Pub Date : 2025-04-15DOI: 10.1109/TUFFC.2025.3560872
Mohamed Tamraoui;Hervé Liebgott;Emmanuel Roux
Sparse arrays offer several advantages over other element reduction techniques for 3-D ultrasound imaging. However, the large interelement spacing in these arrays results in high sidelobe-related artifacts, which significantly degrade image quality and limit their application in 3-D ultrasound imaging. Adaptive beamformers have been proposed to mitigate sidelobe-related artifacts, but they often degrade speckle texture quality, resulting in unnaturally dark images. To overcome these limitations, we propose RSB-Net, a region-specific beamformer based on deep reinforcement learning (DRL). RSB-Net adaptively selects the most suitable beamformer for each pixel of the image, applying adaptive beamforming in regions dominated by sidelobe artifacts and delay-and-sum (DAS) beamforming in regions where speckle texture should be preserved. The effectiveness of RSB-Net was validated on both simulated and experimental synthetic transmit aperture (STA) RF datasets with a newly designed sparse array prototype. On simulated data, RSB-Net achieved significant gains, with improvements of 52.81 dB in contrast ratio (CR) and 0.65 in a generalized contrast-to-noise ratio (gCNR) compared to DAS beamforming. In experimental tissue-mimicking phantom data, RSB-Net demonstrated similar performance, achieving gains of 51.01 dB and 0.64, respectively. These results highlight the potential of RSB-Net as a robust and effective solution for high-quality B-mode 3-D ultrasound imaging using 2-D sparse arrays, advancing the standardization of 3-D ultrasound in clinical settings by enhancing anatomical visualization, reducing operator dependency, and improving measurement accuracy for lesions and calcifications.
{"title":"A Deep Reinforcement Learning Based Region-Specific Beamformer for Sparse Arrays 3-D Ultrasound Imaging","authors":"Mohamed Tamraoui;Hervé Liebgott;Emmanuel Roux","doi":"10.1109/TUFFC.2025.3560872","DOIUrl":"10.1109/TUFFC.2025.3560872","url":null,"abstract":"Sparse arrays offer several advantages over other element reduction techniques for 3-D ultrasound imaging. However, the large interelement spacing in these arrays results in high sidelobe-related artifacts, which significantly degrade image quality and limit their application in 3-D ultrasound imaging. Adaptive beamformers have been proposed to mitigate sidelobe-related artifacts, but they often degrade speckle texture quality, resulting in unnaturally dark images. To overcome these limitations, we propose RSB-Net, a region-specific beamformer based on deep reinforcement learning (DRL). RSB-Net adaptively selects the most suitable beamformer for each pixel of the image, applying adaptive beamforming in regions dominated by sidelobe artifacts and delay-and-sum (DAS) beamforming in regions where speckle texture should be preserved. The effectiveness of RSB-Net was validated on both simulated and experimental synthetic transmit aperture (STA) RF datasets with a newly designed sparse array prototype. On simulated data, RSB-Net achieved significant gains, with improvements of 52.81 dB in contrast ratio (CR) and 0.65 in a generalized contrast-to-noise ratio (gCNR) compared to DAS beamforming. In experimental tissue-mimicking phantom data, RSB-Net demonstrated similar performance, achieving gains of 51.01 dB and 0.64, respectively. These results highlight the potential of RSB-Net as a robust and effective solution for high-quality B-mode 3-D ultrasound imaging using 2-D sparse arrays, advancing the standardization of 3-D ultrasound in clinical settings by enhancing anatomical visualization, reducing operator dependency, and improving measurement accuracy for lesions and calcifications.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"772-785"},"PeriodicalIF":3.0,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143968259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-10DOI: 10.1109/TUFFC.2025.3559870
M. Nicole MacMullin;Theresa Gu;Thomas G. Landry;Nicholas Campbell;Sean D. Christie;Jeremy A. Brown
The transition to minimally invasive spinal surgery over traditional open procedures requires the development of imaging techniques that meet the size constraints. Due to size restrictions associated with minimally invasive spine surgery (MISS), current imaging techniques are largely limited to microscopy, which is only capable of line-of-sight imaging of the tissue surface. A miniature, high-resolution ultrasound imaging endoscope has been developed as a potential alternative imaging method that would enable intraoperative guidance. We have designed and developed a 30-MHz miniature, 64-element high-resolution imaging endoscope using PIN-PMT-PT single crystal as the piezoelectric substrate. The packaged probe had cross-sectional dimensions of $3.8times 4.2$ mm and a length of 14 cm. Two editions of the endoscope were created with a forward facing and 40° angle to enable visualization of structures during a medial and lateral approach, respectively. The probe was combined with a custom imaging system that produced real-time images with a field of view ranging between ±32° and an image depth of 15 mm. The two-way axial resolution was measured to be $38~mu $ m based on the -6-dB width of the pulse envelope. The -6-dB lateral resolution was measured to be 113, 131, and $158~mu $ m at steering angles of 0°, 12°, and 25°, respectively, which were close to the simulated values of 106, 118, and $144~mu $ m. Preliminary clinical imaging studies successfully demonstrated the visualization of pertinent spinal anatomy during minimally invasive surgeries. The imaging probe was also able to demonstrate compression and decompression of nerve roots, supporting its potential use as a clinical tool.
