Category: MR Scanners

MRI Predicts Cognitive Decline

Posted on by Brian Casey

Early detection of cognitive decline is becoming increasingly important as new therapies become available for conditions like Alzheimer’s disease. A new 20-year study in JAMA Network Open shows that MRI can detect structural brain changes indicating future cognitive decline – years before symptoms occur. 

Longitudinal research has shown that subtle changes in body structure – be they in the heart, brain, or other organs – can predict future disease risk, in some cases decades in advance.

  • That enables the possibility of targeted treatments or behavioral interventions to reduce risk before sick patients experience a cascade of expensive and invasive therapies. 

Mild cognitive impairment is an excellent example. MCI can be a transition to more serious diseases like Alzheimer’s, and previous research has connected it to vascular risk factors that are signs of brain atrophy. 

  • In the current paper, researchers analyzed MRI scans acquired as part of the BIOCARD cohort, a longitudinal study started in 1995 in which cognitively normal participants got baseline brain MRI scans and follow-up exams. 

In a group of 185 BIOCARD participants, researchers tracked how many transitioned to MCI over a mean follow-up period of 20 years, then compared structural brain changes on MRI, finding …

  • 60 participants (32%) progressed to MCI, eight of whom later developed dementia (4.3%).
  • Those with white-matter atrophy on MRI had an 86% higher chance of progression to MCI, the highest rate of any variable studied.
  • Participants with enlargement of the ventricles on MRI had 71% higher risk.
  • Other variables like diabetes and amyloid pathology also had higher risk, but not at the rate of the MRI-detected variables. 

The findings indicate that white-matter volume is closely associated with cognitive function in aging, and that people with higher rates of change are more likely to develop MCI. 

  • The association of diabetes with MCI was not a shock, but researchers said they were surprised there was no association from risk factors like hypertension, dyslipidemia, and smoking.

The Takeaway

The new findings demonstrate the power of MRI to predict pathology years in advance – the question is how and whether to put this knowledge into clinical practice. One could almost see structural brain scans incorporated into whole-body MRI screening exams (if anyone’s listening).

MRI Reduces Prostate Biopsies

Posted on by Brian Casey

New research provides additional support for MRI’s role in making prostate screening more effective. In a new study in NEJM, researchers found that MRI can help reduce unnecessary biopsies more than 50%, with a very low chance of missing high-risk disease. 

As we’ve discussed in previous newsletters, prostate cancer screening based on PSA levels is an imprecise test. 

  • Many men with suspiciously high PSA (typically 3-4 ng/mL or higher) undergo biopsies that detect clinically insignificant disease that would never present a health risk during their lifetimes – the classic definition of overdiagnosis. 

Adding MRI can help make prostate screening more precise by directing biopsy-based workup to only those men with clinically significant cancer – but questions still abound about exactly when it should be used. 

In new results from the GÖTEBORG-2 trial in Sweden, researchers compared prostate screening protocols in men with PSA levels 3 ng/mL and higher who got MRI scans:

  • One group automatically got systemic biopsy and then MRI-targeted biopsy based on MRI results.
  • The other group only got MRI-targeted biopsy if they had a suspicious MRI scan.

In 13.2k men who were followed up for a median of four years, researchers found that those in whom systemic biopsy was omitted …

  • Had 57% lower risk of clinically insignificant cancers.
  • Had lower relative risk of clinically insignificant cancers in subsequent screening rounds (RR=0.25 vs. 0.49).
  • Had 16% lower risk of detecting clinically significant cancers.
  • Had 35% lower risk of advanced or high-risk cancers.

On the down side, the protocol eliminating systemic biopsy could lead to later diagnoses for higher-risk disease for 3 in 1k men – but given the slow-growing nature of prostate cancer it’s not clear how significant this is. 

  • Also, the data indicate that “most prostate cancers become visible on MRI” before they are incurable, which increases the likelihood that they would at least be detected on subsequent screening rounds and could be treated effectively.

The Takeaway

The new findings should help clinicians hone in on the best prostate screening protocols for maximizing detection of clinically significant cancer while minimizing unnecessary workup. Hopefully, the addition of new technologies like AI can move this process along.

