1
|
Khan F, Naeem K, Khalid A, Khan MN, Ahmad I. Photoacoustic imaging for characterization of radiofrequency ablated cardiac tissues. Lasers Med Sci 2023; 38:61. [PMID: 36732430 DOI: 10.1007/s10103-023-03723-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023]
Abstract
Photoacoustic (PA) imaging is an emerging technique being explored for various clinical applications. PA imaging offers a portable, inexpensive, stand-alone modality for evaluating optical contrast agents. PA signals are well-correlated with tissue physical parameters and can quantify various physiological variables (e.g., oxygenation of hemoglobin). Moreover, radiofrequency (RF) ablation is a promising treatment for certain cardiac arrhythmias. Assessment of RF-ablated lesions is of clinical importance. The purpose of this study is to elaborate the PA imaging to characterize RF-ablated cardiac tissues. Specifically, we describe the application of PA imaging to identify, characterize, and quantify cardiac RF lesions, highlighting the fundamental principles and unique benefits of this optical imaging technique. Potential future clinical application of PA imaging that reveals additional information about structural damage in RF-treated cardiac tissue are also anticipated.
Collapse
Affiliation(s)
- Farwa Khan
- Services Institute of Medical Sciences, Lahore, Pakistan
| | | | - Amna Khalid
- Nishtar Medical University, Multan, Pakistan
| | | | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan.
| |
Collapse
|
2
|
Khan S, Qadir M, Khalid A, Ashraf S, Ahmad I. Characterization of cervical tissue using Mueller matrix polarimetry. Lasers Med Sci 2023; 38:46. [PMID: 36662327 DOI: 10.1007/s10103-023-03712-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/11/2023] [Indexed: 01/21/2023]
Abstract
The cervix is composed of layers of squamous epithelium and connective tissue. The main component of the cervical connective tissue is collagen, which has specific orientations in different parts of the cervix and provides mechanical strength. Cervical pathologies such as cervical intraepithelial neoplasia (CIN), cancer, pregnancy, and spontaneous preterm birth (sPTB) allow for structural remodeling of both squamous epithelium and connective tissue. Mueller matrix (MM) polarimetry is an optical imaging technique that uses polarized light to characterize the morphologic changes in pathological cervix. In this study, advances in MM polarimetry in characterizing cervical tissue and associated pathologies were reviewed. In particular, the basic structure of the MM polarimeter is described. The interaction of polarized light with cervical tissue in terms of polarimetric parameters such as depolarization and birefringence is discussed. The assessment of cervical pathologies including CIN, cancer, pregnancy, and sPTB with MM polarimetry and the underlying reasons that produce the contrast in optical imaging are outlined. The clinical implementation of MM polarimetry, especially the Müller polarimetry colposcope, is also discussed. Finally, the challenges for MM polarimetry in cervical clinics are also speculated.
Collapse
Affiliation(s)
- Sumera Khan
- Allied Hospital Faisalabad, Faisalabad, Pakistan
| | | | - Amna Khalid
- Nishtar Medical University, Multan, Pakistan
| | - Sumara Ashraf
- Department of Physics, The Women University Multan, Multan, Pakistan
| | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan.
| |
Collapse
|
3
|
Bhatti HS, Khan S, Zahra M, Mustafa S, Ashraf S, Ahmad I. Characterization of radiofrequency ablated myocardium with optical coherence tomography. Photodiagnosis Photodyn Ther 2022; 40:103151. [PMID: 36228980 DOI: 10.1016/j.pdpdt.2022.103151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/07/2022]
Abstract
Certain types of cardiac arrhythmias are best treated with radiofrequency (RF) ablation, in which an electrode is inserted into the targeted area of the myocardium and then RF electrical current is applied to heat and destroy surrounding tissue. The resulting ablation lesion usually consists of a coagulative necrotic core surrounded by a rim region of mixed viable and non-viable cells. The characterization of the RF ablated lesion is of potential clinical importance. Here we aim to elaborate optical coherence tomography (OCT) imaging for the characterization of RF-ablated myocardial tissue. In particular, the underlying principles of OCT and its polarization-sensitive counterpart (PS-OCT) are presented, followed by the knowledge needed to interpret their optical images. Studies focused on real-time monitoring of RF lesion formation in the myocardium using OCT systems are summarized. The design and development of various hybrid probes incorporating both OCT guidance and RF ablation catheters are also discussed. Finally, the challenges related to the transmission of OCT imaging systems to cardiac clinics for real-time monitoring of RF lesions are outlined.
