Biomedical Engineering and Bioengineering Commons^™

Identification And Characterization Of Two Novel Kcnh2 Mutations Contributing To Long Qt Syndrome, Anthony Owusu-Mensah, Jacqueline Treat, Joyce Bernardi, Ryan Pfeiffer, Robert Goodrow, Bright Tsevi, Victoria Lam, Michel Audette, Jonathan M. Cordeiro, Makarand Deo

Electrical & Computer Engineering Faculty Publications

We identified two different inherited mutations in KCNH2 gene, or human ether-a-go-go related gene (hERG), which are linked to Long QT Syndrome. The first mutation was in a 1-day-old infant, whereas the second was in a 14-year-old girl. The two KCNH2 mutations were transiently transfected into either human embryonic kidney (HEK) cells or human induced pluripotent stem-cell derived cardiomyocytes. We performed associated multiscale computer simulations to elucidate the arrhythmogenic potentials of the KCNH2 mutations. Genetic screening of the first and second index patients revealed a heterozygous missense mutation in KCNH2, resulting in an amino acid change (P632L) in the …

Multiple And Consecutive Genome Editing Using I-Gonad And Breeding Enrichment Facilitates The Production Of Genetically Modified Mice, Carolina R Melo-Silva, Cory J Knudson, Lingjuan Tang, Samita Kafle, Lauren E. Springer, Jihae Choi, Christopher M. Snyder, Yajing Wang, Sangwon V. Kim, Luis J. Sigal

Department of Microbiology and Immunology Faculty Papers

Genetically modified (GM) mice are essential tools in biomedical research. Traditional methods for generating GM mice are expensive and require specialized personnel and equipment. The use of clustered regularly interspaced short palindromic repeats (CRISPR) coupled with improved-Genome editing via Oviductal Nucleic Acids Delivery (i-GONAD) has highly increased the feasibility of producing GM mice in research laboratories. However, genetic modification in inbred mouse strains of interest such as C57BL/6 (B6) is still challenging because of their low fertility and embryo fragility. We have successfully generated multiple novel GM mouse strains in the B6 background while attempting to optimize i-GONAD. We found …

System Reliability Analysis Of The Scoliosis Disorder., Fatemeh Nouri, Seyed Hooman Ghasemi, Ji Yun Lee

Henry M. Rowan College of Engineering Faculty Scholarship

BACKGROUND: Scoliosis is a spine abnormal deviation, which is an idiopathic disorder among children and adolescents. As a matter of the fact, distribution of loads on the patient's spine and load-carrying capacity of the vertebral column are both random variables. Therefore, the probabilistic approach may consider as a sophisticated method to deal with this problem.

METHOD: Reliability analysis is a probabilistic-based approach to consider the uncertainties of load and resistance of the vertebral column. The main contribution of this paper is to compare the reliability level of a normal and scoliosis spinal. To do so, the numerical analyses associated with …

Post-Acquisition Processing Confounds In Brain Volumetric Quantification Of White Matter Hyperintensities, Ahmed A. Bahrani, Omar M. Al-Janabi, Erin L. Abner, Shoshana H. Bardach, Richard J. Kryscio, Donna M. Wilcock, Charles D. Smith, Gregory A. Jicha

Neurology Faculty Publications

BACKGROUND: Disparate research sites using identical or near-identical magnetic resonance imaging (MRI) acquisition techniques often produce results that demonstrate significant variability regarding volumetric quantification of white matter hyperintensities (WMH) in the aging population. The sources of such variability have not previously been fully explored.

NEW METHOD: 3D FLAIR sequences from a group of randomly selected aged subjects were analyzed to identify sources-of-variability in post-acquisition processing that can be problematic when comparing WMH volumetric data across disparate sites. The methods developed focused on standardizing post-acquisition protocol processing methods to develop a protocol with less than 0.5% inter-rater variance.

