Multispectral imaging is used in various applications including astronomy, industry and agriculture. In retinal imaging, the single-shot multispectral image stack is typically acquired and analyzed. This multispectral analysis can provide information on various structural or metabolic properties. This paper describes the multispectral improvement of a video-ophthalmoscope, which can acquire retinal video sequences of the optic nerve head and peripapillary area using various spectral light illumination. The description of the multispectral video imaging is provided and several applications are described. These applications include multispectral retinal photoplethysmography, visualization of spontaneous vein pulsation and multispectral RGB image generation.
The RoScan is a novel, high-accuracy multispectral surface scanning system producing colored 3D models that include a thermal layer. (1) Background: at present, medicine still exhibits a lack of objective diagnostic methods. As many diseases involve thermal changes, thermography may appear to be a convenient technique for the given purpose; however, there are three limiting problems: exact localization, resolution vs. range, and impossibility of quantification. (2) Methods: the basic principles and benefits of the system are described. The procedures rely on a robotic manipulator with multiple sensors to create a multispectral 3D model. Importantly, the structure is robust, scene-independent, and features quantifiable measurement uncertainty; thus, all of the above problems of medical thermography are resolved. (3) Results: the benefits were demonstrated by several pilot case studies: medicament efficacy assessment in dermatology, objective recovery progress assessment in traumatology, applied force quantification in forensic sciences, exact localization of the cause of pain in physiotherapy, objective assessment of atopic dermatitis, and soft tissue volumetric measurements. (4) Conclusion: the RoScan addresses medical quantification, which embodies a frequent problem in several medical sectors, and can deliver new, objective information to improve the quality of healthcare and to eliminate false diagnoses.
- MeSH
- Dermatitis, Atopic diagnosis MeSH
- Humans MeSH
- Pain Measurement MeSH
- Robotics * MeSH
- Forensic Sciences MeSH
- Thermography * MeSH
- Imaging, Three-Dimensional * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In traditional optical imaging, limited light penetration constrains high-resolution interrogation to tissue surfaces. Optoacoustic imaging combines the superb contrast of optical imaging with deep penetration of ultrasound, enabling a range of new applications. We used multispectral optoacoustic tomography (MSOT) for functional and structural neuroimaging in mice at resolution, depth, and specificity unattainable by other neuroimaging modalities. Based on multispectral readouts, we computed hemoglobin gradient and oxygen saturation changes related to processing of somatosensory signals in different structures along the entire subcortical-cortical axis. Using temporal correlation analysis and seed-based maps, we reveal the connectivity between cortical, thalamic, and sub-thalamic formations. With the same modality, high-resolution structural tomography of intact mouse brain was achieved based on endogenous contrasts, demonstrating near-perfect matches with anatomical features revealed by histology. These results extend the limits of noninvasive observations beyond the reach of standard high-resolution neuroimaging, verifying the suitability of MSOT for small-animal studies.
Biodegradable nanoparticles based on stearic acid-modified poly(glycerol adipate) (PGAS) are promising carriers for drug delivery. In order to investigate the impact of the particle interface characteristics on the biological fate, PGAS nanoparticles are covalently and noncovalently coated with N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers. HPMA copolymer-modified PGAS nanoparticles have similar particle sizes, but less negative zeta-potentials. Nanoparticles are double labeled with the fluorescent dyes DiR (noncovalently) and DYOMICS-676 (covalently bound to HPMA copolymer), and their biodistribution is investigated noninvasively by multispectral optical imaging. Both covalent and noncovalent coatings cause changes in the pharmacokinetics and biodistribution in healthy and tumor-bearing mice. In addition to the intended tumor accumulation, high signals of both fluorescent dyes are also observed in other organs, including liver, ovaries, adrenal glands, and bone. The unintended accumulation of nanocarriers needs further detailed and systematic investigations, especially with respect to the observed ovarian and adrenal gland accumulation.