Collapse
Affiliation(s)
| | - Shamim Khan
- Department of Physics, Islamia College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Madeeha Zahra
- Department of Physics, The Women University Multan, Pakistan
| | - Sonia Mustafa
- Department of Physics, The Women University Multan, Pakistan
| | - Sumara Ashraf
- Department of Physics, The Women University Multan, Pakistan
| | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan.
| |
Collapse
|
4
|
Bagha T, Kamal AM, Pal UM, Mohan Rao PS, Pandya HJ. Toward the development of a polarimetric tool to diagnose the fibrotic human ventricular myocardium. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:055001. [PMID: 35562842 PMCID: PMC9106211 DOI: 10.1117/1.jbo.27.5.055001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/12/2022] [Indexed: 06/15/2023]
Abstract
SIGNIFICANCE Optical polarimetry is an emerging modality that effectively quantifies the bulk optical properties that correlate with the anisotropic structural properties of cardiac tissues. We demonstrate the application of a polarimetric tool for characterizing healthy and fibrotic human myocardial tissues efficiently with a high degree of accuracy. AIM The study was aimed to characterize the myocardial tissues from the left ventricle and right ventricle of N = 7 control and N = 10 diseased subjects. The diseased subjects were composed of two groups: N = 7 with rheumatic heart disease (RHD) and N = 3 with myxomatous valve (MV) disease. APPROACH A portable, affordable, and accurate linear polarization-based diagnostic tool is developed to measure the degree of linear polarization (DOLP) of the myocardial tissues while working at a wavelength of 850 nm. RESULTS The sensitivity, specificity, and accuracy of the polarimetric tool in distinguishing the control group from the RHD group were found to be 73.33%, 76.92%, and 75%, respectively, and from the MV group were 91.6%, 62.5%, and 80%, respectively, which demonstrates the efficacy of the polarimetric tool to distinguish the healthy myocardial tissues from diseased tissues. CONCLUSIONS We have successfully developed a polarimetric tool that can aid cardiologists in characterizing the myocardial tissues in conjunction with endomyocardial biopsy. This work should be followed up with experiments on a large cohort of control and diseased subjects. We intend to create and develop a probe to quantify the DOLP of in vivo heart tissue during surgery.
Collapse
Affiliation(s)
- Twinkle Bagha
- Indian Institute of Science, Department of Electronic Systems Engineering, Bangalore, Karnataka, India
| | - Arif Mohd. Kamal
- Indian Institute of Science, Department of Electronic Systems Engineering, Bangalore, Karnataka, India
| | - Uttam M. Pal
- Indian Institute of Science, Department of Electronic Systems Engineering, Bangalore, Karnataka, India
- Indian Institute of Information Technology Design and Manufacturing, Kancheepuram, Tamil Nadu, India
| | | | - Hardik J. Pandya
- Indian Institute of Science, Department of Electronic Systems Engineering, Bangalore, Karnataka, India
| |
Collapse
|
5
|
Ali Z, Mahmood T, Shahzad A, Iqbal M, Ahmad I. Assessment of tissue pathology using optical polarimetry. Lasers Med Sci 2021; 37:1907-1919. [PMID: 34689277 DOI: 10.1007/s10103-021-03450-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/18/2021] [Indexed: 11/28/2022]
Abstract
Optical polarimetry have been extensively used for the non-invasive assessment of biological tissues. However, the knowledge regarding differences in polarimetric signatures of different tissue pathologies is very scattered, confounding the deduction of a global trend of the polarimetric variables for healthy and pathological tissues. The purpose of this study was to bridge this gap. We conducted a rigorous online survey to collect all published studies that report the two most common polarimetric variables (i.e., depolarization and retardance) for any type of tissue pathology. A total of 101 studies describing the polarimetric assessment of tissues were collected, wherein 253 (i.e., nhuman = 149, nanimal = 104) different type of tissues were optically characterized. Most tissue samples (172/253) were investigated in ex vivo settings. The data showed 32 different types of tissues pathologies, where the most common pathology was cancer and its subtypes. The skin tissues were the most frequently explored tissues, followed by tissue samples from breast, colon, liver, and cervix. Although differences in polarimetric signatures of different tissue pathologies were summarized from the included studies, generalization of the results was hindered by the presentation of polarimetric data in a non-uniform format. The analyses presented in this study may provide an important reference for future polarimetric studies that conduct optical assessment of tissues at greater depth, particularly in the context of optical biopsy/digital staining.
