Medicine and Health Sciences Commons^™

Protoporphyrin Ix Fluorescence Contrast In Invasive Glioblastomas Is Linearly Correlated With Gd Enhanced Magnetic Resonance Image Contrast But Has Higher Diagnostic Accuracy, Kimberley S. Samkoe, Summer L. Gibbs-Strauss, Harold H. Yang, S. Khan Hekmatyar, P. Jack Hoopes, Julia A. O'Hara, Risto A. Kauppinen, Brian W. Pogue

Dartmouth Scholarship

The sensitivity and specificity of in vivo magnetic resonance (MR) imaging is compared with production of protoporphyrin IX (PpIX), determined ex vivo, in a diffusely infiltrating glioma. A human glioma transfected with green fluorescent protein, displaying diffuse, infiltrative growth, was implanted intracranially in athymic nude mice. Image contrast from corresponding regions of interest (ROIs) in in vivo MR and ex vivo fluorescence images was quantified. It was found that all tumor groups had statistically significant PpIX fluorescence contrast and that PpIX contrast demonstrated the best predictive power for tumor presence. Contrast from gadolinium enhanced T1-weighted (T1W+Gd) and absolute T2 …

In Vivo Cellular Mri In Experimental Traumatic Spinal Cord Injury, Laura E. Gonzalez-Lara

Electronic Thesis and Dissertation Repository

Spinal cord injury (SCI) remains one of the most devastating conditions in medicine; it is a complex medical condition with no cure currently available. Inflammation plays an important role in SCI as it can have both beneficial and detrimental effects. Cell therapy has emerged as a promising treatment for SCI due to the potential for stem cells, including multipotent mesenchymal stromal cells (MSC), for tissue regeneration and immunomodulation of the inflammatory cascade after the initial trauma. However, there are still important, unresolved questions regarding cell therapy that magnetic resonance imaging (MRI) can help to address by producing high-resolution images with …

Remote Positioning Optical Breast Magnetic Resonance Coil For Slice-Selection During Image-Guided Near-Infrared Spectroscopy Of Breast Cancer, Michael A. Mastanduno, Shudong Jiang, Brian W. Pogue, Keith D. Paulsen, Roberta Diflorio-Alexander

Dartmouth Scholarship

The design and testing of a pneumatic optical positioning interface produced with the goal of improving fiber positioning in magnetic resonance (MR)-guided diffuse spectral imaging of breast cancer is presented. The system was created for vertical positioning of optical fibers inside the MR bore during a patient exam to target suspicious lesions with MR scans for reference and collect multiple planes of optical data. The interface includes new fiber plates for mechanical and optical coupling to the breast, and was tested in phantoms and human imaging. Reconstructions with data taken in the new interface show acceptable linearity over different absorber …

Characterization Of Quadriceps Neuromuscular Function In Knee Osteoarthritis, Michael James Berger

Electronic Thesis and Dissertation Repository

PURPOSE: The purpose of this thesis was to characterize quadriceps neuromuscular dysfunction in patients with knee osteoarthritis (OA). Concerns pertaining to study design in this patient population (e.g. disease severity criteria and muscle imaging outcome measures) were also addressed.

METHODS: Five studies were undertaken using data acquired from volunteers recruited at the local institution and from participants in the public source dataset of the Osteoarthritis Initiative (http://oai.epi-ucsf.org/datarelease/). Clinical disease severity was evaluated with the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Radiographic severity was evaluated with Kellgren-Lawrence Grading (KLG). Quadriceps muscle isometric strength and isotonic power were measured …

Do Radiologists, Radiology Administrators, And Radiology Technologists Believe There Is Over Utilization Of Cat Scan And Mri Exams And If So What Do They Recommend To Ameliorate The Issue?, Joseph Gonzales

Regis University Student Publications (comprehensive collection)

Objective: Purpose of this study was to assess the opinions of Radiologist, Radiology Technologist, and Radiology Administrators, as to their belief if CAT Scan and MRI are over utilized, to determine if there are best practices in place if there is over utilization, and set the basis for future studies. Methods: After analyzing several methods, it was determined the most appropriate way to understand what individual's thoughts are, and what they are doing was to reach out to the above groups using a descriptive survey. A survey using the Website www.surveymonkey.com was created to investigate the opinions of radiologists, radiology …

From Isolated Tumour Cells To Overt Lymph Node Metastases: Biological And Imaging Studies On The Development Of Experimental Lymph Node Metastases, Michael M. Lizardo