RESULTS: A series …

Distinct Patterns Of Default Mode And Executive Control Network Circuitry Contribute To Present And Future Executive Function In Older Adults, Christopher A. Brown, Frederick A. Schmitt, Charles D. Smith, Brian T. Gold

Neuroscience Faculty Publications

Executive function (EF) performance in older adults has been linked with functional and structural profiles within the executive control network (ECN) and default mode network (DMN), white matter hyperintensities (WMH) burden and levels of Alzheimer's disease (AD) pathology. Here, we simultaneously explored the unique contributions of these factors to baseline and longitudinal EF performance in older adults. Thirty-two cognitively normal (CN) older adults underwent neuropsychological testing at baseline and annually for three years. Neuroimaging and AD pathology measures were collected at baseline. Separate linear regression models were used to determine which of these variables predicted composite EF scores at baseline …

Diagnosing Growth In Low-Grade Gliomas With And Without Longitudinal Volume Measurements: A Retrospective Observational Study., Hassan M Fathallah-Shaykh, Andrew Deatkine, Elizabeth Coffee, Elias Khayat, Asim K Bag, Xiaosi Han, Paula Province Warren, Markus Bredel, John Fiveash, James Markert, Nidhal Carla Bouaynaya, Louis B Nabors

Henry M. Rowan College of Engineering Faculty Scholarship

BACKGROUND: Low-grade gliomas cause significant neurological morbidity by brain invasion. There is no universally accepted objective technique available for detection of enlargement of low-grade gliomas in the clinical setting; subjective evaluation by clinicians using visual comparison of longitudinal radiological studies is the gold standard. The aim of this study is to determine whether a computer-assisted diagnosis (CAD) method helps physicians detect earlier growth of low-grade gliomas.

METHODS AND FINDINGS: We reviewed 165 patients diagnosed with grade 2 gliomas, seen at the University of Alabama at Birmingham clinics from 1 July 2017 to 14 May 2018. MRI scans were collected during …

A Pilot Study Identifying Brain-Targeting Adaptive Immunity In Pediatric Extracorporeal Membrane Oxygenation Patients With Acquired Brain Injury, Sterling B. Ortega, Poornima Pandiyan, Jana Windsor, Vanessa O. Torres, Uma M. Selvaraj, Amy Lee, Michael Morriss, Fenghua Tian, Lakshmi Raman, Ann M. Stowe

Neurology Faculty Publications

OBJECTIVES: Extracorporeal membrane oxygenation provides short-term cardiopulmonary life support, but is associated with peripheral innate inflammation, disruptions in cerebral autoregulation, and acquired brain injury. We tested the hypothesis that extracorporeal membrane oxygenation also induces CNS-directed adaptive immune responses which may exacerbate extracorporeal membrane oxygenation-associated brain injury.

DESIGN: A single center prospective observational study.

SETTING: Pediatric and cardiac ICUs at a single tertiary care, academic center.

PATIENTS: Twenty pediatric extracorporeal membrane oxygenation patients (0-14 yr; 13 females, 7 males) and five nonextracorporeal membrane oxygenation Pediatric Logistic Organ Dysfunction score matched patients.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Venous blood samples were …

Dynamic Light Scattering Optical Coherence Tomography To Probe Motion Of Subcellular Scatterers., Nico J J Arezza, Marjan Razani, Michael C Kolios

Medical Biophysics Publications

Optical coherence tomography (OCT) is used to provide anatomical information of biological systems but can also provide functional information by characterizing the motion of intracellular structures. Dynamic light scattering OCT was performed on intact, control MCF-7 breast cancer cells and cells either treated with paclitaxel to induce apoptosis or deprived of nutrients to induce oncosis. Autocorrelations (ACs) of the temporal fluctuations of OCT intensity signals demonstrate a significant decrease in decorrelation time after 24 h in both the paclitaxel-treated and nutrient-deprived cell groups but no significant differences between the two groups. The acquired ACs were then used as input for …

Distinct White Matter Changes Associated With Cerebrospinal Fluid Amyloid-Β1-42 And Hypertension, Omar M. Al-Janabi, Christopher A. Brown, Ahmed A. Bahrani, Erin L. Abner, Justin M. Barber, Brian T. Gold, Larry B. Goldstein, Richard R. Murphy, Peter T. Nelson, Nathan F. Johnson, Leslie M. Shaw, Charles D. Smith, John Q. Trojanowski, Donna M. Wilcock, Gregory A. Jicha

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Alzheimer's disease (AD) pathology and hypertension (HTN) are risk factors for development of white matter (WM) alterations and might be independently associated with these alterations in older adults.