Collapse
Affiliation(s)
- Zahra Ali
- DHQ and Teaching Hospital, Sahiwal, Pakistan
| | | | | | - Muaz Iqbal
- Department of Physics, Islamia College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan.
| |
Collapse
|
6
|
He C, He H, Chang J, Chen B, Ma H, Booth MJ. Polarisation optics for biomedical and clinical applications: a review. LIGHT, SCIENCE & APPLICATIONS 2021; 10:194. [PMID: 34552045 PMCID: PMC8458371 DOI: 10.1038/s41377-021-00639-x] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 05/13/2023]
Abstract
Many polarisation techniques have been harnessed for decades in biological and clinical research, each based upon measurement of the vectorial properties of light or the vectorial transformations imposed on light by objects. Various advanced vector measurement/sensing techniques, physical interpretation methods, and approaches to analyse biomedically relevant information have been developed and harnessed. In this review, we focus mainly on summarising methodologies and applications related to tissue polarimetry, with an emphasis on the adoption of the Stokes-Mueller formalism. Several recent breakthroughs, development trends, and potential multimodal uses in conjunction with other techniques are also presented. The primary goal of the review is to give the reader a general overview in the use of vectorial information that can be obtained by polarisation optics for applications in biomedical and clinical research.
Collapse
Affiliation(s)
- Chao He
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
| | - Honghui He
- Guangdong Engineering Center of Polarisation Imaging and Sensing Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Shenzhen, China.
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Shenzhen, China.
| | - Jintao Chang
- Guangdong Engineering Center of Polarisation Imaging and Sensing Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Shenzhen, China
- Department of Physics, Tsinghua University, 100084, Beijing, China
| | - Binguo Chen
- Guangdong Engineering Center of Polarisation Imaging and Sensing Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Shenzhen, China
- Department of Biomedical Engineering, Tsinghua University, 100084, Beijing, China
| | - Hui Ma
- Guangdong Engineering Center of Polarisation Imaging and Sensing Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Shenzhen, China
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Shenzhen, China
- Department of Physics, Tsinghua University, 100084, Beijing, China
| | - Martin J Booth
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
| |
Collapse
|
7
|
Iqbal M, Khan S, Gul B, Ahmad M, Ahmad I. Comparison of Mueller matrix differential decomposition and transformation. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2021.102815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
8
|
Iqbal M, Gul B, Khan S, Ashraf S, Ahmad I. Isolating individual polarization effects from the Mueller matrix: comparison of two non-decomposition techniques. BIOMEDICAL OPTICS EXPRESS 2021; 12:3743-3759. [PMID: 34457377 PMCID: PMC8367253 DOI: 10.1364/boe.426637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/19/2021] [Accepted: 05/19/2021] [Indexed: 05/05/2023]
Abstract
The prevailing formalisms for isolating individual polarization effects from the experimental Mueller matrix M can be broadly divided into two categories; decomposition of M to derive the individual optical effects and directly associating the individual optical effects to specific elements of M (i.e., non-decomposition techniques). Mueller matrix transformation (MMT) and direct interpretation of Mueller matrix (DIMM) are two popular techniques of the latter category. In this study, these two non-decomposition techniques (i.e., MMT and DIMM) are compared in a detailed quantitative analysis comprising of tissues (n = 53) and phantom (n = 45) samples. In particular, two commonly investigated polarimetric variables (i.e., depolarization and retardance) were calculated from the experimentally measured M using both the non-decomposition (i.e., MMT and DIMM) techniques. The comparison carried out with scatter plots (integrated with the correlation coefficients), violin plots and Bland and Altman plots revealed better agreement of depolarization-related variables (as compared to the retardance) between the two non-decomposition techniques. The comparative analyses presented here would be beneficial for the interpretation of polarimetric variables and optical characterization of turbid media.
