Skip to Main Content

INFRASTRUCTURE AND APPLICATIONS IN IMAGE-GUIDED RADIATION ONCOLOGY BREAST AND PROSTATE IMAGING

October 27, 2025
ID
13557

Transcript

  • 00:00Okay. So we're gonna switch
  • 00:01gears and talk about image
  • 00:02analysis and AI. And, incidentally,
  • 00:04if you sign up, you're
  • 00:05gonna get information about the
  • 00:06AI interest group in the
  • 00:07institute.
  • 00:08We'll do some office hours
  • 00:09and some training seminars for
  • 00:10that. So we have three
  • 00:11speakers. Doctor. Guarim is first,
  • 00:13who's an assistant professor from
  • 00:15France,
  • 00:15moved to Yale recently, and
  • 00:17he works in both pet
  • 00:18reconstruction
  • 00:19and algorithms for head
  • 00:21imaging. And then we also
  • 00:23have doctor John Onofrey, who's
  • 00:25also in some processing radiology
  • 00:27and joined with urology, and
  • 00:29he works in variety of
  • 00:31outcome development, particularly prostate cancer,
  • 00:33and then doctor Nizhevornick who's
  • 00:34medicine for some radiology.
  • 00:37And they both have the
  • 00:38Hopkins Yale kind of pipeline
  • 00:41here, and
  • 00:42work is also in outcome
  • 00:43development and also
  • 00:45brain diseases and more recently
  • 00:46in some of the predicting,
  • 00:50birth issues with,
  • 00:52accreta. I will not try
  • 00:53to name that. So with
  • 00:54that,
  • 01:01Thank you for the introduction.
  • 01:03My name is Thibaut Marine.
  • 01:04I'm an assistant professor in
  • 01:05the department of radiology and
  • 01:06biomedical imaging with a secondary
  • 01:08appointment in BITS, and I'm
  • 01:09with the Yale Biomedical Imaging
  • 01:11Institute. Today, I'm gonna talk
  • 01:12about data science infrastructure for
  • 01:14it and some example of
  • 01:16processing pipelines that we have
  • 01:18established.
  • 01:19So, as we've seen through
  • 01:20the description of the calls
  • 01:21and the imaging modalities available
  • 01:23at Yale, we are in
  • 01:24a unique position to use
  • 01:26data from a lot of
  • 01:27modalities, different research groups.
  • 01:29What we are trying to
  • 01:30build is bridges so that
  • 01:31that can become cross modality
  • 01:33and across group. We have
  • 01:34data from PET, from MR,
  • 01:35from the research calls. We
  • 01:37also have data from the
  • 01:37hospital.
  • 01:39It's across the street, but
  • 01:40that data is more difficult
  • 01:41to access because of safety
  • 01:43concerns and privacy concerns. So
  • 01:45what we are trying to
  • 01:46establish is a centralized repository
  • 01:49for data first.
  • 01:50In that central repository, data
  • 01:52from the calls will be
  • 01:53collected. Data from the hospital
  • 01:54will also have a a
  • 01:55bridge that is, allowing us
  • 01:57to get that data in
  • 01:58a secure way and host
  • 01:59it on servers where they
  • 02:01can be hosted safely
  • 02:02without,
  • 02:03identification information.
  • 02:05Along with that, data repository,
  • 02:07we need it to be
  • 02:08searchable. So we need a
  • 02:09database and, an index, and
  • 02:11we need computing, power because
  • 02:13all the processing pipeline pipelines
  • 02:15we've looked at through the,
  • 02:16prism of applications,
  • 02:18they require data processing and
  • 02:20so they require resources.
  • 02:21To this end, we're renovating,
  • 02:23rooms in the,
  • 02:25one hundred Church Street,
  • 02:28building
  • 02:29to host those servers. So
  • 02:30this has been a long
  • 02:31process,
  • 02:32but over the last few
  • 02:33months, the room has, gotten
  • 02:35ready, and we now have
  • 02:36a picture of the room
  • 02:37that is ready for use.
  • 02:38This room will host a
  • 02:40combination of,
  • 02:41computing power and hosting
  • 02:43for data storage.
  • 02:45And so CPUs, GPUs that
  • 02:47are able to work with
  • 02:48the large amount of data
  • 02:49we're dealing with. Imaging is
  • 02:51pretty large compared to other
  • 02:52data processing pipelines, so we
  • 02:54need sufficient storage
  • 02:55along with sufficient computing power.
