this presentation targets radio-diagnosis, neurology and neurosurgery junior staff, it presents simple basics of CT perfusion including principle, technique, applications, interpretation with few quiz cases.
CT perfusion physics and its application in NeuroimagingDr.Suhas Basavaiah
CT perfusion imaging provides functional information about tissue vascularity by measuring temporal changes in tissue attenuation following intravenous injection of iodinated contrast. It quantifies parameters like blood flow, blood volume, mean transit time. While initially developed for research, advances in multidetector CT and software allow clinical use in evaluating cerebral vasculature in acute stroke and tumor response to therapies in oncology. The technique involves rapid dynamic scanning during contrast first-pass to generate time-attenuation curves and calculate perfusion values using deconvolution or other mathematical models.
CT perfusion (CTP) provides important hemodynamic information about cerebral blood flow, blood volume, and mean transit time that complements CT angiography in the evaluation of acute stroke. CTP can help characterize acute ischemic stroke by identifying critically ischemic tissue in the stroke "core" and potentially salvageable tissue in the "penumbra", guiding treatment decisions about thrombolysis within time windows. A typical CTP exam involves an initial non-contrast CT followed by dynamic contrast-enhanced imaging over 40-60 seconds to generate perfusion maps and quantify key parameters.
Perfusion MRI (DSC and DCE perfusion techniques) for radiology residentsRiham Dessouky
This document provides an overview of perfusion weighted MR imaging techniques. It discusses three main types: dynamic susceptibility contrast (DSC) MR perfusion, dynamic contrast enhanced (DCE) MR perfusion, and arterial spin labeling (ASL) MR perfusion. DSC relies on signal loss from gadolinium contrast to measure parameters like relative cerebral blood volume (rCBV) and flow (rCBF). DCE uses T1 shortening effects of contrast to calculate permeability and perfusion. Both techniques are used to evaluate brain tumors and strokes by analyzing signal intensity curves. DCE is also used in breast MRI to classify enhancement curves and measure permeability with the Ktrans parameter.
1. Magnetic resonance spectroscopy (MRS) provides information about the metabolic and biochemical composition of brain tissue by detecting certain metabolites. It can help differentiate between various brain pathologies and tumor types.
2. Common metabolites detected by MRS include NAA, creatine, choline, myoinositol, and lactate. Changes in levels of these metabolites indicate different disease states. For example, decreased NAA and increased choline suggest a brain tumor.
3. MRS has various clinical applications such as distinguishing tumor recurrence from treatment effects like radiation necrosis, tumor grading, aiding tumor biopsy, and monitoring responses to therapy. It provides complementary information to structural MRI for diagnostic and management purposes.
Application of Perfusion imaging in radiology is increasing with advancement in technology. This presentation briefly describes different perfusion modalities including Computed Tomography, Magnetic Resonance Imaging and Nuclear Medicine. Some of the aspects of perfusion imaging are described in this presentation. This topic was Presented in Radiology department, Institute of Medicine, Maharajgunj.
1. The document outlines the workflow and procedures for performing an emergent CT brain perfusion scan for a potential stroke patient. Key steps include alerting necessary personnel, transporting the patient directly to the CT department, performing a non-contrast head CT to check for hemorrhage, and if no hemorrhage is found, performing a CT brain perfusion scan according to the specified protocol.
2. The protocol utilizes a dual-phase CTA technique with 80kV, 50mA scans and intravenous injection of contrast to generate perfusion maps of cerebral blood flow, volume, mean transit time and time to peak to identify areas of reduced flow indicative of a stroke and its severity.
3. If a stroke
Advances in neuroimaging techniques have improved the diagnosis of neurological conditions. Multidetector CT has increased scan speed and volume acquisition. Dual source CT and flat panel CT provide high resolution while reducing artifacts. CT angiography is useful for evaluating aneurysms, strokes, and vascular malformations. MRI improvements include higher field strengths for better resolution, parallel imaging for faster scans, and efficient pulse sequences like FLAIR, HASTE, and MR myelography. These advances allow for more detailed visualization of anatomy and pathology throughout the brain and spinal cord.
