Shishir Dahal
A5050158285- Advanced X-ray and CT Imaging
- Radiation Dose and Imaging
- Medical Imaging Techniques and Applications
- Photoacoustic and Ultrasonic Imaging
- Electrical and Bioimpedance Tomography
- Multiple Sclerosis Research Studies
- Bacterial Infections and Vaccines
- Dental Radiography and Imaging
- Cerebrospinal fluid and hydrocephalus
- Polyomavirus and related diseases
- Cerebrovascular and Carotid Artery Diseases
- Radiation Detection and Scintillator Technologies
- Medical Image Segmentation Techniques
- Advanced Image Fusion Techniques
- Particle Detector Development and Performance
- Orthopedic Infections and Treatments
- Nuclear Physics and Applications
- Infrared Thermography in Medicine
University of Maryland, Baltimore
2022-2024
University of Otago
2018-2021
National Academy of Medical Sciences
2019-2021
Ministry of Health and Population
2019-2021
Government of Nepal
2019
Background/Purpose Leptomeningeal enhancement (LME) on post-contrast FLAIR is described as a potential biomarker of meningeal inflammation in multiple sclerosis (MS). Here we report an assessment the impact MRI field strength and acquisition timing contrast (MCE). Methods This was cross-sectional, observational study 95 participants with MS 17 healthy controls (HC) subjects. Each participant underwent brain both 7 Tesla (7T) 3 (3T) scanner. 7T protocols included image before, soon after (Gd+...
This study demonstrates the translation of small-bore MARS photon-counting CT technology to live human spectral imaging within a clinical radiation dose level. We used same platform (hardware and software) for acquisition data, image reconstruction, material decomposition visualisation as in CT. Small-bore has been produce promising results fields cancer, bone cartilage health, cardio-vascular diseases. With development large-bore CT, small-animal studies can now be translated humans, sheep,...
This study aims to demonstrate that spectral CT imaging can identify and quantify inflammatory components of unstable plaque such as iron, calcium lipid in phantoms excised human atherosclerotic plaques. Spectral acquisition protocol was optimised using the MARS scanner. A phantom with multiple concentrations ferric nitrate (25, 50, 100, 200 400 mg/ml), hydroxyapatite (104.3, 402.3, 603.3 mg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The aim is to perform qualitative and quantitative assessment of metal induced artefacts small titanium biomaterials using photon counting spectral CT. energy binning feature some detectors enables the measured spectrum be segmented into low, mid high bins in a single exposure. In this study, solid porous implants submerged different concentrations calcium solution were scanned animal MARS scanner equipped with polyenergetic X-ray source operated at 118 kVp. Five narrow (7-45 keV, 45-55...
Images from MARS spectral CT scanners show that there is much diagnostic value using small pixels and good energy data. use energy-resolving photon-counting CZT Medipix3RX detectors measure the of photons on a five-point scale with spatial resolution 110 microns. The information gives material discrimination quantification. 3D reconstruction voxel size 70 We present images pre-clinical specimens, including excised atheroma, bone joint samples, nanoparticle contrast agents along living...
Leptomeningeal enhancement (LME) on post-contrast FLAIR is described as a potential biomarker of meningeal inflammation in multiple sclerosis (MS). Here we report comprehensive assessment the impact MRI field strength and acquisition timing contrast (MCE).
Assessment of disease burden and drug efficacy is achieved preclinically using high resolution micro computed tomography (CT). However, micro-CT not applicable to clinical human imaging due operating at dose. In addition, the technology differences between standard CT prevent direct translation preclinical applications. The current proof-of-concept study presents spectral photon-counting as a clinically translatable, molecular tool by assessing contrast uptake in an <italic...
Treatment failure in cancer is often due to variation tumour characteristics within the same tumour, or across sites, over time. At present, most cancers are staged with imaging; treatment selected, then patient re-imaged see if working. We intend transform that approach by using a novel non-invasive spectral imaging technology together targeted and non-targeted gold nanoparticles measure burden as well drug delivery. In this study, we report CT of four different cell types (ovarian, breast,...
The aim of the present study is to show that non-invasive MARS imaging can differentiate between infected and healthy pulmonary tissue using an iodine-based contrast agent at high resolution. One C57BL/6J mouse with chronic tuberculosis (TB) was euthanized CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> excised. TB lungs were incubated in 3% iodine solution. Mouse free also excised solution for control purposes. Calibration scanner...
We describe a CMS-Medipix3RX neutron camera developed by adapting and modifying detector readout electronics at the University of Canterbury. The are part MARS x-ray scanner used for imaging applications [1]. cameras will be precise evaluation complex radiation fields in around Compact Muon Solenoid (CMS) on Large Hadron Collider (LHC) CERN. This help to ascertain performance various sub-systems installed cavern as well predict their useful lifetimes. Medipix3RX can deliver real-time images...
In this article, we propose a slice-based interactive segmentation of spectral CT datasets using bag features method. The data are acquired from MARS scanner that divides up the X-ray spectrum into multiple energy bins for imaging. literature, most existing methods limited to performing specific task or tied particular imaging modality. Therefore, when applying generalized datasets, additional information cannot be sufficiently utilized. We describe new approach circumvents problem by...