Sufayan Ikabal Mulani

• Mulani, Sufayan; Ziksari, Mahsa Sotoodeh; Austeng, Andreas & Näsholm, Sven Peter (2026). Rectified wavenumber algorithms for efficient ultrasound imaging. Ultrasonics. ISSN 0041-624X. 168. doi: 10.1016/j.ultras.2026.108227. Full text in Research Archive Show summary

  Wavenumber-domain beamforming offers substantial computational advantage over conventional time-domain algorithms in ultrasound image formation. However, these methods are found to introduce distortions at large angles and greater depths, making it nontrivial to replace conventional processing pipelines with wavenumber-domain approaches. This paper presents a wavenumber-domain framework that produces images consistent with conventional delay-and-sum (DAS) beamforming, while retaining the computational efficiency of Fourier-domain processing. Building on recent work on DAS-consistent imaging for multistatic acquisition data, the key utility of this novel algorithm is its applicability in plane-wave, focused-transmit, and diverging-wave imaging. The approach compensates for the implicit spatial-frequency filtering of earlier wavenumber-domain formulations through a modified Fourier-domain weighting and an axial scaling to the reconstructed image. Using data from simulations, phantom experiments, and in-vivo liver imaging, we demonstrate that the proposed method preserves DAS-equivalent amplitude, speckle statistics, resolution, and contrast. Quantitative image comparison confirms a close agreement between DAS and the proposed method with Structural Similarity (SSIM) values exceeding 0.99, whereas SSIM between earlier wavenumber-domain beamformers and DAS is lower, ranging from 0.67 to 0.92 depending on the transmit scheme. The proposed method yields approximately one order-of-magnitude reduction in computational cost compared to conventional DAS, making it well-suited for real-time and resource-constrained ultrasound systems.

• Mulani, Sufayan Ikabal; Ziksari, Mahsa Sotoodeh; Austeng, Andreas & Näsholm, Sven Peter (2026). Delay-and-Sum Consistent Wavenumber Algorithm. IEEE Transactions on Ultrasonics. 73(3), p. 379–390. doi: 10.1109/tuson.2026.3667456. Full text in Research Archive Show summary

  Fourier-domain beamforming methods offer a computationally efficient alternative to time domain methods in ultrasound imaging. Among these, the wavenumber algorithm (WA) achieves fast image reconstruction from full-matrix capture (FMC) data but introduces amplitude distortions due to its inherent weighting. In this study, we present a modified Fourier-domain beamforming method that operates on FMC data and reproduces the amplitude response of the conventional delay-and-sum (DAS) method while maintaining the computational efficiency of WA. This is achieved through a derivation of a correction factor that restores DAS-like amplitude characteristics in WA. The correction is implemented in two stages, consisting of a matrix multiplication to the data in the Fourier domain and a subsequent scaling with the z coordinate in the reconstructed image. Validation on simulated point targets, phantom experiment, and in-vivo imaging demonstrates that the proposed method produces images nearly indistinguishable from DAS but with significantly reduced computational burden. We also investigate the role of zero-padding, showing how interpolation accuracy affects reconstruction fidelity and computational efficiency. The proposed approach can, for example, facilitate the development of ultrasound systems with reduced power consumption.

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• Mulani, Sufayan Ikabal; Austeng, Andreas & Näsholm, Sven Peter (2025). Delay-and-sum consistent Fourier beamforming. Full text in Research Archive
• Mulani, Sufayan Ikabal; Ziksari, Mahsa Sotoodeh; Austeng, Andreas & Näsholm, Sven Peter (2025). A Modified Wavenumber Algorithm That Preserves the DAS Image. Full text in Research Archive
• Mulani, Sufayan Ikabal; Ziksari, Mahsa Sotoodeh; Austeng, Andreas & Näsholm, Sven Peter (2025). Efficient Ultrasound Imaging by Integrating Refocus with Fourier Beamforming. Full text in Research Archive

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