Radiology Commons^™

Magnetically Focused Proton Irradiation Of Small Volume Radiosurgery Targets Using A Triplet Of Quadrupole Magnets, Patrick Mcgee, Grant Mcauley, Andrew Wroe, James M. Slater, Jerry D. Slater

Loma Linda University Student Journal

Proton therapy is an advantageous choice for the irradiation of tumors in proximity of critical structures due to rapid dose fall off and high dose deposition at target compared to dose at the surface of the patient (ie, peak-to-entrance dose ratio (P/E)). However, with target fields below 1.0 cm, as often encountered in proton radiosurgery, multiple Coulomb scattering (MCS) broadens proton beams leading to diminished P/E advantages and reduced dose delivery efficiency (DDE). Magnetic focusing tends to counteract MCS and is a promising method to reduce these undesirable effects. The purpose of this research is to investigate the advantages of …

Diffusion Tensor Imaging Findings In Pediatric Patients With Mild Traumatic Brain Injury, Tshea Dowers, B L. Bartnik, Barbara Holshouser, Stephen Ashwal, Samuel Barnes

Loma Linda University Student Journal

Approximately 14% of school age children with sports-related concussions (SRC) remain symptomatic 3 months after injury. Previous studies have used diffusion tensor imaging (DTI) to detect white matter tract changes in regions of interest in symptomatic patients; however data in the pediatric population remains limited. This study was undertaken to determine whether DTI metrics can provide valuable information in pediatric mTBI patients with persistent symptoms.

Mr Screening For Acute Stroke Intervention Using A Patient Specific Screening Paradigm, Brian Cristiano Md

LLUMC Radiology Research Days

No abstract provided.

Automated Computer Analysis Of Core Infarct Size And Perfusion Mismatch, Johnny Suh Md

LLUMC Radiology Research Days

No abstract provided.

Measuring The Change In Size Of Intracranial Hematomas On Swi After Administration Of Normobaric Oxygen, Mohammad Kassir Md

LLUMC Radiology Research Days

No abstract provided.

Metabolic Syndrome And Progression Of Mild Cognitive Impairment, Eric Peters Md

LLUMC Radiology Research Days

No abstract provided.

Cross-Sectional Psoas Area As A Predictor Of Postoperative Morbidity And Mortality In Surgical Oncology Patients, Chad Burk Md

LLUMC Radiology Research Days

No abstract provided.

Cerebral Deoxyhemoglobin Imaging: A Biomarker For Poor Neurological Outcomes In Neonates With Acute Hypoxic Ischemic Brain Injury (Hi-Bi), Austin Trihh Md

LLUMC Radiology Research Days

No abstract provided.

Sensitivity And Specificity Of Sacral Arcuate Line Disruption For Fractures On Plain Radiography, Alex Sun Md

LLUMC Radiology Research Days

No abstract provided.

Gadobenate Disodium (Multihance) Deposition In The Globus Pallidus And Dentate Nucleus, Arian Mashhood Md

LLUMC Radiology Research Days

No abstract provided.

Radiation Dose In Vascular Surgery Procedures, K. Arsalaan Ahmed Md

LLUMC Radiology Research Days

No abstract provided.

Facial Type Analysis Comparison Between Mri, Cbct, And Lateral Cephalometrics, Matthew A. Sanders

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Single Cephalometric measurements are comparable between Cone Beam Computed Tomography (CBCT), Magnetic Resonance Imaging (MRl) and Conventional Lateral Cephalometric (LC) imaging methods. This study evaluated the agreement between the three imaging methods in facial type analysis (using a composite of 5 cephalometric measures).

Methods and Materials: Twenty-two subjects participated in this study. Cranial images were generated via three modalities: LC, CBCT and MRl. Cephalometric landmarks were identified on the three images per subject and a facial type analysis performed. An equally weighted facial type calculation composed of 5 cephalometric measurements (facial axis, facial depth, mandibular plane, lower face height, …

Correlating The Slope Of The Vomer With Cephalometric Vectors Of Facial Growth, Ryan Michael Pulfer

Loma Linda University Electronic Theses, Dissertations & Projects

It is important for orthodontists to have a basic understanding of the growth and development of the face. Scott's nasal septal cartilage theory proposes that the cartilage of the nasal septum proliferates along the anterior slope of the vomer bone by interstitial growth, simultaneously pulling and displacing the maxilla downward and forward. It is therefore logical to conclude that the vector of nasomaxillary growth has a geometric correlation with the anterior slope of the vomer bone.

