Superparamagnetic iron oxide (SPIO) MRI contrast agents are composed of nano-sized iron oxide crystals coated with dextran or carboxydextran. There are two clinically approved SPIO agents: Feridex and Resovist. Feridex has a particle size of 120-180 nm and is used for delayed phase liver imaging. Resovist has a smaller particle size of 60 nm and can be administered as a rapid bolus, allowing for dynamic and delayed liver imaging. Both agents are sequestered by Kupffer cells in the liver, resulting in signal loss and increased lesion detection compared to normal tissue. SPIO agents have been shown to improve detection of liver metastases and lesions.
PET and SPECT Scanning: Functional Brain ImagingBrendan Quinn
PET and SPECT are functional brain imaging techniques. PET has higher resolution but is more expensive, while SPECT has lower resolution but is less expensive. Both techniques involve injecting radioactive tracers and detecting their location in the brain to map blood flow and metabolic activity. fMRI is another functional imaging technique that detects changes in blood oxygenation to map brain activity.
Positron emission tomography pet scan and its applicationsYashawant Yadav
Slides contains physic about the PET scan that is positron emission tomography , its principle , detector configuration types , clinical application of PET Scan and advancement with CT and MRI
Skeletal radionuclide imaging plays an important role in understanding bone metabolism and evaluating bone abnormalities. Various radiotracers are used including 99mTc-MDP, 18F-NaF, and 18F-FDG. SPECT and PET are employed to produce images showing radiotracer distribution. Normal scans show clear, symmetric uptake throughout the skeleton with increased uptake in joints, while abnormal scans can detect changes in blood flow, osteoblastic activity, or bone destruction.
Monitoring live cell viability Comparative studyWerden Keeler
This document compares three live cell imaging techniques: fluorescence microscopy, oblique incidence reflection microscopy, and phase contrast microscopy. It finds that oblique incidence reflection microscopy is the simplest, least expensive, and least phototoxic method, causing the least damage to live cells during long-term monitoring of cell viability. The document describes the equipment and cell lines used, including normal and cancerous cell lines tagged with fluorescent proteins or unlabeled, to evaluate the stresses induced by different illumination techniques.
Magnetic resonance spectroscopy (MRS) is a noninvasive imaging technique that measures metabolite levels in tissues. It works by detecting signals from atomic nuclei such as hydrogen placed in a strong magnetic field. MRS is useful for evaluating brain tumors, infections, demyelinating diseases, and neurodegenerative conditions. It provides diagnostic information by analyzing peak levels of metabolites including NAA, creatine, choline, and lactate. MRS can help distinguish tumors from other lesions, detect radiation necrosis, and monitor treatment response. It is also used to diagnose inborn errors of metabolism and mitochondrial disorders.
PET-CT and PET-MR provide functional imaging through PET as well as anatomical imaging through CT or MRI. PET involves radiolabeling molecules like FDG with positron emitters, injecting them into patients, and using coincident detection of annihilation photons to construct 3D images. PET-CT provides accurate localization of functional abnormalities and distinction of normal from pathological tracer uptake. Whole-body PET-MRI is an emerging technique that combines the molecular imaging of PET with the excellent soft tissue contrast of MRI.
PET scans use radioactive tracers and detectors to generate 3D images of metabolic processes in the body. They have various applications in neurology for diagnosing and monitoring conditions like dementia, epilepsy, movement disorders, and brain tumors. For example, PET can help differentiate Alzheimer's from other dementias based on patterns of hypometabolism in temporal and parietal lobes. It is also useful for localizing epileptic foci before epilepsy surgery. The document discusses the history, mechanisms, common tracers, and limitations of PET scanning as well as its role in evaluating specific neurological conditions and potential future applications.
PET and SPECT Scanning: Functional Brain ImagingBrendan Quinn
PET and SPECT are functional brain imaging techniques. PET has higher resolution but is more expensive, while SPECT has lower resolution but is less expensive. Both techniques involve injecting radioactive tracers and detecting their location in the brain to map blood flow and metabolic activity. fMRI is another functional imaging technique that detects changes in blood oxygenation to map brain activity.
Positron emission tomography pet scan and its applicationsYashawant Yadav
Slides contains physic about the PET scan that is positron emission tomography , its principle , detector configuration types , clinical application of PET Scan and advancement with CT and MRI
Skeletal radionuclide imaging plays an important role in understanding bone metabolism and evaluating bone abnormalities. Various radiotracers are used including 99mTc-MDP, 18F-NaF, and 18F-FDG. SPECT and PET are employed to produce images showing radiotracer distribution. Normal scans show clear, symmetric uptake throughout the skeleton with increased uptake in joints, while abnormal scans can detect changes in blood flow, osteoblastic activity, or bone destruction.
Monitoring live cell viability Comparative studyWerden Keeler
This document compares three live cell imaging techniques: fluorescence microscopy, oblique incidence reflection microscopy, and phase contrast microscopy. It finds that oblique incidence reflection microscopy is the simplest, least expensive, and least phototoxic method, causing the least damage to live cells during long-term monitoring of cell viability. The document describes the equipment and cell lines used, including normal and cancerous cell lines tagged with fluorescent proteins or unlabeled, to evaluate the stresses induced by different illumination techniques.
Magnetic resonance spectroscopy (MRS) is a noninvasive imaging technique that measures metabolite levels in tissues. It works by detecting signals from atomic nuclei such as hydrogen placed in a strong magnetic field. MRS is useful for evaluating brain tumors, infections, demyelinating diseases, and neurodegenerative conditions. It provides diagnostic information by analyzing peak levels of metabolites including NAA, creatine, choline, and lactate. MRS can help distinguish tumors from other lesions, detect radiation necrosis, and monitor treatment response. It is also used to diagnose inborn errors of metabolism and mitochondrial disorders.
PET-CT and PET-MR provide functional imaging through PET as well as anatomical imaging through CT or MRI. PET involves radiolabeling molecules like FDG with positron emitters, injecting them into patients, and using coincident detection of annihilation photons to construct 3D images. PET-CT provides accurate localization of functional abnormalities and distinction of normal from pathological tracer uptake. Whole-body PET-MRI is an emerging technique that combines the molecular imaging of PET with the excellent soft tissue contrast of MRI.
PET scans use radioactive tracers and detectors to generate 3D images of metabolic processes in the body. They have various applications in neurology for diagnosing and monitoring conditions like dementia, epilepsy, movement disorders, and brain tumors. For example, PET can help differentiate Alzheimer's from other dementias based on patterns of hypometabolism in temporal and parietal lobes. It is also useful for localizing epileptic foci before epilepsy surgery. The document discusses the history, mechanisms, common tracers, and limitations of PET scanning as well as its role in evaluating specific neurological conditions and potential future applications.
This document discusses PETMR (positron emission tomography and magnetic resonance imaging). It begins with introductions and discusses the basics of PETMR, including why it is needed and challenges such as PMT malfunction in magnetic fields. Solutions to these challenges include using APDs or SiPMs instead of PMTs. Methods for performing attenuation and scatter fraction corrections with PETMR are also presented. Clinical applications of PETMR are then discussed, including for brain tumors, metastases detection and more. Overall, the document provides an overview of PETMR technology, challenges and solutions, as well as its clinical utility.
Evaluation of Absorbed Dose in Renal Function Studies Due al I123/I131(hippur...IJRES Journal
The estimated absorbed dose to the kidneys for renal function studies of adult patients, can be
performed through the analysis of the biokinetics of radiopharmaceuticals used, containing the I-123 / I-132
(Hippuran) or In-111 (DPTA). The study is to determine whether the dosimetric contributions biokinetics
organs (kidneys, whole body and your bladder) of I-123 / I-131 (Hippuran) and In-111 (DTPA), are significant
in the calculation of the absorbed dose for renal function studies. To determine the dosimetric contribution of
the bladder and the entire body in the kidneys of adult patients, were used MIRD formalism Cristy and
Eckerman representation. The results show that the total absorbed dose due to I123, I131 and In111 are given by
0.0071 mGy / MBq, 0.032 mGy / MBq and 0.0168 mGy / MBq, respectively. While corresponding dosimetric
contributions because their bodiesbiokinetics are given by 11.90%, 4.97% and 28.32%. In all cases, the
dosimetric contribution of organs that are part of the biokinetics of radiopharmaceuticals (except kidneys) are
very significant to be ignored, and are mainly due to the photons emitted by the entire body.