Better Prostate MRI Tools

Posted on by Brian Casey

In past issues of The Imaging Wire, we’ve discussed some of the challenges to prostate cancer screening that have limited its wider adoption. But researchers continue to develop new tools for prostate imaging – particularly with MRI – that could flip the script. 

Three new studies were published in just the last week focusing on prostate MRI, two involving AI image analysis.

In a new study in The Lancet Oncology, researchers presented results from AI algorithms developed for the Prostate Imaging—Cancer Artificial Intelligence (PI-CAI) Challenge.

  • PI-CAI pitted teams from around the world in a competition to develop the best prostate AI algorithms, with results presented at recent RSNA and ECR conferences. 

Researchers measured the ensemble performance of top-performing PI-CAI algorithms for detecting clinically significant prostate cancer against 62 radiologists who used the PI-RADS system in a population of 400 cases, finding that AI …

  • Had performance superior to radiologists (AUROC=0.91 vs. 0.86)
  • Generated 50% fewer false-positive results
  • Detected 20% fewer low-grade cases 

Broader use of prostate AI could reduce inter-reader variability and need for experienced radiologists to diagnose prostate cancer.

In the next study, in the Journal of Urology, researchers tested Avenda Health’s Unfold AI cancer mapping algorithm to measure the extent of tumors by analyzing their margins on MRI scans, finding that compared to physicians, AI … 

  • Had higher accuracy for defining tumor margins compared to two manual methods (85% vs. 67% and 76%)
  • Reduced underestimations of cancer extent with a significantly higher negative margin rate (73% vs. 1.6%)

AI wasn’t used in the final study, but this one could be the most important of the three due to its potential economic impact on prostate MRI.

  • Canadian researchers in Radiology tested a biparametric prostate MRI protocol that avoids the use of gadolinium contrast against multiparametric contrast-based MRI for guiding prostate biopsy. 

They compared the protocols in 1.5k patients with prostate lesions undergoing biopsy, finding…

  • No statistically significant difference in PPV between bpMRI and mpMRI for all prostate cancer (55% vs. 56%, p=0.61) 
  • No difference for clinically significant prostate cancer (34% vs. 34%, p=0.97). 

They concluded that bpMRI offers lower costs and could improve access to prostate MRI by making the scans easier to perform.

The Takeaway

The advances in AI and MRI protocols shown in the new studies could easily be applied to prostate cancer screening, making it more economical, accessible, and clinically effective.  

MRI Makes Prostate Screening More Precise

Posted on by Brian Casey

Prostate cancer screening isn’t a guideline-directed screening test yet, but this could change with the use of MRI and other tools. A series of papers published in several JAMA journals late last week indicates the progress that’s being made. 

As we’ve discussed in previous issues, prostate screening with PSA tests hasn’t met the threshold for clinical benefit achieved by other population-based screening exams.

  • PSA-based screening has been characterized by lower mortality benefits and relatively high rates of overdiagnosis and complications from follow-up procedures. 

But some researchers believe that PSA screening could be made more effective by using additional diagnostic tools like imaging and blood tests to focus on potentially high-risk disease for biopsy while active surveillance is used for less threatening prostate lesions. 

In the ProScreen trial in Finland, researchers tested the combination of PSA, a kallikrein four-panel blood test, and MRI in selecting patients for biopsy. 

  • Patients were sent to MRI if they had PSA scores of 3.0 ng/mL or higher and kallikrein scores of 7.5% or higher; those with abnormal MRI scans got targeted biopsy. 

The researchers tested the ProScreen protocol in a study of 61.2k men, with 15.3k invited to screening and 7.7k getting screened. Over a preliminary three-year follow-up period, researchers found …

  • 9.7% of men met the PSA threshold for a suspicious lesion; this fell to 6.8% after the kallikrein test and 2.7% after MRI, illustrating the protocol’s ability to reduce biopsies
  • Biopsy yield for high-grade cancer was 1.7%, which an editorial called a “remarkably high yield”
  • Overdetection of low-grade disease was 0.4%, compared to 3.2% in a comparable previous study

In a second study, this one in JAMA Oncology, researchers performed a meta-analysis of 80.1k men from 12 studies in which MRI was used to direct patients to prostate biopsy after PSA testing, finding that MRI-directed protocols had …

