD, told The Imaging Wire he expects the average deal value to fall to $18M by year’s end.

The Rich Get Richer – Much of the funding has concentrated in a dozen or so AI companies that have raised over $100M. Big winners include HeartFlow (over $650M), and Cleerly, Shukun Technology, and Viz.ai (over $250M). Signify’s $100M club is rounded out by Aidoc, Cathworks, Keya Medical, Deepwise Shenrui, Imagen Technologies, Perspectum, Lunit, and Annalise.ai.

US and China Dominate – On a regional basis, VC funding is going to companies in the US (almost $2B) and China ($1.1B). Following them are Israel ($513M), the UK ($310M), and South Korea ($255M).  

The Takeaway 

Signify’s report shows the continuation of trends seen in previous years that point to a maturing market for medical imaging AI. As with any such market, winners and losers are emerging, and VCs are clearly being selective about choosing which horses to put their money on.

The Perils of Worklist Cherry-Picking

If you’re a radiologist, chances are at some point in your career you’ve cherry-picked the worklist. But picking easy, high-RVU imaging studies to read before your colleagues isn’t just rude – it’s bad for patients and bad for healthcare.

That’s according to a new study in Journal of Operations Management that analyzes radiology cherry-picking in the context of operational workflow and efficiency. 

Based on previous research, researchers hypothesized that radiologists who are free to pick from an open worklist would choose the easier studies with the highest compensation – the classic definition of cherry-picking.

To test their theory, they analyzed a dataset of 2.2M studies acquired at 62 hospitals from 2014 to 2017 that were read by 115 different radiologists. They developed a statistical metric called “bang for the buck,” or BFB, to classify the value of an imaging study in terms of interpretation time relative to RVU level. 

They then assessed the impact of BFB on turnaround time (TAT) for different types of imaging exams based on priority, classified as Stat, Expedited, and Routine. Findings included:

  • High-priority Stat studies were reported quickly regardless of BFB, indicating little cherry-picking impact
  • For Routine studies, those with higher BFB had much lower reductions in turnaround — a sign of cherry-picking
  • Adding one high-BFB Routine study to a radiologist’s worklist resulted in a much longer increase in TAT for Expedited exams compared to low-BFB studies (increase of 17.7 minutes vs. 2 minutes)
  • The above delays could result in longer patient lengths of stay that translate to $2.1M-$4.2M in extra costs across the 62 hospitals in the study. 

The findings suggest that radiologists in the study prioritized high-BFB Routine studies over Expedited exams – undermining the exam prioritization system and impacting care for priority cases.

Fortunately, the researchers offer suggestions for countering the cherry-picking effect, such as through intelligent scheduling or even hiding certain studies – like high-BFB Routine exams – from radiologists when there are Expedited studies that need to be read. 

The Takeaway 

The study concludes that radiology’s standard workflow of an open worklist that any radiologist can access can become an “imbalanced compensation scheme” that can lead to poorer service for high-priority tasks. On the positive side, the solutions proposed by the researchers seem tailor-made for IT-based interventions, especially ones that are rooted in AI. 

Medical Malpractice Crisis

Is a new crisis looming in medical malpractice insurance? An AMA analysis finds that medical liability premiums are skyrocketing again – and radiologists may be among the physicians most affected due to their higher exposure to malpractice suits.

The proportion of medical liability premiums that increased year-to-year for OB/GYN, general surgery, and internal medicine doctors (radiologists weren’t surveyed) doubled from 2018 to 2019 (13.7% to 26.5%), and went up 30% year-to-year from 2020 to 2022. The last time rates rose this fast was during the medical liability crisis of the early 2000s, according to the AMA paper.

Insurers are raising premiums due to deteriorating underwriting results, lower loss reserve margins, and lower returns on investment, per the report. These trends are echoed in a new analysis of the medical malpractice segment by credit agency AM Best, which describes a “difficult environment” for medical liability insurers. The medical professional liability segment has seen eight straight years of underwriting losses.

Why should radiologists care? Well, radiologists are more likely to have experienced medical liability claims during their career than most other physicians. Another AMA survey of over 6k doctors found

  • Radiologists were more likely to say they had been sued in their career than all physician types (40.2% vs. 32.1%)
  • More radiologists have experienced a lawsuit in the past year than all physicians (4.2% vs. 2.0%)
  • The only other medical specialists more likely to be sued than radiologists were surgeons (48.9%) and emergency medicine physicians (46.8%) 

The first AMA report closes by saying that a medical liability insurance “hard” market – a market characterized by rapid price increases – already exists in a number of states, and is “slowly spreading” across the rest of the US. 

Further, there is “striking” geographic variation in premiums. OB/GYNs in Los Angeles County, California see average manual premiums of $49,804 a year, while those in Miami-Dade County, Florida are staring at a $226,224 liability insurance bill.