Collapse
Affiliation(s)
- Muaz Iqbal
- Department of Physics, Islamia College Peshawar, Khyber Pakhtunkhwa, Pakistan
- these authors contributed equally to the manuscript
| | - Banat Gul
- Pakistan Department of Basic Sciences, Military College of Engineering, National University of Science and Technology (NUST), Islamabad, Pakistan
- these authors contributed equally to the manuscript
| | - Shamim Khan
- Department of Physics, Islamia College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Sumara Ashraf
- Department of Physics, The Women University Multan, Pakistan
| | - Iftikhar Ahmad
- Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar, Pakistan
| |
Collapse
|
9
|
Refractive index of biological tissues: Review, measurement techniques, and applications. Photodiagnosis Photodyn Ther 2021; 33:102192. [PMID: 33508501 DOI: 10.1016/j.pdpdt.2021.102192] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/12/2021] [Accepted: 01/19/2021] [Indexed: 11/24/2022]
Abstract
Refractive index (RI) is a characteristic optical variable that controls the propagation of light in the medium (e.g., biological tissues). Basic research with the aim to investigate the RI of biological tissues is of paramount importance for biomedical optics and associated applications. Herein, we reviewed and summarized the RI data of biological tissues and the associated insights. Different techniques for the measurement of RI of biological tissues are also discussed. Moreover, several examples of the RI applications from basic research, clinics and optics industry are outlined. This study may provide a comprehensive reference for RI data of biological tissues for the biomedical research and beyond.
Collapse
|
10
|
Yousaf MS, Khurshid A, Mahmood R, Ikram M. Polarimetric comparison of fresh and frozen skeletal muscle tissues of goat. Photodiagnosis Photodyn Ther 2020; 32:102071. [PMID: 33130029 DOI: 10.1016/j.pdpdt.2020.102071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/11/2020] [Accepted: 10/19/2020] [Indexed: 10/23/2022]
Abstract
Optical properties can provide rich information about morphology and structure of tissues. Fresh and frozen muscle tissue samples of goat are investigated using imaging polarimetry to understand its structural nature. The outcomes demonstrate that the muscle tissues lose, to some extent, their integrity and organization on freezing. The fresh tissues offer very small circular retardance as compared to frozen samples. However, linear retardance is the main contributor in fresh muscle samples. Ultimately, linear and circular retardance can be used to differentiate fresh and frozen tissues. These investigations illustrate the capabilities of optical polarimetry for the characterization of muscle tissue structures. Specifically, the structure of biological tissue samples can be differentiated using real-time, cost effective and non-invasive optical polarimetry in the field of meat industry and biomedical diagnosis.
Collapse
Affiliation(s)
- Muhammad Sajid Yousaf
- Biophotonics Laboratory, Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan.
| | - Ahmat Khurshid
- Biophotonics Laboratory, Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan; Photomedicine Research Laboratory, Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan
| | - Rashid Mahmood
- Photomedicine Research Laboratory, Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan
| | - Masroor Ikram
- Biophotonics Laboratory, Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan; Photomedicine Research Laboratory, Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan
| |
Collapse
|
11
|
Armstrong K, Larson C, Asfour H, Ransbury T, Sarvazyan N. A Percutaneous Catheter for In Vivo Hyperspectral Imaging of Cardiac Tissue: Challenges, Solutions and Future Directions. Cardiovasc Eng Technol 2020; 11:560-575. [PMID: 32666326 PMCID: PMC7530025 DOI: 10.1007/s13239-020-00476-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 06/30/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Multiple studies have shown that spectral analysis of tissue autofluorescence can be used as a live indicator for various pathophysiological states of cardiac tissue, including ischemia, ablation-induced damage, or scar formation. Yet today there are no percutaneous devices that can detect autofluorescence signals from inside a beating heart. Our aim was to develop a prototype catheter to demonstrate the feasibility of doing so. METHODS AND RESULTS Here we summarize technical solutions leading to the development of a percutaneous catheter capable of multispectral imaging of intracardiac surfaces. The process included several iterations of light sources, optical filtering, and image acquisition techniques. The developed system included a compliant balloon, 355 nm laser irradiance, a high-sensitivity CCD, bandpass filtering, and image acquisition synchronized with the cardiac cycle. It enabled us to capture autofluorescence images from multiple spectral bands within the visible range while illuminating the endocardial surface with ultraviolet light. Principal component analysis and other spectral unmixing post-processing algorithms were then used to reveal target tissue. CONCLUSION Based on the success of our prototype system, we are confident that the development of ever more sensitive cameras, recent advances in tunable filters, fiber bundles, and other optical and computational components makes it possible to create percutaneous catheters capable of acquiring hyper or multispectral hypercubes, including those based on autofluorescence, in real-time. This opens the door for widespread use of this methodology for high-resolution intraoperative imaging of internal tissues and organs-including cardiovascular applications.
