Edward Zhang - Academia.edu (original) (raw)

Papers by Edward Zhang

Research paper thumbnail of Author Correction: Non-invasive multimodal optical coherence and photoacoustic tomography for human skin imaging

Scientific reports, Jan 30, 2018

A correction to this article has been published and is linked from the HTML and PDF versions of t... more A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Research paper thumbnail of Acoustic Wave Field Reconstruction from Compressed Measurements with Application in Photoacoustic Tomography

IEEE Transactions on Computational Imaging

We present a method for the recovery of compressively sensed acoustic fields using patterned, ins... more We present a method for the recovery of compressively sensed acoustic fields using patterned, instead of pointby-point, detection. From a limited number of such compressed measurements, we propose to reconstruct the field on the sensor plane in each time step independently assuming its sparsity in a Curvelet frame. A modification of the Curvelet frame is proposed to account for the smoothing effects of data acquisition and motivated by a frequency domain model for photoacoustic tomography. An ADMM type algorithm, SALSA, is used to recover the pointwise data in each individual time step from the patterned measurements. For photoacoustic applications, the photoacoustic image of the initial pressure is reconstructed using time reversal in k-Wave Toolbox.

Research paper thumbnail of Characteristics of optimized fibre-optic ultrasound receivers for minimally invasive photoacoustic detection

Photons Plus Ultrasound: Imaging and Sensing 2015

Research paper thumbnail of Frequency response and directivity of highly sensitive optical microresonator detectors for photoacoustic imaging

Photons Plus Ultrasound: Imaging and Sensing 2015

Research paper thumbnail of 2D photoacoustic mapping system using a scanned focused spot to address a Fabry Perot polymer film ultrasound sensor

Photons Plus Ultrasound: Imaging and Sensing 2005: The Sixth Conference on Biomedical Thermoacoustics, Optoacoustics, and Acousto-optics

ABSTRACT

Research paper thumbnail of Photoacoustic pump-probe tomography of fluorophores in vivo using interleaved image acquisition for motion suppression

Scientific reports, Jan 16, 2017

In fluorophores, the excited state lifetime can be modulated using pump-probe excitation. By gene... more In fluorophores, the excited state lifetime can be modulated using pump-probe excitation. By generating photoacoustic (PA) signals using simultaneous and time-delayed pump and probe excitation pulses at fluences below the maximum permissible exposure, a modulation of the signal amplitude is observed in fluorophores but not in endogenous chromophores. This provides a highly specific contrast mechanism that can be used to recover the location of the fluorophore using difference imaging. The practical challenges in applying this method to in vivo PA tomography include the typically low concentrations of fluorescent contrast agents, and tissue motion. The former results in smaller PA signal amplitudes compared to those measured in blood, while the latter gives rise to difference image artefacts that compromise the unambiguous and potentially noise-limited detection of fluorescent contrast agents. To address this limitation, a method based on interleaved pump-probe image acquisition was ...

Research paper thumbnail of 3D photoacoustic imaging system for in vivo studies of small animal models - art. no. 68560P

Progress in Biomedical Optics and Imaging Proceedings of Spie 6856, 2008

A 3D photoacoustic (PA) imaging system has been developed for the non-invasive, in vivo character... more A 3D photoacoustic (PA) imaging system has been developed for the non-invasive, in vivo characterization of small animal models of human disease processes. The system utilizes a Fabry Perot polymer film sensing interferometer (FPI) for mapping the spatial-temporal distribution of the PA signals in 2D enabling a 3D PA image to be reconstructed. The mirrors of the sensing FPI are

Research paper thumbnail of Determination of Differential Tumour Vascular Pathophysiology in Vivo by Photoacoustic Imaging

European Journal of Cancer

Research paper thumbnail of <title>A miniature all-optical photoacoustic imaging probe</title>