OBJECTIVE: To evaluate the independent and synergistic effects of HTN and AD pathology on WM alterations.

METHODS: Clinical measures of cerebrovascular disease risk were collected from 62 participants in University of Kentucky Alzheimer's Disease Center studies who also had cerebrospinal fluid (CSF) sampling and MRI brain scans. CSF Aβ_1-42 levels were measured as a marker of AD, and fluid-attenuated inversion recovery imaging and diffusion tensor imaging were obtained to assess …

Blood Transfusions In Preterm Infants: Changes On Perfusion Index And Intermittent Hypoxemia, Katrina T. Ibonia, Henrietta S. Bada, Philip M. Westgate, Enrique Gomez Pomar, Prasad Bhandary, Abhijit R. Patwardhan, Elie G. Abu Jawdeh

Pediatrics Faculty Publications

BACKGROUND

Red blood cell (RBC) transfusion decreases intermittent hypoxemia (IH) events beyond the first week of life. This benefit may be related to improved perfusion to the respiratory control network. Perfusion index (PI) is a perfusion measure provided by the pulse oximeter. We hypothesized that the benefit in IH after RBC transfusion is associated with an increase in PI. In addition, we assessed the value of PI and clinical measures in predicting the effect of RBC transfusion on IH.

STUDY DESIGN AND METHODS

We prospectively enrolled infants less than 30 weeks' gestation age. PI and oxygen saturation (SpO₂) …

Mechanical Demands On The Lower Back In Patients With Non-Chronic Low Back Pain During A Symmetric Lowering And Lifting Task, Iman Shojaei, Elizabeth G. Salt, Quenten L. Hooker, Babak Bazrgari

Biomedical Engineering Faculty Publications

There is limited information in the literature related to the lower back loading in patients with LBP, particularly those with non-chronic LBP. Toward addressing such a research gap, a case-control study was conducted to explore the differences in lower back mechanical loads between a group of females (n=19) with non-chronic, non-specific LBP and a group of asymptomatic females (n=19). The differences in lower back mechanical loads were determined when participants completed one symmetric lowering and lifting of a 4.5 kg load at their preferred cadence. The axial, shearing, and moment components of task demand at the time of peak moment …

Objectively Measuring Effects Of Electro-Acupuncture In Parkinsonian Rhesus Monkeys, Rui Zhang, Anders H. Andersen, Peter A. Hardy, Eric Forman, April Evans, Yi Ai, Jin Yue, Guihua Yue, Don M. Gash, Richard Grondin, Zhiming Zhang

Magnetic Resonance Imaging and Spectroscopy Center Faculty Publications

Acupuncture has increasingly been used as an alternative therapy for treatment of Parkinson’s disease (PD). However, the efficacy of acupunture for PD still remains unclear. The present study was designed to objectively and safely monitor anti-parkinsonian effects of electroacupuncture (EA) and brain activity in nonhuman primates modeling human PD. Six middle-aged rhesus monkeys were extensively studied by a computerized behavioral testing battery and by pharmacological MRI (phMRI) scans with specific dopaminergic drug stimulations. All animals were evaluated for behavior and phMRI responses under normal, parkinsonian, parkinsonian with EA treatment and parkinsonian after EA treatment conditions. Stable parkinsonian features were observed …

White Matter Hyperintensity Associations With Cerebral Blood Flow In Elderly Subjects Stratified By Cerebrovascular Risk, Ahmed A. Bahrani, David K. Powell, Guoqiang Yu, Eleanor S. Johnson, Gregory A. Jicha, Charles D. Smith

