Modern problems in Biomedical Imaging

2026 TTREC Faculty Retreat

Jeremias Sulam

50 years ago ... 

first CT scan
ELECTRIC & MUSICAL INDUSTRIES

50 years ago ... 

imaging
diagnostics

complete hardware & software description

human expert diagnosis and recommendations

imaging was "simple"

... 50 years forward 

Data

Compute & Hardware

Sensors & Connectivity

Research & Engineering

... 50 years forward 

data-driven  imaging
automatic analysis and rec.
societal implications

Data

Compute & Hardware

Sensors & Connectivity

Research & Engineering

data-driven  imaging
automatic analysis and rec.
societal implications

Problems in trustworthy biomedical imaging

inverse problems

uncertainty quantification

robustness

biomarker discovery

demographic fairness

hardware & protocol optimization

model-agnostic interpretability

policy & regulation

monitoring & auditing

data-driven  imaging
automatic analysis and rec.
societal implications

Problems in trustworthy biomedical imaging

inverse problems

uncertainty quantification

robustness

demographic fairness

hardware & protocol optimization

model-agnostic interpretability

policy & regulation

monitoring & auditing

biomarker discovery

=
+

\(x\sim p_x\)

\(z\sim \mathcal N(0,\sigma^2 I)\)

\(y = x + z\)

=

\(x\sim p_x\)

+

\(z\sim \mathcal N(0,\sigma^2 I)\)

\(A~\cdot\)

\(y = Ax + z\)

estimate

Inverse Problems

How can we use modern data-driven methods while characterizing and exploiting what they have learned?

Example 1: learning a prior for MR Spectroscopy

Inverse Problems

Example 1: learning a prior for MR Spectroscopy

baseline

Inverse Problems

Example 1: learning a prior for MR Spectroscopy

baseline

Inverse Problems

Example 1: learning a prior for MR Spectroscopy

baseline

Inverse Problems

Quantitative Susceptibility Mapping

[Lai, Kuo-Wei, et al. "Learned proximal networks for quantitative susceptibility mapping." International Conference on Medical Image Computing and Computer-Assisted Intervention. Cham: Springer International Publishing, 2020.]

[Fang, Zhenghan, et al. "DeepSTI: Towards tensor reconstruction using fewer orientations in susceptibility tensor imaging." Medical image analysis 87 (2023): 102829.]

Susceptibility Tensor Imaging

data-driven  imaging
automatic analysis and rec.
societal implications

Problems in trustworthy biomedical imaging

inverse problems

uncertainty quantification

robustness

biomarker discovery

demographic fairness

hardware & protocol optimization

model-agnostic interpretability

policy & regulation

monitoring & auditing

[Marilyn Bui]

Cancer biology/pathology

[Burke et al]

Protein-Protein interactions

[Herbst-Kralovetz Lab]

Host/microbe interactions

[Allen Institute]

Spatial transcriptomics

[MICrONs]

Connectomics

How can we learn descriptive local patterns for different phenotypes?

Biomarker Discovery

Bi-level Graphs: BiGraph

Bi-level Graphs: BiGraph

graph/patient Kernels

Bi-level Graphs: BiGraph

Bi-level Graphs: BiGraph

Community detection 

(validation)

data-driven  imaging
automatic analysis and rec.
societal implications

Problems in trustworthy biomedical imaging

inverse problems

uncertainty quantification

robustness

biomarker discovery

demographic fairness

hardware & protocol optimization

model-agnostic interpretability

policy & regulation

monitoring & auditing

Problems in trustworthy biomedical imaging

in a box

Denoiser

Measurements

Reconstruction

Uncertainty Quantification

x^=fθ(y)\hat{x} = f_\theta(y)

pixelj\text{pixel}_j

x^j\hat{x}_j

(point predictors)

What is the uncertainty in the guess x^j\hat x_j?

How do we report uncertainty rigorously?

\(y = Ax + z\)

00

11

l(y)j l(y)_j

u(y)j u(y)_j

Uncertainty through Prediction Sets

C:y↦C(y)⊆[0,1]dC: y \mapsto C(y) \subseteq [0,1]^d

C(y)j=[l(y)j,u(y)j]\mathcal C(y)_j = [l(y)_j,u(y)_j]

Miscoverage:

ℓ(y,x)=1d∑j∈[d]1 ⁣{xj∉C(y)j}\ell(y,x) = \frac{1}{d} \sum_{j\in[d]} \mathbf{1}\!\left\{x_j \notin C(y)_j\right\}

ground truth!

Semantic Uncertainty Quantification

risk controlled uniformly for every organ

[Teneggi, Jacopo, J. Webster Stayman, and Jeremias Sulam. "Conformal risk control for semantic uncertainty quantification in computed tomography."  MICCAI , 2025.]

 provides a simple procedure so that

\(\mathbb{E} [\text{miscoverage(C(y))}]\leq \epsilon \)

policy & regulation

robustness

generalization

uncertainty quantification

An exciting time to work on biomedical data science

Cλ(y)j=[lj(y)−λ,  uj(y)+λ]C_{\lambda}(y)_j = [l_j(y)-{\color{green}{\lambda}},\;u_j(y)+{\color{green}\lambda}]

Observation 1:   Single λ\lambda for all dd dimensions... suboptimal

Uncertainty through Prediction Sets

Cλ(y)j=[lj(y)−λ,  uj(y)+λ]C_{\lambda}(y)_j = [l_j(y)-{\color{green}{\lambda}},\;u_j(y)+{\color{green}\lambda}]

Observation 1:   Single λ\lambda for all dd dimensions... suboptimal

Observation 2:   High-dim data is heterogenous

Cλ(y)j=[lj(y)−λj,  uj(y)+λj]C_{\lambda}(y)_j = [l_j(y)-{\color{green}{\lambda_j}},\;u_j(y)+{\color{green}\lambda_j}]

\(\lambda_j\) for each \(j^\text{th}\) organ

Uncertainty through Prediction Sets

data-driven  imaging
automatic analysis and rec.
societal implications

Problems in trustworthy biomedical imaging

inverse problems

uncertainty quantification

robustness

generalization

demographic fairness

hardware & protocol optimization

model-agnostic interpretability

policy & regulation

monitoring & auditing

BiGraph provides complementary information to standard clinical characteristics

Tumor Stage

Tumor Grade

Tumor Subtype

BiGraph provides complementary information to standard clinical characteristics

BiGraph provides complementary information to standard clinical characteristics

Biomarkers for TNBC

Biomarkers for TNBC

  • 279 early triple-negative breast cancer (TNBC) patients in a randomized pre-surgical neoadjuvant immunotherapy clinical trial (ICB)
  • pathology Complete Response (pCR) vs
    residual disease (RD)
all subtypes
TNBC

Biomarkers for TNBC

 

  • TLS are known to promote local immune responses and are generally associated with favorable prognosis in immunologically “hot” tumors.
     
  • Prior studies have shown mixed results in breast cancer overall, but more consistent positive associations in TNBC.

 

all subtypes
TNBC

proportion of

TLS-like niche

proportion of

TLS-like niche

proportion of

TLS-like niche

proportion of

TLS-like niche

[Z Wang et al, Bi-level Graph Learning Unveils Prognosis-Relevant Tumor Microenvironment Patterns from Breast Multiplexed Digital Pathology, Patterns: Cell Press 2025]