Photons Plus Ultrasound: Imaging and Sensing 2011, 2011

A miniature (250 µm outer diameter) photoacoustic probe for endoscopic applications has been deve... more A miniature (250 µm outer diameter) photoacoustic probe for endoscopic applications has been developed. It comprises a single delivery optical fibre with a transparent Fabry Perot (FP) ultrasound sensor at its distal end. The fabrication of the sensor was achieved by depositing a thin film multilayer structure comprising a polymer spacer sandwiched between a pair of dichroic dielectric mirrors on to the tip of a single mode fiber. The probe was evaluated in terms of its acoustic bandwidth and sensitivity. Ultra high acoustic sensitivity has been achieved with a concave FP interferometer cavity design, which effectively suppresses the phase dispersion of multiple reflected beam within the cavity to achieve high finesse. The noise equivalent noise (NEP) achieved is 8 Pa over a 20 MHz bandwidth. Backward mode operation of the probe is demonstrated by detecting photoacoustic signals in a variety of phantoms designed to simulate endoscopic applications. A side-viewing probe is also demonstrated illustrating an all-optical design for intravascular imaging applications.

Research paper thumbnail of A study towards optimal data layout for GPU computing

Proceedings of the 2012 ACM SIGPLAN Workshop on Memory Systems Performance and Correctness - MSPC '12, 2012

ABSTRACT The performance of Graphic Processing Units (GPU) is sensitive to irregular memory refer... more ABSTRACT The performance of Graphic Processing Units (GPU) is sensitive to irregular memory references. A recent study shows the promise of eliminating irregular references through runtime thread-data remapping. However, how to efficiently determine the optimal mapping is yet an open question. This paper presents some initial exploration to the question, especially in the dimension of data layout optimization. It describes three algorithms to compute or approximate optimal data layouts for GPU. These algorithms exhibit a spectrum of tradeoff among the space cost, time cost, and quality of the resulting data layouts.

Research paper thumbnail of Broadband miniature optical ultrasound probe for high resolution vascular tissue imaging

Biomedical Optics Express, 2015

An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generat... more An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generated by pulsed laser illumination of a functionalized carbon nanotube composite coating on the end face of an optical fiber. Ultrasound was detected with a Fabry-Pérot (FP) cavity on the end face of an adjacent optical fiber. The probe diameter was < 0.84 mm and had an ultrasound bandwidth of ~20 MHz. The probe was translated across the tissue sample to create a virtual linear array of ultrasound transmit/receive elements. At a depth of 3.5 mm, the axial resolution was 64 µm and the lateral resolution was 88 µm, as measured with a carbon fiber target. Vascular tissues from swine were imaged ex vivo and good correspondence to histology was observed.

Research paper thumbnail of Au(I)-Catalyzed Synthesis of Cycloalkene-Fused Pyrroles

Research paper thumbnail of <title>In vivo longitudinal photoacoustic imaging of subcutaneous tumours in mice</title>

Photons Plus Ultrasound: Imaging and Sensing 2011, 2011

Photoacoustic tomography can provide high resolution 3D images of vascular networks, making it we... more Photoacoustic tomography can provide high resolution 3D images of vascular networks, making it well suited to characterising the development of tumour vasculature and its response to treatment. In this study, photoacoustic images to depths of up to 9 mm were obtained using an all optical ultrasound detection scheme. Two type of colorectal tumours (LS174T and SW1222) implanted subcutaneously in a

Research paper thumbnail of <title>Transparent Fabry-Perot polymer film ultrasound array for backward-mode photoacoustic imaging</title>

Photons Plus Ultrasound: Imaging and Sensing, 2004

A novel optical ultrasound sensor has been developed for backward-mode photoacoustic imaging. The... more A novel optical ultrasound sensor has been developed for backward-mode photoacoustic imaging. The sensor is based on a Fabry Perot polymer film interferometer, the mirrors of which are transparent to 1064nm, but highly reflective at 850nm. When illuminated by a CW interrogating laser source at the latter wavelength, the system acts as a resonant Fabry Perot (FP) sensing cavity, the

Research paper thumbnail of Multimodal photoacoustic and optical coherence tomography scanner using an all optical detection scheme for 3D morphological skin imaging

Biomedical optics express, 2011

A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for th... more A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm(2). The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather tha...