  • 02:57And so that's what we
  • 02:58are working to build.
  • 03:00The data that comes from
  • 03:02the hospital comes de identified.
  • 03:04So in parallel, led by
  • 03:05Zinnios, we're looking at a
  • 03:07pipeline where we can get
  • 03:08data from the hospital de
  • 03:10identified.
  • 03:11So we have this tool
  • 03:12that comes from, from Duke
  • 03:13that, is the identification tool
  • 03:15that removes
  • 03:16all the HIPAA data and,
  • 03:18has expert determination, which means
  • 03:20that the data can be,
  • 03:22transferred to us. Our servers
  • 03:23also,
  • 03:24comply to the safest procedures
  • 03:26and, guidelines for hosting,
  • 03:28patient data and subject data.
  • 03:30And we are building that
  • 03:31framework so this data can
  • 03:33be combined with the processing
  • 03:34units that we have so
  • 03:35that we can make great
  • 03:37science together and not have,
  • 03:39red tape along the way,
  • 03:41but still having the safety
  • 03:42of the data. So once
  • 03:43we collect the data, we
  • 03:44need to make it accessible
  • 03:45and searchable. And to this
  • 03:47end, we are building a
  • 03:48cross modality database that will
  • 03:50list all the existing data
  • 03:51set that we have,
  • 03:53from the different imaging calls.
  • 03:55So that people can look
  • 03:56and search data that can
  • 03:57be useful for their research,
  • 03:58for comparisons.
  • 03:59Or as George mentioned,
  • 04:01when building a new study,
  • 04:02maybe very valuable to realize
  • 04:04that the control group is
  • 04:05already available that can save
  • 04:06imaging cost quite a bit.
  • 04:08On the table here is
  • 04:10shown the list of, PET
  • 04:11scans that we've had and
  • 04:13sorted by traces.
  • 04:15On the PET side, we
  • 04:16already have a great database
  • 04:17that collects all of this
  • 04:18since two thousand five with
  • 04:19more than twenty thousand scans.
  • 04:21We are building,
  • 04:22something that will include MR
  • 04:24and PET and be able
  • 04:25to be cross searched.
  • 04:28Moving away from,
  • 04:30data infrastructure to data processing,
  • 04:34I wanna talk about a
  • 04:35couple of projects we're working
  • 04:36in that end, and they
  • 04:37are both related to cancer
  • 04:39and treatment planning. So the
  • 04:41first one is,
  • 04:42we're trying to develop methods
  • 04:44that can assist radiologists and
  • 04:46radiation oncologists for sarcomas and
  • 04:48head and neck tumors. The
  • 04:49process
  • 04:50typically, is after imaging,
  • 04:53doing some contouring of the
  • 04:55gross tumor volume, the GTV,
  • 04:56followed by the clinical target
  • 04:58volume, which will be what
  • 05:00the radiation will target.
  • 05:02And so we're trying to
  • 05:03build a pipeline where we
  • 05:04have AI all along the
  • 05:06way. We have basically two
  • 05:07goals. The first one is
  • 05:08end to end pipeline where
  • 05:09AI can assist radiologists and
  • 05:10radiation oncologists.
  • 05:12And the second goal is
  • 05:13to incorporate variability in the
  • 05:15models.
  • 05:16One danger of AI is
  • 05:17when it gives an answer
  • 05:18and we trust this without
  • 05:19questioning it. We're trying to
  • 05:21develop models that will have,
  • 05:23an idea of the confidence
  • 05:24they are providing in the
  • 05:25images they are giving us.
  • 05:27This way, the human is
  • 05:28always in the loop and
  • 05:29we can have a better
  • 05:31targeted
  • 05:32analysis from the humans.
  • 05:34That variability is something we
  • 05:35have quantified,
  • 05:37inter and intra reader for
  • 05:38soft tissue sarcomas, and we
  • 05:40observe that there is always
  • 05:41an amount of variability that
  • 05:43is, that is present there
  • 05:45within readers and across readers.
