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Seminars in Interventional Radiology Oct 2021Transarterial radioembolization with yttrium-90 ( Y) is a mainstay for the treatment of liver cancer. Imaging the distribution following delivery is a concept that... (Review)
Review
Transarterial radioembolization with yttrium-90 ( Y) is a mainstay for the treatment of liver cancer. Imaging the distribution following delivery is a concept that dates back to the 1960s. As β particles are created during Y decay, bremsstrahlung radiation is created as the particles interact with tissues, allowing for imaging with a gamma camera. Inherent qualities of bremsstrahlung radiation make its imaging difficult. SPECT and SPECT/CT can be used but suffer from limitations related to low signal-to-noise bremsstrahlung radiation. However, with optimized imaging protocols, clinically adequate images can still be obtained. A finite but detectable number of positrons are also emitted during Y decay, and many studies have demonstrated the ability of commercial PET/CT and PET/MR scanners to image these positrons to understand Y distribution and help quantify dose. PET imaging has been proven to be superior to SPECT for quantitative imaging, and therefore will play an important role going forward as we try and better understand dose/response and dose/toxicity relationships to optimize personalized dosimetry. The availability of PET imaging will likely remain the biggest barrier to its use in routine post- Y imaging; thus, SPECT/CT imaging with optimized protocols should be sufficient for most posttherapy subjective imaging.
PubMed: 34629714
DOI: 10.1055/s-0041-1735569 -
Biophysical Journal Jul 2022Modern electron-multiplying charge-coupled device (EMCCD) and scientific complementary metal-oxide semiconductor (sCMOS) cameras read out fluorescence data with...
Modern electron-multiplying charge-coupled device (EMCCD) and scientific complementary metal-oxide semiconductor (sCMOS) cameras read out fluorescence data with single-molecule sensitivity at thousands of frames per second. Exploiting these capabilities in full requires data evaluation in real time. The direct camera-read-out tool presented here allows access to the data while the camera is recording. This provides simplified and accurate alignment procedures for total internal reflection fluorescence microscopy (TIRFM) and single-plane illumination microscopy (SPIM), and simplifies and accelerates fluorescence experiments. The tool handles a range of widely used EMCCD and sCMOS cameras and uses imaging fluorescence correlation spectroscopy for its evaluation. It is easily extendable to other camera models and other techniques and is a base for automated TIRFM and SPIM data acquisition.
Topics: Electrons; Equipment Design; Microscopy, Fluorescence; Semiconductors; Spectrometry, Fluorescence
PubMed: 35672950
DOI: 10.1016/j.bpj.2022.06.009 -
Molecules (Basel, Switzerland) May 2021Radiotracers are widely used in medical imaging, using techniques of gamma-camera imaging (scintigraphy and SPECT) or positron emission tomography (PET). In bone marrow... (Review)
Review
INTRODUCTION
Radiotracers are widely used in medical imaging, using techniques of gamma-camera imaging (scintigraphy and SPECT) or positron emission tomography (PET). In bone marrow infection, there is no single routine test available that can detect infection with sufficiently high diagnostic accuracy. Here, we review radiotracers used for imaging of bone marrow infection, also known as osteomyelitis, with a focus on why these molecules are relevant for the task, based on their physiological uptake mechanisms. The review comprises [Ga]Ga-citrate, radiolabelled leukocytes, radiolabelled nanocolloids (bone marrow) and radiolabelled phosphonates (bone structure), and [F]FDG as established radiotracers for bone marrow infection imaging. Tracers that are under development or testing for this purpose include [Ga]Ga-citrate, [F]FDG, [F]FDS and other non-glucose sugar analogues, [O]water, [C]methionine, [C]donepezil, [Tc]Tc-IL-8, [Ga]Ga-Siglec-9, phage-display selected peptides, and the antimicrobial peptide [Tc]Tc-UBI or [Ga]Ga-NOTA-UBI.