Radioisotopes have many important medical uses including medical imaging and therapy. Medical imaging techniques like PET scans, SPECT scans, x-rays, MRI, and CT scans use radioactive tracers to create detailed images of the body. Approximately 10% of medical procedures use radiation therapy to treat diseases like cancer. Common radiation therapy methods include external beam radiation, brachytherapy where radioactive sources are placed inside the body, and boron neutron capture therapy. Radioisotopes are crucial for diagnosing and treating millions of patients worldwide each year.
A PET scan uses radioactive tracers injected into the body to produce 3D images showing functional processes. A short-lived radioactive tracer, FDG, is injected and detected as it breaks down, showing glucose metabolism levels in tissues. Different metabolism levels appear as different colors, allowing the computer to generate images of functional abnormalities like cancers or brain disorders. PET scans can detect diseases earlier than other scans and help avoid unnecessary surgery by precisely identifying areas needing treatment.
PET/MR imaging in neurodegenerative diseasesWalid Rezk
The document discusses the current and future potential applications of PET/MR imaging in neurodegenerative diseases. PET/MR combines the molecular imaging capabilities of PET with the high spatial resolution of MRI. It allows simultaneous acquisition of PET and MRI data. Current applications include detection of amyloid plaques and dopamine deficits. Emerging tracers may image tau and alpha-synuclein. Novel MRI techniques like diffusion tensor imaging and arterial spin labeling also show promise. Combined PET/MR could become a routine first-line tool for diagnosis and may aid basic research into neurodegeneration.
MR spectroscopy is a noninvasive test that uses MRI to measure biochemical changes in the brain and detect tumors. It analyzes molecules like protons to identify different metabolites that are elevated or lowered in tumor tissue compared to normal brain tissue. This allows the radiologist to determine the type and aggressiveness of a tumor, and distinguish between tumor recurrence and radiation necrosis. Various techniques like STEAM, PRESS, ISIS, and CSI are used for single or multi-voxel spectroscopy and provide metabolite information with different echo times and coverage areas.
The document discusses the use of contrast agents for pre-clinical CT imaging of soft tissues and vasculature using the Quantum GX microCT imaging system. It describes how iodine-based and nanoparticle contrast agents can provide enhanced image contrast for visualizing soft tissues compared to CT imaging without contrast. Specifically, it provides examples of kidney imaging using the iodinated agents ExiTron V, OptiPrep, and discusses optimizing the dose of OptiPrep. High resolution sub-volume reconstruction is also described to visualize inner kidney structures like the cortex, medulla, and ureters.
Magnetic resonance spectroscopy (MRS) provides biochemical information about metabolites in tissues. It differs from MRI in that it analyzes spectra rather than anatomy. Common nuclei analyzed include hydrogen (proton MRS), which is most common. MRS can detect metabolites like N-acetylaspartate, creatine, choline, myoinositol, and lactate. Abnormal levels of these metabolites can indicate conditions like tumors, infections, demyelination, and more. MRS is used to study many neurological diseases and assess treatment response. It provides a non-invasive way to analyze brain chemistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
This document provides an overview of magnetic resonance imaging (MRI) and discusses its history, technical aspects, medical uses, safety considerations, comparisons to other imaging techniques, regulations, underlying physics principles, ongoing developments, and potential job opportunities. MRI is a medical imaging technique that produces detailed images of the internal structures and functions of the body without using ionizing radiation. It was developed in the 1970s and continues to be an area of active research and clinical application.
Study of Mitotic Index and DNA profile when exposure to He-Ne laser and UVC r...IOSR Journals
This study examined the effects of He-Ne laser radiation and UVC radiation on mitotic index and DNA profiles in mice. 100 mice were divided into groups exposed to laser radiation at different time periods, UVC radiation for 1 hour, laser pre-exposure followed by UVC, and UVC pre-exposure followed by laser. Mitotic index, which measures the percentage of cells undergoing cell division, and DNA electrophoresis were analyzed at various time points after exposure. Results showed that UVC radiation decreased mitotic index and increased DNA damage over time, while laser pre-exposure protected against these effects of subsequent UVC exposure by inducing antioxidant defenses and DNA repair mechanisms. Laser exposure alone had minor effects on mitotic index.
Pet presentation, positron emission tomography emicica
PET is a nuclear medicine scan that uses radioactive tracers to visualize metabolic processes in the body. It works by administering a radioactive tracer that accumulates in tissues and organs, emitting gamma rays that are detected by a ring of scintillation detectors. This allows reconstruction of 2D images showing tracer concentration. Common tracers include carbon-11, nitrogen-13, oxygen-15 and fluorine-18, which are produced by a cyclotron. PET scans are used to detect and monitor cancer, heart disease, and brain disorders. The scans provide functional information that can be fused with anatomical CT or MRI images. While exposing patients to radiation, PET offers high sensitivity for disease detection at early stages.
PET-MRI is a hybrid imaging technology that combines the functional PET imaging with the high soft tissue contrast of MRI. Early prototypes combined a brain-only PET scanner with MRI, but now full-body scanners exist from Siemens, GE, and Philips. MRI uses hydrogen protons' magnetic properties to generate images, and the human body contains large percentages of hydrogen atoms. PET-MRI provides synergistic molecular and anatomical information without ionizing radiation compared to PET-CT. Clinical uses especially benefit oncology, cardiology, and neurology evaluations where soft tissue detail is important.
This document provides an overview of nuclear medicine and the technologies used. It discusses radiopharmaceuticals, which consist of a chemical molecule and radionuclide, and are used in nuclear medicine to provide information about organ function. Gamma cameras are described as detecting radiation emitted from radiopharmaceuticals and producing images, while SPECT involves a gamma camera rotating around the patient to generate 3D tomographic images. The key components of gamma cameras and their operation are also summarized.
Radionuclide imaging uses radiopharmaceuticals (RPh) containing radioactive isotopes to diagnose diseases. RPh must selectively accumulate in target organs and emit detectable radiation. Common isotopes used include 99mTc, 18F, and 123I. Imaging techniques include planar scintigraphy to visualize organ shape and function, whole-body scintigraphy to detect lesions, and SPECT/PET which provide 3D images of organ function and metabolism. Radionuclide imaging is a valuable tool for diagnosing cancers, heart disease, and other conditions.
This document discusses lensfree microscopy and tomography techniques developed by Serhan Isikman for biomedical applications. [1] Lensfree microscopy uses holograms recorded by a sensor array to digitally reconstruct microscope images over a wide field of view in a compact, low-cost system. [2] It has been used to rapidly count red blood cells on a chip with high accuracy. [3] Lensfree optical tomography similarly uses holograms from multiple angles to computationally generate 3D images without lenses, achieving micrometer-scale resolution.
Lithium Filtration for Improved Dose Penetration in BNCTkent.riley
This document summarizes research into adding an optional 6Li filter to an existing epithermal neutron beam used for boron neutron capture therapy (BNCT) to treat brain tumors. Monte Carlo simulations and measurements were used to design and test a removable 8mm thick 6Li filter. The filter improved penetration of thermal neutrons to depths of 9.9cm while maintaining tumor selectivity. Recalculating past treatment plans showed the filter could increase minimum deliverable tumor doses by up to 9% without increasing normal tissue doses. The filter provides an incremental enhancement to the clinical beam that may help establish a therapeutic window for treating deeper tumors.
MRI uses strong magnetic fields and radio waves to generate images of the inside of the body. It is a medical imaging technique widely used in radiology to visualize anatomy and physiological processes. MRI has many medical uses and applications across different body systems. It is generally a safe technique but there are some risks needing consideration for things like implants, projectile effects, and claustrophobia. Guidelines and certifications aim to standardize roles and ensure safe MRI practices.
Undoubtedly, the use of radiographic imaging has entirely revolutionized diagnosis and treatment planning in medical sciences. The role of imaging in oral malignancies can be broadly grouped into those used to evaluate primary disease and those to evaluate metastatic disease.
It is a useful tool for staging and management planning in oral cancers. Awareness of the presence of cervical node metastasis is important in treatment planning and in prognostic prediction for patients with head and neck cancer (HNC).