The Takeaway 

The AMA said the growing medical malpractice crisis could have multiple ramifications. Physicians in states with difficult liability environments could relocate or even drop some clinical services that raise their risk. Will the worsening environment draw the attention of state and federal regulators? Only time will tell. 

A New Day for Breast Screening

In a breathtaking about-face, the USPSTF said it would reverse 14 years of guidance in breast screening and lower its recommended starting age for routine mammography to 40.

In a proposed guidance, USPSTF said it would recommend screening for women every other year starting at age 40 and continuing through 74. The task force called for research into additional screening with breast ultrasound or MRI for women with dense breasts, and on screening in women older than 75.

The move will reverse a policy USPSTF put in place in 2009, when it withdrew its recommendation that all women start screening at 40, instead advising women in their 40s to consult with their physicians about starting screening. Routine mammography was advised starting at age 50. The move drew widespread condemnation from women’s health advocates, but the USPSTF stuck to the policy even through a 2016 revision.

The task force remained steadfast even as studies showed that the 2009 policy change led to confusion and lower breast screening attendance. The change also gave fuel to anti-mammography extremists who questioned whether any breast screening was a good idea.

That all changes now. In its announcement of the 2023 guidance, USPSTF said it based the new policy on its review of the 2016 update. No new RCTs on breast screening have been conducted for decades (it’s considered unethical to deny screening to women in a control group), so the task force commissioned collaborative modeling studies from CISNET.

USPSTF said the following findings factored into its decision to change the guidance: 

  • Biennial screening from 40-74 would avert 1.3 additional breast cancer deaths per 1,000 women screened compared to biennial screening of women 50-74.
  • The benefits of screening at 40 would be even greater for Black women, at 1.8 deaths averted. 
  • The incidence rate of invasive breast cancer for women 40-49 has increased 2.0% annually from 2015-2019, a higher rate than in previous years. 
  • Biennial screening results in greater incremental life-years gained and mortality reduction per mammogram and better balance of benefits to harms compared to annual screening.

The Takeaway 

As with the FDA’s recent decision to require density reporting nationwide, the USPSTF’s proposal to move the starting age for mammography screening to 40 was long overdue. The question now is how long it will take to repair 14 years of lost momentum and eliminate confusion about breast screening.

Learning Curve in DBT Screening

Digital breast tomosynthesis continues to evolve. First introduced initially as a problem-solving tool in breast imaging, DBT is becoming the workhorse modality for breast screening as well. 

But DBT still requires some adjustment when used for screening. In a study of nearly 15k women in European Radiology, Swedish researchers describe how the false-positive recall rate for DBT cancer screening started higher but then fell over time as radiologists got used to the appearance of lesions on DBT exams.

The Malmö Breast Tomosynthesis Screening Trial was set up to compare one-view DBT to two-view digital mammography for breast screening. Unlike some DBT screening trials, the study did not use synthesized 2D DBT images. DBT images were acquired 2010-2015 with Siemens Healthineers’ Mammomat Inspiration system. 

Findings in the study included: 

  • DBT had a sharply higher false-positive recall rate in year 1 of the study compared to DM (2.6% vs. 0.5%)
  • DBT’s recall rate fell over the five-year course of the study, stabilizing at 1.5% 
  • Recall rates for DM varied between 0.5% and 1% over five years
  • Most of the DBT recalls (37.3%) were for stellate lesions, in which spicules radiate out from a central point or mass. With DM, only 24.0% of recalls were for stellate lesions
  • The number of stellate distortions being recalled with DBT declined over time, a trend the authors attributed to a learning curve in reading DBT images

The authors said that the DBT false-positive recall rate in their study was “in general low” compared to other European trials. They claimed that MBTST is among the first studies to analyze recall rates by lesion appearance, an important point because radiologists may see a different distribution of lesion types on screening DBT compared to what they’re used to with DM.

The Takeaway 

The Malmö Breast Tomosynthesis Screening Trial was one of the first to investigate DBT for breast screening, and previous MBTST research showed that DBT can also reduce interval cancers, which occur between screening rounds. 

The new findings offer further support for DBT breast screening and give hope that whatever shortcomings the technology might have early on in a screening role can be addressed through training and experience. It also confirms recent research indicating that DBT has become the new gold standard for breast screening.

GE HealthCare’s MRI Contrast Play

GE HealthCare has expanded its MRI contrast portfolio with the European debut of Pixxoscan. The gadolinium-based contrast agent gives GE another macrocyclic gadolinium-based contrast agent to sell in Europe, in addition to its Clariscan GBCA.