Research paper thumbnail of Correlating voice handicap index and quantitative videostroboscopy following injection laryngoplasty for unilateral vocal paralysis

Otolaryngology - Head and Neck Surgery, 2010

OBJECTIVE: 1) Determine the correlation between voice handicap index and quantitative videostrobo... more OBJECTIVE: 1) Determine the correlation between voice handicap index and quantitative videostroboscopy for patients undergoing injection laryngoplasty for unilateral vocal paralysis; 2) assess which videostroboscopy measurements correlate best with voice handicap index in patients demonstrating progressive improvement beyond six months following injection laryngoplasty. STUDY DESIGN: Case series with chart review. SETTING: Patients undergoing outpatient injection laryngoplasty with hyaluronic acid between 2005 and 2007. SUBJECTS AND METHODS: Twenty-eight patients were assessed preoperatively and postoperatively using voice handicap index and videostroboscopy. Various videostroboscopy measurements were quantified: glottic open area (ratio of open to total glottic area during closed phase of phonation), glottic closed phase (frame ratio of closed phase to total glottic cycle), supraglottic compression (percent encroachment of supraglottis onto best-fit ellipse around glottis), wave am...

Research paper thumbnail of Low Power VLSI Design for a RFID Passive Tag baseband System Enhanced with an AES Cryptography Engine

2007 1st Annual RFID Eurasia, 2007

Page 1. Abstract— This paper describes a low power implementation of a secure EPC UHF Passive RFI... more Page 1. Abstract— This paper describes a low power implementation of a secure EPC UHF Passive RFID Tag baseband system. To ensure the secure information transaction of the tag, traditionally the focus is on directly applying a low-complexity encryption engine. ...

Research paper thumbnail of Design and Implementation of a Low-power Baseband-system for RFID Tag

2007 IEEE International Symposium on Circuits and Systems, 2007

Page 1. Abstract—this article describes a low power design approach for a UHF Passive RFID Tag ba... more Page 1. Abstract—this article describes a low power design approach for a UHF Passive RFID Tag baseband system. It proposes a new RFID Tag baseband architecture which is compatible with the EPC C1G2 UHF RFID protocol. ...

Research paper thumbnail of Ga-Assisted Synthesis and Optical Properties of ZnO Submicron- and Nanotowers

The Journal of Physical Chemistry B, 2006

Tower-like ZnO submicron- and nanostructures were synthesized by simply evaporating a mixture of ... more Tower-like ZnO submicron- and nanostructures were synthesized by simply evaporating a mixture of Zn and Ga. Scanning electron microscopy and transmission electron microscopy observations showed that the regular hexagonal tower-like structure is likely to be made up in a layer-by-layer fashion and consist of sheets. According to our experiments, the amount of Ga has a large effect on their morphologies. The growth of such tower-like structures is ascribed to the vapor-solid mechanism. The introduction of Ga hinders the growth of ZnO along the [0001] direction, resulting in the formation of the novel tower-like structures. In addition, the photoluminescence of such structures shows a strong green-light emission.

Research paper thumbnail of Correlating voice handicap index and videostroboscopy

Otolaryngology - Head and Neck Surgery, 2009

preoperative values) and VLS measurements were: GOAϭ0.465 (pϽ0.001), GCPϭϪ0.733 (pϽ0.001), SGCϭ0.... more preoperative values) and VLS measurements were: GOAϭ0.465 (pϽ0.001), GCPϭϪ0.733 (pϽ0.001), SGCϭ0.172 (pϭns), AMPϭ0.131 (pϭns), DURϭϪ0.404 (pϽ0.001). A subset of 25 recordings from 8 patients with progressive VHI improvement beyond 6 months showed highest correlation with SGC following IL (rϭ0.504, pϽ0.05). CONCLUSIONS: VHI correlates best with GCP, suggesting that duration of vocal-fold closure during the glottic cycle best represents patients subjective outcome following IL. Progressive improvement in VHI beyond six months in some patients may relate to gradual reduction in compensatory supraglottic compression, with moderate correlation.