  • Higher odds of detecting clinically significant prostate cancer (OR=4.15) compared to PSA screening alone
  • Lower odds ratio for biopsy (OR=0.28)
  • Lower odds ratio for detecting clinically insignificant cancer (OR=0.34)

Finally, a secondary analysis in JAMA of a large UK trial illustrates the challenges of prostate screening without MRI guidance. Researchers reviewed 15-year outcomes of the Cluster Randomized Trial of PSA Testing for Prostate Cancer (CAP), a study of 415k men,196k of whom were screened from 2002 to 2009 without the use of MRI, finding … 

  • PSA screening increased detection of low-grade cancer (2.2% vs. 1.6%) but not intermediate or high-grade disease
  • Screening reduced prostate cancer mortality by a small amount (0.69% vs. 0.78%)

The Takeaway

Taken together, new studies offer a roadmap toward making MRI an integral part of prostate screening, such that perhaps in years to come it can join other cancer tests as a population-based screening tool.

AI Speeds Up MRI Scans

Posted on by Brian Casey

In our last issue, we reported on a new study underscoring the positive return on investment when deploying radiology AI at the hospital level. This week, we’re bringing you additional research that confirms AI’s economic value, this time when used to speed up MRI data reconstruction. 

While AI for medical image analysis has garnered the lion’s share of attention, AI algorithms are also being developed for behind-the-scenes applications like facilitating staff workflow or reconstructing image data. 

  • For example, software developers have created solutions that enable scans to be acquired faster and with less input data (such as radiation dose) and then upscaled to resemble full-resolution images. 

In the new study in European Journal of Radiology, researchers from Finland focused on whether accelerated data reconstruction could help their hospital avoid the need to buy a new MRI scanner. 

  • Six MRI scanners currently serve their hospital, but the radiology department will be losing access to one of them by the end of the year, leaving them with five. 

They calculated that a 20% increase in capacity per remaining scanner could help them achieve the same MRI throughput at a lower cost; to test that hypothesis they evaluated Siemens Healthineers’ Deep Resolve Boost algorithm. 

  • Deep Resolve Boost uses raw-data-to-image deep learning reconstruction to denoise images and enable rapid acceleration of scan times; a total knee MRI exam can be performed in just two minutes. 

Deep Resolve Boost was applied to 3T MRI scans of 78 patients acquired in fall of 2023, with the researchers finding that deep learning reconstruction… 

  • Reduced annual exam costs by 399k euros compared to acquiring a new scanner
  • Enabled an overall increase in scanner capacity of 20-32%
  • Had an acquisition cost 10% of the price of a new MRI scanner, leading to a cost reduction of 19 euros per scan
  • Was a lower-cost option than operating five scanners and adding a Saturday shift

The Takeaway

As with last week’s study, the new research demonstrates that AI’s real value comes from helping radiologists work more efficiently and do more with less, rather than from direct reimbursement for AI use. It’s the same argument that was made to promote the adoption of PACS some 30 years ago – and we all know how that turned out.

MRI’s Value for Prostate Screening

Posted on by Brian Casey

Among cancer screening tests, prostate screening could be the most problematic. But a new study published this week in JAMA Network Open offers guidance on the role that MRI can play in making prostate screening more effective – and opening the door to population-based screening.

The problem with prostate screening is that PSA tests often discover disease that’s either indolent or slow-growing. 

  • This can lead to a cascade of interventions that are expensive and have harms of their own. 

But prostate cancer remains a common – and deadly – cancer, with 1.5M cases globally in 2022, and it’s the second most commonly occurring cancer in men after lung cancer.

  • Given these statistics, there has to be a way to perform prostate screening more effectively.

MRI offers one such alternative, and a clinical consensus has emerged that performing a single MRI scan after a positive PSA result can help stratify men before biopsy. 

  • In this scenario, men might not be referred to biopsy if their MRI scan is negative, and adoption of this protocol has helped reduce prostate biopsies in PSA-positive men while still detecting clinically significant cancer.   

But if one MRI scan is good, are repeat MRI scans even better? In the new study, Swedish researchers investigated this question in a secondary analysis of the STHLM3-MRI trial, which involved repeat screening of 1.5k men 2-3 years after an original prostate screening.

