3. EOS, Oct.2017
“We gaan de komende jaren naar
een technologiegestuurde
wetenschap van objectieve data.
Het zal nog steeds radiologie
heten, maar de term zal een
andere lading dekken.”
8. ML vs DL
• Machine Learning (ML) learns computers
“to think” without being programmed
• ML makes advanced statistical calculations
with algorithms
– it makes “prospections” based upon skills
learned from “training data”
– ML can deal with large, complex datasets
• DL is the type of ML based upon
multiple layers
“Layered cake”
D
E
E
P
PACS congres 2018
9. Neural Network model
• “Multistage information distillation” model to
“purify” information
• Input layer = fed with information
• The “hidden layers” have artificial neurons
combining signals and calculating different
“weights” (parameters) for the data in each neuron
= mathematical framework
• The output of the layer is passed through to the
next layer.
• Output layer = “fully connected layer” = classifier
PACS congres 2018
11. Backpropagation
PACS congres 2018
Goal: finding the
right values for
these weights
Score is used as
feedback signal to
adjust the value of the
weights, to finally lower
the loss score
= backpropagation
13. Radiologists are not unfamiliar with AI
• 1963 – 2013: first 50 years failed
• 2012 ImageNet competition: AlexNet CNN
gave a dramatic reduction in image
classification error rate 26 ->15%
• 2016 Geoffry Hinton: “it's quite obvious that
we should stop training radiologists”
• Last 2–3 yrs: increased activity in
development of DL algorithms for radiology
• For narrow-based tasks the accuracy rates of
CNNs surpass those of humans (e.g. nodule
detection)
PACS congres 2018
14. Current trend for deep learning.
Fei Jiang et al. Stroke Vasc Neurol 2017;2:230-243
PACS congres 2018
16. Radiology AI challenges
RSNA ML challenges
• 2017: Pediatric bone age
• 2018: Pneumonia detection
challenge
– Large NIH data set
– ML showcase RSNA 2018
– 30.000 USD donation by Kaggle
• 1400 teams
• 346 submissions
Prices
• 1st Place - $ 12,000
• 2nd Place - $ 7,000
• 3rd Place - $ 4,000
• 4th Place - 10th Places - $ 1,000 each
PACS congres 2018
https://rsna2018.rsna.org/dailybulletin/index.cfm?pg=18wed42
http://press.rsna.org/timssnet/media/pressreleases/14_pr_target.cfm?ID=2059
17. • 100.000
anonymised X-ray
images and
corresponding data
• Pneumonia
accounts for 15% of
deaths of children <
5 yrs
• In 2015 920.000
children died from
pneumonia
• In top 10 causes of
death in USA
PACS congres 2018
19. Supervised Learning
PACS congres 2018
• Machine-learning tasks in radiology now mostly rely
on supervised learning (> 90%)
• In supervised learning, the algorithm is presented
with data (input; here, images) that have already
been mapped by hand to the correct labels (output;
here, the label to be predicted by AI)
23. Medical imaging applications in which
DL has achieved state-of-the-art results
• Mammographic mass classification (Kooi et al., 2016),
• Segmentation of lesions in the brain (top ranking in
BRATS, ISLES and MRBrains challenges, image from
Ghafoorian et al.
• Leak detection in airway tree segmentation (Charbonnier
et al., 2017)
• Diabetic retinopathy classification (Kaggle Diabetic
Retinopathy challenge 2015, image from van Grinsven et
al. (2016)
• Prostate segmentation (top rank in PROMISE12
challenge)
• Nodule classification (top ranking in LUNA16 challenge),
• Breast cancer metastases detection in lymph nodes
(top ranking and human expert performance in CAMELYON16)
• Human expert performance in skin lesion classification
(Esteva et al., 2017), and
• State-of-the-art bone suppression in x-rays, image from
Yang et al. (2016).
Litjens, G. et al. (2017).
A survey on deep learning in medical image analysis.
Medical Image Analysis, 42, 60–88.
http://doi.org/10.1016/j.media.2017.07.005
PACS congres 2018
24. AI Startups
PACS congres 2018
22% of companies focus on CT, 13% each on mammography and MRI, 9% on ultrasound,
and 3% on X-rays and nuclear imaging. Remaining 31% is not focusing on a modality
https://doi.org/10.1016/j.jacr.2018.09.050
25. UK can lead in Radiology AI. Here’s how...Hugh Harvey, 2017, Medium - http://bit.ly/2CoKJE8
Industry partnerships
• Dominant industry vendors formed strategic
partnerships with academic institutions.
• GE, IBM Watson, Philips and many others have
created deals to allow data access in return for
funding research.
• The American College of Radiologists (ACR) has
announced it’s own Data Science Institute.
• In Europe we can see EU/industry partnerships
forming with the academy
PACS congres 2018
29. Fake news?
• “Algorithm can diagnose pneumonia better
than radiologists”
≠
• “Algorithm can detect pneumonia from
chest X-rays better than radiologists”
PACS congres 2018
30. Analysis Luke Oakden-Rayner
• The training dataset has labels that don’t
really match the images, it has questionable
relevance.