. Panoramic radiography (also called pan tomography or rotational radiography) is a radiographic technique for producing a single image of the facial structures that include both maxillary and mandibular arches and their supporting structures.
Undoubtedly, the use of radiographic imaging has entirely revolutionized the diagnosis and treatment planning in medical sciences. The role of imaging in oral malignancies can be broadly grouped in those used to evaluate primary disease and those to evaluate metastatic disease.
Super paramagnetic iron oxide nanoparticles (SPIONs) are being researched for applications in cancer chemotherapy, including for drug delivery, hyperthermia treatment of tumors, and as contrast agents for magnetic resonance imaging (MRI). SPIONs have advantages such as biocompatibility and an ability to be guided to tumor sites using magnetic fields. However, coating is needed to reduce aggregation and toxicity. Research is exploring conjugating drugs and targeting ligands to SPIONs to selectively deliver higher doses of chemotherapy to tumors while reducing side effects.
This document discusses PET and thyroid scans. PET uses radioactive tracers to provide metabolic and functional imaging, and has better resolution than SPECT but is more expensive. Thyroid scans use radioactive iodine or technetium tracers to evaluate the thyroid gland for abnormalities, nodules, or cancer. Both scans involve injecting or ingesting radioactive tracers and using gamma cameras to detect their accumulation and distribution in the body to assess health and function.
This document discusses PETMR (positron emission tomography and magnetic resonance imaging). It begins with introductions and discusses the basics of PETMR, including why it is needed and challenges such as PMT malfunction in magnetic fields. Solutions to these challenges include using APDs or SiPMs instead of PMTs. Methods for performing attenuation and scatter fraction corrections with PETMR are also presented. Clinical applications of PETMR are then discussed, including for brain tumors, metastases detection and more. Overall, the document provides an overview of PETMR technology, challenges and solutions, as well as its clinical utility.
Evaluation of Absorbed Dose in Renal Function Studies Due al I123/I131(hippur...IJRES Journal
The estimated absorbed dose to the kidneys for renal function studies of adult patients, can be
performed through the analysis of the biokinetics of radiopharmaceuticals used, containing the I-123 / I-132
(Hippuran) or In-111 (DPTA). The study is to determine whether the dosimetric contributions biokinetics
organs (kidneys, whole body and your bladder) of I-123 / I-131 (Hippuran) and In-111 (DTPA), are significant
in the calculation of the absorbed dose for renal function studies. To determine the dosimetric contribution of
the bladder and the entire body in the kidneys of adult patients, were used MIRD formalism Cristy and
Eckerman representation. The results show that the total absorbed dose due to I123, I131 and In111 are given by
0.0071 mGy / MBq, 0.032 mGy / MBq and 0.0168 mGy / MBq, respectively. While corresponding dosimetric
contributions because their bodiesbiokinetics are given by 11.90%, 4.97% and 28.32%. In all cases, the
dosimetric contribution of organs that are part of the biokinetics of radiopharmaceuticals (except kidneys) are
very significant to be ignored, and are mainly due to the photons emitted by the entire body.
Radioisotopes have many important medical uses including medical imaging and therapy. Medical imaging techniques like PET scans, SPECT scans, x-rays, MRI, and CT scans use radioactive tracers to create detailed images of the body. Approximately 10% of medical procedures use radiation therapy to treat diseases like cancer. Common radiation therapy methods include external beam radiation, brachytherapy where radioactive sources are placed inside the body, and boron neutron capture therapy. Radioisotopes are crucial for diagnosing and treating millions of patients worldwide each year.
A PET scan uses radioactive tracers injected into the body to produce 3D images showing functional processes. A short-lived radioactive tracer, FDG, is injected and detected as it breaks down, showing glucose metabolism levels in tissues. Different metabolism levels appear as different colors, allowing the computer to generate images of functional abnormalities like cancers or brain disorders. PET scans can detect diseases earlier than other scans and help avoid unnecessary surgery by precisely identifying areas needing treatment.
PET/MR imaging in neurodegenerative diseasesWalid Rezk
The document discusses the current and future potential applications of PET/MR imaging in neurodegenerative diseases. PET/MR combines the molecular imaging capabilities of PET with the high spatial resolution of MRI. It allows simultaneous acquisition of PET and MRI data. Current applications include detection of amyloid plaques and dopamine deficits. Emerging tracers may image tau and alpha-synuclein. Novel MRI techniques like diffusion tensor imaging and arterial spin labeling also show promise. Combined PET/MR could become a routine first-line tool for diagnosis and may aid basic research into neurodegeneration.
MR spectroscopy is a noninvasive test that uses MRI to measure biochemical changes in the brain and detect tumors. It analyzes molecules like protons to identify different metabolites that are elevated or lowered in tumor tissue compared to normal brain tissue. This allows the radiologist to determine the type and aggressiveness of a tumor, and distinguish between tumor recurrence and radiation necrosis. Various techniques like STEAM, PRESS, ISIS, and CSI are used for single or multi-voxel spectroscopy and provide metabolite information with different echo times and coverage areas.
The document discusses the use of contrast agents for pre-clinical CT imaging of soft tissues and vasculature using the Quantum GX microCT imaging system. It describes how iodine-based and nanoparticle contrast agents can provide enhanced image contrast for visualizing soft tissues compared to CT imaging without contrast. Specifically, it provides examples of kidney imaging using the iodinated agents ExiTron V, OptiPrep, and discusses optimizing the dose of OptiPrep. High resolution sub-volume reconstruction is also described to visualize inner kidney structures like the cortex, medulla, and ureters.
Magnetic resonance spectroscopy (MRS) provides biochemical information about metabolites in tissues. It differs from MRI in that it analyzes spectra rather than anatomy. Common nuclei analyzed include hydrogen (proton MRS), which is most common. MRS can detect metabolites like N-acetylaspartate, creatine, choline, myoinositol, and lactate. Abnormal levels of these metabolites can indicate conditions like tumors, infections, demyelination, and more. MRS is used to study many neurological diseases and assess treatment response. It provides a non-invasive way to analyze brain chemistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
This document provides an overview of magnetic resonance imaging (MRI) and discusses its history, technical aspects, medical uses, safety considerations, comparisons to other imaging techniques, regulations, underlying physics principles, ongoing developments, and potential job opportunities. MRI is a medical imaging technique that produces detailed images of the internal structures and functions of the body without using ionizing radiation. It was developed in the 1970s and continues to be an area of active research and clinical application.
Study of Mitotic Index and DNA profile when exposure to He-Ne laser and UVC r...IOSR Journals
This study examined the effects of He-Ne laser radiation and UVC radiation on mitotic index and DNA profiles in mice. 100 mice were divided into groups exposed to laser radiation at different time periods, UVC radiation for 1 hour, laser pre-exposure followed by UVC, and UVC pre-exposure followed by laser. Mitotic index, which measures the percentage of cells undergoing cell division, and DNA electrophoresis were analyzed at various time points after exposure. Results showed that UVC radiation decreased mitotic index and increased DNA damage over time, while laser pre-exposure protected against these effects of subsequent UVC exposure by inducing antioxidant defenses and DNA repair mechanisms. Laser exposure alone had minor effects on mitotic index.
Pet presentation, positron emission tomography emicica
PET is a nuclear medicine scan that uses radioactive tracers to visualize metabolic processes in the body. It works by administering a radioactive tracer that accumulates in tissues and organs, emitting gamma rays that are detected by a ring of scintillation detectors. This allows reconstruction of 2D images showing tracer concentration. Common tracers include carbon-11, nitrogen-13, oxygen-15 and fluorine-18, which are produced by a cyclotron. PET scans are used to detect and monitor cancer, heart disease, and brain disorders. The scans provide functional information that can be fused with anatomical CT or MRI images. While exposing patients to radiation, PET offers high sensitivity for disease detection at early stages.
PET-MRI is a hybrid imaging technology that combines the functional PET imaging with the high soft tissue contrast of MRI. Early prototypes combined a brain-only PET scanner with MRI, but now full-body scanners exist from Siemens, GE, and Philips. MRI uses hydrogen protons' magnetic properties to generate images, and the human body contains large percentages of hydrogen atoms. PET-MRI provides synergistic molecular and anatomical information without ionizing radiation compared to PET-CT. Clinical uses especially benefit oncology, cardiology, and neurology evaluations where soft tissue detail is important.
