The emission of Cherenkov photons from human and animal tissue can be observed during clinical x-ray or particle beam irradiation. However, imaging this weak emission with the necessary single-photon sensitivity in the clinical room is challenging because of milliwatt-level ambient room lighting and the presence of stray high-energy radiation. In this Letter, we demonstrate, to the best of our knowledge, the first Cherenkov imaging with a time-gated quanta image sensor employing a large single-photon avalanche diode (SPAD) array. Detecting single Cherenkov photons was possible with high photon avalanche gain, fast temporal gating, and moderately high ∼7% photon detection probability. Single-bit digitization and active SPAD quenching enabled stray x-ray noise suppression and photon-noise-limited imaging in a clinical environment. This type of imaging allows the knowledge of location, shape, and surface dose of the therapeutic beam radiotherapy with the stability of solid state-based detection.
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http://dx.doi.org/10.1364/OL.44.004546 | DOI Listing |
Dermatol Ther (Heidelb)
January 2025
Dermatological Centre in Milan, Milan, Italy.
Acne and acne sequelae can have an important impact on patients' quality of life, affecting interpersonal relationships and social functioning. Acne-induced scars (AIS) and acne-induced macular hyperpigmentation (AIH), in particular, are a major concern for patients with acne, as their management is challenging and often unsatisfactory. Retinoids are considered the mainstay of acne treatment because of their action on multiple pathogenetic factors, and there is increasing evidence that they can also improve AIS and AIH.
View Article and Find Full Text PDFMed Phys
December 2024
Siemens Healthineers AG, Forchheim, Germany.
Background: Photon counting computed tomography (PCCT) employs direct and spectrally resolved counting of individual x-ray quanta, enhancing image quality compared to the standard energy-integrating CT (EICT).
Purpose: To evaluate the quantitative improvements in CT image quality metrics by comparing the first medical PCCT with a state-of-the-art EICT.
Methods: The PCCT versus EICT noise improvement ratio R was derived from the quantum statistics of the measurement process and measured across the clinical x-ray flux range for both systems.
Arq Bras Cardiol
October 2024
Hospital do Coração (HCOR), São Paulo, SP - Brasil.
Life (Basel)
October 2024
Haut.AI OÜ, Telliskivi 60a/8, 10412 Tallinn, Harjumaa, Estonia.
Autofluorescence is a remarkable property of human skin. It can be excited by UV and observed in the dark using special detection systems. The method of fluorescence photography (FP) is an effective non-invasive tool for skin assessment.
View Article and Find Full Text PDFProg Brain Res
October 2024
Institute of Biophotonics, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan; Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan. Electronic address:
Spinocerebellar ataxia type 3 (SCA3), or Machado-Joseph disease, presents as a cerebellar cognitive affective syndrome (CCAS) and represents the predominant SCA genotype in Taiwan. Beyond cerebellar involvement, SCA3 patients exhibit cerebral atrophy. While prior neurodegenerative disease studies relied on voxel-based morphometry (VBM) for brain atrophy assessment, its qualitative nature limits individual and region-specific evaluations.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!