  • 05:46So we quantified this, and
  • 05:48we developed methods that allow
  • 05:50us to utilize this in
  • 05:51the model rather than fight
  • 05:52it, basically. It's actually valuable
  • 05:54information. The key observation is
  • 05:56that,
  • 05:57variability across readers is indication
  • 06:00of confidence. When people are
  • 06:01confident, the variability will be
  • 06:02lower, and that can be
  • 06:03very valuable information. If we
  • 06:05can provide segmentations to readers
  • 06:08that have that notion of
  • 06:10confidence, they can spend the
  • 06:11time on the part of
  • 06:12the image that makes sense.
  • 06:13So that will improve the
  • 06:14throughput.
  • 06:16This slide shows, some of
  • 06:18our results and, and papers
  • 06:20on this work where we
  • 06:21use diffusion models to, predict
  • 06:23confidence map, and we, show
  • 06:25that we have,
  • 06:26we tend to outperform existing
  • 06:28state of the art methods
  • 06:29using those advanced AI tools.
  • 06:31We're also extending this work
  • 06:33to head and neck tumors,
  • 06:34where we're also developing new
  • 06:36models that combine diffusions
  • 06:37and,
  • 06:38vision transformers,
  • 06:40typical models using generative
  • 06:43AI to improve the accuracy
  • 06:44and the precision of segmentations.
  • 06:47The second project I wanna
  • 06:48touch on, is, prostate imaging
  • 06:50where we're also trying to
  • 06:51look at diagnostics
  • 06:53and how AI can assist
  • 06:54that. So as it was
  • 06:56discussed in a previous talk,
  • 06:57diagnostics will
  • 06:59be able to, have injection
  • 07:01of lutetium that will be
  • 07:02imaged through the process. For
  • 07:03the next few days, we
  • 07:05can image
  • 07:07we use inspect the lutetium,
  • 07:08and we can build a
  • 07:09dose map.
  • 07:11This is a well known
  • 07:12task how to estimate the
  • 07:13dose from the spec. What
  • 07:14we are trying to achieve
  • 07:15is
  • 07:16where we need the the
  • 07:17AI tools. We're trying to
  • 07:19see whether from the pet,
  • 07:20we can get information on
  • 07:21those. That's one. And second,
  • 07:24from that dose, can we
  • 07:25predict outcomes? Can we refine
  • 07:26treatment? Can we personalize the
  • 07:28treatment? And this is why,
  • 07:30this is particularly challenging. It's
  • 07:32challenging because the PET and
  • 07:33the dose don't correlate the
  • 07:35same way in different organs.
  • 07:37So but it's very important
  • 07:38for us to do it
  • 07:39from the PET. One intermediate
  • 07:41step we're trying to do
  • 07:42is, well, from a single
  • 07:43SPECT trying to get the
  • 07:44dose. The reason why this
  • 07:46is important to do from
  • 07:47the PET is as we
  • 07:48move from Lutetium to Actinium,
  • 07:49SPECT is no longer an
  • 07:50option. And so we PET
  • 07:52is the only thing we
  • 07:53can have to, assess the
  • 07:54dose as we go.
  • 07:56And that's why we're building
  • 07:58this holistic framework where instead
  • 08:00of having a treatment which
  • 08:01is set once and for
  • 08:02all and doesn't change, we're
  • 08:03trying to use AI everywhere
  • 08:05along the way to adjust,
  • 08:07predict the outcomes, and refine
  • 08:09the the planning, if anything,
  • 08:10to know when to stop
  • 08:11when treatment is working.
  • 08:14That concludes my talk on
  • 08:16this, and I will give
  • 08:17the microphone to jump on
  • 08:19the floor.
  • 08:25Thank you. I am going
  • 08:26to now talk for give
  • 08:28you about the six minute
  • 08:29overview
  • 08:30of prostate cancer image analysis
  • 08:32here at Yale.
  • 08:34So prostate cancer is a
  • 08:36global problem.
  • 08:37In the United States alone,
  • 08:39approximately eleven percent of males
  • 08:41will receive a prostate cancer
  • 08:43diagnosis over the course of
  • 08:44their lives.
  • 08:46This means that prostate cancer
  • 08:47accounts for for approximately thirty
  • 08:49percent of cancers in men,
  • 08:51which is estimated to affect
  • 08:52more than three hundred thousand
  • 08:54and results in greater than
  • 08:55thirty five thousand deaths per
  • 08:57year.
  • 08:59So imaging is a critical
  • 09:01component found throughout the prostate
  • 09:03cancer
  • 09:04diagnostic pipeline.