从传统的开放手术过渡到微创脊柱手术，需要满足尺寸限制的成像技术的发展。由于与微创脊柱手术相关的尺寸限制，目前的成像技术主要局限于显微镜，它只能对组织表面进行视线成像。一种微型、高分辨率超声成像内窥镜已经被开发出来，作为一种潜在的替代成像方法，可以实现术中引导。我们设计并开发了一种30 MHz微型，64元件，高分辨率成像内窥镜，使用PIN-PMT-PT单晶作为压电衬底。封装探头的横截面尺寸为3.8 mm x 4.2 mm，长度为14 cm。内窥镜的两个版本分别具有正面和40⁰角度，以便在内侧和外侧入路期间分别实现结构的可视化。该探头与定制成像系统相结合，产生实时图像，视场范围在±32⁰之间，图像深度为15 mm。基于-6 dB的脉冲包络宽度，测量出双向轴向分辨率为38 μm。在0⁰、12⁰和25⁰的转向角度下，测量到的-6 dB横向分辨率分别为113 μm、131 μm和158 μm，接近106 μm、118 μm和144 μm的模拟值。初步的临床影像学研究成功地证明了在微创手术中相关脊柱解剖的可视化。成像探针还能够显示神经根的压迫和减压，支持其作为临床工具的潜在用途。
{"title":"A High-Frequency Ultrasound Endoscope for Minimally Invasive Spine Surgery","authors":"M. Nicole MacMullin;Theresa Gu;Thomas G. Landry;Nicholas Campbell;Sean D. Christie;Jeremy A. Brown","doi":"10.1109/TUFFC.2025.3559870","DOIUrl":"10.1109/TUFFC.2025.3559870","url":null,"abstract":"The transition to minimally invasive spinal surgery over traditional open procedures requires the development of imaging techniques that meet the size constraints. Due to size restrictions associated with minimally invasive spine surgery (MISS), current imaging techniques are largely limited to microscopy, which is only capable of line-of-sight imaging of the tissue surface. A miniature, high-resolution ultrasound imaging endoscope has been developed as a potential alternative imaging method that would enable intraoperative guidance. We have designed and developed a 30-MHz miniature, 64-element high-resolution imaging endoscope using PIN-PMT-PT single crystal as the piezoelectric substrate. The packaged probe had cross-sectional dimensions of <inline-formula> <tex-math>$3.8times 4.2$ </tex-math></inline-formula> mm and a length of 14 cm. Two editions of the endoscope were created with a forward facing and 40° angle to enable visualization of structures during a medial and lateral approach, respectively. The probe was combined with a custom imaging system that produced real-time images with a field of view ranging between ±32° and an image depth of 15 mm. The two-way axial resolution was measured to be <inline-formula> <tex-math>$38~mu $ </tex-math></inline-formula>m based on the -6-dB width of the pulse envelope. The -6-dB lateral resolution was measured to be 113, 131, and <inline-formula> <tex-math>$158~mu $ </tex-math></inline-formula>m at steering angles of 0°, 12°, and 25°, respectively, which were close to the simulated values of 106, 118, and <inline-formula> <tex-math>$144~mu $ </tex-math></inline-formula>m. Preliminary clinical imaging studies successfully demonstrated the visualization of pertinent spinal anatomy during minimally invasive surgeries. The imaging probe was also able to demonstrate compression and decompression of nerve roots, supporting its potential use as a clinical tool.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"828-836"},"PeriodicalIF":3.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144012604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-09DOI: 10.1109/TUFFC.2025.3559458
Ekaterina M. Ponomarchuk;Gilles P. L. Thomas;Minho Song;Yak-Nam Wang;Stephanie Totten;George R. Schade;Vera A. Khokhlova;Tatiana D. Khokhlova
Boiling histotripsy (BH) is a pulsed high-intensity focused ultrasound (HIFU)-based method of extracorporeal nonthermal tissue disintegration under real-time ultrasound (US) guidance. Respiratory motion in abdominal targets can affect BH precision and completeness. This study compares two motion mitigation strategies based on pulse/echo US motion tracking: robotic arm-based unidirectional motion compensation by HIFU transducer manipulation and BH pulse gating during expiratory pause. BH ablations were generated in the liver and kidney of anesthetized pigs with 2–10-ms pulses using a 256-element 1.5-MHz HIFU array. A coaxial US imaging probe was used for targeting, tracking skin surface, and monitoring real-time bubble activity. The axial [anterior-posterior (AP)] displacement of the skin surface was found to be synchronous with liver and kidney motion in both cranio-caudal (CC) and AP directions. BH lesions were produced either with no motion mitigation, or with pulse gating, or with 1-D motion compensation. Dimensions of completely fractionated and affected tissue areas were measured histologically. In liver, gating and motion compensation improved fractionation completeness within targeted volumes and reduced off-target tissue damage in AP direction versus no motion mitigation; only gating reduced off-target damage in CC direction. In kidney, gating improved BH completeness in both directions versus no mitigation, but did not affect off-target damage due to lower displacement amplitudes in the kidney comparable with gating tolerance limits. In both liver and kidney, gating increased treatment time by 24%. These results suggest that BH pulse gating using US-based AP skin surface tracking is an adequate approach for treating organs with pronounced 3-D respiratory motion.