Of the group who got repeat PSA and MRI screening, 667 men had PSA levels of 3 ng/mL or higher, the threshold for MRI testing, with the repeat scans finding … 

  • 51 men (7.6%) had equivocal lesions (PI-RADS score of 3)
  • 33 men (4.9%) had suspicious lesions (PI-RADS score of 4)
  • Only 10 men (1.5%) had lesions with PI-RADS scores of 4 or greater

The findings led the authors to conclude that cancer detection was “limited” in the second round of PSA and MRI prostate screening, and detection of low-grade tumors was low.

The Takeaway

At first blush, STHLM3-MRI may seem like a negative study, but it actually helps frame the debate over prostate cancer screening and MRI’s role by omitting the need for multiple repeat scans. The results also give clinicians confidence that it’s safe to omit prostate biopsies in men who have a single negative MRI result – a key finding in reducing the downstream costs of any population-based screening program.

Siemens Healthineers Targets MRI at Shape 2023

Posted on by Jake Fishman

Siemens Healthineers kicked-off RSNA announcements season with its Shape 23 event, highlighted by a pair of forthcoming MRIs that should serve as the cornerstones of its high-end lineup for years to come.

Magnetom Cima.X – Siemens reinforced its already-solid 3T MR lineup with its new Magnetom Cima.X, calling it the company’s “strongest 3T MRI system ever.”

The Magnetom Cima.X owes that “strongest 3T” title to its new Gemini Gradients, which achieve 200 mT/m amplitude and 200 T/m/s slew rate performance. That’s a 2.5x increase from Siemens’ previous 3T MRIs and it’s higher than any other clinically released whole-body MRI. 

The Magnetom Cima.X also features Siemens Healthineers’ …

  • Benchmark 3T magnet
  • Deep Resolve AI image reconstruction for up to 50% faster scans
  • Open Recon for integrating custom reconstruction and post-processing solutions
  • BioMatrix Technology to automatically adjust exams based on patient biovariability
  • myExam Companion for streamlining technologist workflows

Magnetom Terra.X – Siemens’ new Magnetom Terra.X 7T MR is the long-awaited successor to the Magnetom Terra (the first FDA-cleared 7T MR), bringing improved clinical and research performance. The Magnetom Terra.X leverages Siemens’ new Ultra IQ Technology to achieve even greater image quality and visualization of small structures, Deep Resolve for image reconstruction-based speed and image enhancements, and Open Recon to support custom reconstructions.

The Takeaway

Although both MRIs are still under development, their starring role in Siemens Healthineers’ big RSNA event underscores their significance to Siemens’ high-end MRI lineup, and gives a glimpse of features to expect in future 1.5T and 3T MR launches. That’s especially notable given that Siemens’ last two RSNA announcements focused on its new low-field 0.55T MRIs, and it hasn’t launched any high-field systems in over three years.

MRI Accessibility Advantage

Posted on by Jake Fishman

Memorial MRI and Diagnostic’s COO Todd Greene starred in a recent Aunt Minnie webinar, detailing the role MRI accessibility plays in the Texas imaging group’s strategy, and sharing some very relevant takeaways for imaging providers and vendors.

Founded in 2001, Memorial MRI and Diagnostic (MMD) operates 16 imaging centers across Texas, including eight in greater Houston and eight Dallas-area locations added through its 2021 acquisition of Prime Diagnostic Imaging. 

  • MMD’s strategy focuses on integrating its imaging centers within their local communities, making patient access and referring physician relationships particularly important.

In addition to proximity to patients, MMD’s MRI accessibility strategy historically focused on maintaining a fleet of open bore 1.5T MRI scanners to accommodate larger and claustrophobic patients. 

  • This is especially important given that many of MMD’s patients are “Texas sized” or don’t realize they’re claustrophobic until the scan begins. 

That strategy started to change when MMD installed United Imaging’s 3T uMR OMEGA ultra-wide-bore (75 cm), allowing it to scan larger and claustrophobia-prone patients (plus all other patients) without open MRIs’ scan speed and image quality tradeoffs. 

  • The uMR OMEGA was MMD’s first 3T MRI at any of MMD’s imaging centers, although Greene expects its patient and referrer-friendly advantages to drive a continued shift towards wide-bore 3T MRI systems.