Electronic Thesis and Dissertation Repository

Metastatic colonization and establishment of overt lymph node (LN) tumours indicates poor prognosis for cancer patients. However, the basic biology that influences the development of LN metastasis is poorly understood due to the lack of basic animal models. The following work provides a new lymph node experimental metastasis assay (LEMA) that permits the assessment of tumour cell fate after they arrest in draining LNs. In using this new model, we discovered that only 8% of the tumour cells that arrive in the LN are successful in forming overt tumours. This work also explored the use of imaging approaches to monitor …

Current Review Of In Nivo Gbm Rodent Models: Emphasis On The Cns-1 Tumour Model, Valerie L. Jacobs, Pablo A. Valdes, William F. Hickey, Joyce A. De Leo

Dartmouth Scholarship

GBM (glioblastoma multiforme) is a highly aggressive brain tumour with very poor prognosis despite multi-modalities of treatment. Furthermore, recent failure of targeted therapy for these tumours highlights the need of appropriate rodent models for preclinical studies. In this review, we highlight the most commonly used rodent models (U251, U86, GL261, C6, 9L and CNS-1) with a focus on the pathological and genetic similarities to the human disease. We end with a comprehensive review of the CNS-1 rodent model.

Hippocampal Volume Differences In Gulf War Veterans With Current Versus Lifetime Posttraumatic Stress Disorder Symptoms, Brigitte A. Apfel, Jessica Ross, Jennifer Hlavin, Dieter J. Meyerhoff, Thomas J. Metzler, Charles R. Marmar, Michael W. Weiner, Norbert Schuff, Thomas C. Neylan

Public Health Resources

Background: Decreased hippocampal volume is described in posttraumatic stress disorder (PTSD) and depression. However, it is not known whether it is a risk factor for the development of PTSD or a consequence of PTSD. We sought to determine the effects of PTSD and depressive symptoms on hippocampal volume.

Methods: Clinical and magnetic resonance imaging data were collected in a cross sectional study of 244 GulfWarveterans. Measures included lifetime and current Clinician Administered PTSD Scale, Hamilton Depression Scale, Life Stressor Checklist, and Lifetime Drinking History. Magnetic resonance imaging data were acquired with a 1.5-T scanner and analyzed with automated …

Nitrous Oxide Anesthesia In Children For Mri: A Comparison With Isoflurane And Halothane, Mehmet Emi̇n Orhan, Ferruh Bi̇lgi̇n, Oğuz Kiliçkaya, Abdulkadi̇r Atim, Ercan Kurt

Turkish Journal of Medical Sciences

To compare the anesthetic effects of nitrous oxide, isoflurane, and halothane on hemodynamic stability and recovery characteristics in pediatric patients during magnetic resonance imaging (MRI). Materials and methods: The present study includes 60 ASA I-II children aged 1-12 years undergoing MRI. After endotracheal intubation, patients were randomly assigned into 1 of 3 anesthetic groups. Group N (n = 20) received nitrous oxide and oxygen (N_2O:O_2 60:40), Group I (n = 20) received 0.5% isoflurane and oxygen, Group H (n = 20) received 0.5% halothane and oxygen to maintain anesthesia. At the completion of the procedure, inhalation anesthetic was discontinued. Extubation, …

Histogram Analysis Of Adc In Brain Tumor Patients, Debrup Banerjee, Jihong Wang, Jiang Li, Norbert J. Pelc (Ed.), Ehsan Samei (Ed.), Robert M. Nishikawa (Ed.)

Electrical & Computer Engineering Faculty Publications

At various stage of progression, most brain tumors are not homogenous. In this presentation, we retrospectively studied the distribution of ADC values inside tumor volume during the course of tumor treatment and progression for a selective group of patients who underwent an anti-VEGF trial. Complete MRI studies were obtained for this selected group of patients including pre- and multiple follow-up, post-treatment imaging studies. In each MRI imaging study, multiple scan series were obtained as a standard protocol which includes T1, T2, T1-post contrast, FLAIR and DTI derived images (ADC, FA etc.) for each visit. All scan series (T1, T2, FLAIR, …

Prediction Of Brain Tumor Progression Using Multiple Histogram Matched Mri Scans, Debrup Banerjee, Loc Tran, Jiang Li, Yuzhong Shen, Frederic Mckenzie, Jihong Wang, Ronald M. Summers (Ed.), Bram Van Ginneken (Ed.)

Electrical & Computer Engineering Faculty Publications

In a recent study [1], we investigated the feasibility of predicting brain tumor progression based on multiple MRI series and we tested our methods on seven patients' MRI images scanned at three consecutive visits A, B and C. Experimental results showed that it is feasible to predict tumor progression from visit A to visit C using a model trained by the information from visit A to visit B. However, the trained model failed when we tried to predict tumor progression from visit B to visit C, though it is clinically more important. Upon a closer look at the MRI scans …