-
Current Opinion in Chemical Biology Aug 2016Providing the specific imaging contrast of optical absorption and excellent spatial scalability across the optical and ultrasonic dimensions, photoacoustic imaging has... (Review)
Review
Providing the specific imaging contrast of optical absorption and excellent spatial scalability across the optical and ultrasonic dimensions, photoacoustic imaging has been rapidly emerging and expanding in the past two decades. In this review, I focus on a few latest advances in this enabling technology that hold the potential to transform in vivo functional and molecular imaging at multiple length scales. Specifically, multi-parametric photoacoustic microscopy enables simultaneous high-resolution mapping of hemoglobin concentration, oxygen saturation and blood flow-opening up the possibility of quantifying the metabolic rate of oxygen at the microscopic level. The pump-probe approach harnesses a variety of photoinduced transient optical absorption as novel contrast mechanisms for high-specificity molecular imaging at depth and as nonlinear excitation strategies for high-resolution volumetric microscopy beyond the conventional limit. Novel magneto-optical and photochromic probes lead to contrast-enhanced molecular photoacoustic imaging through differential detection.
Topics: Acoustics; Fluorescent Dyes; Molecular Imaging
PubMed: 27111279
DOI: 10.1016/j.cbpa.2016.04.003 -
Heart (British Cardiac Society) Mar 2018To accurately predict atherosclerotic plaque progression, a detailed phenotype of the lesion at the molecular level is required. Here, we assess the respective merits... (Review)
Review
To accurately predict atherosclerotic plaque progression, a detailed phenotype of the lesion at the molecular level is required. Here, we assess the respective merits and limitations of molecular imaging tools. Clinical imaging includes contrast-enhanced ultrasound, an inexpensive and non-toxic technique but with poor sensitivity. CT benefits from high spatial resolution but poor sensitivity coupled with an increasing radiation burden that limits multiplexing. Despite high sensitivity, positron emission tomography and single-photon emission tomography have disadvantages when applied to multiplex molecular imaging due to poor spatial resolution, signal cross talk and increasing radiation dose. In contrast, MRI is non-toxic, displays good spatial resolution but poor sensitivity. Preclinical techniques include near-infrared fluorescence (NIRF), which provides good spatial resolution and sensitivity; however, multiplexing with NIRF is limited, due to photobleaching and spectral overlap. Fourier transform infrared spectroscopy and Raman spectroscopy are label-free techniques that detect molecules based on the vibrations of chemical bonds. Both techniques offer fast acquisition times with Raman showing superior spatial resolution. Raman signals are inherently weak; however, leading to the development of surface-enhanced Raman spectroscopy (SERS) that offers greatly increased sensitivity due to using metallic nanoparticles that can be functionalised with biomolecules targeted against plaque ligands while offering high multiplexing potential. This asset combined with high spatial resolution makes SERS an exciting prospect as a diagnostic tool. The ongoing refinements of SERS technologies such as deep tissue imaging and portable systems making SERS a realistic prospect for translation to the clinic.
Topics: Cardiovascular Diseases; Disease Progression; Humans; Molecular Imaging; Plaque, Atherosclerotic; Spectrum Analysis, Raman
PubMed: 29061690
DOI: 10.1136/heartjnl-2017-311447 -
Molecules (Basel, Switzerland) Nov 2020Molecular imaging has rapidly developed to answer the need of image contrast in medical diagnostic imaging to go beyond morphological information to include functional... (Review)
Review
Molecular imaging has rapidly developed to answer the need of image contrast in medical diagnostic imaging to go beyond morphological information to include functional differences in imaged tissues at the cellular and molecular levels. Vibrational (infrared (IR) and Raman) imaging has rapidly emerged among the molecular imaging modalities available, due to its label-free combination of high spatial resolution with chemical specificity. This article presents the physical basis of vibrational spectroscopy and imaging, followed by illustration of their preclinical in vitro applications in body fluids and cells, ex vivo tissues and in vivo small animals and ending with a brief discussion of their clinical translation. After comparing the advantages and disadvantages of IR/Raman imaging with the other main modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography/single-photon emission-computed tomography (PET/SPECT), ultrasound (US) and photoacoustic imaging (PAI), the design of multimodal probes combining vibrational imaging with other modalities is discussed, illustrated by some preclinical proof-of-concept examples.