CT perfusion physics and its application in NeuroimagingDr.Suhas Basavaiah
CT perfusion imaging provides functional information about tissue vascularity by measuring temporal changes in tissue attenuation following intravenous injection of iodinated contrast. It quantifies parameters like blood flow, blood volume, mean transit time. While initially developed for research, advances in multidetector CT and software allow clinical use in evaluating cerebral vasculature in acute stroke and tumor response to therapies in oncology. The technique involves rapid dynamic scanning during contrast first-pass to generate time-attenuation curves and calculate perfusion values using deconvolution or other mathematical models.
CT perfusion (CTP) provides important hemodynamic information about cerebral blood flow, blood volume, and mean transit time that complements CT angiography in the evaluation of acute stroke. CTP can help characterize acute ischemic stroke by identifying critically ischemic tissue in the stroke "core" and potentially salvageable tissue in the "penumbra", guiding treatment decisions about thrombolysis within time windows. A typical CTP exam involves an initial non-contrast CT followed by dynamic contrast-enhanced imaging over 40-60 seconds to generate perfusion maps and quantify key parameters.
Perfusion MRI (DSC and DCE perfusion techniques) for radiology residentsRiham Dessouky
This document provides an overview of perfusion weighted MR imaging techniques. It discusses three main types: dynamic susceptibility contrast (DSC) MR perfusion, dynamic contrast enhanced (DCE) MR perfusion, and arterial spin labeling (ASL) MR perfusion. DSC relies on signal loss from gadolinium contrast to measure parameters like relative cerebral blood volume (rCBV) and flow (rCBF). DCE uses T1 shortening effects of contrast to calculate permeability and perfusion. Both techniques are used to evaluate brain tumors and strokes by analyzing signal intensity curves. DCE is also used in breast MRI to classify enhancement curves and measure permeability with the Ktrans parameter.
1. Magnetic resonance spectroscopy (MRS) provides information about the metabolic and biochemical composition of brain tissue by detecting certain metabolites. It can help differentiate between various brain pathologies and tumor types.
2. Common metabolites detected by MRS include NAA, creatine, choline, myoinositol, and lactate. Changes in levels of these metabolites indicate different disease states. For example, decreased NAA and increased choline suggest a brain tumor.
3. MRS has various clinical applications such as distinguishing tumor recurrence from treatment effects like radiation necrosis, tumor grading, aiding tumor biopsy, and monitoring responses to therapy. It provides complementary information to structural MRI for diagnostic and management purposes.
Application of Perfusion imaging in radiology is increasing with advancement in technology. This presentation briefly describes different perfusion modalities including Computed Tomography, Magnetic Resonance Imaging and Nuclear Medicine. Some of the aspects of perfusion imaging are described in this presentation. This topic was Presented in Radiology department, Institute of Medicine, Maharajgunj.
1. The document outlines the workflow and procedures for performing an emergent CT brain perfusion scan for a potential stroke patient. Key steps include alerting necessary personnel, transporting the patient directly to the CT department, performing a non-contrast head CT to check for hemorrhage, and if no hemorrhage is found, performing a CT brain perfusion scan according to the specified protocol.
2. The protocol utilizes a dual-phase CTA technique with 80kV, 50mA scans and intravenous injection of contrast to generate perfusion maps of cerebral blood flow, volume, mean transit time and time to peak to identify areas of reduced flow indicative of a stroke and its severity.
3. If a stroke
Advances in neuroimaging techniques have improved the diagnosis of neurological conditions. Multidetector CT has increased scan speed and volume acquisition. Dual source CT and flat panel CT provide high resolution while reducing artifacts. CT angiography is useful for evaluating aneurysms, strokes, and vascular malformations. MRI improvements include higher field strengths for better resolution, parallel imaging for faster scans, and efficient pulse sequences like FLAIR, HASTE, and MR myelography. These advances allow for more detailed visualization of anatomy and pathology throughout the brain and spinal cord.
CT angiography (CTA) uses computed tomography (CT) and intravenous iodinated contrast to visualize blood vessels. It can be used to assess arteries, veins, and vascular structures throughout the head and neck. Performing a CTA requires optimizing multiple factors including the injection of contrast, timing of the CT scan, and image post-processing techniques. The document provides detailed guidelines on patient preparation, equipment, techniques, and safety considerations for head and neck CTA exams.
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 diffusion weighted imaging (DWI) and its application in evaluating brain pathologies. It provides details on how DWI works using diffusion gradients and endogenous contrast from water motion. Areas of restricted diffusion like cytotoxic edema appear brighter on DWI. DWI is highly sensitive for detecting acute ischemia within minutes. It is useful for distinguishing acute from subacute lesions based on apparent diffusion coefficient (ADC) maps. DWI also has applications in evaluating other conditions like abscesses, tumors, infections and injuries.
