Radiology Commons^™

Automation, Regulation, And Collaboration: Threats And Opportunities For Clinical Medical Physics Careers In Diagnostic Imaging And Nuclear Medicine., David W. Jordan, Eric L. Gingold, Ehsan Samei

Department of Radiology Faculty Papers

No abstract provided.

The Effect Of Glucosamine, Chondroitin And Harpagophytum Procumbens On Femoral Hyaline Cartilage Thickness In Patients With Knee Osteoarthritis– An Mri Versus Ultrasonography Study, Florentin Ananu Vreju, Paulina Lucia Ciurea, Anca Rosu, Beatrice Andreea Chisalau, Cristina Dorina Parvanescu, Sineta Cristina Firulescu, Adina Turcu Stiolica, Andreea Lili Barbulescu, Stefan Cristian Dinescu, Cristiana Iulia Dumitrescu, Roxana Mihaela Dumitrascu, Cristina Criveanu, Lucretiu Radu, Mihai Tusaliu, Daniela Dumitrescu

Journal of Mind and Medical Sciences

Background: the evaluation of cartilage thickness has become possible with new techniques such as musculoskeletal ultrasonography (US) and magnetic resonance imagining (MRI), making the evaluation of the treatment response and the progression of the disease more accurate. Objective: to evaluate the efficacy of a Symptomatic Slow Acting Drug for Osteoarthritis using both US and MRI for measuring cartilage thickness at baseline and after 1 year. Methods: The study included the clinical evaluation of 20 patients at baseline, at 6 and 12 months as well as imaging exams (US and MRI) at baseline and after 1 year. Measurements …

Deep Learning, Medical Physics And Cargo Cult Science., Miguel Romero Phd, Gilmer Valdes Phd, Timothy Solberg Phd, Yannet Interian Phd

Creative Activity and Research Day - CARD

Deep learning algorithms have become widely popular, with considerable success in fields where datasets have hundreds of thousands or million points. As deep learning is increasingly applied to the fields of medical physics and radiation oncology, a reasonable question follows: are these techniques the best approach, given the unique conditions in our field? In this study, we investigate the dependence of dataset size on the performance of deep learning algorithms compared with more traditional radiomics-based methods.

Mindful Meditation Practice For Imaging Professionals, Tanya M. Custer, Kim Michael

Posters and Presentations: Medical Imaging & Therapeutic Sciences

Although a career in medical imaging is very fulfilling and rewarding, research shows that health care professionals are becoming more prone to burnout. The healthcare environment can be face-paced, stressful and demanding. Burnout syndrome results from emotional exhaustion that causes depersonalization and decreased professional accomplishment.1-3 Burnout can have a negative impact not only on the individual, but the environment as well. Decreased patient satisfaction and increased errors are both associated with burnout in the healthcare setting.2

Mindfulness can be defined as the awareness that emerges through paying attention on purpose, in the present moment, and non-judgmentally to the unfolding of …

Process Improvement For Follow-Up Radiology Report Recommendations Of Lung Nodules., Philip S. Lim, Doron Schneider, Jonathan Sternlieb, Michel Taupin, Nicholas Sich, Joan Diaz, Eileen Jameson, Bryan Frambes, Sharon Taylor

Abington Jefferson Health Papers

In the modern healthcare system, there are still wide gaps of communication of imaging results to physician and patient stakeholders and tracking of whether follow-up has occurred. Patients are also unaware of the significance of findings in radiology reports. With the increase in use of cross-sectional imaging such as CT, patients are not only being diagnosed with primary urgent findings but also with incidental findings such as lung nodules; however, they are not being told of their imaging findings nor what actions to take to mitigate their risks. In addition, patients at high risk for developing lung cancer often obtain …

Automated Assessment Of Acute Aortic Dissection On Thoracic Ct Using Deep Learning, Varun Singh, Richard Gorniak, Md, Adam Flanders, Md, Paras Lakhani, Md

Department of Radiology Posters

Purpose

To assess the efficacy of deep convolutional neural networks (DCNNs ) in differentiating acute aortic dissections from non-dissected aortas on thoracic CT.

Initial Results Of A Prospective Study Of Adjuvant Pancreatic Stereotactic Body Radiation Therapy For Close Or Positive Margins, Mark E. Bernard, Philip A. Sutera, Nicholas A. Iarrobino, Kimmen Quan, Steven A. Burton, Nathan Bahary, Melissa Hogg, Amer Zureikat, Dwight E. Heron

Radiation Medicine Faculty Publications

Purpose: Patients with close or positive margins after surgery for pancreatic carcinoma are at a high risk for recurrence. Stereotactic body radiation therapy (SBRT) allows for safe dose escalation with great conformity and short duration of treatment. Herein, we report the initial results of a prospective observational study that evaluated the efficacy and safety of this treatment option.