There are no published studies comparing either the anterior or posterior slope of the vomer with any lateral cephalometric landmarks, the vectors of nasomaxillary …

Creating Prediction Models For Obstructive Sleep Apnea Based On Gender, Jeffrey Hwang

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Obstructive sleep apnea (OSA) is a common chronic disorder that is characterized by repetitive episodes of airflow cessation or reduction occurring during sleep as a result of partial or complete upper airway obstruction. These recurrent events have a tremendous impact on the cardiovascular system with a multitude of dangerous consequences. Numerous studies have been conducted determining etiological risk factors for OSA including anatomical predictors which have been observed with multiple imaging techniques. Cone beam computed tomography (CBCT) is a low-radiation mode of imaging that can be used to accurately identify anatomical landmarks and measure craniofacial relationships and airway dimensions. …

Microct Study Of Critical-Sized Defects Restored With A New Rhbmp-2 Carrier, Joanne S. Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Regenerating bone in critical-sized maxillofacial osseous defects remains a challenge. The utilization of recombinant human bone morphogenetic protein-2 (rhBMP-2) to form new bone has been shown to be a promising alternative to autogenous bone grafts, and the development of a carrier matrix to effectively deliver the rhBMP-2 has been identified as the critical factor necessary for the successful clinical application of rhBMP-2. The objective of this study was to perform a microCT analysis to examine the density of reconstructed bone using different rhBMP-2 carriers in critical-sized defects.

Material and Methods: Critical-sized defects (approximately 2.5 cm) were created in the …

Using Cone Beam Computed Tomography To Identify A Prediction Model For Obstructive Sleep Apnea, Jodi Parker

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Obstructive Sleep Apnea (OSA) patients have increased risk of morbidity and mortality. Early diagnosis may reduce morbidity and mortality. Prediction of OSA from imaging may help to identify OSA patients earlier in life. CBCT can be used for OSA diagnostic imaging due to its three-dimensional (3D) visualization of the upper airway and craniofacial complex. Magnification associated with conventional 2D radiography is eliminated with CBCT, and radiation to the patient is significantly less than previous modalities used to measure craniofacial & airway measurements associated with OSA. During a CBCT scan, the patient's image is taken supine, rather than the upright …

Effects Of Functional Appliances On The Tmj And Mandibular Length Of Skeletal Class Ii Patients: A Cone Beam Computed Tomography Study, David C. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Functional appliances have been efficiently used in the treatment of Class II malocclusions caused by retrognathic mandibles. Cone beam computed tomography has enabled us to make more accurate linear measurements by eliminating superimposition of other structures and to analyze skeletal anatomic detail in all three planes of space. This retrospective study evaluated the osseous changes in the temporomandibular joint (TMJ) and length of the mandible in skeletal Class II malocclusion patients treated with the fixed functional appliances and compared measurements with Class I malocclusion patients treated with orthodontic mechanics that did not alter skeletal relationships.

Materials and Methods: Twelve …

Influence Of Stainless Steel Orthodontic Brackets On Magnetic Resonance Imaging, Christian James Hoybjerg

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Magnetic resonance imaging (MRI) machines provide 2D as well as 3D images that are excellent in contrasting soft-tissue in the maxillofacial region and are void of ionizing radiation. The drawbacks include the lack of depiction of cortical bony detail and image degradation caused by substances in the scanned area. Specifically, in the orthodontic field stainless steel brackets cause more distortion of MR images then any other bracket material. It is unknown what type of stainless steel alloy causes the most MRI distortion. The purpose of this study is to evaluate the degree of craniofacial MR distortion caused by various …

Observer Reliability Of Cephalometric Landmark Identification On 3-D Mr Images, Michael S. Pollack

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cephalometric analysis is a cornerstone of orthodontic diagnosis, yet much information is lost when 3-dimensional structures are assessed with 2-dimensional methods. CBCT offers 3-dimensional imaging but at the cost of higher levels of ionizing radiation. Magnetic resonance imaging provides 3-dimensional imaging without ionizing radiation and additionally imparts visualization of soft tissue structures. Prior to employing MR images for cephalometric analysis, reliability of landmark identification must be assessed. The purpose of this study was to evaluate intra- and interobserver reliability in 3-dimensional landmark identification using MR images.