Collapse
Affiliation(s)
- Kenneth Armstrong
- Nocturnal Product Development, LLC, 8128 Renaissance Pkwy #210, Durham, NC, 27713, USA.
| | - Cinnamon Larson
- Nocturnal Product Development, LLC, 8128 Renaissance Pkwy #210, Durham, NC, 27713, USA
| | - Huda Asfour
- Department of Pharmacology and Physiology, The George Washington University, 2300 Eye Street NW, Washington, DC, 20037, USA
| | - Terry Ransbury
- LuxMed Systems, Inc, 124 Country Drive, Weston, MA, 02493, USA
| | - Narine Sarvazyan
- Department of Pharmacology and Physiology, The George Washington University, 2300 Eye Street NW, Washington, DC, 20037, USA.
| |
Collapse
|
12
|
Rehman AU, Ahmad I, Qureshi SA. Biomedical Applications of Integrating Sphere: A Review. Photodiagnosis Photodyn Ther 2020; 31:101712. [DOI: 10.1016/j.pdpdt.2020.101712] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 02/05/2020] [Accepted: 03/02/2020] [Indexed: 10/24/2022]
|
13
|
Ahmad I, Khaliq A, Iqbal M, Khan S. Mueller matrix polarimetry for characterization of skin tissue samples: A review. Photodiagnosis Photodyn Ther 2020; 30:101708. [DOI: 10.1016/j.pdpdt.2020.101708] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 02/25/2020] [Accepted: 03/02/2020] [Indexed: 10/24/2022]
|
14
|
Hendon CP, Lye TH, Yao X, Gan Y, Marboe CC. Optical coherence tomography imaging of cardiac substrates. Quant Imaging Med Surg 2019; 9:882-904. [PMID: 31281782 DOI: 10.21037/qims.2019.05.09] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cardiovascular disease is the leading cause of morbidity and mortality in the United States. Knowledge of a patient's heart structure will help to plan procedures, potentially identifying arrhythmia substrates, critical structures to avoid, detect transplant rejection, and reduce ambiguity when interpreting electrograms and functional measurements. Similarly, basic research of numerous cardiac diseases would greatly benefit from structural imaging at cellular scale. For both applications imaging on the scale of a myocyte is needed, which is approximately 100 µm × 10 µm. The use of optical coherence tomography (OCT) as a tool for characterizing cardiac tissue structure and function has been growing in the past two decades. We briefly review OCT principles and highlight important considerations when imaging cardiac muscle. In particular, image penetration, tissue birefringence, and light absorption by blood during in vivo imaging are important factors when imaging the heart with OCT. Within the article, we highlight applications of cardiac OCT imaging including imaging heart tissue structure in small animal models, quantification of myofiber organization, monitoring of radiofrequency ablation (RFA) lesion formation, structure-function analysis enabled by functional extensions of OCT and multimodal analysis and characterizing important substrates within the human heart. The review concludes with a summary and future outlook of OCT imaging the heart, which is promising with progress in optical catheter development, functional extensions of OCT, and real time image processing to enable dynamic imaging and real time tracking during therapeutic procedures.
Collapse
Affiliation(s)
| | | | | | - Yu Gan
- Columbia University, New York, NY, USA
| | | |
Collapse
|
15
|
Lo WCY, Uribe-Patarroyo N, Hoebel K, Beaudette K, Villiger M, Nishioka NS, Vakoc BJ, Bouma BE. Balloon catheter-based radiofrequency ablation monitoring in porcine esophagus using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:2067-2089. [PMID: 31086717 PMCID: PMC6484999 DOI: 10.1364/boe.10.002067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/15/2019] [Accepted: 03/12/2019] [Indexed: 05/05/2023]
Abstract
We present a microscopic image guidance platform for radiofrequency ablation (RFA) using a clinical balloon-catheter-based optical coherence tomography (OCT) system, currently used in the surveillance of Barrett's esophagus patients. Our integrated thermal therapy delivery and monitoring platform consists of a flexible, customized bipolar RFA electrode array designed for use with a clinical balloon OCT catheter and a processing algorithm to accurately map the thermal coagulation process. Non-uniform rotation distortion was corrected using a feature tracking-based technique, which enables robust, frame-to-frame analysis of the temporal fluctuation of the complex OCT signal. With proper noise calibration, precise delineation of the thermal therapy zone was demonstrated using cumulative complex differential variance in porcine esophagus ex vivo with the integrated OCT-RFA system, as validated by nitroblue tetrazolium chloride (NBTC) histology. The ability to directly and accurately visualize the thermal coagulation process at high resolution is critical to the precise delivery of thermal energy to a wide range of epithelial lesions.