  • 09:05So after initial screening with
  • 09:07prostate specific antigen blood testing,
  • 09:10radiologists
  • 09:11then interpret and read multi
  • 09:13parametric MRI to identify suspected
  • 09:16lesions according to the PI
  • 09:17RADS reporting standard.
  • 09:19Urologists then use ultrasound to
  • 09:21perform image guided biopsy.
  • 09:23Pathologists
  • 09:24then interpret this biopsy tissue,
  • 09:26which can be digitized using
  • 09:28whole slide imaging.
  • 09:29And then finally, the patient
  • 09:30can be stratified into risk
  • 09:32groups to determine whether they
  • 09:33receive active surveillance
  • 09:35or they go on to
  • 09:36immediate treatment.
  • 09:37Now imaging continues to be
  • 09:39important during the treatment process.
  • 09:41For example,
  • 09:42PSMA PET and SPECT can
  • 09:44be used for theranostics,
  • 09:46as we've seen, and CT
  • 09:47imaging can be used for
  • 09:48radiation therapy.
  • 09:51Image analysis powered by artificial
  • 09:53intelligence and machine learning methods
  • 09:56seeks to leverage,
  • 09:58all these imaging modalities to
  • 10:00enhance clinical insights. And this
  • 10:02is accomplished through a few
  • 10:04tasks such as classification,
  • 10:06segmentation,
  • 10:07registration, and data integration.
  • 10:10So one of the first
  • 10:10fundamental tasks in prostate image
  • 10:12analysis is to segment the
  • 10:14gland within MRI.
  • 10:15Not only do these volume
  • 10:16measurements,
  • 10:17are they used to allow
  • 10:18allow us to compute PSA
  • 10:19density,
  • 10:20but it also serves as
  • 10:21a preprocessing step for many
  • 10:23of the analyses that we'll
  • 10:24see following here. However, this
  • 10:26is a challenge due to
  • 10:27the variability, the heterogeneity, the
  • 10:29MR images themselves that you
  • 10:30see in this picture. And
  • 10:32additionally, these AI algorithms can
  • 10:34are overly sensitive, can over
  • 10:35train to the scanner themselves.
  • 10:37So as demonstrated by techniques
  • 10:40developed here at Yale, image
  • 10:41analysis is critical to robustly
  • 10:43apply these AI algorithms across
  • 10:45different clinical sites.
  • 10:47And note for all of
  • 10:48you AI users,
  • 10:50don't ever trust an algorithm
  • 10:51unless you validate against, like,
  • 10:53multi site data or external
  • 10:54data. K?
  • 10:56So going beyond gland segmentation,
  • 10:58we also wanna differentiate different
  • 11:00zonal anatomy of the prostate,
  • 11:01which is part of their
  • 11:02PyRAADS reporting, system.
  • 11:04In this work here, we
  • 11:05directly integrated both anatomical and
  • 11:08geometric constraints to segment this
  • 11:10challenging boundary.
  • 11:12This approach has been directly
  • 11:14translated,
  • 11:15into clinical use
  • 11:17by our commercial partners, Eigen
  • 11:19Health, into their, ProFuseCAD
  • 11:21software platform. So this is
  • 11:23pretty exciting to see it
  • 11:24actually going from the lab
  • 11:25to the real world.
  • 11:27And our final MRI segmentation
  • 11:29application here is to identify
  • 11:31lesions,
  • 11:32which are extremely challenging to
  • 11:34identify even for experienced radiologists.
  • 11:36So to tackle this problem
  • 11:38here, we developed an approach
  • 11:39that directly integrates clinical data,
  • 11:42in this case, PSA,
  • 11:43into the segmentation
  • 11:45process.
  • 11:46So this human in the
  • 11:47loop approach allows the radiate
  • 11:49radiologist then to mimic the
  • 11:50variability in PSA levels
  • 11:53and is able and you're
  • 11:54able to visualize the effect
  • 11:55it has on the algorithm
  • 11:56segmentation
  • 11:57output. So from this image
  • 11:58here you can see from
  • 11:59left to right as you
  • 12:01increase the PSA value
  • 12:03the lesion actually grows during
  • 12:05the segmentation process.
  • 12:07This too is being integrated
  • 12:09into the ProFuseCAD system, so
  • 12:11another good example of translational
  • 12:13science here.