Research paper thumbnail of Author Correction: Non-invasive multimodal optical coherence and photoacoustic tomography for human skin imaging

Scientific reports, Jan 30, 2018

A correction to this article has been published and is linked from the HTML and PDF versions of t... more A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Research paper thumbnail of Acoustic Wave Field Reconstruction from Compressed Measurements with Application in Photoacoustic Tomography

IEEE Transactions on Computational Imaging

We present a method for the recovery of compressively sensed acoustic fields using patterned, ins... more We present a method for the recovery of compressively sensed acoustic fields using patterned, instead of pointby-point, detection. From a limited number of such compressed measurements, we propose to reconstruct the field on the sensor plane in each time step independently assuming its sparsity in a Curvelet frame. A modification of the Curvelet frame is proposed to account for the smoothing effects of data acquisition and motivated by a frequency domain model for photoacoustic tomography. An ADMM type algorithm, SALSA, is used to recover the pointwise data in each individual time step from the patterned measurements. For photoacoustic applications, the photoacoustic image of the initial pressure is reconstructed using time reversal in k-Wave Toolbox.

Research paper thumbnail of Characteristics of optimized fibre-optic ultrasound receivers for minimally invasive photoacoustic detection

Photons Plus Ultrasound: Imaging and Sensing 2015

Research paper thumbnail of Frequency response and directivity of highly sensitive optical microresonator detectors for photoacoustic imaging

Photons Plus Ultrasound: Imaging and Sensing 2015

Research paper thumbnail of 2D photoacoustic mapping system using a scanned focused spot to address a Fabry Perot polymer film ultrasound sensor

Photons Plus Ultrasound: Imaging and Sensing 2005: The Sixth Conference on Biomedical Thermoacoustics, Optoacoustics, and Acousto-optics

ABSTRACT

Research paper thumbnail of Photoacoustic pump-probe tomography of fluorophores in vivo using interleaved image acquisition for motion suppression

Scientific reports, Jan 16, 2017

In fluorophores, the excited state lifetime can be modulated using pump-probe excitation. By gene... more In fluorophores, the excited state lifetime can be modulated using pump-probe excitation. By generating photoacoustic (PA) signals using simultaneous and time-delayed pump and probe excitation pulses at fluences below the maximum permissible exposure, a modulation of the signal amplitude is observed in fluorophores but not in endogenous chromophores. This provides a highly specific contrast mechanism that can be used to recover the location of the fluorophore using difference imaging. The practical challenges in applying this method to in vivo PA tomography include the typically low concentrations of fluorescent contrast agents, and tissue motion. The former results in smaller PA signal amplitudes compared to those measured in blood, while the latter gives rise to difference image artefacts that compromise the unambiguous and potentially noise-limited detection of fluorescent contrast agents. To address this limitation, a method based on interleaved pump-probe image acquisition was ...

Research paper thumbnail of 3D photoacoustic imaging system for in vivo studies of small animal models - art. no. 68560P

Progress in Biomedical Optics and Imaging Proceedings of Spie 6856, 2008

A 3D photoacoustic (PA) imaging system has been developed for the non-invasive, in vivo character... more A 3D photoacoustic (PA) imaging system has been developed for the non-invasive, in vivo characterization of small animal models of human disease processes. The system utilizes a Fabry Perot polymer film sensing interferometer (FPI) for mapping the spatial-temporal distribution of the PA signals in 2D enabling a 3D PA image to be reconstructed. The mirrors of the sensing FPI are

Research paper thumbnail of Determination of Differential Tumour Vascular Pathophysiology in Vivo by Photoacoustic Imaging

European Journal of Cancer

Research paper thumbnail of <title>A miniature all-optical photoacoustic imaging probe</title>