Dual energy CT utilizes two different x-ray spectra to characterize tissues. It can help address challenges with single energy CT like lesion detection and image noise. Dual energy CT works by analyzing how materials attenuate x-rays differently at various energies, allowing differentiation of substances like iodine and calcium. There are several technical approaches to dual energy CT, including sequential acquisition with two scans, rapid voltage switching between two voltages, and dual-source CT with two tube-detector pairs. Post-processing involves material decomposition and differentiation using image-domain or projection-domain algorithms.
This document summarizes evidence from 27 trials involving over 10,000 participants on the safety and efficacy of clot-dissolving drugs (thrombolytics) such as alteplase for treating acute ischemic stroke. The trials compared thrombolytics administered intravenously or intra-arterially within 4.5 hours of stroke onset to placebo or no treatment. Thrombolytics were found to improve outcomes after stroke but also increase the risk of serious bleeding in the brain. While thrombolytics can restore blood flow and reduce brain damage if given promptly, the risks and benefits were shown to depend on the time since stroke onset.
This document provides information on imaging of the carotid arteries and carotid angiography. It discusses various imaging modalities used to image the carotid arteries including ultrasound, CT, MRI, CT angiography, MR angiography, duplex ultrasound, and plain films. It then provides detailed information on carotid angiography including definitions, indications, complications, techniques, and how to avoid complications. Transcranial ultrasound in premature infants is also briefly discussed.
MRI provides detailed images of the brain without exposing patients to radiation. It is useful for evaluating conditions like tumors, strokes, and multiple sclerosis. The document describes the MRI procedure for brain imaging including patient preparation, head coils, sequences, and protocols. Key sequences discussed are T1-weighted, T2-weighted, FLAIR, diffusion weighted, MR angiography, and MR venography.
This document discusses cerebrospinal fluid (CSF) flow studies using magnetic resonance imaging (MRI). It describes CSF production, circulation, and functions. It explains phase contrast and Time-SLIP imaging sequences used to visualize CSF flow. Parameters measured from flow quantification curves are outlined. Examples of CSF flow studies in normal pressure hydrocephalus, Chiari malformation, and pre- and post-shunt placement are provided. The conclusion states that Time-SLIP is a new technique that can visualize CSF dynamics for up to 5 seconds.
CT perfusion of the head uses x-rays to show which areas of the brain are adequately supplied with blood. It provides detailed information about blood flow and is useful for evaluating conditions like stroke, brain vessel diseases, and tumors. The procedure involves injecting contrast dye and taking multiple scans as it circulates through the brain. It is fast, painless, and can help diagnose conditions and guide treatment.
Multi detector ct cerebral angiographyEhab Elftouh
This document discusses techniques for computed tomography (CT) angiography. It covers advances in CT technology that have improved angiography, including faster scan speeds and thinner slices. Optimal CT angiography depends on scan technique factors like protocol and contrast injection, as well as image post-processing techniques. Newer multi-detector CT machines allow covering volumes more quickly and with higher resolution. Methods like multi-planar reformation and volume rendering help visualize vascular structures from CT image data.
This document outlines the protocol for performing CT angiography (CTA) from the cerebral arteries to the lower limbs. It discusses indications for CTA including aneurysms, stenosis, dissections, and more. The preparation, positioning, and scanning protocols are provided for CTA of the head to lower limbs as well as the subclavian arteries. Pediatric protocols are also summarized. The document concludes with examples of CTA findings and references.
MR spectroscopy is a non-invasive technique that uses MRI to measure brain chemistry. It provides information about metabolites like NAA, creatine, and choline to help characterize lesions and diseases. Single-voxel MRS is less advanced but faster, while multi-voxel MRS examines more areas but takes longer. MRS is an additive test that is interpreted along with conventional MRI images to aid diagnosis.
This document provides an overview of brain anatomy, beginning with the structures of the skull and meninges. It describes the major divisions of the brain including the forebrain, midbrain, and hindbrain. It outlines the lobes of the cerebral hemispheres and internal structures such as the basal ganglia and corpus callosum. Key structures such as the ventricles and cisterns are identified. The rest of the document illustrates various sections of the brain with labeled diagrams and MRI images.