Collapse
Affiliation(s)
- William C Y Lo
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
| | - Katharina Hoebel
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
| | - Kathy Beaudette
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
| | - Martin Villiger
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
| | - Norman S Nishioka
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Department of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, USA
| | - Benjamin J Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Brett E Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
16
|
Yao X, Gan Y, Ling Y, Marboe CC, Hendon CP. Multicontrast endomyocardial imaging by single-channel high-resolution cross-polarization optical coherence tomography. JOURNAL OF BIOPHOTONICS 2018; 11:e201700204. [PMID: 29165902 PMCID: PMC6186148 DOI: 10.1002/jbio.201700204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/19/2017] [Accepted: 11/20/2017] [Indexed: 05/10/2023]
Abstract
A single-channel high-resolution cross-polarization (CP) optical coherence tomography (OCT) system is presented for multicontrast imaging of human myocardium in one-shot measurement. The intensity and functional contrasts, including the ratio between the cross- and co-polarization channels as well as the cumulative retardation, are reconstructed from the CP-OCT readout. By comparing the CP-OCT results with histological analysis, it is shown that the system can successfully delineate microstructures in the myocardium and differentiate the fibrotic myocardium from normal or ablated myocardium based on the functional contrasts provided by the CP-OCT system. The feasibility of using A-line profiles from the 2 orthogonal polarization channels to identify fibrotic myocardium, normal myocardium and ablated lesion is also discussed.
Collapse
Affiliation(s)
- Xinwen Yao
- Department of Electrical Engineering, Columbia University, New York, New York
| | - Yu Gan
- Department of Electrical Engineering, Columbia University, New York, New York
| | - Yuye Ling
- Department of Electrical Engineering, Columbia University, New York, New York
| | - Charles C. Marboe
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Christine P. Hendon
- Department of Electrical Engineering, Columbia University, New York, New York
| |
Collapse
|
17
|
Swift LM, Asfour H, Muselimyan N, Larson C, Armstrong K, Sarvazyan NA. Hyperspectral imaging for label-free in vivo identification of myocardial scars and sites of radiofrequency ablation lesions. Heart Rhythm 2017; 15:564-575. [PMID: 29246829 DOI: 10.1016/j.hrthm.2017.12.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Treatment of cardiac arrhythmias often involves ablating viable muscle tissue within or near islands of scarred myocardium. Yet, today there are limited means by which the boundaries of such scars can be visualized during surgery and distinguished from the sites of acute injury caused by radiofrequency (RF) ablation. OBJECTIVE We sought to explore a hyperspectral imaging (HSI) methodology to delineate and distinguish scar tissue from tissue injury caused by RF ablation. METHODS RF ablation of the ventricular surface of live rats that underwent thoracotomy was followed by a 2-month animal recovery period. During a second surgery, new RF lesions were placed next to the scarred tissue from the previous ablation procedure. The myocardial infarction model was used as an alternative way to create scar tissue. RESULTS Excitation-emission matrices acquired from the sites of RF lesions, scar region, and the surrounding unablated tissue revealed multiple spectral changes. These findings justified HSI of the heart surface using illumination with 365 nm UV light while acquiring spectral images within the visible range. Autofluorescence-based HSI enabled to distinguish sites of RF lesions from scar or unablated myocardium in open-chest rats. A pilot version of a percutaneous HSI catheter was used to demonstrate the feasibility of RF lesion visualization in atrial tissue of live pigs. CONCLUSION HSI based on changes in tissue autofluorescence is a highly effective tool for revealing-in vivo and with high spatial resolution-surface boundaries of myocardial scar and discriminating it from areas of acute necrosis caused by RF ablation.