Topics: Algorithms; Animals; Humans; Infrared Rays; Magnetic Resonance Imaging; Models, Theoretical; Molecular Imaging; Positron-Emission Tomography; Spectrum Analysis, Raman; Tomography, X-Ray Computed; Ultrasonography
PubMed: 33256052
DOI: 10.3390/molecules25235547 -
Molecules (Basel, Switzerland) Oct 2022Molecular imaging is the visual representation of biological processes that take place at the cellular or molecular level in living organisms. To date, molecular imaging... (Review)
Review
Molecular imaging is the visual representation of biological processes that take place at the cellular or molecular level in living organisms. To date, molecular imaging plays an important role in the transition from conventional medical practice to precision medicine. Among all imaging modalities, positron emission tomography (PET) has great advantages in sensitivity and the ability to obtain absolute imaging quantification after corrections for photon attenuation and scattering. Due to the ability to label a host of unique molecules of biological interest, including endogenous, naturally occurring substrates and drug-like compounds, the role of PET has been well established in the field of molecular imaging. In this article, we provide an overview of the recent advances in the development of PET radiopharmaceuticals and their clinical applications in oncology.
Topics: Radiopharmaceuticals; Positron-Emission Tomography; Molecular Imaging
PubMed: 36296381
DOI: 10.3390/molecules27206790 -
The British Journal of Radiology Oct 2015Molecular imaging provides considerable insight into biological processes for greater understanding of health and disease. Numerous advances in medical physics,... (Review)
Review
Molecular imaging provides considerable insight into biological processes for greater understanding of health and disease. Numerous advances in medical physics, chemistry and biology have driven the growth of this field in the past two decades. With exquisite sensitivity, depth of detection and potential for theranostics, radioactive imaging approaches have played a major role in the emergence of molecular imaging. At the same time, developments in materials science, characterization and synthesis have led to explosive progress in the nanoparticle (NP) sciences. NPs are generally defined as particles with a diameter in the nanometre size range. Unique physical, chemical and biological properties arise at this scale, stimulating interest for applications as diverse as energy production and storage, chemical catalysis and electronics. In biomedicine, NPs have generated perhaps the greatest attention. These materials directly interface with life at the subcellular scale of nucleic acids, membranes and proteins. In this review, we will detail the advances made in combining radioactive imaging and NPs. First, we provide an overview of the NP platforms and their properties. This is followed by a look at methods for radiolabelling NPs with gamma-emitting radionuclides for use in single photon emission CT and planar scintigraphy. Next, utilization of positron-emitting radionuclides for positron emission tomography is considered. Finally, recent advances for multimodal nuclear imaging with NPs and efforts for clinical translation and ongoing trials are discussed.
Topics: Humans; Molecular Imaging; Nanoparticles; Positron-Emission Tomography; Radiochemistry; Radioisotopes; Tomography, Emission-Computed, Single-Photon
PubMed: 26133075
DOI: 10.1259/bjr.20150185 -
Physiological Reviews Apr 2012Molecular imaging is revolutionizing the way we study the inner workings of the human body, diagnose diseases, approach drug design, and assess therapies. The field as a... (Review)
Review
Molecular imaging is revolutionizing the way we study the inner workings of the human body, diagnose diseases, approach drug design, and assess therapies. The field as a whole is making possible the visualization of complex biochemical processes involved in normal physiology and disease states, in real time, in living cells, tissues, and intact subjects. In this review, we focus specifically on molecular imaging of intact living subjects. We provide a basic primer for those who are new to molecular imaging, and a resource for those involved in the field. We begin by describing classical molecular imaging techniques together with their key strengths and limitations, after which we introduce some of the latest emerging imaging modalities. We provide an overview of the main classes of molecular imaging agents (i.e., small molecules, peptides, aptamers, engineered proteins, and nanoparticles) and cite examples of how molecular imaging is being applied in oncology, neuroscience, cardiology, gene therapy, cell tracking, and theranostics (therapy combined with diagnostics). A step-by-step guide to answering biological and/or clinical questions using the tools of molecular imaging is also provided. We conclude by discussing the grand challenges of the field, its future directions, and enormous potential for further impacting how we approach research and medicine.