CONCLUSION
Molecular radiotracers allow studies of physiological processes such as infection. None of the reviewed molecules are ideal for the imaging of infections, whether bone marrow or otherwise, but each can give information about a separate aspect such as physiology or biochemistry. Knowledge of uptake mechanisms, pitfalls, and challenges is useful in both the use and development of medically relevant radioactive tracers.
Topics: Bone Marrow; Humans; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon
PubMed: 34070537
DOI: 10.3390/molecules26113159 -
Nuclear Medicine and Molecular Imaging Oct 2021Since the foundation of the Korean Society of Nuclear Medicine in 1961, clinical nuclear oncology has been a major part of clinical nuclear medicine in Korea. There are... (Review)
Review
Since the foundation of the Korean Society of Nuclear Medicine in 1961, clinical nuclear oncology has been a major part of clinical nuclear medicine in Korea. There are several important events for the development of clinical nuclear oncology in Korea. First, a scintillating type gamma camera was adopted in 1969, which enabled to perform modern oncological gamma imaging. Second, Tc-99 m generator was imported to Korea since 1979, which promoted the wide clinical use of gamma camera imaging by using various kinds of Tc-99 m labeled radiopharmaceuticals. Third, a gamma camera with single photon emission tomography (SPECT) capability was first installed in 1980, which has been used for various kinds of tumor SPECT imaging. Fourth, in 1994, clinical positron emission tomography (PET) scanner and cyclotron with a production of F-18 fluorodeoxyglucose were first installed in Korea. Fifth, Korean Board of Nuclear Medicine was established in 1995, which contributed in the education and manpower training of dedicated nuclear medicine physicians in Korea. Finally, an integrated PET/CT scanner was first installed in 2002. Since that, PET/CT imaging has been a major imaging tool in clinical nuclear oncology in Korea. In this review, a brief history of clinical nuclear oncology in Korea is described.
PubMed: 34721714
DOI: 10.1007/s13139-021-00711-9 -
Seminars in Nuclear Medicine May 2021Amyloid-β (Aβ) PET imaging has now been available for over 15 years. The ability to detect Aβ in vivo has greatly improved the clinical and research landscape of... (Review)
Review
Amyloid-β (Aβ) PET imaging has now been available for over 15 years. The ability to detect Aβ in vivo has greatly improved the clinical and research landscape of Alzheimer's disease (AD) and other neurodegenerative conditions. Aβ imaging provides very reliable, accurate, and reproducible measurements of regional and global Aβ burden in the brain. It has proved invaluable in anti-Aβ therapy trials, and is now recognized as a powerful diagnostic tool. The appropriate use of Aβ PET, when combined with comprehensive clinical evaluation by a dementia-trained specialist, can improve the accuracy of a clinical diagnosis of AD and substantially alter management. It can assist in differentiating AD from other neurodegenerative conditions, often by its ability to rule out the presence of Aβ. When combined with tau imaging, further increase in specificity for the diagnosis of AD can be achieved. The integration of Aβ PET, in conjunction with biomarkers of tau, neurodegeneration and neuroinflammation, into large, longitudinal, observational cohort studies continues to increase our understanding of the development of AD. Its incorporation into clinical trials has been pivotal in defining the most effective anti-Aβ biological therapies and optimal dosing so that effective disease modifying therapy now appears imminent. Aβ deposition is a gradual and protracted process, permitting a wide treatment window for anti-Aβ therapies and Aβ PET has made trials in this preclinical AD period feasible. Continuing improvement in Aβ tracer target to background ratio is allowing trials in earlier AD that tailor drug dosage to Aβ level. The quest to standardize quantification and define universally applicable thresholds for all Aβ tracers has produced the Centiloid method. Centiloid values that correlate well with neuropathologic findings and prognosis have been identified. Rapid cloud-based automated individual scan analysis is now possible and does not require MRI. Challenges remain, particularly around cross camera standardized uptake value ratio variation that need to be addressed. This review will compare available Aβ radiotracers, discuss approaches to quantification, as well as the clinical and research applications of Aβ PET.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Brain; Humans; Positron-Emission Tomography; tau Proteins
PubMed: 33482999
DOI: 10.1053/j.semnuclmed.2020.12.005