Collapse
Affiliation(s)
- Luther M Swift
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia
| | - Huda Asfour
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia
| | - Narine Muselimyan
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia
| | | | | | - Narine A Sarvazyan
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia.
| |
Collapse
|
18
|
González-Suárez A, Herranz D, Berjano E, Rubio-Guivernau JL, Margallo-Balbás E. Relation between denaturation time measured by optical coherence reflectometry and thermal lesion depth during radiofrequency cardiac ablation: Feasibility numerical study. Lasers Surg Med 2017; 50:222-229. [PMID: 29168554 DOI: 10.1002/lsm.22771] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2017] [Indexed: 11/11/2022]
Abstract
BACKGROUND/OBJECTIVE Radiofrequency (RF) catheter ablation is a minimally invasive medical procedure used to thermally destroy the focus of cardiac arrhythmias. Novel optical techniques are now being integrated into RF catheters in order to detect the changes in tissue properties. Loss of birefringence due to fiber denaturation at around 70°C is related to changes in accumulated phase retardation and can be measured by polarization-sensitive optical coherence reflectometry (PS-OCR). Since irreversible thermal lesions are produced when the tissue reaches 50°C, our goal was to seek the mathematical relationship between both isotherms. MATERIALS AND METHODS A two-dimensional model based on a coupled electric-thermal problem was built and solved using the finite element method. The model consisted of cardiac tissue, blood, and a non-irrigated electrode with a sensor embedded in its tip to maintain a specific target electrode temperature. Computer simulations were conducted by varying the tissue characteristics. Lesion depth was estimated by the 50°C isotherm, while the denaturation time (TD) was taken as the time at which the 70°C isotherm reached a depth of 0.75 mm (which corresponds to the optical depth reached by PS-OCR technology). RESULTS A strong correlation (R2 > 0.83) was found between TD and lesion depth and an even stronger correlation (R2 > 0.96) was found between TD and the time required to achieve a specific lesion depth. For instance, the ablation time required to ensure a minimum lesion depth of 3 mm was 1.33 × TD + 3.93 × seconds. CONCLUSIONS The computer results confirmed the strong relationship between denaturation time and lesion depth and suggest that measuring denaturation time by PS-OCR could provide information on the ablation time required to reach a specific lesion depth. Lasers Surg. Med. 50:222-229, 2018. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Ana González-Suárez
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | | | - Enrique Berjano
- BioMIT, Department of Electronic Engineering, Universitat Politècnica de València, Valencia, Spain
| | | | | |
Collapse
|
19
|
Muselimyan N, Jishi MA, Asfour H, Swift L, Sarvazyan NA. Anatomical and Optical Properties of Atrial Tissue: Search for a Suitable Animal Model. Cardiovasc Eng Technol 2017; 8:505-514. [PMID: 28884368 DOI: 10.1007/s13239-017-0329-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/28/2017] [Indexed: 12/12/2022]
Abstract
The purpose of this study was to evaluate structural and optical properties of atrial tissue from common animal models and to compare it with human atria. We aimed to do this in a format that will be useful for development of better ablation tools and/or new means for visualizing atrial lesions. Human atrial tissue from clinically relevant age group was compared and contrasted with atrial tissue of large animal models commonly available for research purposes. These included pigs, sheep, dogs and cows. The presented data include area measurements of smooth atrial surface available for ablation and estimates of thickness of collagen and muscle for five different species. We also described methods to quantify presence of collagen and overall thickness of atrial wall. Provided information enables placement of atrial lesions to locations with clinically relevant atrial wall thickness and macroscopic structure ultimately helping investigators to develop better ablation and imaging tools. It also highlights the impact of collagen thickness on optical measurements and lesion visualization.
Collapse
Affiliation(s)
- Narine Muselimyan
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington, DC, 20052, USA
| | - Mohammed Al Jishi
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington, DC, 20052, USA
| | - Huda Asfour
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington, DC, 20052, USA
| | - Luther Swift
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington, DC, 20052, USA
| | - Narine A Sarvazyan
- Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington, DC, 20052, USA.