Methods and Materials: Patients eligible for the study had pathologically proven T1-4N0-1M0 pancreatic adenocarcinoma with a positive margin (≤ 1 mm) or a close margin defined as < 2.5 mm. Patients were treated with either neoadjuvant or adjuvant chemotherapy, if eligible for systemic therapy. All patients received 36 Gy in 3 fractions to the close or positive margin site.

Results: From February 2013 to January 2018, 50 patients were enrolled with 49 patients treated …

Survival And Treatment Outcomes Of Metaplastic Breast Carcinoma: Single Tertiary Care Center Experience In Pakistan, Zarka Samoon, Madiha Beg, Romana Idress, Adnan Jabbar

Department of Radiation Oncology

Background: Metaplastic breast carcinoma (MBC) is a rare disease with incidence of less than 1%. MBC present with a larger tumor size, less number of nodes involved, mostly undifferentiated triple negative tumors. We aimed to determine progression-free and overall survival and reported hospital-based incidence of MBC.
Material and Methods: A retrospective closed Cohort study elicited data of 42 patients with MBC from January 2008 to December 2013; followed till August 2016. Kaplan-Meier method was applied to compute overall and progression-free survival analysis. Cox Proportional hazard ratios were computed to assess associations between survival and independent variables.
Results: Hospital-based incidence of …

Efficacy Of Leukemia Inhibitory Factor As A Therapeutic For Permanent Large Vessel Stroke Differs Among Aged Male And Female Rats, Stephanie M. Davis, Lisa A. Collier, Sarah J. Goodwin, Douglas E. Lukins, David K. Powell, Keith R. Pennypacker

Neurology Faculty Publications

Preclinical studies using rodent models of stroke have had difficulty in translating their results to human patients. One possible factor behind this inability is the lack of studies utilizing aged rodents of both sexes. Previously, this lab showed that leukemia inhibitory factor (LIF) promoted recovery after stroke through antioxidant enzyme upregulation. This study examined whether LIF promotes neuroprotection in aged rats of both sexes. LIF did not reduce tissue damage in aged animals, but LIF-treated female rats showed partial motor skill recovery. The LIF receptor (LIFR) showed membrane localization in young male and aged rats of both sexes after stroke. …

Effectiveness Of 10-Valent Pneumococcal Conjugate Vaccine Against Vaccine-Type Invasive Pneumococcal Disease In Pakistan, Atif Riaz, Syed Mohiuddin, Sara Husain, Mohammad Tahir Yousafzai, Muhammad Sajid, Furqan Kabir, Najeeb Rehman, Waseem Mirza, Basit Salam, Naila Naila, Khatidja Pardhan, Anita K. M. Zaidi, Syed Asad Ali

Department of Paediatrics and Child Health

Objective: To assess the effectiveness of 10-valent pneumococcal conjugate vaccine (PCV10) against invasive pneumococcal disease (IPD) due to vaccine serotypes of Streptococcus pneumoniae post introduction of the vaccine into the routine immunization program in Pakistan.
Methods: A matched case-control study was conducted at 16 hospitals in Sindh Province, Pakistan. Children aged (eligible to receive PCV10) who presented with radiographically confirmed pneumonia and/or meningitis were enrolled as cases. PCR for the lytA gene was conducted on blood (for radiographic pneumonia) and cerebrospinal fluid (for meningitis) samples to detect S. pneumoniae. The proportion of IPD due to vaccine serotypes (including vaccine-related serogroups) …

Effect Of 10-Valent Pneumococcal Conjugate Vaccine On The Incidence Of Radiologically-Confirmed Pneumonia And Clinically-Defined Pneumonia In Kenyan Children: An Interrupted Time-Series Analysis, Micah Silaba, Michael Ooko, Christian Bottomley, Joyce Sande, Rachel Benamore, Kate Park, James Ignas, Kathryn Maitland, Neema Mturi, Anne Makumi

Imaging & Diagnostic Radiology, East Africa

Background: Pneumococcal conjugate vaccines (PCV) are highly protective against invasive pneumococcal disease caused by vaccine serotypes, but the burden of pneumococcal disease in low-income and middle-income countries is dominated by pneumonia, most of which is non-bacteraemic. We examined the effect of 10-valent PCV on the incidence of pneumonia in Kenya.