MRI contrast developers have been working to address one of the most persistent problems in MRI: their reliance on gadolinium. Gadolinium works great for lighting up MR images, but it’s a toxic metal that has to be bonded with a chelate – a sort of molecular cage – in order to be used safely in humans. 

Pixxoscan is a macrocyclic GBCA that’s based on gadobutrol, a formulation already used in Bayer’s Gadovist GBCA and that’s now available generically. Macrocyclic GBCAs are considered more stable and less likely to release gadolinium than linear agents. 

Most linear GBCAs have been barred from the European market since 2017. The FDA never took a similar approach, but the US market has largely shifted from linear GBCAs to macrocyclic agents due to safety concerns. 

GE HealthCare highlighted that Pixxoscan is formulated at twice the concentration of gadolinium ions, which reportedly enables it to be used at half the injection volume of other GBCAs. The company also said that the agent’s cage-like macrocyclic chelate provides high kinetic stability. 

Pixxoscan will start shipping initially in Austria, and GE HealthCare expects to expand it across Europe. A spokesperson didn’t confirm plans for a US rollout.   

Pixxoscan’s launch comes as two of GE HealthCare’s competitors, Guerbet and Bracco, are rolling out their formulations of gadopiclenol, a high-relaxivity agent that can be used at half the dose of conventional GBCAs. The companies collaborated on the development of the agent, which Guerbet is selling as Elucirem and Bracco as Vueway. 

The Takeaway

GE HealthCare’s launch of Pixxoscan gives the company another macrocyclic agent to sell in Europe in addition to Clariscan. The question is how the agent will compete with gadopiclenol from Bracco and Guerbet, which are already touting its dose and relaxivity advantages.

ABUS Boosts Breast Screening

Automated breast ultrasound led to sharp increases in cancer detection rates and sensitivity when it was performed as a supplement to screening digital mammography in a study of Asian women. 

In Radiology, researchers from South Korea explain the shortcomings of X-ray-based mammography, which has limited sensitivity in women with dense breast tissue. Handheld ultrasound can be used as a screening supplement, but it has drawbacks of its own, such as longer exam time and operator variability. 

ABUS has been proposed as an alternative, acquiring 3D volumes of the entire breast in an automated mode that’s more structured and standardized. ABUS also provides coronal-plane images that can help differentiate malignant from benign lesions.

But most of the studies validating ABUS have been conducted on Western women, and Asian women tend to have mammographically denser breasts.

So researchers decided to test ABUS as a supplement to digital mammography with 2,301 South Korean women who were screened from 2018 to 2019. Women were first screened with digital mammography (either Hologic’s Selenia Dimensions or Siemens Healthineers’ Mammomat Revelation), then received ABUS scans with GE HealthCare’s Invenia ABUS system. 

For women with dense breasts, screening with ABUS and DM turned in better performance than DM alone in multiple categories, including:

  • Higher cancer detection rate per 1,000 screening exams (9.3 vs. 6.5)
  • Better sensitivity (90.9% vs. 63.6%)
  • Higher AUC (0.89 vs. 0.79)
  • Detection of smaller cancers, with a mean size of 1.2 cm vs. 2.3 cm

On the down side, ABUS + DM in women with dense breasts had lower specificity (86.8% vs. 94.6%), driving higher biopsy rates (3.3% vs. 1.9%) and false-positive biopsy rates (2.4% vs. 1.3%).

The Takeaway

In a time when breast cancer inequities are under the microscope, the new study provides encouraging news that imaging technology can help compensate for the shortcomings of the traditional “one size fits all” paradigm of breast screening. 

The results are also a shot in the arm for ABUS as it seeks to cement a role as a complement to X-ray-based screening mammography, although work remains to be done in improving specificity and recall rates.

Health Inequity & Breast Cancer

The last several years have seen growing awareness of how structural inequities can impact individual health outcomes. Two powerful new JAMA Network Open studies reinforced what we know about structural inequity, particularly as it relates to breast cancer. 

In the first study on April 19 addressing racial differences in breast cancer mortality, researchers looked at over 415k women from 2011 to 2020, finding:

  • Black women between 40 and 49 years old had the highest breast cancer mortality rates per 100,000 person years, at 27 deaths. This compares to 15 deaths for White women, and 11 deaths for other ethnicities.
  • If breast screening were tailored based on risk at age 50, Black women should start screening eight years earlier than White women, at 42 years of age versus 51. 
  • Biennial mammography screening of Black women starting at age 40 would reduce the gap in breast cancer mortality compared to White women by 57%. 

In the second study on April 21, researchers drilled even deeper into structural inequity, focusing on breast cancer outcomes in disadvantaged neighborhoods in a large, racially diverse region in southern Florida that’s home to 6.2M people. 

