Evidence map›Paper›PMID 34953431›Full record

ArticleComputerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society2022

Unified Focal loss: Generalising Dice and cross entropy-based losses to handle class imbalanced medical image segmentation.

Michael Yeung, Evis Sala, Carola-Bibiane Schönlieb, Leonardo Rundo

Abstract read
In one paragraph

Article in Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 140 papers, 1 of them a synthesis that pooled it.

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0cells of the map it votes in
140citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

140 citing papers in PubMed, 1 synthesis or guideline pooled it.

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  17. [Research on surgical instrument segmentation algorithm based on frequency-domain adaptive feature decomposition and visual Mamba].Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi · 2026
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80 more citing papers are in PubMed but not listed here.

4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Michael YeungDepartment of Radiology, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; School of Clinical Medicine, University of Cambridge, Cambridge CB2 0SP, United Kingdom. Electronic address: mjyy2@cam.ac.uk.
Evis SalaDepartment of Radiology, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; Cancer Research UK Cambridge Centre, University of Cambridge, Cambridge CB2 0RE, United Kingdom. Electronic address: es220@medschl.cam.ac.uk.
Carola-Bibiane SchönliebDepartment of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, United Kingdom. Electronic address: cbs31@cam.ac.uk.
Leonardo RundoDepartment of Radiology, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; Cancer Research UK Cambridge Centre, University of Cambridge, Cambridge CB2 0RE, United Kingdom; Department of Information and Electrical Engineering and Applied Mathematics (DIEM), University of Salerno, Fisciano, SA 84084, Italy. Electronic address: lr495@cam.ac.uk.

Funding

Wellcome Trust
6 · The paper itself

Abstract

Automatic segmentation methods are an important advancement in medical image analysis. Machine learning techniques, and deep neural networks in particular, are the state-of-the-art for most medical image segmentation tasks. Issues with class imbalance pose a significant challenge in medical datasets, with lesions often occupying a considerably smaller volume relative to the background. Loss functions used in the training of deep learning algorithms differ in their robustness to class imbalance, with direct consequences for model convergence. The most commonly used loss functions for segmentation are based on either the cross entropy loss, Dice loss or a combination of the two. We propose the Unified Focal loss, a new hierarchical framework that generalises Dice and cross entropy-based losses for handling class imbalance. We evaluate our proposed loss function on five publicly available, class imbalanced medical imaging datasets: CVC-ClinicDB, Digital Retinal Images for Vessel Extraction (DRIVE), Breast Ultrasound 2017 (BUS2017), Brain Tumour Segmentation 2020 (BraTS20) and Kidney Tumour Segmentation 2019 (KiTS19). We compare our loss function performance against six Dice or cross entropy-based loss functions, across 2D binary, 3D binary and 3D multiclass segmentation tasks, demonstrating that our proposed loss function is robust to class imbalance and consistently outperforms the other loss functions. Source code is available at: https://github.com/mlyg/unified-focal-loss.

Indexed as

Image Processing, Computer-AssistedNeural Networks, ComputerAlgorithmsEntropyRetinal VesselsClass imbalanceConvolutional neural networksLoss functionMachine learningMedical image segmentation

Identifiers

PMID34953431
PMCPMC8785124

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LicenceCC BY
Read underepoch 390

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.