Methods: We linked prospective hospital surveillance for clinically-defined WHO severe or very severe pneumonia at Kilifi County Hospital, Kenya, from 2002 to 2015, to population surveillance at Kilifi Health and Demographic Surveillance System, comprising 45000 children younger than 5 years. Chest radiographs were read according to a WHO standard. A …

Ultrasound-Triggered Antibiotic Release From Peek Clips To Prevent Spinal Fusion Infection: Initial Evaluations., Lauren J. Delaney, Daniel Macdonald, Jay Leung, Keith Fitzgerald, Alex M. Sevit, John R. Eisenbrey, Neil Patel, Flemming Forsberg, Christopher K. Kepler, Taolin Fang, Steven M. Kurtz, Noreen J. Hickok

Department of Orthopaedic Surgery Faculty Papers

Despite aggressive peri-operative antibiotic treatments, up to 10% of patients undergoing instrumented spinal surgery develop an infection. Like most implant-associated infections, spinal infections persist through colonization and biofilm formation on spinal instrumentation, which can include metal screws and rods for fixation and an intervertebral cage commonly comprised of polyether ether ketone (PEEK). We have designed a PEEK antibiotic reservoir that would clip to the metal fixation rod and that would achieve slow antibiotic release over several days, followed by a bolus release of antibiotics triggered by ultrasound (US) rupture of a reservoir membrane. We have found using human physiological fluid …

Parallel Transjugular Intrahepatic Portosystemic Shunt With Viatorr® Stents For Primary Tips Insufficiency: Case Series And Review Of Literature, Driss Raissi, Qian Yu, Michael Nisiewicz, Steven Krohmer

Radiology Faculty Publications

BACKGROUND

Transjugular intrahepatic portosystemic shunts (TIPS) can alleviate complications of portal hypertension such as ascites and variceal bleeding by decreasing the portosystemic gradient. In limited clinical situations, parallel TIPS may be only solution to alleviate either variceal bleeding or ascites secondary to portal hypertension when the primary TIPS fails to do so. Data specifically addressing the use of this partially polytetrafluoroethylene covered nitinol stent (Viatorr^®) is largely lacking despite Viatorr^® being the current gold standard for modern TIPS placement.

CASE SUMMARY

All three patients had portal hypertension and already had a primary Viatorr^® TIPS placed previously. …

A Comparison Of The Diagnosis Of Gastroparesis In 4 H Pediatric Gastric Emptying Studies Versus 2 H Studies., Sarah T. Edwards, Jose Cocjin, Stephanie B. Theut, Douglas C. Rivard, Ashley K. Sherman, Craig A. Friesen

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: In adults, there is a consensus for standards to diagnose gastroparesis utilizing a gastric emptying study as the key diagnostic modality but there is no consensus for a standard in pediatrics. Additionally, some cost savings might be achieved if symptoms could be utilized to predict patients with gastroparesis. The aims of the current study were to confirm the sensitivity of a 4 h study in the pediatric population and to assess whether the severity of symptoms were predictive of delayed gastric emptying.

STUDY: This was a single site, two part study. In the first part, results were reviewed for …

Li-Rads: A Conceptual And Historical Review From Its Beginning To Its Recent Integration Into Aasld Clinical Practice Guidance, Khaled M. Elsayes, Ania Z. Kielar, Victoria Chernyak, Ali Morshid, Alessandro Furlan, William R. Masch, Robert M. Marks, Aya Kamaya, Richard K. G. Do, Yuko Kono, Kathryn J. Fowler, An Tang, Mustafa R. Bashir, Elizabeth M. Hecht, Kedar Jambhekar, Andrej Lyshchik, Shuchi K. Rodgers, Jay P. Heiken, Marc Kohli, David T. Fetzer, Stephanie R. Wilson, Zahra Kassam, Mishal Mendiratta-Lala, Amit G. Singal, Christopher S. Lim, Irene Cruite, James Lee, Ryan Ash, Donald G. Mitchell, Matthew D. F. Mcinnes

Radiology Faculty Publications

The Liver Imaging Reporting and Data System (LI-RADS^®) is a comprehensive system for standardizing the terminology, technique, interpretation, reporting, and data collection of liver observations in individuals at high risk for hepatocellular carcinoma (HCC). LI-RADS is supported and endorsed by the American College of Radiology (ACR). Upon its initial release in 2011, LI-RADS applied only to liver observations identified at CT or MRI. It has since been refined and expanded over multiple updates to now also address ultrasound-based surveillance, contrast-enhanced ultrasound for HCC diagnosis, and CT/MRI for assessing treatment response after locoregional therapy. The LI-RADS 2018 version was …