In all, their study covered 5,027 women with breast cancer, and they categorized neighborhoods into three levels based on socioeconomic status. Findings included:

  • Patients living in the second most disadvantaged neighborhoods were 36% more likely to die of breast cancer (HR=1.36).  
  • Women living in the most disadvantaged neighborhoods were 77% more likely to die (HR=1.77).

The researchers pointed out that their results went beyond merely linking race to health outcomes, as they adjusted for race and ethnicity “as a proxy for structural racism.” They suggested that there could be “unaccounted,” biologic mechanisms related to neighborhood disadvantage that lead to shorter breast cancer survival. The findings echo other studies that have linked patient location to access to imaging.

The Takeaway

Over the past several decades, breast cancer’s dropping mortality rate has been a health policy success story. But the new studies indicate that progress has been uneven, and more attention is needed to ensure that the benefits of improved breast cancer diagnosis and treatment are distributed more equitably.

Salary Data Reveal Medicine’s Golden Cage

Are you a glass-half-full or a glass-half-empty kind of person? Either way, there’s lots to unpack in the latest data on physician salaries, this time from Medscape

Medscape’s survey of over 10k US physicians across over 29 medical specialties found that overall physician salaries have grown 18% over the last five years, to $352k, while specialists made an average of $382k. 

As with last year, radiologists landed in the top 10 of highest-compensated specialists, a finding that’s in line with previous salary surveys, such as from Doximity. Medscape found that radiologists had an average annual salary of $483k in 2023, compared to $437k in 2022. Radiologists had an average annual salary of $504k in the Doximity data. 

Other nuggets from the Medscape survey:

  • “Stagnant” reimbursement relative to rising practice costs has cut into physician income. 
  • The gender gap is narrowing. Male primary care doctors in 2023 earn 19% more than females, compared to about 25% previously.
  • Male specialist physicians earn 27% more than females, down from 31% last year and 33% the year before that.
  • Only 19% of radiologists are women – one of the lowest rates of female participation among medical specialties. 
  • 58% of radiologists feel they are fairly paid.
  • Radiologists report working an average of 49.6 hours a week.
  • 90% of radiologists say they would choose their specialty again, ranking #10.

The Takeaway

On the positive side, physician salaries continue to rise, and medicine is making encouraging progress in narrowing the gender gap. Radiologists seem to be well-compensated and relatively happy, but the specialty has more to do to attract women.

Underlying the raw data is a disturbing undercurrent of physician dissatisfaction, with many feeling as though medicine is a golden cage. In the free-response portion of the survey, doctors described themselves as caught between falling reimbursement and rising costs, with overwork also leading to burnout

The Medscape survey shows that addressing physician burnout must become a priority for the US healthcare system, and it can’t be solved merely by boosting salaries. Increasing the number of residency slots is a good first step (see below).

Cardiac Imaging in 2040

What will cardiac imaging look like in 2040? It will be more automated and preventive, and CT will continue to play a major – and growing – role.

That’s according to an April 11 article in Radiology in which Dr. David Bluemke and Dr. João Lima look into the future and offer a top 10 list of major developments in cardiovascular imaging in 2040.

Cardiovascular disease carries a massive medical burden, with over 800,000 myocardial infarctions occurring annually in the US alone. By 2030 almost one-third of deaths worldwide are expected to be due to cardiovascular disease.

Multiple different imaging modalities are adept at identifying both ischemic and nonischemic heart disease, but CT has risen to the top for ischemic imaging, making “quantum” advances in the last decade thanks to its growing prowess in the coronary arteries.

CT’s advances have been so great that the modality occupies seven of the top 10 spots on Bluemke and Lima’s list. In brief, they see: 

  • Coronary CTA becoming totally automated, a development that will no doubt benefit AI developers like HeartFlow (see below).
  • CCTA becoming a preventive tool rather than a gatekeeper to interventional cardiology (also hinted at in a recent study from Denmark). For example, CCTA will be used to track the effectiveness of statin therapy
  • Photon-counting CT flexing its muscles for coronary artery evaluation and routine plaque characterization and quantification
  • Next-generation cardiac CT becoming more like MRI
  • Next-generation cardiac MRI becoming more like CT
Table of Top 10 Cardiovascular Imaging Developments by 2040

They also see a major growing role for software-assisted cardiac CT with AI and other tools. Software-based automation has simplified the “postprocessing nightmares” once common with coronary CT, making it “wonderfully ordinary” to perform. 

The Takeaway

Bluemke and Lima offer a fascinating glimpse of cardiac imaging’s future. But one area they don’t touch on is whether CT’s rising prominence means radiologists will start taking back turf in heart imaging once ceded to cardiologists. Heart specialists haven’t taken over cardiac CT in the same way that they monopolized echocardiography and nuclear cardiology. Could we be seeing a renaissance of radiology in the heart?

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