{"title":"Respiratory Motion Effects and Mitigation Strategies on Boiling Histotripsy in Porcine Liver and Kidney","authors":"Ekaterina M. Ponomarchuk;Gilles P. L. Thomas;Minho Song;Yak-Nam Wang;Stephanie Totten;George R. Schade;Vera A. Khokhlova;Tatiana D. Khokhlova","doi":"10.1109/TUFFC.2025.3559458","DOIUrl":"10.1109/TUFFC.2025.3559458","url":null,"abstract":"Boiling histotripsy (BH) is a pulsed high-intensity focused ultrasound (HIFU)-based method of extracorporeal nonthermal tissue disintegration under real-time ultrasound (US) guidance. Respiratory motion in abdominal targets can affect BH precision and completeness. This study compares two motion mitigation strategies based on pulse/echo US motion tracking: robotic arm-based unidirectional motion compensation by HIFU transducer manipulation and BH pulse gating during expiratory pause. BH ablations were generated in the liver and kidney of anesthetized pigs with 2–10-ms pulses using a 256-element 1.5-MHz HIFU array. A coaxial US imaging probe was used for targeting, tracking skin surface, and monitoring real-time bubble activity. The axial [anterior-posterior (AP)] displacement of the skin surface was found to be synchronous with liver and kidney motion in both cranio-caudal (CC) and AP directions. BH lesions were produced either with no motion mitigation, or with pulse gating, or with 1-D motion compensation. Dimensions of completely fractionated and affected tissue areas were measured histologically. In liver, gating and motion compensation improved fractionation completeness within targeted volumes and reduced off-target tissue damage in AP direction versus no motion mitigation; only gating reduced off-target damage in CC direction. In kidney, gating improved BH completeness in both directions versus no mitigation, but did not affect off-target damage due to lower displacement amplitudes in the kidney comparable with gating tolerance limits. In both liver and kidney, gating increased treatment time by 24%. These results suggest that BH pulse gating using US-based AP skin surface tracking is an adequate approach for treating organs with pronounced 3-D respiratory motion.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"837-846"},"PeriodicalIF":3.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143963274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-09DOI: 10.1109/TUFFC.2025.3559238
Yang Liu;Yongchao Wang;Pakpong Chirarattananon;Jianbo Tang
Directional filtering has been applied to distinguish between the ascending and descending flows in functional ultrasound imaging; however, it can lead to incorrect measurement of the flow speed and direction when using the directional filtering-based improved directional color Doppler ultrasound (iCD_US) velocimetry. Specifically, in cases where the frequency spectrum bandwidth of a unidirectional flow extends into both negative and positive frequency domains, directional filtering may erroneously produce bidirectional velocities. Here, we propose an adaptive color Doppler ultrasound (aCD_US) technique, which addresses this issue by analyzing the envelope of the Doppler spectrum and then adaptively using the whole spectrum integration or directional filtering-based approach to estimate the flow velocity. The proposed aCD_US was validated through numerical simulations and phantom experiments under various flow conditions, demonstrating superior performance in estimating axial velocities of unidirectional, bidirectional, and horizontal flows. Notably, numerical simulations showed that aCD_US achieved over 90% directional accuracy and less than 15% velocity deviation at signal-to-noise ratios (SNRs) larger than −1 dB. In vivo, experiments on mouse cerebral blood flow further highlighted its advantages, with aCD_US surpassing conventional color Doppler velocimetry and iCD_US in reconstructing axial flow velocity maps. The quantitative comparison between aCD_US and vULM shows a strong overall correlation in their axial velocity measurements, with a Pearson correlation coefficient of 0.760 (${p} =0.000$ ). These results demonstrate the advantage of aCD_US in precise microvessel network velocity quantification and its potential to advance microvascular imaging accuracy in both research and clinical applications.
