Ph.D Thesis

Ph.D StudentPerlman Or
SubjectInvestigation of Multimodal Methods for Detection and
Imaging of Nanoparticles
DepartmentDepartment of Biomedical Engineering
Supervisor PROF. Haim Azhari
Full Thesis textFull thesis text - English Version


 Imaging is a key component in modern medical diagnosis. To improve pathology detection ability, intravenous injections of contrast media is often performed. Such materials change a specific physical property of the tissue into which they spread, resulting in an improved image contrast and more reliable diagnosis. The recent developments in the field of nanotechnology have created vast opportunities for improved medical care, including better diagnosis and treatment as well. The extremely small size of the nanoparticles (NPs), their high surface area to volume ratio, and their unique physical properties, can, in some cases, augment the sensitivity of the imaging modalities as well as provide targeted tumor visualization and therapeutic benefits. Multimodal imaging is gaining increased weight in the clinic. This stems from the fact that data acquired from different physical phenomena may provide complementary information and improve the clinical outcome. The aim of this research was to explore new methods for multimodal imaging of nanoparticles. The research was comprised of four main elements. In the first part of the research we examined the feasibility of increasing image contrast using seven nanometer in diameter copper oxide nanoparticles under magnetic resonance imaging (MRI) and ultrasound. Experiments revealed that the particles are detectable by both ultrasound and MRI as they increase the ultrasonic attenuation coefficient and shorten the magnetic T1-relaxation coefficient. In the second part of the research the FDA approved (for MRI) iron oxide NPs were ultrasonically studied. The results have shown that iron oxide NPs increase the speed of sound and are detectible by through transmission ultrasound (TTUS). Hence, they can be utilized for contrast enhancement in breast ultrasound. In the third part of the research we explored the feasibility of image-guided microwave hyperthermia monitoring using NPs injection under TTUS. The results indicated that the suggested methodology provides accurate target detection with approximately 0.5 degrees Celsius temperature resolution. In the fourth part of the research copper oxide nanoparticles were embedded in poly lactic-co-glycolic acid (PLGA) nanospheres for toxicity reduction. In addition, the resulting complex was found to be detectible by the clinically available B-scan ultrasound. Another clinically important application demonstrated in the studies of the synthesized nanospheres was their potential use for ultrasound ablation treatment (designated for tumor destruction). The experiments have shown that a concentration dependent temperature elevation effect can be obtained, potentially allowing a more effective therapeutic procedure. In conclusion, the described research resulted in the development of several nano-scaled based complexes and imaging methodologies, which may potentially be useful for cancer imaging and treatment.