
Rayyan ManwarUniversity of Illinois Chicago | UIC · Department of Bioengineering
Rayyan Manwar
Doctor of Philosophy
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84
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Introduction
Skills and Expertise
Publications
Publications (84)
Pattern recognition analysis in brain research has improved understanding of sensory processing and led to the identification of default brain networks in neuroimaging studies. The current study uses pattern recognition analysis to extend our previous findings showing conditioned fear learning and novelty-exposure (i.e. sham conditioning) equally i...
Transcranial ultrasound imaging is a popular method to study cerebral functionality and diagnose brain injuries. However, the detected ultrasound signal is greatly distorted due to the aberration caused by the skull bone. The aberration mechanism mainly depends on thickness and porosity, two important skull physical characteristics. Although skull...
During head examinations, real-time information relevant to potential cerebral injuries can be obtained using a simple, non-invasive, and portable ultrasound scanning protocol. However, for adult human applications, the clinical diagnostic process based on transcranial ultrasound imaging remains inconclusive. This is due to acoustic aberrations, i....
Photoacoustic imaging (PAI) utilizes the photoacoustic effect to record both vascular and functional characteristics of a biological tissue. Photoacoustic signals have typically low amplitude that cannot be read efficiently by data acquisition systems. This necessitates the use of one or more amplifiers. These amplifiers are somewhat bulky (e.g., t...
This article provides an overview of the progress made in skin imaging using two emerging imaging modalities, optical coherence tomography (OCT) and photoacoustic imaging (PAI). Over recent years, these technologies have significantly advanced our understanding of skin structure and function, offering non-invasive and high-resolution insights previ...
Mohs micrographic surgery (MMS) is considered the gold standard for treating high-risk cutaneous basal cell carcinoma (BCC), but is expensive, time-consuming, and can be unpredictable as to how many stages will be required or how large the final lesion and corresponding surgical defect will be. This study is meant to investigate whether optical coh...
Significance
There are many neuroscience questions that can be answered by a high-resolution functional brain imaging system. Such a system would require the capability to visualize vasculature and measure neural activity by imaging the entire brain continually and in rapid succession in order to capture hemodynamic changes. Utilizing optical excit...
Significance
Cutaneous melanoma (CM) has a high morbidity and mortality rate, but it can be cured if the primary lesion is detected and treated at an early stage. Imaging techniques such as photoacoustic (PA) imaging (PAI) have been studied and implemented to aid in the detection and diagnosis of CM.
Aim
Provide an overview of different PAI system...
Due to the high possibility of mechanical damage to the underlying tissues attached to the rat skull during a craniectomy, previously described methods for visualization of the rat brain in vivo are limited to unilateral craniotomies and small cranial windows, often measuring 4–5 mm. Here, we introduce a novel method for producing bilateral craniec...
The predictive value of the weeke score in the prognosis of hypoxic-ischemic encephalopathy treated with therapeutichypothermiaIgreja L1, Ferreira A2, Rita Gomes R2,3, Sousa B2,3,Novo A2, Eduardo Alves J1, Proença E2, CarvalhoC21Neuroradiology Department, Centro HospitalarUniversitário do Porto, Largo do Prof. Abel Salazar, 4099-001, Porto, Portuga...
Intraventricular (IVH) and periventricular (PVH) hemorrhages in preterm neonates are common because the periventricular blood vessels are still developing up to 36 weeks and are fragile. Currently, transfontanelle ultrasound (US) imaging is utilized for screening for IVH and PVH, largely through the anterior fontanelle. However for mild hemorrhages...
Understanding the neurobiology of complex behaviors requires measurement of activity in the discrete population of active neurons, neuronal ensembles, which control the behavior. Conventional neuroimaging techniques ineffectively measure neuronal ensemble activity in the brain in vivo because they assess the average regional neuronal activity inste...
One common method to improve the low signal‐to‐noise ratio of the photoacoustic (PA) signal generated from weak absorbers or absorbers located in deep tissue is to acquire signal multiple times from the same region and perform averaging. However, pulse‐to‐pulse laser fluctuations together with differences in the beam profile of the pulses create un...