{"title":"Adaptive Color Doppler for Axial Velocity Imaging of Microvessel Networks","authors":"Yang Liu;Yongchao Wang;Pakpong Chirarattananon;Jianbo Tang","doi":"10.1109/TUFFC.2025.3559238","DOIUrl":"10.1109/TUFFC.2025.3559238","url":null,"abstract":"Directional filtering has been applied to distinguish between the ascending and descending flows in functional ultrasound imaging; however, it can lead to incorrect measurement of the flow speed and direction when using the directional filtering-based improved directional color Doppler ultrasound (iCD_US) velocimetry. Specifically, in cases where the frequency spectrum bandwidth of a unidirectional flow extends into both negative and positive frequency domains, directional filtering may erroneously produce bidirectional velocities. Here, we propose an adaptive color Doppler ultrasound (aCD_US) technique, which addresses this issue by analyzing the envelope of the Doppler spectrum and then adaptively using the whole spectrum integration or directional filtering-based approach to estimate the flow velocity. The proposed aCD_US was validated through numerical simulations and phantom experiments under various flow conditions, demonstrating superior performance in estimating axial velocities of unidirectional, bidirectional, and horizontal flows. Notably, numerical simulations showed that aCD_US achieved over 90% directional accuracy and less than 15% velocity deviation at signal-to-noise ratios (SNRs) larger than −1 dB. In vivo, experiments on mouse cerebral blood flow further highlighted its advantages, with aCD_US surpassing conventional color Doppler velocimetry and iCD_US in reconstructing axial flow velocity maps. The quantitative comparison between aCD_US and vULM shows a strong overall correlation in their axial velocity measurements, with a Pearson correlation coefficient of 0.760 (<inline-formula> <tex-math>${p} =0.000$ </tex-math></inline-formula>). These results demonstrate the advantage of aCD_US in precise microvessel network velocity quantification and its potential to advance microvascular imaging accuracy in both research and clinical applications.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"709-720"},"PeriodicalIF":3.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143994327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-04DOI: 10.1109/TUFFC.2025.3558017
Xin Yan;Xiaodong Yang;Lingling Jing;Wei Guo;Yingqi Wang;Xinwei Su;Yuanyuan Wang
Enhancing the resolution and contrast of ultrafast ultrasound imaging is imperative for the accuracy of clinical diagnostics. Null subtraction imaging (NSI) is a nonlinear beamforming technique capable of significantly enhancing lateral resolution. However, it suffers from issues of low-quality speckle pattern and poor contrast performance. To address this issue, we propose a novel contrast-enhanced NSI method that utilizes dynamic dc bias. Innovatively, we construct the dynamic dc bias using a generalized coherence factor (GCF) and a sigmoid transformation function that adapts the dc value based on the signal characteristics of different imaging regions. Furthermore, a normalization scheme is proposed to optimize the beamforming output, ensuring uniform pixel intensity throughout the final image. Simulation, phantom, and in vivo data are utilized for ultrasound beamforming to evaluate the performance of the proposed method. Quantitative results show that the proposed method significantly enhances the contrast ratio (CR) by 197%, the contrast-to-noise ratio (CNR) by 341%, the speckle signal-to-noise ratio (sSNR) by 302%, and the generalized CNR (gCNR) by 106% compared to the original NSI (in phantom). Point target imaging results indicate that the proposed method achieves a main lobe width slightly wider than the original NSI method, but much narrower than those of delay and sum (DAS) and GCF. These findings confirm that the proposed method significantly enhances imaging contrast while preserving high resolution, which is of great significance for the further clinical application of ultrafast ultrasound imaging.