This document discusses the use of various imaging modalities such as CT, MRI, CTA, and CTP in evaluating patients presenting with acute stroke. It outlines the goals of acute stroke imaging as establishing the diagnosis, obtaining information on vasculature, and guiding appropriate therapy. CT is described as the initial test to rule out hemorrhage and identify early signs of infarction. MRI sequences such as DWI, T2WI, and FLAIR are also summarized. The roles of CTA in evaluating vessels and CTP in identifying tissue at risk of infarction are covered. Imaging findings of ischemic and hemorrhagic stroke subtypes are presented.
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.
Magnetic Resonance Angiography and VenographyAnjan Dangal
Introduction to MR Angiography and Venography Procedure of Brain . Includes Indication, MRI protocol, planning and anatomy as well as brief intoduction to physics behind MRA and MRV principle.
Computed tomography (CT) of the head is used to assess head injuries, headaches, dizziness, and symptoms of conditions like aneurysms, bleeding, strokes, and brain tumors. It can also help evaluate the face, sinuses, and skull. CT of the head uses X-rays to generate cross-sectional images of the head and brain which provide more detailed information than regular X-rays, particularly for soft tissues and blood vessels. Common protocols for head CT include non-contrast exams for conditions like trauma or stroke, as well as contrast-enhanced exams to evaluate tumors, aneurysms, or other conditions. Precautions are taken to minimize radiation exposure, especially for children.
Tissue harmonic imaging is an ultrasound technique that provides higher quality images compared to conventional ultrasound by collecting harmonic signals generated in tissues and filtering out transducer-generated fundamental echo signals, resulting in clearer images with improved contrast resolution, reduced artifacts, and better visualization of deeper structures and vessels. While tissue harmonic imaging improves image quality in many clinical applications, it can decrease axial resolution compared to fundamental frequency imaging due to the narrowed signal bandwidth.
This presentation includes stroke and infarct latest defination an pathophysiology and CT MRI imaging features and management . This presntation help alot. Thanks
CT angiography (CTA) uses computed tomography (CT) and intravenous iodinated contrast to visualize blood vessels. It can be used to assess arteries, veins, and vascular structures throughout the head and neck. Performing a CTA requires optimizing multiple factors including the injection of contrast, timing of the CT scan, and image post-processing techniques. The document provides detailed guidelines on patient preparation, equipment, techniques, and safety considerations for head and neck CTA exams.
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 diffusion weighted imaging (DWI) and its application in evaluating brain pathologies. It provides details on how DWI works using diffusion gradients and endogenous contrast from water motion. Areas of restricted diffusion like cytotoxic edema appear brighter on DWI. DWI is highly sensitive for detecting acute ischemia within minutes. It is useful for distinguishing acute from subacute lesions based on apparent diffusion coefficient (ADC) maps. DWI also has applications in evaluating other conditions like abscesses, tumors, infections and injuries.
Dual energy CT utilizes two different x-ray spectra to characterize tissues. It can help address challenges with single energy CT like lesion detection and image noise. Dual energy CT works by analyzing how materials attenuate x-rays differently at various energies, allowing differentiation of substances like iodine and calcium. There are several technical approaches to dual energy CT, including sequential acquisition with two scans, rapid voltage switching between two voltages, and dual-source CT with two tube-detector pairs. Post-processing involves material decomposition and differentiation using image-domain or projection-domain algorithms.
This document summarizes evidence from 27 trials involving over 10,000 participants on the safety and efficacy of clot-dissolving drugs (thrombolytics) such as alteplase for treating acute ischemic stroke. The trials compared thrombolytics administered intravenously or intra-arterially within 4.5 hours of stroke onset to placebo or no treatment. Thrombolytics were found to improve outcomes after stroke but also increase the risk of serious bleeding in the brain. While thrombolytics can restore blood flow and reduce brain damage if given promptly, the risks and benefits were shown to depend on the time since stroke onset.
This document provides information on imaging of the carotid arteries and carotid angiography. It discusses various imaging modalities used to image the carotid arteries including ultrasound, CT, MRI, CT angiography, MR angiography, duplex ultrasound, and plain films. It then provides detailed information on carotid angiography including definitions, indications, complications, techniques, and how to avoid complications. Transcranial ultrasound in premature infants is also briefly discussed.