We have developed and optimized an imaging system to study and improve the detection of brain hemorrhage and to quantify oxygenation. Since this system is intended to be used for brain imaging in neonates through the skull opening, i.e., fontanelle, we called it, Transfontanelle Photoacoustic Imaging (TFPAI) system. The system is optimized in terms...
Hypoxia causes the expression of signaling molecules which regulate cell division, lead to angiogenesis, and further, in the tumor microenvironment, promote resistance to chemotherapy and radiotherapy, and induce metastasis. Photoacoustic imaging (PAI) takes advantage of unique absorption characteristics of chromophores in tissues and provides the...
Ultrasound transducer is a crucial component for several imaging modalities, where acoustic sensing is utilized as a part of hybrid or combination of pure optical and ultrasound imaging. However, conventional ultrasound transducers are opaque, and the optical components in the system require a different pathway to avoid any interference. The absenc...
Brain hemorrhage, specifically intraventricular hemorrhage (IVH), is considered one of the primary and leading causes of cerebral anomalies in neonates. Several imaging modalities including the most popular, cranial ultrasound, are not capable of detecting early stage IVHs. Photoacoustic imaging (PAI) exhibited great potential for detecting cerebra...
Background
Phacomatosis pigmentokeratotica (PPK) is a distinct and rare type of epidermal nevus syndrome characterized by coexisting nonepidermolytic organoid sebaceous nevus (SN) with one or more speckled lentiginous nevi (SLN). Atypical nevi including compound Spitz and compound dysplastic may manifest within regions of SLN. Patients with PPK, or...
The onset of intracerebral hemorrhage and its progression toward acute brain injury have been correlated with the concentration of unconjugated bilirubin (BR). In addition, BR has been considered a novel predictor of outcome from intracranial hemorrhage. Since the existing invasive approach for determining localized BR and biliverdin (BV) concentra...
Photoacoustic microscopy (PAM) is a high‐resolution imaging modality that has been mainly implemented with small field of view applications. Here, we developed a fast PAM system that utilizes a unique spiral laser scanning mechanism and a wide acoustic detection unit. The developed system can image an area of 12.5 cm ² in 6.4 s. The system has been...
During medical investigations of the head, ultrasound measurements can offer information with simple, non-invasive, and real-time procedure. However, for human adult applications, the clinical treatment of transcranial acoustic imaging remains a challenge by the presence of the skull, results in acoustic aberrations caused by two main phenomena, i....
Abstract The capability of photoacoustic (PA) imaging to measure oxygen saturation through a fontanelle has been demonstrated in large animals in-vivo. We called this method, transfontanelle photoacoustic imaging (TFPAI). A surgically induced 2.5 cm diameter cranial window was created in an adult sheep skull to model the human anterior fontanelle....
A synthetic phantom model is typically utilized to evaluate the initial performance of a photoacoustic image reconstruction algorithm. The characteristics of the phantom model (structural, optical, and acoustic) are required to be very similar to those of the biological tissue. Typically, generic two-dimensional shapes are used as imaging targets t...
Acoustic biosensors are widely used in physical, chemical, and biosensing applications. One of the major concerns in acoustic biosensing is the delicacy of the medium through which acoustic waves propagate and reach acoustic sensors. Even a small airgap diminishes acoustic signal strengths due to high acoustic impedance mismatch. Therefore, the pre...
One of the key challenges in linear array transducer‐based photoacoustic computed tomography is to image structures embedded deep within the biological tissue with limited optical energy. Here, we utilized a manually controlled multi‐angle illumination technique to allow the incident photons to interact with the imaging targets for longer periods o...
In transcranial brain imaging, the presence of the skull represents a challenge in the generation of clear signals and
in its understanding. For human adult skull, and animals with thick skull, optical and ultrasound propagations are
significantly degraded due to the bone properties. This study aims to understand and quantify the optical, ultraso...