This document provides an overview of nuclear medicine and the technologies used. It discusses radiopharmaceuticals, which consist of a chemical molecule and radionuclide, and are used in nuclear medicine to provide information about organ function. Gamma cameras are described as detecting radiation emitted from radiopharmaceuticals and producing images, while SPECT involves a gamma camera rotating around the patient to generate 3D tomographic images. The key components of gamma cameras and their operation are also summarized.
Radionuclide imaging uses radiopharmaceuticals (RPh) containing radioactive isotopes to diagnose diseases. RPh must selectively accumulate in target organs and emit detectable radiation. Common isotopes used include 99mTc, 18F, and 123I. Imaging techniques include planar scintigraphy to visualize organ shape and function, whole-body scintigraphy to detect lesions, and SPECT/PET which provide 3D images of organ function and metabolism. Radionuclide imaging is a valuable tool for diagnosing cancers, heart disease, and other conditions.
This document discusses lensfree microscopy and tomography techniques developed by Serhan Isikman for biomedical applications. [1] Lensfree microscopy uses holograms recorded by a sensor array to digitally reconstruct microscope images over a wide field of view in a compact, low-cost system. [2] It has been used to rapidly count red blood cells on a chip with high accuracy. [3] Lensfree optical tomography similarly uses holograms from multiple angles to computationally generate 3D images without lenses, achieving micrometer-scale resolution.
Lithium Filtration for Improved Dose Penetration in BNCTkent.riley
This document summarizes research into adding an optional 6Li filter to an existing epithermal neutron beam used for boron neutron capture therapy (BNCT) to treat brain tumors. Monte Carlo simulations and measurements were used to design and test a removable 8mm thick 6Li filter. The filter improved penetration of thermal neutrons to depths of 9.9cm while maintaining tumor selectivity. Recalculating past treatment plans showed the filter could increase minimum deliverable tumor doses by up to 9% without increasing normal tissue doses. The filter provides an incremental enhancement to the clinical beam that may help establish a therapeutic window for treating deeper tumors.
MRI uses strong magnetic fields and radio waves to generate images of the inside of the body. It is a medical imaging technique widely used in radiology to visualize anatomy and physiological processes. MRI has many medical uses and applications across different body systems. It is generally a safe technique but there are some risks needing consideration for things like implants, projectile effects, and claustrophobia. Guidelines and certifications aim to standardize roles and ensure safe MRI practices.
Undoubtedly, the use of radiographic imaging has entirely revolutionized diagnosis and treatment planning in medical sciences. The role of imaging in oral malignancies can be broadly grouped into those used to evaluate primary disease and those to evaluate metastatic disease.
It is a useful tool for staging and management planning in oral cancers. Awareness of the presence of cervical node metastasis is important in treatment planning and in prognostic prediction for patients with head and neck cancer (HNC).
. Panoramic radiography (also called pan tomography or rotational radiography) is a radiographic technique for producing a single image of the facial structures that include both maxillary and mandibular arches and their supporting structures.
Undoubtedly, the use of radiographic imaging has entirely revolutionized the diagnosis and treatment planning in medical sciences. The role of imaging in oral malignancies can be broadly grouped in those used to evaluate primary disease and those to evaluate metastatic disease.
Super paramagnetic iron oxide nanoparticles (SPIONs) are being researched for applications in cancer chemotherapy, including for drug delivery, hyperthermia treatment of tumors, and as contrast agents for magnetic resonance imaging (MRI). SPIONs have advantages such as biocompatibility and an ability to be guided to tumor sites using magnetic fields. However, coating is needed to reduce aggregation and toxicity. Research is exploring conjugating drugs and targeting ligands to SPIONs to selectively deliver higher doses of chemotherapy to tumors while reducing side effects.
This document discusses PET and thyroid scans. PET uses radioactive tracers to provide metabolic and functional imaging, and has better resolution than SPECT but is more expensive. Thyroid scans use radioactive iodine or technetium tracers to evaluate the thyroid gland for abnormalities, nodules, or cancer. Both scans involve injecting or ingesting radioactive tracers and using gamma cameras to detect their accumulation and distribution in the body to assess health and function.
MR spectroscopy is a noninvasive test that uses MRI to measure biochemical changes in the brain and detect tumors. It analyzes molecules like protons to identify different metabolites that are elevated or lowered in tumor tissue compared to normal brain tissue. This allows the test to determine the type and aggressiveness of a tumor, and distinguish between tumor recurrence and radiation necrosis. The test is safe and uses radio waves and a magnetic field to produce images and spectroscopy data without health risks.
MRI has become an integral imaging tool over the last 20 years. It uses magnetic fields and radio waves to create detailed images of organs and tissues without exposing patients to ionizing radiation. Different pulse sequences (T1, T2, proton density etc.) along with contrast agents allow MRI to characterize soft tissues and pathology. It is commonly used to image the brain, spine, joints, soft tissues, and for angiography. Recent advances include diffusion MRI, spectroscopy, and functional MRI. MRI has good soft tissue contrast but is more expensive than other modalities.
This document provides an overview of nanotechnology applications. It discusses the history of nanotechnology, types including dry, wet and computational nanotechnology, and structures such as nanoparticles, polymeric micelles, dendrimers, and magnetic nanoparticles. Applications of nanotechnology discussed include drug delivery, therapeutics such as cancer treatment and spinal fusion, diagnostics, sensors, and theranostics. Limitations regarding drug delivery such as toxicity and accumulation are also mentioned.
Dr. Rajesh Venunath Nair teaches radiology at K.S Hegde Medical Academy in Mangalore. His presentation discusses the history, basic principles, hardware, imaging sequences, and clinical applications of magnetic resonance imaging (MRI). It explains how MRI uses radiofrequency pulses and magnetic fields to produce detailed images of internal organs and soft tissues without using ionizing radiation. The presentation covers the main components of MRI scanners, different pulse sequences, tissue contrast mechanisms, use of contrast agents, safety considerations, and recent technical advances that have expanded clinical use of MRI.
LASERS – IT’S ROLE IN PERIODONTAL REGENERATIONhiij
The use of lasers has evolved as clinical experience along with scientific investigation. The dental
lasers of today have benefited from decades of laser research and have their basis in certain
theories from the field of quantum mechanics. When used efficaciously and ethically, lasers are an
exceptional modality of treatment for many clinical conditions that dental specialists treat on a
daily basis. The concept of using lasers for the treatment of periodontal disease elicits very strong
reactions from all sides of spectrum. Evidence suggests that lasers are useful as an adjunct or
alternative to traditional approaches in periodontal therapy. Future direction of lasers would be
towards a minimally invasive regenerative procedures along with laser assisted calculus detection
systems using laser fluorescence that is optical coherence tomography and a laser system which
selectively and completely removes the plaque and calculus that is under development. With recent
advances and development of wide range of laser wavelengths, different instrument designs and
different delivery systems, the purpose of this review is to determine the application and current
concept of lasers in the regeneration of periodontal tissues.
LASERS – IT’S ROLE IN PERIODONTAL REGENERATIONhiij
The use of lasers has evolved as clinical experience along with scientific investigation. The dental
lasers of today have benefited from decades of laser research and have their basis in certain
theories from the field of quantum mechanics. When used efficaciously and ethically, lasers are an
exceptional modality of treatment for many clinical conditions that dental specialists treat on a
daily basis. The concept of using lasers for the treatment of periodontal disease elicits very strong
reactions from all sides of spectrum. Evidence suggests that lasers are useful as an adjunct or
alternative to traditional approaches in periodontal therapy. Future direction of lasers would be
towards a minimally invasive regenerative procedures along with laser assisted calculus detection
systems using laser fluorescence that is optical coherence tomography and a laser system which
selectively and completely removes the plaque and calculus that is under development. With recent
advances and development of wide range of laser wavelengths, different instrument designs and
different delivery systems, the purpose of this review is to determine the application and current
concept of lasers in the regeneration of periodontal tissues.