Greene also detailed Memorial MRI’s alliance with United Imaging (the webinar’s sponsor), specifically highlighting the scalability of UIH’s “Software for Life” (scanners automatically updated with future software) and “All-In” (scanners include all possible features/packages) policies.

As the webinar wrapped up, Greene warned imaging centers not to blindly rely on what has worked in the past, predicting that “ease of access is what is going to shape the future of healthcare.” 

The Takeaway

We get plenty of insights from the medical center side of radiology, but it’s still rare to hear from imaging center chains. That makes MDD’s insights particularly useful for the many regional imaging providers who’d like to improve MRI accessibility (without open MRI’s tradeoffs) and for MRI OEMs looking to drive 3T MRI adoption in an imaging provider segment that historically favored 1.5T systems.

GE’s Productive RSNA

Posted on by Jake Fishman

GE Healthcare had another busy RSNA, highlighted by several major modality launches and an overarching focus on helping imaging teams be more productive. 

Return to MR Hardware – After focusing on AIR Recon DL during the last two RSNAs, GE Healthcare’s MR team made sure to roll-out new hardware at this year’s show. 

  • GE’s MR section was headlined by its new SIGNA Hero 3T MR, which brings a wide range of improvements (image quality, workflows, productivity, comfort, reconstruction, helium & energy), and a major focus on operator efficiency.  
  • GE also unveiled the SIGNA Artist Evo, which allows health systems / imaging centers to upgrade their existing 1.5T 60cm-bore MRs with 70cm bore systems (w/ AIR Recon DL & AIR Coils), without the construction and downtime typically required when upgrading to a net new MR system.

GE’s Scalable CT Platform – GE unveiled the unique Revolution Apex platform, which offers the modularity and scalability to cover a wide range of current and future needs, and represents GE’s biggest CT launch since 2014. 

  • The FDA-cleared Revolution Apex CT is available with multiple detector coverage configurations (40mm, 80mm, 160mm, upgradable w/o replacing gantry) and is offered with GE’s new Smart Subscription service (allows software upgrades/downgrades, plus auto updates). 
  • True to GE’s productivity focus, the Revolution Apex also includes a range of features to improve technologist efficiency and/or expand clinical applications (e.g. “Effortless Workflow,” patient positioning camera, TrueFidelity DLIR, motion correction for cardiac).

Much More – GE Healthcare has been busy throughout 2021, so although the other products in its RSNA booth were still quite new, they’ve already been detailed in previous Imaging Wire issues. Some of these other highlights include its in-development Photon Counting CT, it’s now FDA-approved Endotracheal Tube X-ray AI tool, its StarGuide SPECT/CT scanner, and its recent alliance with Optellum.

Philips’ RSNA MRIs

Posted on by Jake Fishman

After two straight solution-centric RSNAs, Philips’ RSNA 2021 booth will be headlined by a pair of new MR systems (plus some MR solutions) and a major focus on operational efficiency.

MR 5300 – The FDA-cleared MR 5300 (1.5T) is Philips’ second helium-free BlueSeal MR scanner, arriving three years after the Ingenia Ambition X, and launching with new AI-powered features intended to automate clinical and operational tasks. Philips also emphasized the image quality advantages of the MR 5300’s 55cm field-of-view and dStream Breeze coils.

MR 7700 – Philips’ forthcoming MR 7700 system (3T) is positioned for both clinical and research use, although its features and messaging largely emphasize its value to researchers. The MR 7700 boasts new multinuclear clinical capabilities, including diffusion imaging and advanced neuroscience sequences, while its XP gradients (65 mT/m) support neuroscience.

MR Workspace – Philips’ new MR Workspace is intended to support technologist productivity, providing a dashboard that automates the planning and execution of many routine scans and supports decision making by suggesting the most suitable Exam Card for each patient. MR Workspace will be included with all new and installed Philips MR scanners. 

Philips SmartSpeed – The SmartSpeed image reconstruction platform is designed to speed up image acquisition and enhance image quality, leveraging Philips’ Compressed SENSE acquisition technique and AI to reconstruct full images from under-sampled data, “while maintaining virtually equivalent image quality.”

The Takeaway – Philips’ MR lineup has been relatively quiet during the last few years, while its main MR competitors made some solid progress (particularly w/ reconstruction, operability, comfort, and low-helium tech). It seems like that won’t be the case at RSNA 2021.

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