Materials and Methods: Fifteen cranial MR images (3.0 T, MP-RAGE) from subjects between …

Comparison Of Mandibular Alveolar Bone With Facial Type Using Cbct, Jason M. Loop

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the relationship between facial type and cortical bone thickness (mm), cortical bone density (rHU) and trabecular bone density (rHU) in the mandibular alveolar bone. Twenty-five consecutive dolichofacial, 25 consecutive mesiofacial, and 25 consecutive brachyfacial patients with T1 lateral cephalograms and CBCT scans were used in this study. A Ricketts analysis was used to compute the VERT index for each patient. All statistical analyses were performed at the significance level of α = 0.05. The one-way ANOVA and LSD post hoc tests indicated there was a statistically significant relationship between facial type and …

Buccal Bone Changes Following Rapid Maxillary Expansion (Rmf), Long-Term Results, Elena S. Iacob

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to use Cone Beam Computed Tomography (CBCT) images to quantitatively evaluate buccal bone changes of maxillary first premolar (P1), second premolar (P2) and first molar (M1) shortly after Rapid Maxillary Expansion (RME) and at the end of orthodontic treatment, as well as to evaluate the variables that may be associated with the short-term and long-term changes. Forty-seven consecutive patients (25 males and 22 females) with a mean age of 14.5years and who required RME as part of their orthodontic treatment and had pre-RME (T1) and post-RME (T2) CBCT images available were used for the …

Cephalometric Analysis Using Magnetic Resonance Imaging, Wade A. Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine if T1-weighted 3D magnetic resonance images performed at 3.0 Tesla could be used to conduct routine orthodontic cephalometric analysis.

Methods: Three cranial imaging methods were compared using sixteen non-growing subjects (10 male and 6 female) who were not claustrophobic, did not have any metallic restorations on the distal of first molars, had no medical implants and the female subjects were not pregnant. Sagittal cranial images were produced by three methods: (1) a digital lateral cephalometric (LC) radiograph (Orthophos XG Plus, Sirona^TM, Bensheim, Germany), (2) a 12-inch FOV cone beam …

Orthodontic Mini-Implant Failure: Assessing The Relationship To Bone Quality Using Qcbct, Joshua Schneider

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the cortical bone thickness (mm), cortical bone density (HU), and trabecular bone density (HU) of mini-implants sites in both the maxilla and mandible using QCBCT to determine if they had any effect on mini-implant failure rate. Patient characteristics (age, gender, facial type), mini-implant characteristics (date of placement, manufacturer, length, and diameter), and the mini-implant site (region) were also evaluated. One hundred and six mini-implants in 50 consecutive patients with complete patient records, CBCT information, and T1 radiographs were included in the study. Thirty-four of the 106 mini-implants were considered "failures" resulting in …

Predictive Measures Of Cognitive Outcome In Adults Sustaining Brain Injury, Herminia De La Rosa-Trujillo

Loma Linda University Electronic Theses, Dissertations & Projects

To date, there is no consistent and accurate outcome prediction method for patients with traumatic brain injury (TBI). Commonly used clinical measures such as the Glasgow Coma Scale (GCS) and traditional radiological methods of x-rays and computed tomography (CT) scans do not always accurately predict patient functional outcome. These radiological methods are adequate in determining gross structural anatomical disturbances, however, they are unable to detect more diffuse cellular damage believed to be responsible for the functional impairments evidenced in patients sustaining TBI. Magnetic resonance imaging allows for various non-invasive sequencing techniques that have demonstrated to be a potentially valuable method …

The Comparative Radiopacity Between Primary And Permanent Teeth, Robert C. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This in vitro study compared the radiopacity between human primary and permanent enamel and dentin. It also compared the radiopacity between human anterior and posterior teeth.

