Medicine and Health Sciences Commons^™

Genome-Wide Significant Linkage Of Schizophrenia-Related Neuroanatomical Trait To 12q24, Emma Sprooten, Cota Navin Gupta, Emma Knowles, D. Reese Mckay, Samuel R. Mathias, Joanne E. Curran, Jack W. Kent Jr., Melanie A. Carless, Marcio Almeida, Thomas D. Dyer, Harald H. H. Goring, Rene L. Olvera, Peter T. Fox, Ravi Duggirala, Laura Almasy, John Blangero

School of Medicine Publications and Presentations

The insula and medial prefrontal cortex (mPFC) share functional, histological, transcriptional and developmental characteristics and they serve higher cognitive functions of theoretical relevance to schizophrenia and related disorders. Meta-analyses and multivariate analysis of structural magnetic resonance imaging (MRI) scans indicate that gray matter density and volume reductions in schizophrenia are the most consistent and pronounced in a network primarily composed of the insula and mPFC. We used source-based morphometry, a multivariate technique optimized for structural MRI, in a large sample of randomly ascertained pedigrees (N = 887) to derive an insula-mPFC component and to investigate its genetic determinants. Firstly, we …

Characterization Of Maga Expression And Iron Uptake In P19 Cells: Implications For Use As A Gene-Based Contrast Agent, Linshan Liu

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) is one of the non-invasive imaging modalities used in longitudinal cell tracking. Previous studies suggest that MagA, a putative iron transport protein from magnetotactic bacteria, is a useful gene-based magnetic resonance contrast agent. Hemagglutinin (HA)-tagged MagA was stably expressed in undifferentiated embryonic mouse teratocarcinoma, multipotent P19 stem cells to provide a suitable model for tracking these cells during differentiation. Western blot and immunocytochemistry confirmed the expression and membrane localization of MagA-HA in P19 cells. Elemental iron analysis using inductively-coupled plasma mass spectrometry revealed significant iron uptake in both parental and MagA-HA-expressing P19 cells, cultured in the …

Magnetic Resonance Imaging Compatible Remote Catheter Navigation System, Mohammad Ali Tavallaei

Electronic Thesis and Dissertation Repository

Many vascular and cardiac diseases are diagnosed and treated using a medical technique known as percutaneous transluminal catheter intervention (PTC). In PTC, the interventionalist inserts a catheter into the vasculature, and using the vessel as the guiding passageway, the catheter is navigated to desired anatomical targets where it would be used for various purposes such as catheter ablation for the treatment/management of cardiac arrhythmias. The catheterization procedure is conventionally guided with x-ray fluoroscopic imaging and more recently, but rarely, with Magnetic Resonance Imaging (MRI). X-ray imaging irradiates the patient directly during the procedure, and the staff and interventionalists indirectly through …

Disruption Of White Matter Integrity In Adult Survivors Of Childhood Brain Tumors: Correlates With Long-Term Intellectual Outcomes, Tricia Z. King, Liya Wang, Hui Mao

Psychology Faculty Publications

Background

Although chemotherapy and radiation treatment have contributed to increased survivorship, treatment-induced brain injury has been a concern when examining long-term intellectual outcomes of survivors. Specifically, disruption of brain white matter integrity and its relationship to intellectual outcomes in adult survivors of childhood brain tumors needs to be better understood.

Methods

Fifty-four participants underwent diffusion tensor imaging in addition to structural MRI and an intelligence test (IQ). Voxel-wise group comparisons of fractional anisotropy calculated from DTI data were performed using Tract Based Spatial Statistics (TBSS) on 27 survivors (14 treated with radiation with and without chemotherapy and 13 treated without …

In Ovo Serial Skeletal Muscle Diffusion Tractography Of The Developing Chick Embryo Using Dti: Feasibility And Correlation With Histology, Zien Zhou, Zachary Delproposto, Lianming Wu, Jianrong Xu, Jia Hua, Yan Zhou, Yongquan Ye, Zishu Zhang, Jiani Hu, E Mark Haacke

Yan Zhou 周彦文档

Abstract Background Magnetic resonance imaging is a noninvasive method of evaluating embryonic development. Diffusion tensor imaging (DTI), based on the directional diffusivity of water molecules, is an established method of evaluating tissue structure. Yet embryonic motion degrades the in vivo acquisition of long-duration DTI. We used a dual-cooling technique to avoid motion artifact and aimed to investigate whether DTI can be used to monitor chick embryonic skeletal muscle development in ovo, and to investigate the correlation between quantitative DTI parameters fractional anisotropy (FA) and fiber length and quantitative histologic parameters fiber area percentage (FiberArea%) and limb length. Results From 84 …