Biomedical Engineering Faculty Publications

Objective: This study aims to add clarity to the relationship between deep and periventricular brain white matter hyperintensities (WMHs), cerebral blood flow (CBF), and cerebrovascular risk in older persons. Methods: Deep white matter hyperintensity (dWMH) and periventricular white matter hyperintensity (pWMH) and regional gray matter (GM) and white matter (WM) blood flow from arterial spin labeling were quantified from magnetic resonance imaging scans of 26 cognitively normal elderly subjects stratified by cerebrovascular disease (CVD) risk. Fluidattenuated inversion recovery images were acquired using a high-resolution 3-dimensional (3-D) sequence that reduced partial volume effects seen with slicebased techniques. Results: dWMHs but not …

Using A Respiratory Navigator Significantly Reduces Variability When Quantifying Left Ventricular Torsion With Cardiovascular Magnetic Resonance, Sean M. Hamlet, Christopher M. Haggerty, Jonathan D. Suever, Gregory J. Wehner, Kristin N. Andres, David K. Powell, Richard J. Charnigo, Brandon K. Fornwalt

Electrical and Computer Engineering Faculty Publications

Background: Left ventricular (LV) torsion is an important indicator of cardiac function that is limited by high inter-test variability (50% of the mean value). We hypothesized that this high inter-test variability is partly due to inconsistent breath-hold positions during serial image acquisitions, which could be significantly improved by using a respiratory navigator for cardiovascular magnetic resonance (CMR) based quantification of LV torsion.

Methods: We assessed respiratory-related variability in measured LV torsion with two distinct experimental protocols. First, 17 volunteers were recruited for CMR with cine displacement encoding with stimulated echoes (DENSE) in which a respiratory navigator was used to measure …

Timing And Magnitude Of Lumbar Spine Contribution To Trunk Forward Bending And Backward Return In Patients With Acute Low Back Pain, Iman Shojaei, Milad Vazirian, Elizabeth G. Salt, Linda R. Van Dillen, Babak Bazrgari

Biomedical Engineering Faculty Publications

Alterations in the lumbo-pelvic coordination denote changes in neuromuscular control of trunk motion as well as load sharing between passive and active tissues in the lower back. Differences in timing and magnitude aspects of lumbo-pelvic coordination between patients with chronic low back pain (LBP) and asymptomatic individuals have been reported; yet, the literature on lumbo-pelvic coordination in patients with acute LBP is scant. A case-control study was conducted to explore the differences in timing and magnitude aspects of lumbo-pelvic coordination between females with (n=19) and without (n=19) acute LBP. Participants in each group completed one experimental session wherein they performed …

Comparison Of Lumbo-Pelvic Kinematics During Trunk Forward Bending And Backward Return Between Patients With Acute Low Back Pain And Asymptomatic Controls, Iman Shojaei, Elizabeth G. Salt, Quenten L. Hooker, Linda R. Van Dillen, Babak Bazrgari

Biomedical Engineering Faculty Publications

Background—Prior studies have reported differences in lumbo-pelvic kinematics during a trunk forward bending and backward return task between individuals with and without chronic low back pain; yet, the literature on lumbo-pelvic kinematics of patients with acute low back pain is scant. Therefore, the purpose of this study was set to investigate lumbo-pelvic kinematics in this cohort.

Methods—A case-control study was conducted to investigate the differences in pelvic and thoracic rotation along with lumbar flexion as well as their first and second time derivatives between females with and without acute low back pain. Participants in each group completed one …

Noncontact Diffuse Correlation Tomography Of Human Breast Tumor, Lian He, Yu Lin, Chong Huang, Daniel Irwin, Margaret M. Szabunio, Guoqiang Yu