| |
Collapse
|
20
|
Gil DA, Swift LM, Asfour H, Muselimyan N, Mercader MA, Sarvazyan NA. Autofluorescence hyperspectral imaging of radiofrequency ablation lesions in porcine cardiac tissue. JOURNAL OF BIOPHOTONICS 2017; 10:1008-1017. [PMID: 27545317 PMCID: PMC5511096 DOI: 10.1002/jbio.201600071] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 06/21/2016] [Accepted: 07/29/2016] [Indexed: 05/22/2023]
Abstract
Radiofrequency ablation (RFA) is a widely used treatment for atrial fibrillation, the most common cardiac arrhythmia. Here, we explore autofluorescence hyperspectral imaging (aHSI) as a method to visualize RFA lesions and interlesional gaps in the highly collagenous left atrium. RFA lesions made on the endocardial surface of freshly excised porcine left atrial tissue were illuminated by UV light (365 nm), and hyperspectral datacubes were acquired over the visible range (420-720 nm). Linear unmixing was used to delineate RFA lesions from surrounding tissue, and lesion diameters derived from unmixed component images were quantitatively compared to gross pathology. RFA caused two consistent changes in the autofluorescence emission profile: a decrease at wavelengths below 490 nm (ascribed to a loss of endogenous NADH) and an increase at wavelengths above 490 nm (ascribed to increased scattering). These spectral changes enabled high resolution, in situ delineation of RFA lesion boundaries without the need for additional staining or exogenous markers. Our results confirm the feasibility of using aHSI to visualize RFA lesions at clinically relevant locations. If integrated into a percutaneous visualization catheter, aHSI would enable widefield optical surgical guidance during RFA procedures and could improve patient outcome by reducing atrial fibrillation recurrence.
Collapse
Affiliation(s)
- Daniel A. Gil
- Department of Pharmacology & Physiology, George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, USA
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, PMB 351631, 2301 Vanderbilt Place, Nashville, TN, USA
| | - Luther M. Swift
- Department of Pharmacology & Physiology, George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, USA
| | - Huda Asfour
- Department of Pharmacology & Physiology, George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, USA
| | - Narine Muselimyan
- Department of Pharmacology & Physiology, George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, USA
| | - Marco A. Mercader
- Division of Cardiology, George Washington University Medical Faculty Associates, 2150 Pennsylvania Avenue NW, Suite 4-417, Washington DC, USA
| | - Narine A. Sarvazyan
- Department of Pharmacology & Physiology, George Washington University School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, USA
| |
Collapse
|
21
|
Ahmad I, Gribble A, Murtza I, Ikram M, Pop M, Vitkin A. Polarization image segmentation of radiofrequency ablated porcine myocardial tissue. PLoS One 2017; 12:e0175173. [PMID: 28380013 PMCID: PMC5381909 DOI: 10.1371/journal.pone.0175173] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/21/2017] [Indexed: 11/19/2022] Open
Abstract
Optical polarimetry has previously imaged the spatial extent of a typical radiofrequency ablated (RFA) lesion in myocardial tissue, exhibiting significantly lower total depolarization at the necrotic core compared to healthy tissue, and intermediate values at the RFA rim region. Here, total depolarization in ablated myocardium was used to segment the total depolarization image into three (core, rim and healthy) zones. A local fuzzy thresholding algorithm was used for this multi-region segmentation, and then compared with a ground truth segmentation obtained from manual demarcation of RFA core and rim regions on the histopathology image. Quantitative comparison of the algorithm segmentation results was performed with evaluation metrics such as dice similarity coefficient (DSC = 0.78 ± 0.02 and 0.80 ± 0.02), sensitivity (Sn = 0.83 ± 0.10 and 0.91 ± 0.08), specificity (Sp = 0.76 ± 0.17 and 0.72 ± 0.17) and accuracy (Acc = 0.81 ± 0.09 and 0.71 ± 0.10) for RFA core and rim regions, respectively. This automatic segmentation of parametric depolarization images suggests a novel application of optical polarimetry, namely its use in objective RFA image quantification.
Collapse
Affiliation(s)
- Iftikhar Ahmad
- Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Science (PIEAS), Nilore, Islamabad, Pakistan
- * E-mail:
| | - Adam Gribble
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Division of Biophysics and Bioimaging, Princess Margaret Cancer Centre, University Health Network, 610 University Avenue, Toronto, Ontario, Canada
| | - Iqbal Murtza
- Department of Computer and Information Sciences, Pakistan Institute of Engineering and Applied Science (PIEAS), Nilore, Islamabad, Pakistan
| | - Masroor Ikram
- Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Science (PIEAS), Nilore, Islamabad, Pakistan
| | - Mihaela Pop
- Sunnybrook Research Institute, Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario, Canada
| | - Alex Vitkin
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Division of Biophysics and Bioimaging, Princess Margaret Cancer Centre, University Health Network, 610 University Avenue, Toronto, Ontario, Canada
- Department of Radiation Oncology, University of Toronto, 610 University Avenue, Toronto, Ontario Canada
| |
Collapse
|