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Full-Text Articles in Physics
Compton Scattering Of Mammographic Soft X-Ray Beams By Alkali And Transition Metal Salt Filters Produce X-Ray Interference Zones That May Have Treatment Potential For Localized Cancer Lesions, Subhendra N. Sarkar, Eric Lobel, Sabina Rakhmatova, Derbie Desir, Somdat Kissoon, Daler Djuraev, Katie Tam
Compton Scattering Of Mammographic Soft X-Ray Beams By Alkali And Transition Metal Salt Filters Produce X-Ray Interference Zones That May Have Treatment Potential For Localized Cancer Lesions, Subhendra N. Sarkar, Eric Lobel, Sabina Rakhmatova, Derbie Desir, Somdat Kissoon, Daler Djuraev, Katie Tam
Publications and Research
In breast x-ray imaging scattered radiation adds 50% of harmful radiation dose from anisotropic Compton scattering mechanism. We have been working with double layered inorganic salt materials that can induce Compton scattering to the incident mammographic x ray beams (in 20-30 kVp range) with adequate isotropy (angular control). Typically metal nitrates and alkali halide salt layers are shown here to cause low energy radiation interference zones with high and low photon intensities and local flux heterogeneity in terms of flux covariance. Spatial variation of low energy photon flux creates concentrated and sparse radiation zones that may be used to induce …
Three‐Dimensional Brain Mri For Dbs Patients Within Ultra‐Low Radiofrequency Power Limits, Subhendra N. Sarkar, Efstathios Papavassiliou, David Hackney, David Alsop, Ananth Madhuranthakam, Ludy Shih, Reed Busse, Susan Laruche, Rafeeque Bhadelia
Three‐Dimensional Brain Mri For Dbs Patients Within Ultra‐Low Radiofrequency Power Limits, Subhendra N. Sarkar, Efstathios Papavassiliou, David Hackney, David Alsop, Ananth Madhuranthakam, Ludy Shih, Reed Busse, Susan Laruche, Rafeeque Bhadelia
Publications and Research
Background: For patients with deep brain stimulators (DBS), local absorbed radiofrequency (RF) power is unknown and is much higher than what the system estimates. We developed a comprehensive, highquality brain magnetic resonance imaging (MRI) protocol for DBS patients utilizing three-dimensional (3D) magnetic resonance sequences at very low RF power. Methods: Six patients with DBS were imaged (10 sessions) using a transmit/receive head coil at 1.5 Tesla with modified 3D sequences within ultra-low specific absorption rate (SAR) limits (0.1 W/kg) using T2, fast fluid-attenuated inversion recovery (FLAIR) and T1- weighted image contrast. Tissue signal and tissue contrast from the low-SAR images …
Advances In Ultrafast Time Resolved Fluorescence Physics For Cancer Detection In Optical Biopsy, R. R. Alfano
Advances In Ultrafast Time Resolved Fluorescence Physics For Cancer Detection In Optical Biopsy, R. R. Alfano
Publications and Research
We discuss the use of time resolved fluorescence spectroscopy to extract fundamental kinetic information on molecular species in tissues. The temporal profiles reveal the lifetime and amplitudes associated with key active molecules distinguishing the local spectral environment of tissues. The femtosecond laser pulses at 310 nm excite the tissue. The emission profile at 340 nm from tryptophan is non-exponential due to the micro-environment. The slow and fast amplitudes and lifetimes of emission profiles reveal that cancer and normal states can be distinguished. Time resolved optical methods offer a new cancer diagnostic modality for the medical community.