Magnetic Resonance Imaging Of Folic Acid-Coated Magnetite Nanoparticles Reflects Tissue Biodistribution Of Long-Acting Antiretroviral Therapy., Tianyuzi Li, Howard Gendelman, Gang Zhang, Pavan Puligujja, Joellyn Mcmillan, Tatiana K. Bronich, Benson Edagwa, Xin-Ming Liu, Michael D. Boska

Journal Articles: Pharmacology & Experimental Neuroscience

Regimen adherence, systemic toxicities, and limited drug penetrance to viral reservoirs are obstacles limiting the effectiveness of antiretroviral therapy (ART). Our laboratory's development of the monocyte-macrophage-targeted long-acting nanoformulated ART (nanoART) carriage provides a novel opportunity to simplify drug-dosing regimens. Progress has nonetheless been slowed by cumbersome, but required, pharmacokinetic (PK), pharmacodynamics, and biodistribution testing. To this end, we developed a small magnetite ART (SMART) nanoparticle platform to assess antiretroviral drug tissue biodistribution and PK using magnetic resonance imaging (MRI) scans. Herein, we have taken this technique a significant step further by determining nanoART PK with folic acid (FA) decorated magnetite …

Anisotropic Smoothing Improves Dt-Mri-Based Muscle Fiber Tractography, Amanda K W Buck, Zhaohua Ding, Christopher P. Elder, Theodore F. Towse, Bruce M. Damon

Peer Reviewed Articles

Purpose

To assess the effect of anisotropic smoothing on fiber tracking measures, including pennation angle, fiber tract length, and fiber tract number in the medial gastrocnemius (MG) muscle in healthy subjects using diffusion-weighted magnetic resonance imaging (DW-MRI).

Materials and Methods

3T DW-MRI data were used for muscle fiber tractography in the MG of healthy subjects. Anisotropic smoothing was applied at three levels (5%, 10%, 15%), and pennation angle, tract length, fiber tract number, fractional anisotropy, and principal eigenvector orientation were quantified for each smoothing level.

Results

Fiber tract length increased with pre-fiber tracking smoothing, and local heterogeneities in fiber direction …

Belief About Nicotine Selectively Modulates Value And Reward Prediction Error Signals In Smokers, Xiaosi Gu, Terry Lohrenz, Ramiro Salas, Philip R. Baldwin, Alireza Soltani

Dartmouth Scholarship

Little is known about how prior beliefs impact biophysically described processes in the presence of neuroactive drugs, which presents a profound challenge to the understanding of the mechanisms and treatments of addiction. We engineered smokers' prior beliefs about the presence of nicotine in a cigarette smoked before a functional magnetic resonance imaging session where subjects carried out a sequential choice task. Using a model-based approach, we show that smokers' beliefs about nicotine specifically modulated learning signals (value and reward prediction error) defined by a computational model of mesolimbic dopamine systems. Belief of "no nicotine in cigarette" (compared with "nicotine in …

Short-Term Cortical Plasticity Associated With Feedback-Error Learning After Locomotor Training In A Patient With Incomplete Spinal Cord Injury, Amanda E. Chisholm, Sue Peters, Michael R. Borich, Lara A. Boyd, Tania Lam

Physical Therapy Publications

Background and purpose: For rehabilitation strategies to be effective, training should be based on principles of motor learning, such as feedback-error learning, that facilitate adaptive processes in the nervous system by inducing errors and recalibration of sensory and motor systems. This case report suggests that locomotor resistance training can enhance somatosensory and corticospinal excitability and modulate resting-state brain functional connectivity in a patient with motor-incomplete spinal cord injury (SCI).

Case description: The short-term cortical plasticity of a 31-year-old man who had sustained an incomplete SCI 9.5 years previously was explored in response to body-weight-supported treadmill training with velocity-dependent resistance applied …

Pulmonary Abnormalities And Carotid Atherosclerosis In Ex-Smokers Without Airflow Limitation., Damien Pike, Miranda Kirby, Tamas J Lindenmaier, Khadija Sheikh, Casey E Neron, Daniel G Hackam, J David Spence, Aaron Fenster, Nigel A M Paterson, Don D Sin, Harvey O Coxson, David G Mccormack, Grace Parraga