  • 12:14We can also perform classification
  • 12:16using the MRI to predict
  • 12:18if patients have benign, non
  • 12:19significant disease, or clinically significant
  • 12:21prostate cancer. So as shown
  • 12:23here, using the image by
  • 12:24itself is quite underwhelming in
  • 12:26this AUC curve.
  • 12:27However, by integrating additional clinical
  • 12:30data such as patient age,
  • 12:31PSA, and PI RADS reporting,
  • 12:33we see the synergistic effect
  • 12:35where that significantly enhances the
  • 12:37prostate cancer classification
  • 12:38performance.
  • 12:40Next, during the biopsy procedure,
  • 12:43lesions are extremely challenging to
  • 12:44identify in the ultrasound image.
  • 12:46Therefore, what we want to
  • 12:47use is MRI to identify
  • 12:49lesions of interest for targeted
  • 12:51biopsy.
  • 12:52The challenge here is coregistration
  • 12:53or aligning these two vastly
  • 12:55different imaging modalities.
  • 12:56So to overcome this hurdle,
  • 12:58we use a surface based
  • 12:59registration approach that uses the
  • 13:01segmentations for both the MRI
  • 13:02and the ultrasound.
  • 13:04Here we incorporated a geometric
  • 13:06model,
  • 13:07to model the deformation of
  • 13:08the gland during the biopsy
  • 13:10procedure to improve this image
  • 13:12fusion process.
  • 13:14Once we have the needle
  • 13:16biopsy specimens, a challenge is
  • 13:17then to determine if the
  • 13:18full extent of tissue in
  • 13:20that gland
  • 13:21when this biopsy constitutes only
  • 13:23a small fraction of the
  • 13:24gland sampling.
  • 13:26So using AI, we can
  • 13:27then map this histopathology
  • 13:29results back to the MRI
  • 13:31to fill in the gaps.
  • 13:33In this way, by identifying
  • 13:34tissue with similar properties to
  • 13:35the needle biopsy specimens, we
  • 13:37can provide a full three
  • 13:38d comprehensive assessment of disease
  • 13:40risk throughout the gland.
  • 13:43Also, as Tiba already mentioned,
  • 13:46segmentation is great, but the
  • 13:48real,
  • 13:49critical practical question is, can
  • 13:51we trust our predictions? So
  • 13:52we've been at the forefront
  • 13:53of developing methods to try
  • 13:55to quantify uncertainty. And as
  • 13:56you can see in the
  • 13:57picture here, our frequency domain
  • 13:59dropout here performs better in
  • 14:01identifying the segmentation errors.
  • 14:03So in pathology,
  • 14:05one of the things that
  • 14:06we're interested in is segmenting
  • 14:07tissue and whole slide imaging.
  • 14:08One of the major limitations
  • 14:10of AI is that approaches
  • 14:11are sensitive to how the
  • 14:12data is oriented.
  • 14:14So So as as that
  • 14:15data rotates, biomarkers actually rotate
  • 14:17around and they change position,
  • 14:19which is bad for our
  • 14:19performance.
  • 14:21We've developed this new method
  • 14:22that is able to robustly
  • 14:24handle these features. So as
  • 14:25the image rotates, the biomarker
  • 14:27stays stable.
  • 14:28Once we have these stable
  • 14:29biomarkers we can then robustly
  • 14:31segment the pathology images in
  • 14:33an unsupervised manner.
  • 14:36So finally, we're seeking to
  • 14:37apply these image analysis approaches
  • 14:39to treatment imaging such as
  • 14:41theranostics
  • 14:42And so these show some
  • 14:43initial results segmenting tumor METs
  • 14:46in,
  • 14:47PSMA PET, and we're trying
  • 14:49to quantify tumor burden throughout
  • 14:50the body making this a
  • 14:52really time consuming task more
  • 14:54efficient and precise.
  • 14:56So in summary, image analysis
  • 14:58integrates multimodal data
  • 15:00powered by AI is really
  • 15:01a critical component in our
  • 15:02toolbox for fight, fighting prostate
  • 15:04cancer.
  • 15:05So thank you for your
  • 15:06time, and as we'll see
  • 15:07next with Nisha that these
  • 15:09similar methods can be applied
  • 15:10also to breast cancer. So
  • 15:12thank you.
  • 15:18Hi, everyone. Again, my name
  • 15:20is Nisha Dvornick, and thanks,
  • 15:22first to the Imaging Institute
  • 15:24leaders for this opportunity to
  • 15:25share some of our work
  • 15:26today in breast cancer imaging.