Amoebic Liver Abscess: Outcomes Of Percutaneous Needle Aspiration Vs Drain Placement In Paediatric Population, Areej Saleem, Saqib Hamid Qazi, Waseem Mirza, Sarah Masroor Jeelani

Section of Paediatric Surgery

Objective: To compare the effectiveness of percutaneous catheter drain placement with percutaneous needle aspiration in terms of hospital stay, time to resolution of symptoms and cost of intervention performed.
Methods: The retrospective cohort study was conducted at Aga Khan University Hospital, Karachi, and comprised data of patients with amoebic liver abscess from, January 2006 to December 2016 which was collected using non-probability purposeful sampling. Primary outcome included length of hospital stay, time to resolution of symptoms and cost of intervention. Secondary outcomes included development of complications, need for re-intervention and abscess resolution. SPSS 22 was used for data analysis. . …

Is Excision Of Radial Scars Identified On Cnb Necessary?, K. Nimtz, K. Hookim, Md, A. Sevrukov, Md, T. Tsangaris, Md, A. Willis, Md, A. Berger, Md, M. Lazar, Md

Phase 1

Introduction: Quantifying the risk of upgrade to malignancy with radial scars has been an ongoing challenge, as the published upgrade rate varies widely from 0-40%, making management strategy controversial. The lack of consensus on optimal management highlights the need for further analysis. We sought to identify our institutional upgrade rate of radial scar identified on core needle biopsy (CNB).

Methods: A retrospective review of pathology and radiology databases was performed to identify radial scars found on CNB. We excluded patients with malignancy associated with radial scar and those who did not undergo surgical excision. The upgrade rates to …

Adaptive Statistical Iterative Reconstruction-V For Lung Nodule Analysis, Cherry Au, Zhenteng Li, Md, Eric Gingold, Md, Ethan Halpern, Md, Baskaran Sundaram, Md

Phase 1

Introduction: Low-dose CT in lung cancer screening has demonstrated benefits in select patients. As the traditional filtered back projection (FBP) technique is limited by poor image quality, adaptive statistical iterative reconstruction-V (ASIR-V) algorithm has been developed to achieve higher image quality with processing efficiency.

Objective: To investigate the impact of various CT scan parameters on the semi-automated measurement of lung nodules using a Computer Aided Detection (CAD) program.

Methods: This IRB-exempt phantom experiment was conducted with a CT scanner capable of ASIR-V algorithm. Eight lung nodules sized 5-12 mm, of solid or ground glass type, were placed inside a multipurpose …

Network Influence Of The Cerebellum For Predicting Dbs Response In Patients With Advanced Parkinson’S Disease, Lucy Li, Jennifer Muller, Sara Thalheimer, Mackenzie D. Silverman, Mahdi Alizadeh, Tsao-Wei Liang, Kelly Layton, Daniel Kremens, Victor Romo, Feroze Mohamed, Chengyuan Wu

Phase 1

Introduction: Deep brain stimulation (DBS) is a treatment option for reducing motor symptoms in patients with Parkinson’s Disease (PD) when first-line medication becomes ineffective. Existing literature has hypothesized that the clinical outcome of DBS may depend on brain connectivity profiles of the stimulation site to distant brain regions. However, the potential of brain connectivity profiles to predict response to DBS in PD remains unclear.

Objective: This study aimed to investigate how changes in structural and functional connectivity may relate to patient response to DBS, through the examination of brain network changes using graph theory.

Methods: Ten patients with advanced PD …

Effect Of Tort Reform On Diagnostic Imaging Rates, Israel Ojalva, Ba, Arthur Hong, Md, Mph

Phase 1

Introduction: Defensive medicine, is defined as “order[ing] tests, procedures, or visits, or avoid certain high-risk patients or procedures, primarily (but not solely) because of concern about malpractice liability.” Nearly all physician who fear malpractice litigation have admitted to practicing some degree of defensive medicine. In response, many states have enacted policy reforms to lighten the threat of malpractice on physicians.