Methods: Extracted primary and permanent teeth were used in this study. One mm enamel and one mm dentin slices were cut from each extracted tooth. Radiographs were taken of each enamel and dentin specimen 1 mm in thickness along with an aluminum step-wedge using procedures specified in International Standards Organization (ISO) 4049:2000. A densitometer was used to measure the Optical Density (OD) of the radiographs of the specimen and the accompanying aluminum step-wedge. …

Immediate Provionalization Of Single Threaded Oxidized Implants On Maxillary Premolars Healed Sites: One-Year Study, Kiyotaka Umezu

Loma Linda University Electronic Theses, Dissertations & Projects

Osseointegrated endosseous implants have been widely used and become a predictable treatment option for completely and partially edentulous patients. The viability and predictability of this treatment modality have been supported with the high success rates in numerous studies. Clinical guideline requires a healing period of 3 to 6 months without functional loading to achieve osseointegration with machine surface implants. Therefore, numerous studies on immediately loaded implants have been conducted in an attempt to minimize or eliminate this healing period. The purpose of this study was to evaluate the success rate of the immediately provisionalized oxidized-surface implants in healed sites supporting …

Predicting Long-Term Memory In Adult Brain Injury Patients Using Mr Spectroscopy, Herminia De La Rosa-Trujillo

Loma Linda University Electronic Theses, Dissertations & Projects

Accurate outcome prediction has proven to be somewhat elusive for patients with traumatic brain injury (TBI). The difficulty is due to the sometimes inaccurate methods of prediction currently available. Despite the advances seen in radiological technology, the traditional methods of x-rays, CT scans and MRIs are not always accurately able to predict patient functional outcome. These radiological methods are adequate in determining gross structural anatomical disturbances, however, they unable to detect more diffuse cellular damage believed to be responsible for the functional impairments evidenced in patients sustaining TBI. Magnetic Resonance Spectroscopy (MRS) is an imaging technique which measures brain metabolites …

Detection Of Simulated Apical Root Resorption Using Three Cone Beam Ct Machines, Marcus Paulson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine orthodontists' ability to discriminate small differences of simulated apical root resorption (SARR) on extracted teeth, using the output from three cone beam computed tomography (CBCT) machines. Twenty-four unrestored maxillary anterior teeth exhibiting normal morphology, were collected. The teeth were scanned by three CBCT machines: 1) the NewTom 3G (AFP imaging, USA), 2) the iCAT (Imaging Sciences, USA) 3) and the MicroCAT II (Siemens Medical, USA). Using a sandblaster the apical portion of each tooth was reduced in 0.5 mm increments up to a total reduction of 1.5 mm. Each root modification was …

Electromagnetic Differences In The Brain During Memory Retrieval, Warren Scott Merrifield

Loma Linda University Electronic Theses, Dissertations & Projects

The primary objectives for this experiment were to analyze the neuroanatomical correlates of autobiographical, episodic and semantic memory, use a different paradigm to promote episodic memory retrieval, and employ a different analysis technique to understand retrieval processes. Autobiographical and episodic memories are personal memories from the past. Autobiographical is more general (e.g. a street name of a house growing up) and episodic is more specific to time (e.g. 13th birthday party that took place on a street). For autobiographical and episodic memory retrieval operations, there is no general consensus as to the localization of function, but bilateral activation of the …

Reproducibility Of Two Non-Consecutive Scans Using A Newtom 3g; In Vitro Model, Hyoung Jin Park

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to evaluate the reproducibility of mineral density measurement expressed in Hounsfield Units (HU) using a phantom device with known mineral densities and the NewTom 3G Cone Beam Computerized Tomography (CBCT).

Materials and Methods: A phantom device made of 21 HA cylindrical disks with known densities was fabricated. The phantom was scanned in 6, 9, and 12 inch fields of view using a NewTom 3G CBCT. The scans were repeated at non-consecutive sessions. Volumetric data in each of the scans were formatted to DICOM images. HU values of the regions of interest were retrieved …