Photoacoustic microscopy (PAM) images can assist specialists in disease diagnosis by providing vascular information. However, the size of such data is usually extremely large (i.e, gigabytes), thus, a real‐time, efficient compression method can facilitate easy storage and transportation of these images. We have implemented multiple data compression...
Transfontanelle ultrasound imaging (TFUI) is the conventional approach for diagnosing brain injury in neonates. Despite being the first stage imaging modality, TFUI lacks accuracy in determining the injury at an early stage due to degraded sensitivity and specificity. Therefore, a modality like photoacoustic imaging that combines the advantages of...
Cerebral hypoxia is a severe injury caused by oxygen deprivation to the brain. Hypoxia in the neonatal period increases the risk for the development of neurological disorders, including hypoxic-ischemic encephalopathy, cerebral palsy, periventricular leukomalacia, and hydrocephalus. It is crucial to recognize hypoxia as soon as possible because ear...
Measuring neuroactivity underlying complex behaviors facilitates understanding the microcircuitry that supports these behaviors. We have developed a functional and molecular photoacoustic tomography (F/M-PAT) system which allows direct imaging of Fos-expressing neuronal ensembles in Fos-LacZ transgenic rats with a large field-of-view and high spati...
Photoacoustic imaging (PAI) is an emerging functional and molecular imaging technology that has attracted much attention in the past decade. Recently, many researchers have used the vantage system from Verasonics for simultaneous ultrasound (US) and photoacoustic (PA) imaging. This was the motivation to write on the details of US/PA imaging system...
Photoacoustic imaging (PAI) is a powerful imaging modality that relies on the PA effect. PAI works on the principle of electromagnetic energy absorption by the exogenous contrast agents and/or endogenous molecules present in the biological tissue, consequently generating ultrasound waves. PAI combines a high optical contrast with a high acoustic sp...
Melanoma is the deadliest form of skin cancer and remains a diagnostic challenge in the dermatology clinic. Several non-invasive imaging techniques have been developed to identify melanoma. The signal source in each of these modalities is based on the alteration of physical characteristics of the tissue from healthy/benign to melanoma. However, as...
Photoacoustic imaging (PAI) is a powerful imaging modality that relies on the PA effect. PAI works on the principle of electromagnetic energy absorption by the exogenous contrast agents and/or endogenous molecules present in the biological tissue, consequently generating ultrasound waves. PAI combines a high optical contrast with a high acoustic sp...
In this chapter, we will give a brief overview of fundus photography, SLO, and OCT while discussing photoacoustic imaging potential as the next major ocular imaging modality.
Although transcranial photoacoustic imaging (TCPAI) has been used in small animal brain imaging, in animals with thicker skull bones or in humans both light illumination and ultrasound propagation paths are affected. Hence, the PA image is largely degraded and in some cases completely distorted. This study aims to investigate and determine the maxi...
One of the key limitations for the clinical translation of photoacoustic imaging is penetration depth that is linked to the tissue maximum permissible exposures (MPE) recommended by the American National Standards Institute (ANSI). Here, we propose a method based on deep learning to virtually increase the MPE in order to enhance the signal‐to‐noise...
Ultrasound detection is one of the major components of photoacoustic imaging systems. Advancement in ultrasound transducer technology has a significant impact on the translation of photoacoustic imaging to the clinic. Here, we present an overview on various ultrasound transducer technologies including conventional piezoelectric and micromachined tr...
Diffuse optical tomography (DOT) and photoacoustic tomography (PAT) are functional imaging modalities that provide absorption coefficient maps of the tissue. Spatial resolution of DOT is relatively low due to light scattering characteristics of the tissue. On the other hand, although PAT can resolve regions of different absorptions with a high spat...
Optical coherence tomography (OCT), with a high spatial resolution (<10 microns), intermediate penetration depth (~1.5 mm), and volumetric imaging capability is a great candidate to be used as a diagnostic‐assistant modality in dermatology. At this time, the accuracy of OCT for melanoma detection is lower than anticipated. In this letter, we studie...