Objective: The most common defensive medicine behavior is ordering diagnostic imaging tests when it is potentially unwarranted. Many states have enacted non-economic damage caps from 2000-2010. We explored if these laws had an impact on the rates of diagnostic imaging …

Deep Learning Based Medical Image Analysis With Limited Data, Jiaxing Tan

Dissertations, Theses, and Capstone Projects

Deep Learning Methods have shown its great effort in the area of Computer Vision. However, when solving the problems of medical imaging, deep learning’s power is confined by limited data available. We present a series of novel methodologies for solving medical imaging analysis problems with limited Computed tomography (CT) scans available. Our method, based on deep learning, with different strategies, including using Generative Adversar- ial Networks, two-stage training, infusing the expert knowledge, voting based or converting to other space, solves the data set limitation issue for the cur- rent medical imaging problems, specifically cancer detection and diagnosis, and shows very …

Labrad : Vol 45, Issue 1 - February 2019, Aga Khan University Hospital, Karachi

LABRAD - Departments of Pathology & Laboratory Medicine and Radiology Archives

• Cardiac Manifestation of Inherited Metabolic Disorders
• Utility of Plasma Homocysteine in Identifying Inherited Metabolic Disorders (IMDs)
• Chediak-Higashi Syndrome, an Inherited Disorder in Phagocytic Function
• Radiology-Pathology Correlation Rare Diseases of Bone
• Dried Blood Spot (DBS) Sampling: A Method for Blood Collection without Venipuncture
• Newborn Screening Program for Congenital Hypothyroidism
• Rare Disease in Dermatopathology
• Screening for Carbohydrate Metabolism Disorders by Sugar Chromatography in Urine
• Hypophosphatasia a Rare Skeletal Disorder

Primary Malignant Melanoma Of Brainstem Medulla Mimicking As Cavernoma, Adnan Naeem, Fatima Mubarak

Department of Radiology

Aim of this case report is to present a rare case of primary malignant melanoma of brain stem at the region of medulla oblongata mimicking as cavernoma. 40-year-old male presented with vertigo, headache, dizziness for 1 month. MRI showed pear shaped T1 hyperintense lesion at medulla oblongata and predominantly hypointense on T2 with focal area of hemorrhage. Lesion showed diffuse enhancement on postcontrast images. On plain CT lesion was Hyperdense. It was initially reported as Cavernoma. Surgical excision of lesion was done with per-op findings of solid, dark maroon colored lesion with hemorrhage. Histopathology showed neoplastic lesion with abundant melanin …

Diffusion-Weighted Magnetic Resonance Imaging May Be Useful In Differentiating Fungal Abscess From Malignant Intracranial Lesion: Case Report, Syeda Maheen Batool, Fatima Mubarak, Ather Enam

Section of Neurosurgery

Background: Diffusion-weighted magnetic resonance has a well-defined role in differentiating between important intracranial lesions. Sometimes, the surgeon is faced with a dilemma of how to diagnose an infectious versus malignant lesion.
Case Description: A 28-year-old male presented to the neurosurgery clinic with complaints of headache and left-sided weakness for 2 weeks. Neurological examination was intact. Magnetic resonance imaging (MRI) scan showed a large infiltrating heterogeneous mass involving the right parietal lobe. On further reviewing, there was homogenous diffusion restriction in the center of lesion. In addition, its aggressive behavior confirmed it to be a fungal abscess.
Conclusions: Correctly identifying an …

Excluding Ptv From Lung Volume May Better Predict Radiation Pneumonitis For Intensity Modulated Radiation Therapy In Lung Cancer Patients, Yinnan Meng, Haihua Yang, Wei Wang, Xingni Tang, Caiping Jiang, Yichao Shen, Wei Luo

Radiation Medicine Faculty Publications

Background: Lung dose-volume histogram (DVH) in radiotherapy could be calculated from multiple normal lung definitions. The lung dosimetric parameters generated from various approaches are significantly different. However, limited evidence shows which definition should be used to more accurately predict radiation pneumonitis (RP). We aimed to compare the RP prediction accuracy of dosimetric parameters from three lung volume methods in lung cancer patients treated with Intensity-Modulated Radiation Therapy (IMRT).

Methods: We retrospectively reviewed 183 consecutive lung cancer patients treated with IMRT from January 2014 to October 2017. The normal lungs were defined by total bilateral lung volume (Total Lung), excluding PTV …

Target® Intracranial Aneurysm Coiling Prospective Multicenter Registry: Final Analysis Of Peri-Procedural And Long-Term Safety And Efficacy Results, Osama O. Zaidat, Alicia C. Castonguay, Ansaar T. Rai, Aamir Badruddin, William J. Mack, Amer K. Alshekhlee, Qaisar A. Shah, Syed I. Hussain, Mouhammed R. Kabbani, Ketan R. Bulsara, Asif M. Taqi, Vallabh Janardhan, Mary S. Patterson, Britany L. Nordhaus, Lucas Elijovich, Ajit S. Puri

Faculty & Staff Scholarship

Background and Purpose: To describe the final results of the TARGET Registry, a multicenter, real-world study of patients with intracranial aneurysms treated with new generation TARGET Coils.