  • 15:28So breast cancer is one
  • 15:30of the most common and
  • 15:30deadly cancers worldwide
  • 15:32and the lifetime risk for
  • 15:33women here in the US
  • 15:34is about one in eight.
  • 15:37Breast imaging plays a critical
  • 15:38role from screening, to treatment
  • 15:40of breast cancer.
  • 15:42For example, mammography,
  • 15:43type of X-ray imaging is
  • 15:45the most commonly used modality
  • 15:46for breast cancer screening and
  • 15:47also used for diagnostic workup.
  • 15:50MRI is used for high
  • 15:52risk screening. We all heard
  • 15:53with Todd Constable's work that
  • 15:55eventually this affordable MRI will
  • 15:56be for all women for
  • 15:58screening, but for now it's
  • 15:59just for high risk screening,
  • 16:01for diagnosis, and also treatment
  • 16:02planning and monitoring to see
  • 16:04the extent of tumors.
  • 16:06And finally, ultrasound imaging is
  • 16:07used for for screening in
  • 16:08some circumstances, diagnosis, and for
  • 16:11biopsy guidance.
  • 16:13Now analyzing all of these
  • 16:15images faces a number of
  • 16:16challenges including the large quantity
  • 16:18of data, a growing shortage
  • 16:19of breast radiologists, and subjective
  • 16:21interpretation that depends on expertise.
  • 16:25So to address these challenges,
  • 16:27our group is developing novel
  • 16:28approaches to enhance the analysis
  • 16:30of breast images
  • 16:31and we're adopting modern AI
  • 16:33methods such as contrastive pre
  • 16:35training to learn how to
  • 16:36best model our data,
  • 16:39utilizing multimodal image and text
  • 16:41information,
  • 16:42and leveraging domain knowledge of
  • 16:43the imaging process to better
  • 16:45constrain the image analysis models.
  • 16:48So I'd like to just
  • 16:49introduce a bit this idea
  • 16:50of contrastive pre training for
  • 16:52learning how to model or
  • 16:53best represent this these imaging
  • 16:55data.
  • 16:56So the goal here is
  • 16:57to learn a mapping
  • 16:59oh, this is gone a
  • 17:00mapping which is this image
  • 17:01encoder,
  • 17:02from the image to an
  • 17:03embedding space where the image
  • 17:05data will then be organized
  • 17:06in a way that's easier
  • 17:07to analyze in downstream tasks.
  • 17:09So say we have this
  • 17:10mammogram, it gets input through
  • 17:11our image encoder and it
  • 17:12maps to some embedding,
  • 17:14and now we have another
  • 17:16image, for the same patient
  • 17:17but a different view, goes
  • 17:19through this encoder, gets a
  • 17:20different embedding,
  • 17:21and now we have a
  • 17:22third mammogram that comes from
  • 17:24a different patient and goes
  • 17:25through the same encoder and
  • 17:26lands right there at the
  • 17:27green triangle.
  • 17:28So now the idea in
  • 17:30contrastive learning is to learn
  • 17:31this embedding where similar data
  • 17:32are going to live closer
  • 17:33together in this high dimensional
  • 17:35space and dissimilar data are
  • 17:36going to live farther apart.
  • 17:38So the contrastive learning algorithm
  • 17:40in this case is gonna
  • 17:41work to align these blue
  • 17:42circles that represent the images
  • 17:43from the same patient
  • 17:45while seeking to push apart
  • 17:46data that come from different
  • 17:47patients.
  • 17:48And once we've learned this
  • 17:49embedding and this useful representation
  • 17:51of the data, we can
  • 17:52build more accurate models for
  • 17:54different image analysis tasks on
  • 17:56top of it.
  • 17:57So we use this image
  • 17:59contrast to pre training approach
  • 18:00to improve the identification of
  • 18:02abnormal digital breast tumor synthesis
  • 18:04scans, also known as three
  • 18:05d mammography.
  • 18:06And here our framework looks
  • 18:07to align an image slice
  • 18:08from a tonal volume with
  • 18:10other slices from the same
  • 18:11patient while pushing away the
  • 18:12images from the other patients.
  • 18:14After we've performed this contrastive
  • 18:16pre training, we fine tune
  • 18:18the model to learn to
  • 18:18predict whether an input tomosynthesis
  • 18:20slice is normal or abnormal.