- MeSH
- Biodegradable Plastics chemistry MeSH
- HT29 Cells MeSH
- Fluorescent Dyes chemistry MeSH
- Drug Delivery Systems * MeSH
- Humans MeSH
- Methacrylates administration & dosage chemistry MeSH
- Mice MeSH
- Neoplasms drug therapy genetics pathology MeSH
- Nanoparticles administration & dosage chemistry MeSH
- Drug Carriers administration & dosage chemistry MeSH
- Polyesters administration & dosage chemistry MeSH
- Tissue Distribution drug effects MeSH
- Xenograft Model Antitumor Assays MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The enzymatic release of a model drug from a polymer carrier inside a tumor using multispectral optical imaging in vivo in nude mice bearing colorectal carcinomas HT-29 and DLD-1 is demonstrated. Much higher release rate in vivo from a linear (30 kDa) (N-2-hydroxypropyl)methacrylamide-based polymer compared with a high molecular weight branched (170 kDa) polymer conjugate is observed, probably due to steric hindrance of the cleavable spacer of the latter polymer to proteolytic enzymes. There is no significant difference in the relative biodistribution of the two polymers, but the branched polymer circulates much longer. Both polymers are labeled with two different fluorophores. Dyomics-676 as a drug model is attached to the polymer via an enzymatically cleavable Gly-Phe-Leu-Gly spacer; Dyomics 782 is bound to the same polymer via a nondegradable amide bond, enabling the tracking of the polymer carrier after i.v. application to mice.
- MeSH
- Acrylamides * chemistry pharmacokinetics pharmacology MeSH
- Fluorescent Dyes * chemistry pharmacokinetics pharmacology MeSH
- Colorectal Neoplasms * drug therapy metabolism pathology MeSH
- Humans MeSH
- Mice, Nude MeSH
- Mice MeSH
- Drug Carriers * chemistry pharmacokinetics pharmacology MeSH
- Xenograft Model Antitumor Assays MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
In recent years, polymer drug carriers based on N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers with pH-triggered drug release have shown enhanced uptake in solid tumors and excellent antitumor activity. Here, the impact of the structure of the acid-labile spacer between the drug and the polymer carrier on the biodistribution of both the drug and the carrier was studied using in vivo noninvasive multispectral optical imaging of dual fluorescently labeled HPMA copolymers. Five different spacers containing a pH-sensitive hydrazone bond were synthesized and used to combine a fluorescent model drug with a polymer backbone, conjugated with another non-releasable fluorescent dye. Two copolymers differing in polymer chain structure (linear and star-like) and molecular weight (30 and 200kDa) were used to distinguish between carriers with molecular weights above and below the limit for renal filtration. The rate of model drug release from the conjugates was determined in vitro. The biodistributions of the six most promising conjugates were investigated in vivo in athymic nude mice inoculated with human colon carcinoma xenograft. The structure of the spacer in the vicinity of the hydrazone bond significantly influenced the release rate of the model drug. The slow release rate of a pyridyl group bearing spacer resulted in a greater amount of the model drug being transported to the tumor, which was independent of the carrier structure. The results of this study emphasize the importance of careful selection of the structure and appropriate spacer when designing polymer conjugates intended for passive tumor targeting.
- MeSH
- Acrylamides analysis MeSH
- Fluorescent Dyes administration & dosage pharmacokinetics MeSH
- Indoles administration & dosage pharmacokinetics MeSH
- Carbocyanines administration & dosage pharmacokinetics MeSH
- Hydrogen-Ion Concentration MeSH
- Delayed-Action Preparations analysis MeSH
- Humans MeSH
- Models, Molecular MeSH
- Mice, Nude MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Colonic Neoplasms drug therapy MeSH
- Tissue Distribution MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
... Development of Radiation Therapy 12 -- Wambersie A., Brussels -- IL12 Modem Trends in Diagnostic Imaging ... ... Fast Fourier Transform 86 Wolschendorf K., Nittikowski J., Niedermayer W., Kiel -- NTDR P1 Volume Imaging ... ... -J., Braunschweig -- QADR P2 Quality Assurance for X-ray Imaging Systems - A Comparison 106 of Methods ... ... J., Heidelberg -- In Vivo Measurement of Partial Oxygen Pressures Using 19F-NMR 370 Imaging -- Nöth U ... ... J., Heidelberg -- Perfusion-Weighted Magnetic Resonance Imaging in Patients 374 with Unilateral Carotid ...
xxii, 430 s. : il., tab. ; 21 cm
- MeSH
- Biophysics MeSH
- Radiography MeSH
- Radiology MeSH
- Radiotherapy MeSH
- Publication type
- Congress MeSH
- Collected Work MeSH
- Conspectus
- Lékařské vědy. Lékařství
- NML Fields
- fyzika, biofyzika
- radiologie, nukleární medicína a zobrazovací metody