{"title":"A Contrast-Enhanced Null Subtraction Imaging Method Using Dynamic DC Bias in Ultrafast Ultrasound Imaging","authors":"Xin Yan;Xiaodong Yang;Lingling Jing;Wei Guo;Yingqi Wang;Xinwei Su;Yuanyuan Wang","doi":"10.1109/TUFFC.2025.3558017","DOIUrl":"10.1109/TUFFC.2025.3558017","url":null,"abstract":"Enhancing the resolution and contrast of ultrafast ultrasound imaging is imperative for the accuracy of clinical diagnostics. Null subtraction imaging (NSI) is a nonlinear beamforming technique capable of significantly enhancing lateral resolution. However, it suffers from issues of low-quality speckle pattern and poor contrast performance. To address this issue, we propose a novel contrast-enhanced NSI method that utilizes dynamic dc bias. Innovatively, we construct the dynamic dc bias using a generalized coherence factor (GCF) and a sigmoid transformation function that adapts the dc value based on the signal characteristics of different imaging regions. Furthermore, a normalization scheme is proposed to optimize the beamforming output, ensuring uniform pixel intensity throughout the final image. Simulation, phantom, and in vivo data are utilized for ultrasound beamforming to evaluate the performance of the proposed method. Quantitative results show that the proposed method significantly enhances the contrast ratio (CR) by 197%, the contrast-to-noise ratio (CNR) by 341%, the speckle signal-to-noise ratio (sSNR) by 302%, and the generalized CNR (gCNR) by 106% compared to the original NSI (in phantom). Point target imaging results indicate that the proposed method achieves a main lobe width slightly wider than the original NSI method, but much narrower than those of delay and sum (DAS) and GCF. These findings confirm that the proposed method significantly enhances imaging contrast while preserving high resolution, which is of great significance for the further clinical application of ultrafast ultrasound imaging.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"755-771"},"PeriodicalIF":3.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143784458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-04DOI: 10.1109/TUFFC.2025.3557374
Yuyang Hu;Didem Dogan;Michael Brown;Geert Leus;Antonius F. W. van der Steen;Pieter Kruizinga;Johannes G. Bosch
Ultrasonography could allow operator-independent examination and continuous monitoring of the carotid artery (CA) but normally requires complex and expensive transducers, especially for 3-D. By employing computational ultrasound imaging (cUSi), using an aberration mask and model-based reconstruction, a monitoring device could be constructed with a more affordable simple transducer design comprising only a few elements. We aim to apply the cUSi concept to create a CA monitoring system. The system’s possible configurations for the 2-D imaging case were explored using a linear array setup emulating a cUSi device in silico, followed by in vitro testing and in vivo CA imaging. Our study shows enhanced reconstruction performance with the use of an aberrating mask, improved lateral resolution through proper choice of the mask delay variation, and more accurate reconstructions using least-squares with QR (LSQR) decomposition compared to matched filtering (MF). Together, these advancements enable B-mode reconstruction and power Doppler imaging (PDI) of the CA with sufficient quality for monitoring using a configuration of 12 transceivers coupled with a random aberration mask with a maximum delay variation of four wave periods (WPs).