Medical Biophysics Publications

Abstract It is well-established that COPD patients have a burden of vascular disease that cannot be fully-explained by smoking history but the mechanistic links between atherosclerosis and pulmonary disease in COPD patients are not well-understood. Moreover, in ex-smokers without symptoms or other evidence of COPD, subclinical pulmonary and vascular disease, although potentially present, has not been described or evaluated. Hence our aim was to use sensitive three-dimensional (3D) pulmonary and carotid imaging to quantify pulmonary airway/parenchyma abnormalities and atherosclerosis in ex-smokers without airflow limitation or symptoms consistent with COPD. We evaluated 61 subjects without airflow limitation including 34 never- (72 …

What Are The Recommended Timing And Screening Modalities For Women At Higher Risk Of Developing Breast Cancer? A Clin-Iq, Summer Jatala, Shawn Fitzgerald, Pamela Tietze, Kalyanakrishnan Ramakrisnan, Laine H. Mccarthy, Elizabeth Wickersham

Journal of Patient-Centered Research and Reviews

Early detection of breast cancer is desirable to prevent progression to advanced disease. This subject has been one of significant study and debate for women at normal risk, and recommendations continue to evolve. However, with regard to women at high risk, the recommendations from various health care professional organizations, including the U.S. Preventive Services Task Force, are different and also inconsistent concerning when to begin screening and which modalities should be used. We review several randomized controlled trials and consensus opinions regarding when to begin screening for breast cancer and how to best screen women at high risk. Specifically, we …

Adiposity And Spinal Cord Injury, Ashraf S. Gorgey, Kathryn M. Wells, Timothy L. Austin

Physical Medicine and Rehabilitation Publications

The drastic changes in body composition following spinal cord injury (SCI) have been shown to play a significant role in cardiovascular and metabolic health. The pattern of storage and distribution of different types of adipose tissue may impact metabolic health variables similar to carbohydrate, lipid and bone metabolism. The use of magnetic resonance imaging provides insights on the interplay among different regional adipose tissue compartments and their role in developing chronic diseases. Regional adipose tissue can be either distributed centrally or peripherally into subcutaneous and ectopic sites. The primary ectopic adipose tissue sites are visceral, intramuscular and bone marrow. Dysfunction …

Tumor-Specific Expression And Detection Of A Cest Reporter Gene, Il Minn, Amnon Bar-Shir, Keerthi Yarlagadda, Jeff W. M. Bulte, Paul B. Fisher, Hao Wang, Assaf A. Gilad, Martin G. Pomper

Human and Molecular Genetics Publications

Purpose

To develop an imaging tool that enables the detection of malignant tissue with enhanced specificity using the exquisite spatial resolution of MRI.

Methods

Two mammalian gene expression vectors were created for the expression of the lysine-rich protein (LRP) under the control of the cytomegalovirus (CMV) promoter and the progression elevated gene-3 promoter (PEG-3 promoter) for constitutive and tumor-specific expression of LRP, respectively. Using those vectors, stable cell lines of rat 9L glioma, 9LCMV-LRP and 9LPEG-LRP, were established and tested for CEST contrast in vitro and in vivo.

Results

9LPEG-LRP cells showed increased CEST contrast compared with 9L cells …

Tumor-Specific Expression And Detection Of A Cest Reporter Gene, Il Minn, Amnon Bar-Shir, Keerthi Yarlagadda, Jeff W. M. Bulte, Paul B. Fisher, Hao Wang, Assaf A. Gilad, Martin G. Pomper

Human and Molecular Genetics Publications

Purpose

To develop an imaging tool that enables the detection of malignant tissue with enhanced specificity using the exquisite spatial resolution of MRI.

Methods

Two mammalian gene expression vectors were created for the expression of the lysine-rich protein (LRP) under the control of the cytomegalovirus (CMV) promoter and the progression elevated gene-3 promoter (PEG-3 promoter) for constitutive and tumor-specific expression of LRP, respectively. Using those vectors, stable cell lines of rat 9L glioma, 9LCMV-LRP and 9LPEG-LRP, were established and tested for CEST contrast in vitro and in vivo.

Results

9LPEG-LRP cells showed increased CEST contrast compared with 9L cells …

Craniopharyngioma Causing Bilateral Vision Loss 4 Months After Unremarkable Magnetic Resonance Imaging Of The Brain, Rainy Betts, Curtis E. Margo, Mitchell Drucker

Ophthalmology Faculty Publications

A 65-year-old man developed bilateral vision loss 4 months after magnetic resonance imaging demonstrated no lesion in the vicinity of the optic chiasm, hypothalamus, and suprasellar tissues. Repeat computed tomography 3 months later showed a predominantly cystic mass of the suprasellar cistern with extension into the anterior third ventricle, which histologically was a craniopharyngioma. The clinical course of this case fuels the controversy whether craniopharyngiomas arise from embryonic rests or can be acquired. From a clinical perspective, it raises questions about when to obtain imaging studies dedicated to the chiasm and the appropriate interval in which a scan should be …

Tracking The Fate Of Stem Cell Implants With Fluorine-19 Mri., Jeffrey M Gaudet, Emeline J Ribot, Yuhua Chen, Kyle M Gilbert, Paula J Foster

Medical Biophysics Publications

BACKGROUND: In this study we used cellular magnetic resonance imaging (MRI) to detect mesenchymal stem cells (MSC) labeled with a Fluorine-19 (19F) agent. 19F-MRI offers unambiguous detection and in vivo quantification of labeled cells.

