Ultrasound images vary widely across scanners, operators, and anatomical targets, which often causes models trained in one setting to generalize poorly to new hospitals and clinical conditions. The Foundation Model Challenge for Ultrasound Image Analysis (FMC-UIA) reflects this difficulty by requiring a single model to handle multiple tasks, including segmentation, detection, classification, and landmark regression across diverse organs and datasets. We propose a unified multi-task framework based on a transformer visual encoder from the Qwen3-VL family. Intermediate token features are projected into spatial feature maps and fused using a lightweight multi-scale feature pyramid, enabling both pixel-level predictions and global reasoning within a shared representation. Each task is handled by a small task-specific prediction head, while training uses task-aware sampling and selective loss balancing to manage heterogeneous supervision and reduce task imbalance. Our method is designed to be simple to optimize and adaptable across a wide range of ultrasound analysis tasks. The performance improved from 67% to 85% on the validation set and achieved an average score of 81.84% on the official test set across all tasks. The code is publicly available at: https://github.com/saitejalekkala33/FMCUIA-ISBI.git
Figures & tables
Figure 1: Overview of the proposed unified multi-task framework. Shared Qwen3-VL encoder extracts multi-depth tokens, reshaped and fused into a four-level pyramid. Dense heads use pyramid features; global heads use pooled multi-scale embeddings.
Task
Category
IoU
MRE
Segmentation
Classification
Task Score
IoU Raw
MRE Raw
DSC Raw
HD Raw
AUC Raw
F1 Raw
MCC Raw
Detection
thyroid_nodule_det
0.717
–
–
–
–
–
–
0.920
Regression
IUGC
–
47.915
–
–
–
–
–
0.685
FUGC
–
17.911
–
–
–
–
–
0.858
fetal_femur
–
71.954
–
–
–
–
–
0.960
Segmentation
cardiac_multi
–
–
0.525
177.195
–
–
–
0.385
Table 1: Unified results table (raw metrics only). Dashes indicate metrics not applicable to that task.
Figure 2: Ablation across model variants, reported the overall average score for the validation split with backbones Qwen2.5-VL-7B-Instruct and Qwen3-VL-8B-Instruct.
Appendix figures & tables4 assets
Supplementary material from the paper’s appendix.
Appendix
Section
Hyperparameter
Value
Task sampling / loss
Temperature
0.7
Loss EMA β
0.98
Dynamic weighting γ
0.5
Weight clamp
[0.25,4.0]
Sampler type
Temperature-based (frequency + EMA loss)
Input / preprocessing
Image resize
448×448
Appendix
Table 2: Training and inference hyperparameters.
Component
Setting
Operating System
Ubuntu 24.04.4 LTS
Programming Language
Python
GPU
NVIDIA L40S
VRAM
48GiB
Processor
AMD EPYC 7R13 Processor
Training Framework
Hugging Face Transformers, Accelerate
Appendix
Table 3: Implementation and environment details.
Task
Features
Head details
Segmentation
fpn_v1
SegmentationHeadV1 : P5 projection, three bilinear up-fuse blocks, dropout, and a 1×1 classifier. Logits are sliced to the task-specific class count and upsampled to the input image size.
Classification
global
ClassificationHead : dynamic linear projection to 1024 dimensions, layer normalization, GELU, two gated-MLP residual blocks, and a final linear classifier.
Regression
global_v1
RegressionHeadV1 : dynamic linear projection to 1024 dimensions, layer normalization, GELU, dropout, and a linear regressor. The first 2M outputs are retained and passed through a sigmoid.
Detection
fpn
DetectionGridHead : uses P2 together with upsampled P3 and P4 , plus normalized coordinate channels. A residual convolutional tower predicts four box channels and one objectness channel per grid cell.
Appendix
Table 4: Task routing and prediction heads.
Task
Category
IoU
MRE
Segmentation
Classification
Task Score
IoU Norm
MRE Norm
DSC Norm
HD Norm
AUC Norm
F1 Norm
MCC Norm
Detection
thyroid_nodule_det
0.920
–
–
–
–
–
–
0.920
Regression
IUGC
–
0.685
–
–
–
–
–
0.685
FUGC
–
0.858
–
–
–
–
–
0.858
fetal_femur
–
0.960
–
–
–
–
–
0.960
Segmentation
cardiac_multi
–
–
0.295
0.474
–
–
–
0.385
Appendix
Table 5: Unified results table (normalized metrics only). Dashes indicate metrics not applicable to that task.
School of Computer Science, University of Nottingham Ningbo China, Ningbo, Zhejiang, China · School of Mathematical Sciences, University of Nottingham Ningbo China, Ningbo, Zhejiang, China · School of Computer Science, University of Nottingham, Nottingham NG72RD, UK +3