Methods: The TARGET Registry is a prospective, single-arm study with independent medical event monitoring and core-lab adjudication. Patients with de novo intracranial aneurysms were embolized with either TARGET-360° or helical coils in 12 US centers. The primary outcome was aneurysm packing density (PD), which was assessed immediately post-procedure. The secondary outcomes were immediate and long-term aneurysm occlusion rate using the Raymond Scale, and independent functional outcome using the modified Rankin Scale (mRS). A …

Evaluation Of Plan Quality And Treatment Efficiency For Single-Isocenter/Two-Lesion Lung Stereotactic Body Radiation Therapy, Lana Sanford, Janelle A. Molloy, Sameera S. Kumar, Marcus Randall, Ronald C. Mcgarry, Damodar Pokhrel

Radiation Medicine Faculty Publications

Purpose/objectives: To evaluate the plan quality and treatment delivery efficiency of single‐isocenter/two‐lesions volumetric modulated arc therapy (VMAT) lung stereotactic body radiation therapy (SBRT).

Materials/methods: Eight consecutive patients with two peripherally located early stage nonsmall‐cell‐lung cancer (NSCLC) lung lesions underwent single‐isocenter highly conformal noncoplanar VMAT SBRT treatment in our institution. A single‐isocenter was placed between the two lesions. Doses were 54 or 50 Gy in 3 and 5 fractions respectively. Patients were treated every other day. Plans were calculated in Eclipse with AcurosXB algorithm and normalized to at least 95% of the planning target volume (PTV) receiving 100% of the prescribed …

Comparison Of Quantitative Analysis To Qualitative Analysis For Interpretation Of Lower‑Limb Lymphoscintigraphy, Edward Nganga, Khalid Makhdomi

Imaging & Diagnostic Radiology, East Africa

Qualitative analysis of lymphoscintigrams is subject to wide variability and may miss subtle differences in ilioinguinal uptake between normal and abnormal limbs. This study compared quantitative analysis to qualitative analysis of lower‑limb lymphoscintigraphy in diagnosing lymphedema. Fifty‑two lymphoscintigrams performed using standardized protocol, 99‑metastable technetium nanocolloid intradermal injection at the first interdigital space, were analyzed quantitatively. Fifty‑three normal and 51 abnormal limbs were analyzed. For each limb, a region of interest (ROI) was drawn around the injection site, and ilioinguinal nodes on the 1.5 h static images and the counts in these ROIs were recorded. Percentage ilioinguinal nodes uptake was then …

Sparsity Promoting Regularization For Effective Noise Suppression In Spect Image Reconstruction, Wei Zheng, Si Li, Andrzej Krol, C. Ross Schmidtlein, Xueying Zeng, Yuesheng Xu

Mathematics & Statistics Faculty Publications

The purpose of this research is to develop an advanced reconstruction method for low-count, hence high-noise, Single-Photon Emission Computed Tomography (SPECT) image reconstruction. It consists of a novel reconstruction model to suppress noise while conducting reconstruction and an efficient algorithm to solve the model. A novel regularizer is introduced as the nonconvex denoising term based on the approximate sparsity of the image under a geometric tight frame transform domain. The deblurring term is based on the negative log-likelihood of the SPECT data model. To solve the resulting nonconvex optimization problem a Preconditioned Fixed-point Proximity Algorithm (PFPA) is introduced. We prove …

Calibrated Short Tr Recovery Mri For Rapid Measurement Of Brain-Blood Partition Coefficient And Correction Of Quantitative Cerebral Blood Flow, Scott William Thalman

Theses and Dissertations--Biomedical Engineering

The high prevalence and mortality of cerebrovascular disease has led to the development of several methods to measure cerebral blood flow (CBF) in vivo. One of these, arterial spin labeling (ASL), is a quantitative magnetic resonance imaging (MRI) technique with the advantage that it is completely non-invasive. The quantification of CBF using ASL requires correction for a tissue specific parameter called the brain-blood partition coefficient (BBPC). Despite regional and inter-subject variability in BBPC, the current recommended implementation of ASL uses a constant assumed value of 0.9 mL/g for all regions of the brain, all subjects, and even all species.

The …