LASERS – IT’S ROLE IN PERIODONTAL REGENERATIONhiij
The use of lasers has evolved as clinical experience along with scientific investigation. The dental lasers of today have benefited from decades of laser research and have their basis in certain theories from the field of quantum mechanics. When used efficaciously and ethically, lasers are an exceptional modality of treatment for many clinical conditions that dental specialists treat on a daily basis. The concept of using lasers for the treatment of periodontal disease elicits very strong reactions from all sides of spectrum. Evidence suggests that lasers are useful as an adjunct or alternative to traditional approaches in periodontal therapy. Future direction of lasers would be towards a minimally invasive regenerative procedures along with laser assisted calculus detection systems using laser fluorescence that is optical coherence tomography and a laser system which selectively and completely removes the plaque and calculus that is under development. With recent advances and development of wide range of laser wavelengths, different instrument designs and different delivery systems, the purpose of this review is to determine the application and current concept of lasers in the regeneration of periodontal tissues.
This document provides an overview of magnetic resonance spectroscopy (MRS). It begins with the objectives and introduction, explaining that MRS is a noninvasive technique that measures tissue metabolite levels. It then covers the basic principles, techniques, steps in acquisition, observable metabolites and their significance in normal and abnormal conditions. Finally, it discusses the clinical applications of MRS in diseases such as brain tumors, stroke, epilepsy and more, as well as its limitations and artifacts. In summary, the document serves as a comprehensive guide to the basic concepts and clinical uses of MRS.
This document discusses image-guided radiotherapy (IGRT) for gynecologic malignancies. It begins by defining IGRT and noting that its definition is not standardized. It then discusses various imaging modalities that can be used for IGRT, including CT, MRI, PET, and ultrasound. In particular, it explores how these advanced imaging techniques can help with target delineation and treatment delivery verification. It also examines different IGRT approaches like planar, volumetric, and adaptive IGRT. Adaptive IGRT holds promise for adjusting treatment plans based on tumor response over the course of therapy but faces technical challenges that require further study.
Functional MRI Techniques in modern MRI.pdfrajaarjunan74
This document discusses various MRI techniques including functional MRI (fMRI), magnetic resonance angiography (MRA), magnetic resonance cholangiopancreatography (MRCP), MR urography, and basic MRI concepts like k-space. It provides details on the principles, sequences, and clinical applications of each technique. fMRI maps brain activity during tasks using the BOLD response. MRA noninvasively images blood vessels using techniques like time-of-flight. MRCP visualizes the biliary and pancreatic ducts without contrast. These techniques allow evaluation of various anatomical and functional systems in a noninvasive manner.
Clinical Applications of Proton MR Spectroscopy.pdfSilvana Ciardullo
1) Proton MR spectroscopy provides greater tissue characterization than MR imaging alone by detecting metabolic abnormalities. It can be performed on most clinical 1.5T MR units in 10-15 minutes without significant additional scan time.
2) The technique detects metabolite concentrations based on peak intensities and locations on generated spectra graphs. The most commonly detected brain metabolites are NAA, creatine, choline, and lactate. Abnormal concentrations of these metabolites can indicate various neurological conditions.
3) Proton MR spectroscopy is useful for evaluating tumors, infections, demyelinating diseases, and other neurological disorders by detecting deviations from normal metabolite levels and ratios that provide physiological information about tissue status.
Radioactive isotopes were first used in medicine in the 1930s and helped establish the field of nuclear medicine. Nuclear medicine uses radioactive tracers administered to patients to generate diagnostic images of organ function. Positron emission tomography (PET) is an important diagnostic technique that uses isotopes produced by a cyclotron. Radioactive isotopes are also used for targeted cancer treatments. Some commonly used medical isotopes include technetium-99m, iodine-131, and fluorine-18.
Nanoparticles for magnetic resonance imagingAlex Chris
This document discusses the use of various types of nanoparticles for molecular imaging applications such as magnetic resonance imaging (MRI) and computer tomography (CT). It describes how gold nanoparticles, quantum dots, iron oxide nanoparticles, carbon nanotubes, dendrimers, and other nanoparticles are being investigated and developed as contrast agents for molecular imaging due to their tunable properties and potential for functionalization and targeted delivery. For example, one study demonstrated how antibody-conjugated gold nanorods could selectively target and image squamous cell carcinoma tumors using CT. Overall, the controlled properties of engineered nanoparticles show promise for improving molecular imaging techniques.
This document discusses radium-223, a radiopharmaceutical used to treat metastatic castration-resistant prostate cancer. It provides an overview of radium-223's mechanism of action as an alpha particle emitter that deposits high doses of radiation within tumor cells while minimizing bone marrow toxicity. The document also summarizes a key phase III trial which found radium-223 improved median overall survival by 3.6 months compared to placebo in men with symptomatic metastatic castration-resistant prostate cancer.
Does Over-Masturbation Contribute to Chronic Prostatitis.pptxwalterHu5
In some case, your chronic prostatitis may be related to over-masturbation. Generally, natural medicine Diuretic and Anti-inflammatory Pill can help mee get a cure.
TEST BANK For Community and Public Health Nursing: Evidence for Practice, 3rd...Donc Test
TEST BANK For Community and Public Health Nursing: Evidence for Practice, 3rd Edition by DeMarco, Walsh, Verified Chapters 1 - 25, Complete Newest Version TEST BANK For Community and Public Health Nursing: Evidence for Practice, 3rd Edition by DeMarco, Walsh, Verified Chapters 1 - 25, Complete Newest Version TEST BANK For Community and Public Health Nursing: Evidence for Practice, 3rd Edition by DeMarco, Walsh, Verified Chapters 1 - 25, Complete Newest Version Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Pdf Chapters Download Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Pdf Download Stuvia Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Study Guide Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Ebook Download Stuvia Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Questions and Answers Quizlet Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Studocu Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Quizlet Test Bank For Community and Public Health Nursing: Evidence for Practice 3rd Edition Stuvia Community and Public Health Nursing: Evidence for Practice 3rd Edition Pdf Chapters Download Community and Public Health Nursing: Evidence for Practice 3rd Edition Pdf Download Course Hero Community and Public Health Nursing: Evidence for Practice 3rd Edition Answers Quizlet Community and Public Health Nursing: Evidence for Practice 3rd Edition Ebook Download Course hero Community and Public Health Nursing: Evidence for Practice 3rd Edition Questions and Answers Community and Public Health Nursing: Evidence for Practice 3rd Edition Studocu Community and Public Health Nursing: Evidence for Practice 3rd Edition Quizlet Community and Public Health Nursing: Evidence for Practice 3rd Edition Stuvia Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Pdf Chapters Download Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Pdf Download Stuvia Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Study Guide Questions and Answers Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Ebook Download Stuvia Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Questions Quizlet Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Studocu Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Quizlet Community and Public Health Nursing: Evidence for Practice 3rd Edition Test Bank Stuvia
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.
Clinic ^%[+27633867063*Abortion Pills For Sale In Tembisa Central19various
Clinic ^%[+27633867063*Abortion Pills For Sale In Tembisa Central Clinic ^%[+27633867063*Abortion Pills For Sale In Tembisa CentralClinic ^%[+27633867063*Abortion Pills For Sale In Tembisa CentralClinic ^%[+27633867063*Abortion Pills For Sale In Tembisa CentralClinic ^%[+27633867063*Abortion Pills For Sale In Tembisa Central
Our backs are like superheroes, holding us up and helping us move around. But sometimes, even superheroes can get hurt. That’s where slip discs come in.
Rasamanikya is a excellent preparation in the field of Rasashastra, it is used in various Kushtha Roga, Shwasa, Vicharchika, Bhagandara, Vatarakta, and Phiranga Roga. In this article Preparation& Comparative analytical profile for both Formulationon i.e Rasamanikya prepared by Kushmanda swarasa & Churnodhaka Shodita Haratala. The study aims to provide insights into the comparative efficacy and analytical aspects of these formulations for enhanced therapeutic outcomes.