  • 18:23And as we can see
  • 18:24in this performance,
  • 18:25ROC curves here
  • 18:27compared to the other pre
  • 18:28training approaches,
  • 18:30down below our model in
  • 18:31red performs the best
  • 18:33and in particular we achieved
  • 18:34a very high negative predictive
  • 18:35value suggesting we might be
  • 18:37able to use this to
  • 18:38filter out negative cases and
  • 18:39reduce the radiologists workload.
  • 18:43We then extended this contrastive
  • 18:44pre training approach to align
  • 18:46images and radiology reports. So
  • 18:48this general method of aligning
  • 18:50image and text data is
  • 18:51known as contrastive language pre
  • 18:52training or CLIP.
  • 18:54So now in addition to
  • 18:55the image encoder, we now
  • 18:56have this text encoder to
  • 18:57map the radiology reports into
  • 18:59now this shared embedding space.
  • 19:01And the contrastive,
  • 19:03learning algorithm is going to
  • 19:04now try to
  • 19:05align the paired image and
  • 19:07radiology reports and at the
  • 19:09same time push away other
  • 19:10reports that were not related
  • 19:11to the target image
  • 19:13and push away other images
  • 19:14that are not related to
  • 19:15the target report.
  • 19:17So we use this CLIP
  • 19:18framework to perform a multi
  • 19:19view and multi scale alignment
  • 19:21from mammography data
  • 19:23where our model considers again
  • 19:24this multi view image alignment
  • 19:26at top, similar to the
  • 19:27tone synthesis model. And then
  • 19:29we add in this global
  • 19:31image report alignment using the
  • 19:32CLIP framework and also local
  • 19:34level image report alignment
  • 19:36where we learn to match
  • 19:37sentence level information in the
  • 19:38radiology report with the most
  • 19:40relevant image patch in the
  • 19:41mammogram and vice versa.
  • 19:44So after we perform this
  • 19:45pretraining,
  • 19:46we can then fine tune
  • 19:47the model to do different
  • 19:48image analysis tasks including,
  • 19:51prediction of the BI RADS
  • 19:52category,
  • 19:53breast density, and cancer. And
  • 19:56we can see our approach
  • 19:57in the blue gray on
  • 19:58the very right of each
  • 19:59of these plots, performs the
  • 20:00best for each of these
  • 20:01model learning scenarios.
  • 20:04Finally, we leverage the geometry
  • 20:06of the multi view imaging
  • 20:08process to learn how to
  • 20:09align local image features before
  • 20:10we're just looking at kind
  • 20:11of the global image. And
  • 20:13we can see here, at
  • 20:14the bottom that red dot,
  • 20:15this, small region of interest
  • 20:17actually corresponds to multiple locations
  • 20:19in the blue tube on
  • 20:20the left,
  • 20:22that, goes through the same
  • 20:23slice on the breast. And
  • 20:25so we use this geometric
  • 20:26constraint to perform this contrast
  • 20:27of pretraining to align each
  • 20:29patch in one view with
  • 20:30each corresponding slice in the
  • 20:31other view. And using this
  • 20:33local alignment, we again see
  • 20:34improvement in this BI RADS
  • 20:36category prediction.
  • 20:38So finally, I'm just gonna
  • 20:40touch on our breast MRI
  • 20:41work, where we're looking to
  • 20:42improve the segmentation of tumors
  • 20:43with additional knowledge of the
  • 20:44imaging process. So here's kind
  • 20:46of a standard AI model
  • 20:48for segmentation where the image
  • 20:49goes into a unit and
  • 20:50then we get our prediction
  • 20:51for our tumor mask.
  • 20:53But in our approach, we're
  • 20:54going to incorporate the timing
  • 20:55of these contrast enhanced MRI
  • 20:57to modulate the model parameters
  • 20:59and we saw a nice
  • 21:00increase in our early results
  • 21:02in the segmentation performance.
  • 21:04So to conclude, I hope
  • 21:05I've given you all an
  • 21:06idea of how modern AI
  • 21:07approaches can help, enhance breast
  • 21:09image analysis. And if you
  • 21:10have any ideas on how
  • 21:12this might apply to your
  • 21:12data or some specific task,
  • 21:14I'd be very happy to
  • 21:15discuss further. Thank you.