{"title":"Computational Ultrasound Carotid Artery Imaging With a Few Transceivers: An Emulation Study","authors":"Yuyang Hu;Didem Dogan;Michael Brown;Geert Leus;Antonius F. W. van der Steen;Pieter Kruizinga;Johannes G. Bosch","doi":"10.1109/TUFFC.2025.3557374","DOIUrl":"10.1109/TUFFC.2025.3557374","url":null,"abstract":"Ultrasonography could allow operator-independent examination and continuous monitoring of the carotid artery (CA) but normally requires complex and expensive transducers, especially for 3-D. By employing computational ultrasound imaging (cUSi), using an aberration mask and model-based reconstruction, a monitoring device could be constructed with a more affordable simple transducer design comprising only a few elements. We aim to apply the cUSi concept to create a CA monitoring system. The system’s possible configurations for the 2-D imaging case were explored using a linear array setup emulating a cUSi device in silico, followed by in vitro testing and in vivo CA imaging. Our study shows enhanced reconstruction performance with the use of an aberrating mask, improved lateral resolution through proper choice of the mask delay variation, and more accurate reconstructions using least-squares with QR (LSQR) decomposition compared to matched filtering (MF). Together, these advancements enable B-mode reconstruction and power Doppler imaging (PDI) of the CA with sufficient quality for monitoring using a configuration of 12 transceivers coupled with a random aberration mask with a maximum delay variation of four wave periods (WPs).","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"721-731"},"PeriodicalIF":3.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143784461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-03DOI: 10.1109/TUFFC.2025.3556030
Vishwas V. Trivedi;Katia Flores Basterrechea;Kenneth B. Bader;Himanshu Shekhar
Histotripsy is a noninvasive focused ultrasound therapy that liquifies tissue via bubble activity. Conventional ultrasound imaging is used in current clinical practice to monitor histotripsy. Developing surrogate imaging metrics for successful treatment outcomes remains an unmet clinical need. The goal of this work was twofold. First, we investigated whether histotripsy bubble clouds detected with nonlinear imaging (chirp-coded subharmonic imaging with and without Volterra filtering) could be used to assess the ablation zone in vitro. Second, we evaluated the feasibility of improving bubble cloud contrast with this approach in ex vivo porcine kidney. Histotripsy bubble clouds were generated in red blood cell-doped agarose phantoms and imaged with a curvilinear ultrasound probe. The ablation zone was assessed based on images collected with a digital camera. The relationship between the bubble cloud area and the ablation area was assessed using receiver operating characteristic (ROC) analysis, F1 score, accuracy, and Matthews correlation coefficient. Histotripsy bubble clouds were also generated in ex vivo porcine tissue and the ability to improve bubble cloud contrast to tissue was evaluated. Implementing chirp-coded subharmonic imaging with the third-order Volterra filter enhanced contrast-to-tissue ratio (CTR) by up to $40.06~pm ~0.70$ dB relative to standard imaging in vitro. Furthermore, subharmonic imaging combined with Volterra filtering estimated bubble cloud areas that best matched the ablation zone area based on the analysis metrics. Furthermore, ex vivo studies showed CTR improvement of up to $26.95~pm ~6.49$ dB. Taken together, these findings advance image guidance and monitoring approaches for histotripsy.
组织活检是一种非侵入性聚焦超声治疗，通过气泡活动液化组织。常规超声成像在目前的临床实践中用于监测组织切片。开发替代成像指标的成功治疗结果仍然是一个未满足的临床需求。这项工作的目标是双重的。首先，我们研究了用非线性成像（带或不带Volterra滤波的啁啾编码次谐波成像）检测到的组织层状气泡云是否可以用于体外评估消融区。其次，我们评估了这种方法在离体猪肾脏中改善气泡云对比的可行性。在红细胞掺杂琼脂糖的幻影中产生了组织分层的气泡云，并用曲线超声探头成像。根据数码相机采集的图像对消融区进行评估。利用受者工作特征分析、f1评分和Intersection over Union评分评估气泡云面积与消融面积的关系。在离体猪组织中也产生了组织分层气泡云，并评估了改善气泡云与组织对比度的能力。与体外标准成像相比，使用三阶Volterra滤波器实现啁啾编码次谐波成像可使组织对比度提高40.06±0.70 dB。此外，亚谐波成像结合Volterra滤波，根据分析指标估计出与烧蚀区最匹配的气泡云区域。此外，离体研究表明，组织比提高高达26.95±6.49 dB。综上所述，这些发现促进了组织切片术的图像引导和监测方法。