2. 36 Wang. Clinical application of SPIO contrast agents
SPIO contrast agents for MRI . acquire the perfusion properties of the lesion during the arterial
and portal venous phases of the contrast agent. On dynamic MR
A conglomerate of numerous nano-sized iron oxide crystals imaging using T1-weighted GRE, enhancement was positive
coated with dextran or carboxydextran forms SPIO contrast in the liver for at least 30 s after bolus injection of SPIO (3).
agents (1). Two SPIO particle formulations are now clinically However, positive enhancement of hypervascular hepatocellular
available, namely ferumoxides and ferucarbotran. Both are carcinoma (HCC) in early phase of T1W-GRE has been
approved specifically for MR imaging of the liver. After reported to be weak to assess the tumor perfusion. Although this
intravenous administration, clinical approved SPIO particles agent was found to cause significant T1 shortening of blood, its
are cleared from the blood by phagocytosis accomplished by use for MR angiography was found to be suboptimal (4). Due
reticuloendothelial system (RES) so that uptake is observed in to the high r2 relaxivity, Resovist is more suited to T2/T2*-
the normal liver, spleen, bone marrow, and lymph nodes. After weighted imaging. On delayed images after 10 min, the T2/T2*
the intracellular uptake, SPIOs are metabolized in the lysosomes effects are observed due to the reticuloendothelial uptake in the
into a soluble, nonsuperparamagnetic form of iron that becomes liver. Perfusion study using echo planar imaging (EPI) yields
part of the normal iron pool (eg, ferritin, hemoglobin) (1). negative enhancement of hypervascular tumors (5), and one-
Feridex: Ferumoxides (Feridex IV, Berlex Laboratories; and stop shop diagnosis (involving both dynamic and RES-targeted
Endorem, Guerbet) are developed by AMAG Pharma (former MR imaging) for hypervascular HCC are feasible. Resovist
Advanced Magnetics) and was referred to as AMI-25. The r2 come as 0.5 mmol Fe/ml solution in prefilled syringe. The
and r1 relaxivites are 98.3 and 23.9 mM-1sec -1 respectively. recommended dose of Resovist is: for patients weighing less than
Ferumoxides is available in USA, Europe, and Japan. Feridex 60 kg: 0.9 ml Resovist (equivalent to 0.45 mmol iron); for adults
is an SPIO colloid with low molecular weight dextran coating, patients weighing 60 kg or more: 1.4 ml Resovist® (equivalent
with a particle size of 120-180 nm. To reduce the incidence to 0.7 mmol iron). Resovist’s overall incidence of adverse
of some side effects such as hypotension, Feridex is prepared events was 7.1%, with vasodilatation and paraesthesia the most
as a dilution in 100 ml of 5% dextrose and administered as a common event reported (<2%). Although considerably less
drip infusion over about 30 min. At about 8 min following the post-marketing data is available on the safety of Resovist than on
intravenous injection, iron oxide particles are taken up by the Feridex, the safety profile appears more favorable for Resovist.
reticululoendothelial cells in the liver and in the spleen with Ferumoxtran-10 (AMI-227; Combidex, AMAG Pharma;
an approximate uptake of 80% and 6-10%, respectively (2). Sinerem, Guerbet): The r2 and r1 relaxivites of Combidex/
Maximum signal loss is obtained after 1 h with an imaging Sinerem are 60 and 10 mM-1sec-1 respectively. The small size
window ranging from 30 min to 6 h after the injection. The and hydrophilic coating result in a longer circulation in the
recommended dosage of Feridex IV (ferumoxides injectable intravascular space, and the particles escape rapid accumulation
solution) is 0.56 milligrams of iron (0.05 mL Feridex IV) per in the RES. These particles are phagocytosed by macrophages
kilogram of body weight. Hypotension and lumbar pain/leg pain and accumulate in the lymphatic system. Normal lymph
represent the most frequent symptoms associated with Feridex nodes are characterized by a dramatic signal drop on T2*-
administration with an incidence ranging from 2 to 10%. Pain weighted images, whereas malignant lymph nodes, being
severe enough to cause interruption or discontinuation of the devoid of macrophages, do not accumulate iron oxide particles
infusion was reported to occur in 2.5% patients. and maintain a high MRI signal intensity. It takes 24 to 36 h
Resovist: Ferucarbotran (Resovist, Bayer Healthcare) is for Combidex/Sinerem to accumulate in the lymph nodes,
developed by Schering AG, and was referred to as SH U 555A. thus, postcontrast imaging is usually obtained 24 h after
Resovist is available in Europe and Japan. The active particles are administration of the contrast agent. Sinerem was used in some
carboxydextrane-coated SPIO, with a hydrodynamic diameter European countries (not available now) — but not in the USA.
ranging between 45 and 60 nm. The r2 and r1 relaxivites are In 2003, a paper by Harisinghani et al. (6) offered extraordinary
151.0 and 25.4 mM-1sec-1 respectively. Unlike Feridex, Resovist results of the way in which ferumoxtran-10 could demonstrate
can be safely injected rapidly in a bolus fashion, and the incidence the presence of positive lymph nodes in patients with prostate
of cardiovascular adverse events and back pain are significantly cancer. However, a recent, multi-center study by Heesakkers et
less. Resovist has an effect on the shortening of both T1 and T2 al. (7) evaluated the use of ferumoxtran-10 and MRI to detect
relaxation time. Resovist enables T1-weighted imaging ensuring and identify lymph node metastases occurring outside the
a valuable although less pronounced positive T1 contrast effect. normal area of pelvic lymph node dissection in 296 patients
Dynamic T1-weighted GRE 3D sequences can be performed to with prostate cancer. All patients had intermediate to high risk
3. Quantitative Imaging in Medicine and Surgery, Vol 1, No 1, December 2011 37
for nodal metastases. There was a 24.1 % false positive rate in negatively enhances on T2- or T2*-weighted images (ie, it turns
this study, leading to unnecessary surgical intervention. The dark), resulting in increased conspicuity of pathologic lesions
clinical development for ferumoxtran-10 was stopped due to that do not contain reticuloendothelial cells. The degree of SPIO
these results. Since ferumoxtran-10’ safety profile has been good uptake and the consecutive extent of signal intensity drop are
as an imaging agent, perhaps the most appropriate question used to differentiate and characterize lesions. Pulse sequence
that researchers need to ask is where it is possible to develop a optimization for SPIO-enhanced MR imaging has recently been
“second generation” form of ferumoxtran-10 which will have a discussed. Tanimoto et al. proposed long TE SPGR exhibited the
significantly lower rate of false positive findings. best signal-to-noise ratio and detectability, and the flip angle was
Clariscan: Clariscan (PEG-fero; Feruglose; NC100150) 45–600 (8). SPIO agents provide a long imaging window after
was developed by former Nycomed Imaging (now part of IV infusion, thus facilitating high-spatial-resolution thin-section
GE healthcare). NC100150 is consisted of SPIO particles imaging.
that are composed of single crystals (4 to 7nm diameter) and SPIO-enhanced MRI is more accurate than nonenhanced
stabilized with a carbohydrate polyethylene glycol (PEG) coat. MRI for the detection of focal hepatic lesions, and combined
The iron oxide particles have to be suspended in an isotonic analysis of non-enhanced and SPIO-enhanced images is more
glucose solution. The final diameter of an NC100150 particle accurate in the characterization of focal hepatic lesions than
is approximately 20 nm. Blood pool half-life is more than two review of SPIO-enhanced images alone (9). In one early
hours in humans. It can be used as a MR angiography agent, multicenter trial, Feridex -enhanced T2-weighted images
and has been tested clinically for characterization of tumor revealed additional lesions not seen on unenhanced images in
microvasculature. NC100150 particles are eventually taken up 27% of cases and additional lesions not seen by conventional
by the mononuclear phagocyte system and distributed mainly (non-spiral) computed tomography (CT) scans in 40%; the
to the liver and spleen. The development of NC100150 was additional information would have changed therapy in 59% of
discontinued due to safety concern. cases (10). The detection of metastases is apparently improved
Iron oxide-based agents for gastrointestinal contrast: with SPIO agent, as well as cholangiocellular carcinoma, due to
There have been a few oral iron oxide-based agents developed the absence of Kupffer cells within these lesions. Undifferentiated
for gastoinetestine luminal contrast (filling of gastrointestinal HCC usually demonstrate no change in signal intensity when
lumen), including AMI-121 (Ferumoxsil, Lumirem for Guerbet compared with T2/T2*-weighted images in unenhanced
and Gastromark for Advanced Magentics) and OMP (Abdoscan, and SPIO-enhanced imaging. This leads to an improvement
Nycomed Imaging). Though those agents are effective and safe, in the contrast-to-noise ratio of the lesion with subsequent
there has been very little market take-up. improvement of demarcation as well as visualization and an
increased detection rate for HCC. On the other hand, lesions
Clinical application of Feridex and . that contain reticuloendothelial cells, such as focal nodular
Resovist for liver Imaging hyperplasia, may become isointense to normal liver because of a
decreased lesion-to-liver contrast ratio (11). A questionable focal
Due to the high prevalence of benign liver lesions in the adult nodular hyperplasia may be confirmed on SPIO enhanced MR.