Biomedical Engineering Faculty Publications

Our first step to adapt our recently developed noncontact diffuse correlation tomography (ncDCT) system for three-dimensional (3-D) imaging of blood flow distribution in human breast tumors is reported. A commercial 3-D camera was used to obtain breast surface geometry, which was then converted to a solid volume mesh. An ncDCT probe scanned over a region of interest on the mesh surface and the measured boundary data were combined with a finite element framework for 3-D image reconstruction of blood flow distribution. This technique was tested in computer simulations and in vivo human breasts with low-grade carcinoma. Results from computer simulations …

Effects Of Individualized Centrifugation Training On Orthostatic Tolerance In Men And Women, Nandu Goswami, Joyce Evans, Stefan Schneider, Melanie Von Der Wiesche, Edwin Mulder, Andreas Rössler, Helmut Hinghofer-Szalkay, Andrew P. Blaber

Biomedical Engineering Faculty Publications

AIMS: Exposure to artificial gravity (AG) at different G loads and durations on human centrifuges has been shown to improve orthostatic tolerance in men. However, the effects on women and of an individual-specific AG training protocol on tolerance are not known.

METHODS: We examined the effects of 90 minutes of AG vs. 90 minutes of supine rest on the orthostatic tolerance limit (OTL), using head up tilt and lower body negative pressure until presyncope of 7 men and 5 women. Subjects were placed in the centrifuge nacelle while instrumented and after one-hour they underwent either: 1) AG exposure …

Magnetic Resonance Imaging And Histology Correlation In The Neocortex In Temporal Lobe Epilepsy., Maged Goubran, Robert R Hammond, Sandrine De Ribaupierre, Jorge G Burneo, Seyed Mirsattari, David A Steven, Andrew G Parrent, Terry M Peters, Ali R Khan

Robarts Imaging Publications

OBJECTIVE: To investigate the histopathological correlates of quantitative relaxometry and diffusion tensor imaging (DTI) and to determine their efficacy in epileptogenic lesion detection for preoperative evaluation of focal epilepsy.

METHODS: We correlated quantitative relaxometry and DTI with histological features of neuronal density and morphology in 55 regions of the temporal lobe neocortex, selected from 13 patients who underwent epilepsy surgery. We made use of a validated nonrigid image registration protocol to obtain accurate correspondences between in vivo magnetic resonance imaging and histology images.

RESULTS: We found T1 to be a predictor of neuronal density in the neocortical gray matter (GM) …

Registration Of In-Vivo To Ex-Vivo Mri Of Surgically Resected Specimens: A Pipeline For Histology To In-Vivo Registration., Maged Goubran, Sandrine De Ribaupierre, Robert R Hammond, Catherine Currie, Jorge G Burneo, Andrew G Parrent, Terry M Peters, Ali R Khan

Robarts Imaging Publications

BACKGROUND: Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to develop and evaluate a protocol for deformable image registration of in-vivo to ex-vivo resected brain specimen MRI. This protocol, in conjunction with our previous work on ex-vivo to histology registration, completes a registration pipeline for histology to in-vivo MRI, enabling voxel-based validation of novel and existing MRI techniques with histopathology.

NEW METHOD: A combination of image-based and landmark-based 3D …

In Vivo Mri Signatures Of Hippocampal Subfield Pathology In Intractable Epilepsy., Maged Goubran, Boris C Bernhardt, Diego Cantor-Rivera, Jonathan C Lau, Charlotte Blinston, Robert R Hammond, Sandrine De Ribaupierre, Jorge G Burneo, Seyed M Mirsattari, David A Steven, Andrew G Parrent, Andrea Bernasconi, Neda Bernasconi, Terry M Peters, Ali R Khan

Robarts Imaging Publications

OBJECTIVES: Our aim is to assess the subfield-specific histopathological correlates of hippocampal volume and intensity changes (T1, T2) as well as diff!usion MRI markers in TLE, and investigate the efficacy of quantitative MRI measures in predicting histopathology in vivo.