{"title":"Chirp-Coded Subharmonic Imaging With Volterra Filtering: Histotripsy Bubble Cloud Assessment In Vitro and Ex Vivo","authors":"Vishwas V. Trivedi;Katia Flores Basterrechea;Kenneth B. Bader;Himanshu Shekhar","doi":"10.1109/TUFFC.2025.3556030","DOIUrl":"10.1109/TUFFC.2025.3556030","url":null,"abstract":"Histotripsy is a noninvasive focused ultrasound therapy that liquifies tissue via bubble activity. Conventional ultrasound imaging is used in current clinical practice to monitor histotripsy. Developing surrogate imaging metrics for successful treatment outcomes remains an unmet clinical need. The goal of this work was twofold. First, we investigated whether histotripsy bubble clouds detected with nonlinear imaging (chirp-coded subharmonic imaging with and without Volterra filtering) could be used to assess the ablation zone in vitro. Second, we evaluated the feasibility of improving bubble cloud contrast with this approach in ex vivo porcine kidney. Histotripsy bubble clouds were generated in red blood cell-doped agarose phantoms and imaged with a curvilinear ultrasound probe. The ablation zone was assessed based on images collected with a digital camera. The relationship between the bubble cloud area and the ablation area was assessed using receiver operating characteristic (ROC) analysis, F1 score, accuracy, and Matthews correlation coefficient. Histotripsy bubble clouds were also generated in ex vivo porcine tissue and the ability to improve bubble cloud contrast to tissue was evaluated. Implementing chirp-coded subharmonic imaging with the third-order Volterra filter enhanced contrast-to-tissue ratio (CTR) by up to <inline-formula> <tex-math>$40.06~pm ~0.70$ </tex-math></inline-formula> dB relative to standard imaging in vitro. Furthermore, subharmonic imaging combined with Volterra filtering estimated bubble cloud areas that best matched the ablation zone area based on the analysis metrics. Furthermore, ex vivo studies showed CTR improvement of up to <inline-formula> <tex-math>$26.95~pm ~6.49$ </tex-math></inline-formula> dB. Taken together, these findings advance image guidance and monitoring approaches for histotripsy.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 5","pages":"591-600"},"PeriodicalIF":3.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-03DOI: 10.1109/TUFFC.2025.3557519
Xiaochuan Wu;Wei-Ning Lee
Matrix arrays with small apertures limit spatial and contrast resolutions of volumetric ultrasound imaging. Coherence-based beamformers are prevalent for sidelobe suppression and resolution improvement. While the spatial coherence of a matrix array is fundamentally a 2-D function, conventional coherence factor (CF) methods neglect the directional variation of an ${M} times {N}$ matrix array when calculating volumetric coherence. We hereby propose a projection-based directional CF (DCF) to exploit the 2-D nature of volumetric coherence function. Instead of computing the coherent and incoherent summations across the entire 2-D aperture, DCF projects aperture data onto azimuthal, elevational, diagonal, and anti-diagonal directions and subsequently calculates the CFs for each direction separately. The orthogonal coherence pairs, i.e., azimuth and elevation, and diagonal and anti-diagonal, are multiplied to obtain DCFRC and DCFDiag, respectively. The Jaccard similarity of DCFRC and DCFDiag is used to derive the final DCF to weigh the reconstructed images. We evaluated the performance of DCF beamforming in point-target simulations, multipurpose phantom experiments, and in vivo muscle imaging and compared it to delay-and-sum (DAS) and CF beamformers. Our DCF achieved sidelobe reduction throughout the entire volume compared to conventional CF. Moreover, diagonal weighting significantly improved, on average, the azimuthal resolution by 41.3% versus DAS and 7.35% versus CF as well as the elevational resolution by 40.4% versus DAS and 38.7% versus CF. Our proposed DCF offers a practical solution for resolution and contrast enhancement of volumetric imaging in 2-D matrix array configurations.