population, liver lesion characterization is an important objective However, because of the relative inconsistency in the amount of
during hepatic imaging. This is especially true for patients with reticuloendothelial cells in focal nodular hyperplasia and hepatic
known extra-hepatic malignancies, who are being evaluated adenoma, cares should be taken with such clinical use.
for liver metastases, because benign and malignant lesions Differentiation between HCC and dysplastic nodules (DN)
may coexist. Furthermore, due to advances in cross-sectional is of great importance for the early and precise treatment of
imaging, small sub-centimetre lesions are being detected with HCC in cirrhotic liver. One study reported that the ratio of the
increasing frequency, making liver lesion characterization intensity of tumorous lesion to that of nontumorous area on
particularly challenging. It is for liver lesions these SPIO agents SPIO-enhanced MR images (SPIO intensity ratio) correlated
already found their useful application. SPIO particles are inversely with Kupffer-cell-count ratio in HCCs and dysplastic
opsonized and sequestered by phagocytic Kupffer cells of normal nodules, and increased as the degree of differentiation of HCCs
RES. Phagocytosed SPIO particles in Kupffer cells produce decreased, indicating that the uptake of SPIO in HCCs decreased
strong T2/T2* relaxation effects in the liver parenchyma. as the degree of differentiation of HCCs declined (12). Phagocytic
Following the administration of this agent, the liver (because activity might overlap among some borderline lesions. One study
of a homogeneous distribution of reticuloendothelial cells) found no significant difference in number of Kupffer cells between
4. 38 Wang. Clinical application of SPIO contrast agents
well-differentiated HCC and surrounding liver tissue (13). MR imaging with triple-phase multi-detector CT (MDCT) for
Tanimoto et al. (8) reported that some well-differentiated HCC preoperative detection of HCC (16). In their study, the mean
exhibited signal decrease similar to the surrounding liver on T2W- sensitivities of MR imaging and triple-phase MDCT were 90.2%
FSE images, but less signal decrease than surrounding liver on and 91.3%, respectively, and their mean specificities were 97.0%
T2*W-GRE images. Conversely, DNs exhibited strong decrease and 95.3%, respectively. SPIO-enhanced MR imaging was as
in signal on both T2W and T2*W images. In well-differentiated accurate as triple-phase MDCT in preoperative detection of
HCC, Kupffer cell density would be maintained but Kupffer cell HCC (16). In addition, SPIO-enhanced MR imaging provides
function could be reduced compared to surrounding liver. One information supplementary to that obtained with dynamic CT,
criterion, of a threshold signal loss of 10% on SPIO enhanced MR particularly by excluding pseudolesions. SPIO-enhanced MR
images, had been proposed to distinguish benign from malignant imaging may be preferable due to its lack of radiation.
lesions (sensitivity 88%, specificity 89%) by receiver operating SPIO-MRI versus Gd-based dynamic MRI: Several studies
characteristic analysis (14). have shown that Gd-based dynamic MRI is slightly better than
The decrease in signal intensity of cirrhotic liver with SPIO SPIO-enhanced MR imaging in the detection of small HCCs
is reduced compared to that in normal liver. The percentage of (17,18). In lesion conspicuity, Gd-enhanced MR imaging is better
signal-intensity loss and liver-lesion contrast-to-noise ratio on than SPIO-enhanced MRI. However, SPIO yields additional
SPIO-enhanced images was significantly higher in patients with information when imaging findings on Gd-based dynamic MRI
mild liver cirrhosis than in patients with severe liver cirrhosis. are questionable because of intrahepatic arterioportal shunt (AP
Inflammation, scarring, regeneration and shunting in cirrhotic shunt) and/or post-therapeutic liver damage (19). Ward et al.
liver reduces hepatic uptake of SPIO, shifts distribution to the (20) reported the usefulness of double-contrast MR imaging, i.e.
spleen, and produces signal heterogeneity (8,11). Structural and combined SPIO- and Gd-dynamic MR imaging, for diagnosis
functional inhomogeneity in cirrhosis may cause false-positive of HCC. SPIO-enhanced MR imaging (mean accuracy=0.76)
lesions after SPIO administration. was more accurate than non-enhanced MR imaging (mean
To clarify the clinical role of SPIO-enhanced MR imaging accuracy=0.64, P<0.04), and double-contrast MR imaging (mean
in multi-modality decision-making, numerous comparative accuracy=0.86) was more accurate than SPIO-enhanced imaging
studies have been conducted. However, results drawn from such (P<0.05). Combined Gd-enhanced dynamic and SPIO-enhanced
comparative studies should be carefully weighed since imaging MR imaging may obviate the need for more invasive combined
equipment and parameters were not uniform among institutions. arterial portography and CT hepatic arteriography for preoperative
Investigators’ experiences and preferences might also play a evaluation of patients with HCC (8).
role in the results. Final consensus has not been reached yet, or SPIO-MRI versus paramagnetic hepatobiliary agents-
may not be reached due to consistent evolution of CT and MRI enhanced MRI: Paramagnetic hepatobiliary compounds,
technologies. such as Mangafodipir trisodium (Mn-DPDP, Teslascan, GE
SPIO-MRI versus dynamic CT: The combined approach Healthcare), Gadoxetic acid (Gd-EOB-DTPA, Primovist,
of non-enhanced and SPIO enhanced T2-weighted MR images Schering AG), and Gadobenate dimeglumine (MultiHance,
together resulted in a significantly higher sensitivity as well as Gd-BOPTA, Bracco Diagnostics), are partially taken up by
in significantly more accurate differentiation of benign from hepatocytes, yielding positive and sustained enhancement of
malignant lesions as compared with results from spiral CT the liver parenchyma on T1-weighted images. There are few
images, non-enhanced T2-weighted MR images or SPIO- reports regarding comparison of efficacy between SPIO and
enhanced T2-weighted images alone (9). For the depiction paramagnetic hepatobiliary agents. A recent report suggested
of small hypervascular HCC, Lee et al. showed that the mean that gadobenate dimeglumine-enhanced 3D dynamic imaging
sensitivity of SPIO-enhanced MR imaging was significantly exhibited better diagnostic performance than SPIO-enhanced
higher (70.6%, P<0.05) than that of dual-phase spiral CT imaging in the detection of HCC (21). More studies are needed
(58.1%) (15). Tanimoto et al. (8) compared three imaging to confirm this finding.
modalities in the detection of 72 HCCs. Detection rates were
69% for triple-phase dynamic CT (single helical), 89% for triple- Investigational clinical applications of SPIO .
phase dynamic MR imaging, and 86% for SPIO-MR imaging.
