*Result*: Unsupervised 1D CNN -bidirectional long short-term memory model with multi-head attention for generating intravoxel incoherent motion maps.

Title:
Unsupervised 1D CNN -bidirectional long short-term memory model with multi-head attention for generating intravoxel incoherent motion maps.
Authors:
Li ZY; Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei City, Taiwan.; Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China., Huang HM; Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei City, Taiwan.; Program for Precision Health and Intelligent Medicine, Graduate School of Advanced Technology, National Taiwan University, Taipei City, Taiwan.
Source:
Medical physics [Med Phys] 2026 Mar; Vol. 53 (3), pp. e70396.
Publication Type:
Journal Article
Language:
English
Journal Info:
Publisher: John Wiley and Sons, Inc Country of Publication: United States NLM ID: 0425746 Publication Model: Print Cited Medium: Internet ISSN: 2473-4209 (Electronic) Linking ISSN: 00942405 NLM ISO Abbreviation: Med Phys Subsets: MEDLINE
Imprint Name(s):
Publication: 2017- : Hoboken, NJ : John Wiley and Sons, Inc.
Original Publication: Lancaster, Pa., Published for the American Assn. of Physicists in Medicine by the American Institute of Physics.
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Grant Information:
NSTC114-2221-E-002-093 National Science and Technology Council, Taiwan
Contributed Indexing:
Keywords: convolutional neural network; diffusion MRI; intravoxel incoherent motion imaging; unsupervised learning
Entry Date(s):
Date Created: 20260319 Date Completed: 20260319 Latest Revision: 20260319
Update Code:
20260320
DOI:
10.1002/mp.70396
PMID:
41855015
Database:
MEDLINE

*Further Information*

*Background: Intravoxel incoherent motion (IVIM) imaging, a diffusion magnetic resonance imaging technique, is commonly used to quantify tissue perfusion and diffusion. Traditional pixel-by-pixel fitting methods, however, often suffer from high noise, causing unreliable parameter estimates.
Purpose and Methods: To address this issue, a novel unsupervised learning-based framework combining a one-dimensional (1D) convolutional neural network (CNN) with a bidirectional long short-term memory (BiLSTM) network and a multi-head attention mechanism (MHAM) was proposed. Several techniques were proposed to reduce the effect of random weight initialization, noisy input data, and overfitting/underfitting on the estimation of IVIM parameters. The performance of the proposed method was evaluated using both simulated and experimental data, and the results were compared with those obtained using the deep neural network (DNN) method and the Bayesian-Markov random fields (MRF) method.
Results: Simulation results showed that the proposed method achieved lower root mean square error values than the other two methods, indicating more reliable IVIM parameter estimates. The only exception was at a signal-to-noise ratio of 100, where it performed similarly to the Bayesian-MRF method. For the abdominal datasets, the proposed method yielded IVIM parameter estimates that closely matched the literature-reported values and avoided the overestimation of pseudo-diffusion coefficients (D<sup>*</sup>) observed in the other two methods. For the brain dataset, the perfusion fractions and diffusion coefficients obtained from all three methods were consistent with the literature-reported ranges; however, only the DNN method tended to overestimate D<sup>*</sup>.
Conclusions: These findings suggest that the proposed CNN-BiLSTM-MHAM model is a promising approach for IVIM parameter estimation.
(© 2026 American Association of Physicists in Medicine.)*