Photons Plus Ultrasound: Imaging and Sensing 2011, 2011

A miniature (250 µm outer diameter) photoacoustic probe for endoscopic applications has been deve... more A miniature (250 µm outer diameter) photoacoustic probe for endoscopic applications has been developed. It comprises a single delivery optical fibre with a transparent Fabry Perot (FP) ultrasound sensor at its distal end. The fabrication of the sensor was achieved by depositing a thin film multilayer structure comprising a polymer spacer sandwiched between a pair of dichroic dielectric mirrors on to the tip of a single mode fiber. The probe was evaluated in terms of its acoustic bandwidth and sensitivity. Ultra high acoustic sensitivity has been achieved with a concave FP interferometer cavity design, which effectively suppresses the phase dispersion of multiple reflected beam within the cavity to achieve high finesse. The noise equivalent noise (NEP) achieved is 8 Pa over a 20 MHz bandwidth. Backward mode operation of the probe is demonstrated by detecting photoacoustic signals in a variety of phantoms designed to simulate endoscopic applications. A side-viewing probe is also demonstrated illustrating an all-optical design for intravascular imaging applications.

Research paper thumbnail of A study towards optimal data layout for GPU computing

Proceedings of the 2012 ACM SIGPLAN Workshop on Memory Systems Performance and Correctness - MSPC '12, 2012

ABSTRACT The performance of Graphic Processing Units (GPU) is sensitive to irregular memory refer... more ABSTRACT The performance of Graphic Processing Units (GPU) is sensitive to irregular memory references. A recent study shows the promise of eliminating irregular references through runtime thread-data remapping. However, how to efficiently determine the optimal mapping is yet an open question. This paper presents some initial exploration to the question, especially in the dimension of data layout optimization. It describes three algorithms to compute or approximate optimal data layouts for GPU. These algorithms exhibit a spectrum of tradeoff among the space cost, time cost, and quality of the resulting data layouts.

Research paper thumbnail of Broadband miniature optical ultrasound probe for high resolution vascular tissue imaging

Biomedical Optics Express, 2015

An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generat... more An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generated by pulsed laser illumination of a functionalized carbon nanotube composite coating on the end face of an optical fiber. Ultrasound was detected with a Fabry-Pérot (FP) cavity on the end face of an adjacent optical fiber. The probe diameter was < 0.84 mm and had an ultrasound bandwidth of ~20 MHz. The probe was translated across the tissue sample to create a virtual linear array of ultrasound transmit/receive elements. At a depth of 3.5 mm, the axial resolution was 64 µm and the lateral resolution was 88 µm, as measured with a carbon fiber target. Vascular tissues from swine were imaged ex vivo and good correspondence to histology was observed.

Research paper thumbnail of Au(I)-Catalyzed Synthesis of Cycloalkene-Fused Pyrroles

Research paper thumbnail of <title>In vivo longitudinal photoacoustic imaging of subcutaneous tumours in mice</title>

Photons Plus Ultrasound: Imaging and Sensing 2011, 2011

Photoacoustic tomography can provide high resolution 3D images of vascular networks, making it we... more Photoacoustic tomography can provide high resolution 3D images of vascular networks, making it well suited to characterising the development of tumour vasculature and its response to treatment. In this study, photoacoustic images to depths of up to 9 mm were obtained using an all optical ultrasound detection scheme. Two type of colorectal tumours (LS174T and SW1222) implanted subcutaneously in a

Research paper thumbnail of <title>Transparent Fabry-Perot polymer film ultrasound array for backward-mode photoacoustic imaging</title>

Photons Plus Ultrasound: Imaging and Sensing, 2004

A novel optical ultrasound sensor has been developed for backward-mode photoacoustic imaging. The... more A novel optical ultrasound sensor has been developed for backward-mode photoacoustic imaging. The sensor is based on a Fabry Perot polymer film interferometer, the mirrors of which are transparent to 1064nm, but highly reflective at 850nm. When illuminated by a CW interrogating laser source at the latter wavelength, the system acts as a resonant Fabry Perot (FP) sensing cavity, the

Research paper thumbnail of Multimodal photoacoustic and optical coherence tomography scanner using an all optical detection scheme for 3D morphological skin imaging

Biomedical optics express, 2011

A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for th... more A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm(2). The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather tha...