Topics: Animals; Diagnostic Imaging; Female; Humans; Magnetic Resonance Imaging; Male; Mice; Molecular Imaging; Nanoparticles; Rats; Tomography, X-Ray Computed
PubMed: 22535898
DOI: 10.1152/physrev.00049.2010 -
Current Opinion in Neurobiology Jun 2018One of the greatest challenges of modern neuroscience is to incorporate our growing knowledge of molecular and cellular-scale physiology into integrated,... (Review)
Review
One of the greatest challenges of modern neuroscience is to incorporate our growing knowledge of molecular and cellular-scale physiology into integrated, organismic-scale models of brain function in behavior and cognition. Molecular-level functional magnetic resonance imaging (molecular fMRI) is a new technology that can help bridge these scales by mapping defined microscopic phenomena over large, optically inaccessible regions of the living brain. In this review, we explain how MRI-detectable imaging probes can be used to sensitize noninvasive imaging to mechanistically significant components of neural processing. We discuss how a combination of innovative probe design, advanced imaging methods, and strategies for brain delivery can make molecular fMRI an increasingly successful approach for spatiotemporally resolved studies of diverse neural phenomena, perhaps eventually in people.
Topics: Animals; Brain; Brain Mapping; Humans; Magnetic Resonance Imaging; Molecular Imaging
PubMed: 29649765
DOI: 10.1016/j.conb.2018.03.009 -
The International Journal of... Aug 2018The recent surge in spectroscopic Single-Molecule Localization Microscopy (sSMLM) offers exciting new capabilities for combining single molecule imaging and... (Review)
Review
The recent surge in spectroscopic Single-Molecule Localization Microscopy (sSMLM) offers exciting new capabilities for combining single molecule imaging and spectroscopic analysis. Through the synergistic integration of super-resolution optical microscopy and single-molecule spectroscopy, sSMLM offers combined strengths from both fields. By capturing the full spectra of single molecule fluorescent emissions, sSMLM can distinguish minute spectroscopic variations from individual fluorescent molecules while preserving nanoscopic spatial localization precision. It can significantly extend the coding space for multi-molecule super-resolution imaging. Furthermore, it has the potential to detect spectroscopic variations in fluorescence emission associated with molecular interactions, which further enables probing local chemical and biochemical inhomogeneities of the nano-environments. In this review, we seek to explain the working principle of sSMLM technologies and the status of sSMLM techniques towards new super-resolution imaging applications.
Topics: Amyloid beta-Peptides; Animals; COS Cells; Chlorocebus aethiops; Fluorescent Dyes; Humans; Hydrophobic and Hydrophilic Interactions; Lipid Bilayers; Microscopy, Fluorescence; Molecular Imaging; Oxazines; Rhodamines; Single Molecule Imaging; alpha-Synuclein
PubMed: 29874548
DOI: 10.1016/j.biocel.2018.06.002 -
The International Journal of Biological... Feb 2020The utility of positron emission tomography (PET) for the evaluation of response to immunotherapy has been considered a hot topic, particularly in the last 2 to 3 years....
The utility of positron emission tomography (PET) for the evaluation of response to immunotherapy has been considered a hot topic, particularly in the last 2 to 3 years. Different experiences have been collected in clinical practice, with 18F-Fluorodeoxyglucose (FDG) PET/computed tomography (CT), particularly in patients affected by lymphoma, malignant melanoma, and lung cancer. It has been tested in different settings of disease, from the prediction to the prognosis relative to the response to immunotherapy. In the present mini-review, some evidence is reported about the role of FDG PET/CT in patient candidates to or treated with immunotherapy.
Topics: Aged; Female; Humans; Immunotherapy; Male; Molecular Imaging
PubMed: 32079465
DOI: 10.1177/1724600819899099 -
Journal of Nuclear Medicine : Official... Jun 2019Cancer immunotherapy is now established as a central therapeutic pillar in hematologic oncology. Cell-based therapies, with or without genetic modification ex vivo, have... (Review)
Review
Cancer immunotherapy is now established as a central therapeutic pillar in hematologic oncology. Cell-based therapies, with or without genetic modification ex vivo, have reached the clinic as the standard of care in limited indications and remain the subject of intense preclinical and translational development. Expanding on this, related therapeutic approaches are in development for solid-tumor and nonmalignant indications, broadening the scope of this technology. It has long been recognized that in vivo tracking of infused cellular therapies would provide unique opportunities to optimize their efficacy and aid in the assessment and management of toxicity. Recently, we have witnessed the introduction of novel tracers for passive labeling of cell products and advances in the introduction and use of reporter genes to enable longitudinal imaging. This review highlights the key developments over the last 5 y.
Topics: Animals; Cell- and Tissue-Based Therapy; Humans; Isotope Labeling; Molecular Imaging; Nanoparticles
PubMed: 30979822
DOI: 10.2967/jnumed.118.213348