• For detecting pneumonia-like image features
on chest x-rays, this system performs at least
on par with human experts.
https://lukeoakdenrayner.wordpress.com/2018/01/24/chexnet-an-in-depth-review/
PACS congres 2018
32. AI
Patient and
Referring
Provider
Imaging
Appropriateness
& Utilization
Patient
Scheduling
Imaging Protocol
selection
Imaging
Modality
operations, QA,
dose reduction
Hanging
protocols,
Optimization
staffing &
worklist
Interpretation
and reporting
Communication
and billing
Source: JM Morey et al.Applications of AI Beyond Image Interpretation, Springer 2018 –
in press
A.I. Imaging
Value Chain
33. Reduced acquistion time
• Collaboration between NYU (CAI2R) and Facebook (FAIR) to make MRI
scans 10x faster with neural networks (AI)
• Automated calculation of missing information gaps with DL
• 10.000 clinical cases with 3 million images
PACS congres 2018
34. Left: Standard high dose CT at 12.4mGy. Middle: Ultra-low dose CT at 1.3mGy. Right: AI-enhanced ultra-low dose CT at 1.3mGy.
Diagnostic image quality between the left and right images was rated as comparable by independent radiologists, despite a
significant dose reduction of 11.1mGy. The middle image is noisy and non-diagnostic. Images courtesy of Algomedica.
SIIM 2017 Poster
35. P. Lakhani et al. JACR https://doi.org/10.1016/j.jacr.2017.09.044
Automated hanging protocol
• Radiologist opens study
• ML assistant creates optimal
hanging protocol
• Radiologist makes report and
sends it to RIS or EHR
PACS congres 2018
36. Triage and prioritization
• Detection of Intracranial Hemorrhage (ICH)
• Algorithm processes exam and generates
binary output (negative or positive ICH).
• If results are positive, priority of study is
upgraded to “stat”.
• The reading list is updated in real-time.
• Possible to reduce TAT up to 96% for head CT
exams
npj Digital Medicine (2018) 1:9 ; doi:10.1038/s41746-017-0015-z
PACS congres 2018
38. Google and others?
• Google (GCP), Amazon
(AWS), Microsoft
believe that delivering
AI through the cloud
will be a big, lucrative
trend in computing in
coming years.
PACS congres 2018
39. Amazon
• Amazon sees a new grow market
in HC and will offer HC services
• Own health insurance – first for
Amazon employees (500.000 !)
• “We have the size for influencing
the insurance companies. The
problem of the rising costs in HC is
only becoming worse. Innovation
is necessary”.
Chief Technology
Officer Amazon
NRC, 6 april 2018
PACS congres 2018
40. Human bias & transparency
• Training data can be biased
– Google Photos image classifier
tagged black person as gorilla
• What is the real purpose of
the algorithm?
– Transparency of “black box”
https://medium.com/@DrHughHarvey/building-ethical-ai-in-healthcare-why-we-must-demand-it-ca60f4d28412
PACS congres 2018
41. AI-bias
• Automation bias (automation
induced complacency)
– the tendency to over-rely on
automation, failure to recognise
new errors that AI can introduce
Carol Beer, Little Britain
“The exemplary receptionist”
The
computer
says no...
PACS congres 2018
42. Adversarial Examples (AE’s)
• Inputs to ML models that have been crafted to force the model to make a
classification error.
• AE’s can be crafted to be very effective... without being visible to human
eyes!
PACS congres 2018
43. Adversarial noise
• Although deep neural networks have been
able to achieve high levels of accuracy in the
ImageNet competition distinguishing between
highly similar species of animals,
they also can be fooled by adversarial noise
that is imperceptible to the human eye
PACS congres 2018
2018 American College of Radiology
1546-1440/18/$36.00 n https://doi.org/10.1016/j.jacr.2018.10.008
45. Major roadblocks for AI
Sli.do live survey, EuSoMII Annual Meeting, Rotterdam, Nov 3, 2018
46. Automated analysis
Integration of quantitative data in SR
Seamless integration of AI with
PACS and EMR, “all-in-one”
Interoperability
Facilitates training of
new algorithms &
applications
Data
Swiss-knife for radiologists: all-in-one
48. Curtis Langlotz
“Artificial intelligence will
not replace radiologists.
Yet, those radiologists who
use AI will replace the
ones who don’t.”
Curtis Langlotz, Professor of Radiology and
Biomedical Informatics at Stanford University, GPU
Tech Conference in San Jose, May 2017
PACS congres 2018
49. PACS congres 2018
springer.com
1st ed. 2019, X, 396 p. 105 illus., 93 illus.
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Erik R. Ranschaert, Sergey Morozov, Paul R. Algra (Eds.)
Artificial Intelligence in
Medical Imaging
Opportunities, Applications and Risks
Provides a thorough overview of the impact of artificial intelligence (AI ) on
medical imaging
I ncludes contributions from radiologists and I T professionals, ensuring a
multidisciplinary approach
Makes practical recommendations for the use of AI technology for both
clinical and nonclinical applications
This book provides a thorough overview of the ongoing evolution in the application of artificial
intelligence (AI) within healthcare and radiology, enabling readers to gain a deeper insight into
the technological background of AI and the impacts of new and emerging technologies on
medical imaging.After an introduction on game changers in radiology, such as deep learning
technology, the technological evolution of AI in computing science and medical image
computing is described, with explanation of basic principles and the types and subtypes of AI.
Subsequent sections address the use of imaging biomarkers, the development and validation of
AI applications, and various aspects and issues relating to the growing role of big data in
radiology. Diverse real-life clinical applications of AI are then outlined for different body parts,
demonstrating their ability to add value to daily radiology practices. The concluding section
focuses on the impact of AI on radiology and the implications for radiologists, for example with
respect to training. Written by radiologists and IT professionals, the book will be of high value
for radiologists, medical/clinical physicists, IT specialists, and imaging informatics professionals.