EXPERIMENTAL DESIGN: We correlated in vivo volumetry, T2 signal, quantitative T1 mapping, as well as diffusion MRI parameters with histological features of hippocampal sclerosis in a subfield-specific manner. We made use of on an advanced co-registration pipeline that provided a seamless integration of preoperative 3 T MRI with postoperative histopathological data, on which metrics of cell loss and gliosis were quantitatively …

Noninvasive Assessment Of Cardiac Abnormalities In Experimental Autoimmune Myocarditis By Magnetic Resonance Microscopy Imaging In The Mouse., Chandirasegaran Massilamany, Vahid Khalilzad-Sharghi, Arunakumar Gangaplara, David Steffen, Shadi F. Othman, Jay Reddy

All Faculty Articles - School of Engineering and Computer Science

Myocarditis is an inflammation of the myocardium, but only -10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-α 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-α 334-352 is shown. EAM and healthy mice …

Quantitative Relaxometry And Diffusion Mri For Lateralization In Mts And Non-Mts Temporal Lobe Epilepsy., Ali R Khan, Maged Goubran, Sandrine De Ribaupierre, Robert R Hammond, Jorge G Burneo, Andrew G Parrent, Terry M Peters

Robarts Imaging Publications

We developed novel methodology for investigating the use of quantitative relaxometry (T1 and T2) and diffusion tensor imaging (DTI) for lateralization in temporal lobe epilepsy. Patients with mesial temporal sclerosis confirmed by pathology (N=8) and non-MTS unilateral temporal lobe epilepsy (N=6) were compared against healthy controls (N=19) using voxel-based analysis restricted to the anterior temporal lobes, and laterality indices for each MRI metric (T1, T2, fractional anisotropy (FA), mean diffusivity, axial and radial diffusivities) were computed based on the proportion of significant voxels on each side. The diffusivity metrics were the most lateralizing MRI metrics in MTS and non-MTS subsets, …

An Imaging-Based Platform For High-Content, Quantitative Evaluation Of Therapeutic Response In 3d Tumour Models, Jonathan P. Celli, Imran Rizvi, Adam R. Blanden, Iqbal Massodi, Iqbal Massodi, Michael D. Glidden, Brian Pogue, Tayyaba Hasan

Dartmouth Scholarship

While it is increasingly recognized that three-dimensional (3D) cell culture models recapitulate drug responses of human cancers with more fidelity than monolayer cultures, a lack of quantitative analysis methods limit their implementation for reliable and routine assessment of emerging therapies. Here, we introduce an approach based on computational analysis of fluorescence image data to provide high-content readouts of dose-dependent cytotoxicity, growth inhibition, treatment-induced architectural changes and size-dependent response in 3D tumour models. We demonstrate this approach in adherent 3D ovarian and pancreatic multiwell extracellular matrix tumour overlays subjected to a panel of clinically relevant cytotoxic modalities and appropriately designed controls …

Detection Of Temporal Lobe Epilepsy Using Support Vector Machines In Multi-Parametric Quantitative Mr Imaging., Diego Cantor-Rivera, Ali R Khan, Maged Goubran, Seyed M Mirsattari, Terry M Peters

Robarts Imaging Publications

The detection of MRI abnormalities that can be associated to seizures in the study of temporal lobe epilepsy (TLE) is a challenging task. In many cases, patients with a record of epileptic activity do not present any discernible MRI findings. In this domain, we propose a method that combines quantitative relaxometry and diffusion tensor imaging (DTI) with support vector machines (SVM) aiming to improve TLE detection. The main contribution of this work is two-fold: on one hand, the feature selection process, principal component analysis (PCA) transformations of the feature space, and SVM parameterization are analyzed as factors constituting a classification …

Image Registration Of Ex-Vivo Mri To Sparsely Sectioned Histology Of Hippocampal And Neocortical Temporal Lobe Specimens., Maged Goubran, Cathie Crukley, Sandrine De Ribaupierre, Terence M Peters, Ali R Khan