Since 1886, when the first picture of the human retina was taken, ocular imaging has played a crucial role in the diagnosis and management of ophthalmic diseases. One of the biggest contributors to the advancement of ocular imaging is the adoption of optical imaging techniques. Optical imaging is a method of looking into the body in a noninvasive w...
Photoacoustic imaging (PAI) is an emerging label-free and non-invasive modality for imaging biological tissues. PAI has been implemented in different configurations, one of which is photoacoustic computed tomography (PACT) with a potential wide range of applications, including brain and breast imaging. Hemispherical Array PACT (HA-PACT) is a variat...
Background:
Optical coherence tomography (OCT) is a promising imaging modality for skin cancer diagnosis. However, this capability has been hindered by the low contrast between normal and neoplastic tissue. To overcome this limitation, gold nanoparticles have been used to enhance the contrast in OCT images and are topically administered to reduce...
In karate sparring (kumite), punches are used more than kicks to score points. Among these punches, gyaku tsuki is a very commonly used punch. The objective of the punch is to hit the target at a medium range in a very short time, producing a maximum force. In this study, we proposed the development of a novel standalone Punch-O-Meter system to mea...
Photoacoustic Computed Tomography (PACT) is a major configuration of photoacoustic imaging, a hybrid noninvasive modality for both functional and molecular imaging. PACT has rapidly gained importance in the field of biomedical imaging due to superior performance as compared to conventional optical imaging counterparts. However, the overall cost of...
The marked increase in the incidence of melanoma coupled with the rapid drop in the survival rate after metastasis has promoted the investigation into improved diagnostic methods for melanoma. High-frequency ultrasound (US), optical coherence tomography (OCT), and photoacoustic imaging (PAI) are three potential modalities that can assist a dermatol...
By manipulating the phase map of a wavefront of light using a spatial light modulator, the scattered light can be sharply focused on a specific target. Several iterative optimization algorithms for obtaining the optimum phase map have been explored. However, there has not been a comparative study on the performance of these algorithms. In this pape...
Background
Echolocation is a technique whereby the location of objects is determined via reflected sound. Currently, some visually impaired individuals use a form of echolocation to locate objects and to orient themselves. However, this method takes years of practice to accurately utilize.
Objective
This paper describes the development and validat...
Galvo scanners are popular devices for fast transversal scanning. A triangular signal is usually employed to drive galvo scanners at scanning rates close to the inverse of their response time where scanning deflection becomes a nonlinear function of applied voltage. To address this, the triangular signal is synthesized from several short ramps with...
Photoacoustic Computed Tomography (PACT) is a major configuration of photoacoustic imaging, a hybrid noninvasive modality for both functional and molecular imaging. PACT has rapidly gained importance in the field of biomedical imaging due to superior performance as compared to conventional optical imaging counterparts. However, the overall cost of...
A low-cost Photoacoustic Computed Tomography (PACT) system consisting of 16 single-element transducers has been developed. Our design proposes a fast rotating mechanism of 360o rotation around the imaging target, generating comparable images to those produced by large-number-element (e.g., 512, 1024, etc.) ring-array PACT systems. The 2D images wit...
In practice, photoacoustic (PA) waves generated with cost-effective and low-energy laser diodes, are weak and almost buried in noise. Reconstruction of an artifact-free PA image from noisy measurements requires an effective denoising technique. Averaging is widely used to increase the signal-to-noise ratio (SNR) of PA signals; however, it is time c...
In recent years, the minimum variance (MV) beamforming has been widely studied due to its high resolution and contrast in B-mode Ultrasound imaging (USI). However, the performance of the MV beamformer is degraded at the presence of noise, as a result of the inaccurate covariance matrix estimation which leads to a low quality image. Second harmonic...
Non-invasive vascular elastography is an emerging technique in vascular tissue imaging. During the past decades, several techniques have been suggested to estimate the tissue elasticity by measuring the displacement of the Carotid vessel wall. Cross correlation-based methods are the most prevalent approaches to measure the strain exerted in the wal...