{"title":"Directional Coherence Factor for Volumetric Ultrasound Imaging With Matrix Arrays","authors":"Xiaochuan Wu;Wei-Ning Lee","doi":"10.1109/TUFFC.2025.3557519","DOIUrl":"10.1109/TUFFC.2025.3557519","url":null,"abstract":"Matrix arrays with small apertures limit spatial and contrast resolutions of volumetric ultrasound imaging. Coherence-based beamformers are prevalent for sidelobe suppression and resolution improvement. While the spatial coherence of a matrix array is fundamentally a 2-D function, conventional coherence factor (CF) methods neglect the directional variation of an <inline-formula> <tex-math>${M} times {N}$ </tex-math></inline-formula> matrix array when calculating volumetric coherence. We hereby propose a projection-based directional CF (DCF) to exploit the 2-D nature of volumetric coherence function. Instead of computing the coherent and incoherent summations across the entire 2-D aperture, DCF projects aperture data onto azimuthal, elevational, diagonal, and anti-diagonal directions and subsequently calculates the CFs for each direction separately. The orthogonal coherence pairs, i.e., azimuth and elevation, and diagonal and anti-diagonal, are multiplied to obtain DCFRC and DCFDiag, respectively. The Jaccard similarity of DCFRC and DCFDiag is used to derive the final DCF to weigh the reconstructed images. We evaluated the performance of DCF beamforming in point-target simulations, multipurpose phantom experiments, and in vivo muscle imaging and compared it to delay-and-sum (DAS) and CF beamformers. Our DCF achieved sidelobe reduction throughout the entire volume compared to conventional CF. Moreover, diagonal weighting significantly improved, on average, the azimuthal resolution by 41.3% versus DAS and 7.35% versus CF as well as the elevational resolution by 40.4% versus DAS and 38.7% versus CF. Our proposed DCF offers a practical solution for resolution and contrast enhancement of volumetric imaging in 2-D matrix array configurations.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"817-827"},"PeriodicalIF":3.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-31DOI: 10.1109/TUFFC.2025.3556305
Ugur Guneroglu;Adnan Zaman;Abdulrahman Alsolami;Ivan F. Rivera;Jing Wang
This article deliberately explores the frequency trimming and performance enhancement of piezoelectric MEMS resonators through localized annealing induced by Joule heating. Targeting the effective postfabrication treatment of thin-film piezoelectric-on-silicon (TPoS) resonators, we employ a novel annealing approach that modifies the silicon resonator body-bottom electrode interface to enable meticulous resonance frequency trimming and enhanced overall performance. By applying a controlled dc current directly through the resonator’s body, precise resonance frequency shifts on the order of 0.1%–0.4% and significant increase in quality factor, from 981 to 2155, from 8214 to 9362, have been realized for rectangular-plate and disk-shaped resonators, respectively. Furthermore, this localized annealing process reduces the motional impedance from 3.43 to 1.65 k$Omega $ for a rectangular-plate resonator and from 1.79 to 1.58 k$Omega $ for a disk-shaped resonator, thus demonstrating its viability as a postfabrication treatment technique for a wide variety of MEMS devices. These results highlight the great potential of Joule heating-induced localized annealing in advancing RF systems that demand high precision, reliable filtering, and stable timing functions. This work provides new insights into the thermal annealing effects on MEMS resonators and lays a foundation for future innovations in related microsystem technologies.
{"title":"Study of Frequency Trimming Ability and Performance Enhancement of Thin-Film Piezoelectric-on-Silicon MEMS Resonators by Joule Heating via Localized Annealing","authors":"Ugur Guneroglu;Adnan Zaman;Abdulrahman Alsolami;Ivan F. Rivera;Jing Wang","doi":"10.1109/TUFFC.2025.3556305","DOIUrl":"10.1109/TUFFC.2025.3556305","url":null,"abstract":"This article deliberately explores the frequency trimming and performance enhancement of piezoelectric MEMS resonators through localized annealing induced by Joule heating. Targeting the effective postfabrication treatment of thin-film piezoelectric-on-silicon (TPoS) resonators, we employ a novel annealing approach that modifies the silicon resonator body-bottom electrode interface to enable meticulous resonance frequency trimming and enhanced overall performance. By applying a controlled dc current directly through the resonator’s body, precise resonance frequency shifts on the order of 0.1%–0.4% and significant increase in quality factor, from 981 to 2155, from 8214 to 9362, have been realized for rectangular-plate and disk-shaped resonators, respectively. Furthermore, this localized annealing process reduces the motional impedance from 3.43 to 1.65 k<inline-formula> <tex-math>$Omega $ </tex-math></inline-formula> for a rectangular-plate resonator and from 1.79 to 1.58 k<inline-formula> <tex-math>$Omega $ </tex-math></inline-formula> for a disk-shaped resonator, thus demonstrating its viability as a postfabrication treatment technique for a wide variety of MEMS devices. These results highlight the great potential of Joule heating-induced localized annealing in advancing RF systems that demand high precision, reliable filtering, and stable timing functions. This work provides new insights into the thermal annealing effects on MEMS resonators and lays a foundation for future innovations in related microsystem technologies.","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 5","pages":"686-696"},"PeriodicalIF":3.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143763606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-29DOI: 10.1109/TUFFC.2025.3569143
{"title":"IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control Publication Information","authors":"","doi":"10.1109/TUFFC.2025.3569143","DOIUrl":"https://doi.org/10.1109/TUFFC.2025.3569143","url":null,"abstract":"","PeriodicalId":13322,"journal":{"name":"IEEE transactions on ultrasonics, ferroelectrics, and frequency control","volume":"72 6","pages":"C2-C2"},"PeriodicalIF":3.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11018085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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