Robarts Imaging Publications

Intractable or drug-resistant epilepsy occurs in up to 30% of epilepsy patients, with many of these patients undergoing surgical excision of the affected brain region to achieve seizure control. Recent magnetic resonance imaging (MRI) sequences and analysis techniques have the potential to detect abnormalities not identified with diagnostic MRI protocols. Prospective studies involving pre-operative imaging and collection of surgically-resected tissue provide a unique opportunity for verification and tuning of these image analysis techniques, since direct comparison can be made against histopathology, and can lead to better prediction of surgical outcomes and potentially less invasive procedures. To carry out MRI and …

Dopaminergic Modulation Of Memory And Affective Processing In Parkinson Depression, Lee X. Blonder, John T. Slevin, Richard J. Kryscio, Catherine A. Martin, Anders H. Andersen, Charles D Smith, Frederick A. Schmitt

Magnetic Resonance Imaging and Spectroscopy Center Faculty Publications

Depression is common in Parkinson's disease and is associated with cognitive impairment. Dopaminergic medications are effective in treating the motor symptoms of Parkinson's disease; however, little is known regarding the effects of dopaminergic pharmacotherapy on cognitive function in depressed Parkinson patients. This study examines the neuropsychological effects of dopaminergic pharmacotherapy in Parkinsonian depression. We compared cognitive function in depressed and non-depressed Parkinson patients at two time-points: following overnight withdrawal and after the usual morning regimen of dopaminergic medications. A total of 28 non-demented, right-handed patients with mild to moderate idiopathic Parkinson's disease participated. Ten of these patients were depressed according …

Scanning In Situ Spectroscopy Pplatform For Imaging Surgical Breast Tissue Specimens, Venkataramanan Krishnaswamy, Ashley M. Laughney, Wendy A. Wells, Keith D. Paulsen, Brian W. Pogue

Dartmouth Scholarship

A non-contact localized spectroscopic imaging platform has been developed and optimized to scan 1 x 1 cm² square regions of surgically resected breast tissue specimens with ~150-micron resolution. A color corrected, image-space telecentric scanning design maintained a consistent sampling geometry and uniform spot size across the entire imaging field. Theoretical modeling in ZEMAX allowed estimation of the spot size, which is equal at both the center and extreme positions of the field with ~5% variation across the designed waveband, indicating excellent color correction. The spot sizes at the center and an extreme field position were also measured experimentally using the …

Load-Relaxation Properties Of The Human Trunk In Response To Prolonged Flexion: Measuring And Modeling The Effect Of Flexion Angle, Nima Toosizadeh, Maury A. Nussbaum, Babak Bazrgari, Michael L. Madigan

Biomedical Engineering Faculty Publications

Experimental studies suggest that prolonged trunk flexion reduces passive support of the spine. To understand alterations of the synergy between active and passive tissues following such loadings, several studies have assessed the time-dependent behavior of passive tissues including those within spinal motion segments and muscles. Yet, there remain limitations regarding load-relaxation of the lumbar spine in response to flexion exposures and the influence of different flexion angles. Ten healthy participants were exposed for 16 min to each of five magnitudes of lumbar flexion specified relative to individual flexion-relaxation angles (i.e., 30, 40, 60, 80, and 100%), during which lumbar flexion …

A Digital X-Ray Tomosynthesis Coupled Near Infrared Spectral Tomography System For Dual-Modality Breast Imaging, Venkataramanan Krishnaswamy, Kelly E. Michaelsen, Brian W. Pogue, Steven P. Poplack, Ian Shaw, Ken Defrietas, Ken Brooks, Keith D. Paulsen

Dartmouth Scholarship

A Near Infrared Spectral Tomography (NIRST) system has been developed and integrated into a commercial Digital Breast Tomosynthesis (DBT) scanner to allow structural and functional imaging of breast in vivo. The NIRST instrument uses an 8-wavelength continuous wave (CW) laser-based scanning source assembly and a 75-element silicon photodiode solid-state detector panel to produce dense spectral and spatial projection data from which spectrally constrained 3D tomographic images of tissue chromophores are produced. Integration of the optical imaging system into the DBT scanner allows direct co-registration of the optical and DBT images, while also facilitating the synergistic use of x-ray contrast as …