There was a significant difference among the three modalities in Following intravenous injection, SPIO is incorporated into
rate of detection of HCC (P<0.01), but not between dynamic macrophages via endocytosis. The uptake of SPIO by phagocytic
MRI and SPIO-MRI. Kim et al. compared SPIO-enhanced monocytes and macrophages provides a valuable in-vivo tool by
5. Quantitative Imaging in Medicine and Surgery, Vol 1, No 1, December 2011 39
which MRI can be used to monitor involvement of macrophages Eur Radiol 2001;11:2319-31.
in inflammatory processes (22), such as multiple sclerosis, 2. Weissleder R, Stark DD, Engelstad BL, et al. Superparamagnetic iron oxide:
traumatic nerve injury, stroke, brain tumours, and vulnerable pharmacokinetics and toxicity. AJR Am J Roentgenol 1989;152:167-73.
plaque in carotid artery. Saleh et al. (23) performed an MRI 3. Reimer P, Müller M, Marx C, et al. T1 effects of a bolus-injectable
study with Sinerem in ischaemic stroke patients; macrophage superparamagnetic iron oxide, SH U 555 A: dependence on field strength
activity was observed in all patients. For multiple sclerosis, and plasma concentration--preliminary clinical experience with dynamic
Dousset et al. (24) used Sinerem to demonstrate visualisation T1-weighted MR imaging. Radiology 1998;209:831-6.
of macrophage activity in patients with relapsing–remitting 4. Reimer P, Balzer T. Ferucarbotran (Resovist): a new clinically
multiple sclerosis. Neuwelt et al. (25) conducted clinical studies approved RES-specific contrast agent for contrast-enhanced MRI of
with MRI monitoring of macrophages in brain tumours. The the liver: properties, clinical development, and applications. Eur Radiol
macrophage MRI detection with SPIO of tumour morphology 2003;13:1266-76.
might facilitate the surgical resection or biopsy of brain tumours. 5. Ichikawa T, Arbab AS, Araki T, et al. Perfusion MR imaging with a
Trivedi et al. (26) reported that, 24-36 h after infusion, Sinerem superparamagnetic iron oxide using T2-weighted and susceptibility-
particles accumulated in macrophages of carotid atheroma which sensitive echoplanar sequences: evaluation of tumor vascularity in
was detectable in vivo by MRI. Recently, the therapeutic use hepatocellular carcinoma. AJR Am J Roentgenol 1999;173:207-13.
of stem and progenitor cells as a substitute for malfunctioning 6. Harisinghani MG, Barentsz J, Hahn PF, et al. Noninvasive detection of
endogenous cell populations has received considerable attention clinically occult lymph-node metastases in prostate cancer. N Engl J Med
in tissue engineering. The development of stem cell–based 2003;348:2491-9.
therapies requires a quantitative and qualitative assessment of 7. Heesakkers RA, Jager GJ, Hövels AM, et al. Prostate cancer: detection of
their distribution to target organs and their engraftment. To lymph node metastases outside the routine surgical area with ferumoxtran-
be visualized with MRI, these stem cells can be labelled with 10-enhanced MR imaging. Radiology 2009;251:408-14.
SPIO. However, SPIO stem cell labeling is not a FDA approved 8. Tanimoto A, Kuribayashi S. Application of superparamagnetic iron oxide
indication. How SPIO affect the function and fate of stem cells to imaging of hepatocellular carcinoma. Eur J Radiol 2006;58:200-16.
remains further clarification (27,28). 9. Reimer P, Jähnke N, Fiebich M, et al. Hepatic lesion detection and
characterization: value of nonenhanced MR imaging, superparamagnetic
Conclusion . iron oxide-enhanced MR imaging, and spiral CT-ROC analysis. Radiology
2000;217:152-8.
Until now, dynamic MRI after bolus injection of Gd-based 10. Ros PR , Freeny PC, Harms SE, et al. Hepatic MR imaging with
extracellular agents is still the workhorse of liver imaging. SPIO- ferumoxides: a multicenter clinical trial of the safety and efficacy in the
enhanced MR imaging is an effective means of pre-therapeutic detection of focal hepatic lesions. Radiology 1995;196:481-8.
evaluation and follow-up diagnosis of liver tumors, featuring 11. Ba-Ssalamah A, Uffmann M, Saini S, et al. Clinical value of MRI liver-
improved detection of HCC and capacity to differentiate specific contrast agents: a tailored examination for a confident non-invasive
lesions. It improves the selection of patients who are candidates diagnosis of focal liver lesions. Eur Radiol 2009;19:342-57.
for curative liver surgery, since with it invasive surgery can be 12. Imai Y, Murakami T, Yoshida S, et al. Superparamagnetic iron oxide-
avoided if multiple lesions are present. The clinical application enhanced magnetic resonance images of hepatocellular carcinoma:
of new SPIO contrast agents must evolve into an integrated correlation with histological grading. Hepatology 2000;32:205-12.
diagnostic scheme as a problem-solving tool in patients with 13. Tanaka M, Nakashima O, Wada Y, et al. Pathomorphological study of
atypical features of focal liver lesions and to supplement Kupffer cells in hepatocellular carcinoma and hyperplastic nodular lesions
information provided by the use of non-specific extracellular Gd- in the liver. Hepatology 1996;24:807-12.
based agents (or iodinated agent enhanced CT). For non-liver 14. Vogl TJ, Hammerstingl R, Schwarz W, et al. Superparamagnetic iron
imaging, new applications of approved SPIO are being explored. oxide--enhanced versus gadolinium-enhanced MR imaging for differential
Newer SPIOs with clinically relevant characteristics remain to be diagnosis of focal liver lesions. Radiology 1996;198:881-7.
further developed. 15. Lee JM, Kim IH, Kwak HS, et al. Detection of small hypervascular
hepatocellular carcinomas in cirrhotic patients: comparison of
References . superparamagnetic iron oxide-enhanced MR imaging with dual-phase
spiral CT. Korean J Radiol 2003;4:1-8.
1. Wang YX, Hussain SM, Krestin GP. Superparamagnetic iron oxide contrast 16. Kim SH, Choi D, Kim SH, et al. Ferucarbotran-enhanced MRI versus
agents: physicochemical characteristics and applications in MR imaging. triple-phase MDCT for the preoperative detection of hepatocellular
6. 40 Wang. Clinical application of SPIO contrast agents
carcinoma. AJR Am J Roentgenol 2005;184:1069-76. Kong Med J 2008;14:469-78.
17. Tang Y, Yamashita Y, Arakawa A, et al. Detection of hepatocellular 23. Saleh A , Schroeter M, Jonkmanns C, et al. In vivo MRI of brain
carcinoma arising in cirrhotic livers: comparison of gadolinium- inflammation in human ischaemic stroke. Brain 2004;127:1670-7.
and ferumoxides-enhanced MR imaging. A JR Am J Roentgenol 24. Dousset V, Brochet B, Deloire MS, et al. MR imaging of relapsing multiple
1999;172:1547-54. sclerosis patients using ultra-small-particle iron oxide and compared with
18. Pauleit D, Textor J, Bachmann R, et al. Hepatocellular carcinoma: detection gadolinium. AJNR Am J Neuroradiol 2006;27:1000-5.
with gadolinium- and ferumoxides-enhanced MR imaging of the liver. 25. Neuwelt EA , Várallyay P, Bagó AG, et al. Imaging of iron oxide
Radiology 2002;222:73-80. nanoparticles by MR and light microscopy in patients with malignant brain
19. Oudkerk M, van den Heuvel AG, Wielopolski PA, et al. Hepatic lesions: tumours. Neuropathol Appl Neurobiol 2004;30:456-71.
detection with ferumoxide-enhanced T1-weighted MR imaging. Radiolog 26. Trivedi RA, U-King-Im JM, Graves MJ, et al. In vivo detection of
1997;203:449-56. macrophages in human carotid atheroma: temporal dependence of
20. Ward J, Guthrie JA, Scott DJ, et al. Hepatocellular carcinoma in the ultrasmall superparamagnetic particles of iron oxide-enhanced MRI. Stroke
cirrhotic liver: double-contrast MR imaging for diagnosis. Radiology 2004;35:1631-5.
2000;216:154-62. 27. Wang YX, Wang HH, Au DW, et al. Pitfalls in employing superparamagnetic
21. Kim YK, Kim CS, Lee YH, et al. Comparison of superparamagnetic iron iron oxide particles for stem cell labelling and in vivo MRI tracking. Br J
oxide-enhanced and gadobenate dimeglumine-enhanced dynamic MRI Radiol 2008;81:987-8.
for detection of small hepatocellular carcinomas. AJR Am J Roentgenol 28. Schäfer R, Kehlbach R, Müller M, et al. Labeling of human mesenchymal
2004;182:1217-23. stromal cells with superparamagnetic iron oxide leads to a decrease in
22. Wang YX, Lam WW. Characterisation of brain disorders and evaluation of migration capacity and colony formation ability. Cytotherapy 2009;11:68-78.
therapy by functional and molecular magnetic resonance techniques. Hong
Cite this article as: Wang YX. Superparamagnetic iron oxide based MRI
contrast agents: Current status of clinical application. Quant Imaging Med
Surg 2011;1:35-40. DOI: 10.3978/j.issn.2223-4292.2011.08.03