Real-World AI Experiences

Clinical studies showing that AI helps radiologists interpret medical images are great, but how well does AI work in the real world – and what do radiologists think about it? These questions are addressed in a new study in Applied Ergonomics that takes a deep dive into the real-world implementation of a commercially available AI algorithm at a German hospital. 

A slew of clinical studies supporting AI were published in 2023, from the MASAI study on AI for breast screening to smaller studies on applications like opportunistic screening or predicting who should get lung cancer screening

  • But even an AI algorithm with the best clinical evidence behind it could fall flat if it’s difficult to use and doesn’t integrate well with existing radiology workflow.

To gain insight into this issue, the new study tracked University Hospital Bonn’s implementation of Quantib’s Prostate software for interpreting and documenting prostate MRI scans (Quantib was acquired by RadNet in January 2022). 

  • Researchers described the solution as providing partial automation of prostate MRI workflow, such as helping segment the prostate, generating heat maps of areas of interest, and automatically producing patient reports based on lesions it identifies. 

Prostate was installed at the hospital in the spring of 2022, with nine radiology residents and three attending physicians interviewed before and after implementation, finding…

  • All but one radiologist had a positive attitude toward AI before implementation and one was undecided 
  • After implementation, seven said their attitudes were unchanged, one was disappointed, and one saw their opinion shift positively
  • Use of the AI was inconsistent, with radiologists adopting different workflows and some using it all the time with others only using it occasionally
  • Major concerns cited included workflow delays due to AI use, additional steps required such as sending images to a server, and unstable performance

The findings prompted the researchers to conclude that AI is likely to be implemented and used in the real world differently than in clinical trials. Radiologists should be included in AI algorithm development to provide insights into workflow where the tools will be used.

The Takeaway

The new study is unique in that – rather than focusing on AI algorithm performance – it concentrated on the experiences of radiologists using the software and how they changed following implementation. Such studies can be illuminating as AI developers seek broader clinical use of their tools. 

A Case for VERDICT MRI

A new Radiology Journal study showed that VERDICT MRI-based analysis could significantly improve prostate cancer lesion characterization, and might solve PCa screening’s unnecessary biopsy problem.

Before we jump into the study… VERDICT MRI (Vascular, Extracellular, and Restricted Diffusion for Cytometry in Tumor) is a novel diffusion MRI modeling technique that estimates microstructural tissue properties, and has shown promise for cancer diagnosis and assessments. It can also be performed using standard 3T MRI exams.

The UK-based researchers had 165 men with suspected prostate cancer undergo mpMRI and VERDICT MRI (73 later confirmed w/ significant PCa). Over the 3.5yr study, they found that VERDICT MRI-based ‘lesion fractional intracellular’ volumes (FICs) have significant characterization advantages versus mpMRI-based apparent diffusion coefficient and PSA density measurements (ADC & PSAD):

  • VERDICT MRI-based FICs classified clinically significant prostate cancer lesions far more accurately than ADC and PSAD (AUCs: 0.96 vs. 0.85 & 0.74). 
  • VERDICT-based FICs also clearly differentiated clinically insignificant and significant prostate cancer among the study’s Likert 3 lesions (median FICs: 0.53 & 0.18) and Likert 4 lesions (median FICs: 0.60 & 0.28), while ADC and PSAD measurements couldn’t be used to show which of these lesions would be cancerous. 

The Takeaway

Noting that up to 50% of men with positive PI-RADS scores or >3 Likert scores end up with negative biopsy results, these findings suggest that VERDICT MRI could reduce unnecessary prostate biopsies by a whopping 90%.

That makes this study a “massive leap forward” for prostate cancer diagnostics, and provides enough evidence to make VERDICT MRI just one successful large multi-center trial away from clinical adoption.

Prostate MR AI’s Experience Boost

A new European Radiology study showed that Siemens Healthineers’ AI-RAD Companion Prostate MR solution can improve radiologists’ lesion assessment accuracy (especially less-experienced rads), while reducing reading times and lesion grading variability. 

The researchers had four radiologists (two experienced, two inexperienced) assess lesions in 172 prostate MRI exams, with and without AI support, finding that AI-RAD Companion Prostate MR improved:

  • The less-experienced radiologists’ performance, significantly (AUCs: 0.66 to 0.80 & 0.68 to 0.80)
  • The experienced rads’ performance, modestly (AUCs: 0.81 to 0.86 & 0.81 to 0.84)
  • Overall PI-RADS category and Gleason score correlations (r = 0.45 to 0.57)
  • Median reading times (157 to 150 seconds)

The study also highlights Siemens Healthineers’ emergence as an AI research leader, leveraging its relationship / funding advantages over AI-only vendors and its (potentially) greater focus on AI research than its OEM peers to become one of imaging AI’s most-published vendors (here are some of its other recent studies).

The Takeaway

Given the role that experience plays in radiologists’ prostate MRI accuracy, and noting prostate MRI’s historical challenges with variability, this study makes a solid case for AI-RAD Companion Prostate MR’s ability to improve rads’ diagnostic performance (without slowing them down). It’s also a reminder that Siemens Healthineers is serious about supporting its homegrown AI portfolio through academic research.

HM-MRI Beats mpMRI

University of Chicago researchers provided solid evidence that hybrid multidimensional MRI (HM-MRI) might be superior to multiparametric MRI (mpMRI) for diagnosing clinically significant prostate cancer.

That’s a big statement after nearly two decades of prostate MRI exams, but mpMRI’s continued variability challenges still leave room for improvement, and some believe HM-MRI’s quantitative approach could help add objectivity.

To test that theory, the researchers had four radiologists with different career experience (1 to 20yrs) interpret HM-MRI and mpMRI exams from 61 men with biopsy-confirmed prostate cancer, finding that the HM-MRI exams produced:

  • Higher AUCs among three of the four readers (0.61 vs. 0.66; 0.71 vs. 0.60; 0.59 vs. 0.50; 0.64 vs. 0.46), with the least experienced rad achieving the greatest AUC improvement 
  • Higher specificity among all four readers (48% vs. 37%; 78% vs. 26%; 48% vs. 0%; 46% vs. 7%)
  • Significantly greater interobserver agreement rates (Cronbach alpha: 0.88 vs. 0.26; >0.60 indicates reliability)
  • Far shorter average interpretation times (73 vs. 254 seconds)

The Takeaway
As the study’s editorial put it, HM-MRI appears to be a “quantitative step in the right direction” for prostate MRI, and has the potential to address mpMRI’s variability, accuracy, and efficiency challenges.

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