Research paper thumbnail of Correlating voice handicap index and quantitative videostroboscopy following injection laryngoplasty for unilateral vocal paralysis

Otolaryngology - Head and Neck Surgery, 2010

OBJECTIVE: 1) Determine the correlation between voice handicap index and quantitative videostrobo... more OBJECTIVE: 1) Determine the correlation between voice handicap index and quantitative videostroboscopy for patients undergoing injection laryngoplasty for unilateral vocal paralysis; 2) assess which videostroboscopy measurements correlate best with voice handicap index in patients demonstrating progressive improvement beyond six months following injection laryngoplasty. STUDY DESIGN: Case series with chart review. SETTING: Patients undergoing outpatient injection laryngoplasty with hyaluronic acid between 2005 and 2007. SUBJECTS AND METHODS: Twenty-eight patients were assessed preoperatively and postoperatively using voice handicap index and videostroboscopy. Various videostroboscopy measurements were quantified: glottic open area (ratio of open to total glottic area during closed phase of phonation), glottic closed phase (frame ratio of closed phase to total glottic cycle), supraglottic compression (percent encroachment of supraglottis onto best-fit ellipse around glottis), wave am...

Research paper thumbnail of Low Power VLSI Design for a RFID Passive Tag baseband System Enhanced with an AES Cryptography Engine

2007 1st Annual RFID Eurasia, 2007

Page 1. Abstract— This paper describes a low power implementation of a secure EPC UHF Passive RFI... more Page 1. Abstract— This paper describes a low power implementation of a secure EPC UHF Passive RFID Tag baseband system. To ensure the secure information transaction of the tag, traditionally the focus is on directly applying a low-complexity encryption engine. ...

Research paper thumbnail of Design and Implementation of a Low-power Baseband-system for RFID Tag

2007 IEEE International Symposium on Circuits and Systems, 2007

Page 1. Abstract—this article describes a low power design approach for a UHF Passive RFID Tag ba... more Page 1. Abstract—this article describes a low power design approach for a UHF Passive RFID Tag baseband system. It proposes a new RFID Tag baseband architecture which is compatible with the EPC C1G2 UHF RFID protocol. ...

Research paper thumbnail of Ga-Assisted Synthesis and Optical Properties of ZnO Submicron- and Nanotowers

The Journal of Physical Chemistry B, 2006

Tower-like ZnO submicron- and nanostructures were synthesized by simply evaporating a mixture of ... more Tower-like ZnO submicron- and nanostructures were synthesized by simply evaporating a mixture of Zn and Ga. Scanning electron microscopy and transmission electron microscopy observations showed that the regular hexagonal tower-like structure is likely to be made up in a layer-by-layer fashion and consist of sheets. According to our experiments, the amount of Ga has a large effect on their morphologies. The growth of such tower-like structures is ascribed to the vapor-solid mechanism. The introduction of Ga hinders the growth of ZnO along the [0001] direction, resulting in the formation of the novel tower-like structures. In addition, the photoluminescence of such structures shows a strong green-light emission.

Research paper thumbnail of Correlating voice handicap index and videostroboscopy

Otolaryngology - Head and Neck Surgery, 2009

preoperative values) and VLS measurements were: GOAϭ0.465 (pϽ0.001), GCPϭϪ0.733 (pϽ0.001), SGCϭ0.... more preoperative values) and VLS measurements were: GOAϭ0.465 (pϽ0.001), GCPϭϪ0.733 (pϽ0.001), SGCϭ0.172 (pϭns), AMPϭ0.131 (pϭns), DURϭϪ0.404 (pϽ0.001). A subset of 25 recordings from 8 patients with progressive VHI improvement beyond 6 months showed highest correlation with SGC following IL (rϭ0.504, pϽ0.05). CONCLUSIONS: VHI correlates best with GCP, suggesting that duration of vocal-fold closure during the glottic cycle best represents patients subjective outcome following IL. Progressive improvement in VHI beyond six months in some patients may relate to gradual reduction in compensatory supraglottic compression, with moderate correlation.