METHODS: We investigated two common stem cell transplant mouse models: an immune competent, syngeneic transplant model and an immune compromised, xenograft transplant model. 19F labelled stem cells were implanted intramuscularly into the hindlimb of healthy mice. The transplant was then monitored for up to 17 days using 19F-MRI, after which the tissue was excised for fluorescence microscopy and immunohistochemisty.

RESULTS: Immediately following transplantation, 19F-MRI quantification correlated …

Information Maximizing Component Analysis Of Left Ventricular Remodeling Due To Myocardial Infarction, Xingyu Zhang, Bharath Ambale-Venkatesh, David A. Bluemke, Brett R. Cowan, J. Paul Finn, Alan H. Kadish, Pau Medrano-Gracia

Office of the President Publications and Research

Background: Although adverse left ventricular shape changes (remodeling) after myocardial infarction (MI) are predictive of morbidity and mortality, current clinical assessment is limited to simple mass and volume measures, or dimension ratios such as length to width ratio. We hypothesized that information maximizing component analysis (IMCA), a supervised feature extraction method, can provide more efficient and sensitive indices of overall remodeling.

Methods: IMCA was compared to linear discriminant analysis (LDA), both supervised methods, to extract the most discriminatory global shape changes associated with remodeling after MI. Finite element shape models from 300 patients with myocardial infarction from the …

Low-Field Magnetic Resonance Anatomic Features Of The Neonatalfoal Thorax: An Ex Vivo Study, Alberto Arencibia, José Ángel Sandoval, Francisco Gil, José Raduán Jaber, Diego Blanco, Andrés Diz, José María Vázquez

Turkish Journal of Veterinary & Animal Sciences

The purpose of this study was to describe the normal appearance of the bony and soft tissue structures of the thorax of neonatal foals by low-field magnetic resonance imaging (MRI) and the use of anatomical dissections and gross sections. Three purebred Spanish neonatal foals that died for medical reasons unrelated to thoracic disease were used to obtain T1- and T2-weighted MR images using a magnet of 0.2 Tesla. Anatomic structures on the MR images were evaluated according to characteristics of signal intensity of the different organic tissues. The bones, different associated muscles, diaphragm, trachea, main bronchi, lungs, esophagus, heart chambers, …

Heart Performance Of Lambs And Its Relation To Muscle Volume And Body Surface, Róbert Romvári, Csaba Hancz, Péter Horn, Zsolt Petrási, András Szabó, Dávid Mezöszentgyörgyi, Imre Repa

Turkish Journal of Veterinary & Animal Sciences

Electrocardiography-gated dynamic magnetic resonance imaging (MRI) methodology was developed for the in vivo examination of sheep heart characteristics. By combining noninvasive determination of skeletal muscle mass, we studied the relationship between total body skeletal muscle content and heart performance. Measurements were carried out on male Merino lambs using 1.5 T field strength equipment. Average left ventricular volumes were determined and stroke volume was estimated during image postprocessing. Ejection fraction was calculated (73 ± 1.8%) and the cardiac output (CO) value was estimated (2.75 ± 0.16 L/min). After measuring left ventricular wall thickness, contraction values were determined at the septum (62%), …

A Comparative Study Of Two Prediction Models For Brain Tumor Progression, Deqi Zhou, Loc Tran, Jihong Wang, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.)

Electrical & Computer Engineering Faculty Publications

MR diffusion tensor imaging (DTI) technique together with traditional T1 or T2 weighted MRI scans supplies rich information sources for brain cancer diagnoses. These images form large-scale, high-dimensional data sets. Due to the fact that significant correlations exist among these images, we assume low-dimensional geometry data structures (manifolds) are embedded in the high-dimensional space. Those manifolds might be hidden from radiologists because it is challenging for human experts to interpret high-dimensional data. Identification of the manifold is a critical step for successfully analyzing multimodal MR images.

We have developed various manifold learning algorithms (Tran et al. 2011; Tran et al. …