There’s no question AI is the future of radiology. But AI’s drive to widespread clinical use is going to hit some speed bumps along the way.
This week is a case in point. Two studies were published showing AI’s limitations and underscoring the challenges faced in making AI an everyday clinical reality.
In the first study, researchers found that radiologists outperformed four commercially available AI algorithms for analyzing chest X-rays (Annalise.ai, Milvue, Oxipit, and Siemens Healthineers) in a study of 2k patients in Radiology.
Researchers from Denmark found the AI tools had moderate to high sensitivity for three detection tasks:
- airspace disease (72%-91%)
- pneumothorax (63%-90%)
- pleural effusion (62%-95%).
But the algorithms also had higher false-positive rates and performance dropped in cases with smaller pathology and multiple findings. The findings are disappointing, especially since they got such widespread play in the mainstream media.
But this week’s second study also brought worrisome news, this time in Radiology: Artificial Intelligence about an AI training method called foundation models that many hope holds the key to better algorithms.
Foundation models are designed to address the challenge of finding enough high-quality data for AI training. Most algorithms are trained with actual de-identified clinical data that have been labeled and referenced to ground truth; foundation models are AI neural networks pre-trained with broad, unlabeled data and then fine-tuned with smaller volumes of more detailed data to perform specific tasks.
Researchers in the new study found that a chest X-ray algorithm trained on a foundation model with 800k images had lower performance than an algorithm trained with the CheXpert reference model in a group of 42.9k patients. The foundation model’s performance lagged for four possible results – no finding, pleural effusion, cardiomegaly, and pneumothorax – as follows…
- Lower by 6.8-7.7% in females for the “no finding” result
- Down by 10.7-11.6% in Black patients in detecting pleural effusion
- Lower performance across all groups for classifying cardiomegaly
The decline in female and Black patients is particularly concerning given recent studies on bias and lack of generalizability for AI.
The Takeaway
This week’s studies show that there’s not always going to be a clear road ahead for AI in its drive to routine clinical use. The study on foundation models in particular could have ramifications for AI developers looking for a shortcut to faster algorithm development. They may want to slow their roll.