MRI provides detailed images of the brain without exposing patients to radiation. It is useful for evaluating conditions like tumors, strokes, and multiple sclerosis. The document describes the MRI procedure for brain imaging including patient preparation, head coils, sequences, and protocols. Key sequences discussed are T1-weighted, T2-weighted, FLAIR, diffusion weighted, MR angiography, and MR venography.
This document discusses cerebrospinal fluid (CSF) flow studies using magnetic resonance imaging (MRI). It describes CSF production, circulation, and functions. It explains phase contrast and Time-SLIP imaging sequences used to visualize CSF flow. Parameters measured from flow quantification curves are outlined. Examples of CSF flow studies in normal pressure hydrocephalus, Chiari malformation, and pre- and post-shunt placement are provided. The conclusion states that Time-SLIP is a new technique that can visualize CSF dynamics for up to 5 seconds.
CT perfusion of the head uses x-rays to show which areas of the brain are adequately supplied with blood. It provides detailed information about blood flow and is useful for evaluating conditions like stroke, brain vessel diseases, and tumors. The procedure involves injecting contrast dye and taking multiple scans as it circulates through the brain. It is fast, painless, and can help diagnose conditions and guide treatment.
Multi detector ct cerebral angiographyEhab Elftouh
This document discusses techniques for computed tomography (CT) angiography. It covers advances in CT technology that have improved angiography, including faster scan speeds and thinner slices. Optimal CT angiography depends on scan technique factors like protocol and contrast injection, as well as image post-processing techniques. Newer multi-detector CT machines allow covering volumes more quickly and with higher resolution. Methods like multi-planar reformation and volume rendering help visualize vascular structures from CT image data.
This document outlines the protocol for performing CT angiography (CTA) from the cerebral arteries to the lower limbs. It discusses indications for CTA including aneurysms, stenosis, dissections, and more. The preparation, positioning, and scanning protocols are provided for CTA of the head to lower limbs as well as the subclavian arteries. Pediatric protocols are also summarized. The document concludes with examples of CTA findings and references.
MR spectroscopy is a non-invasive technique that uses MRI to measure brain chemistry. It provides information about metabolites like NAA, creatine, and choline to help characterize lesions and diseases. Single-voxel MRS is less advanced but faster, while multi-voxel MRS examines more areas but takes longer. MRS is an additive test that is interpreted along with conventional MRI images to aid diagnosis.
This document provides an overview of brain anatomy, beginning with the structures of the skull and meninges. It describes the major divisions of the brain including the forebrain, midbrain, and hindbrain. It outlines the lobes of the cerebral hemispheres and internal structures such as the basal ganglia and corpus callosum. Key structures such as the ventricles and cisterns are identified. The rest of the document illustrates various sections of the brain with labeled diagrams and MRI images.
This document discusses the use of various imaging modalities such as CT, MRI, CTA, and CTP in evaluating patients presenting with acute stroke. It outlines the goals of acute stroke imaging as establishing the diagnosis, obtaining information on vasculature, and guiding appropriate therapy. CT is described as the initial test to rule out hemorrhage and identify early signs of infarction. MRI sequences such as DWI, T2WI, and FLAIR are also summarized. The roles of CTA in evaluating vessels and CTP in identifying tissue at risk of infarction are covered. Imaging findings of ischemic and hemorrhagic stroke subtypes are presented.
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.
Magnetic Resonance Angiography and VenographyAnjan Dangal
Introduction to MR Angiography and Venography Procedure of Brain . Includes Indication, MRI protocol, planning and anatomy as well as brief intoduction to physics behind MRA and MRV principle.
Computed tomography (CT) of the head is used to assess head injuries, headaches, dizziness, and symptoms of conditions like aneurysms, bleeding, strokes, and brain tumors. It can also help evaluate the face, sinuses, and skull. CT of the head uses X-rays to generate cross-sectional images of the head and brain which provide more detailed information than regular X-rays, particularly for soft tissues and blood vessels. Common protocols for head CT include non-contrast exams for conditions like trauma or stroke, as well as contrast-enhanced exams to evaluate tumors, aneurysms, or other conditions. Precautions are taken to minimize radiation exposure, especially for children.
Tissue harmonic imaging is an ultrasound technique that provides higher quality images compared to conventional ultrasound by collecting harmonic signals generated in tissues and filtering out transducer-generated fundamental echo signals, resulting in clearer images with improved contrast resolution, reduced artifacts, and better visualization of deeper structures and vessels. While tissue harmonic imaging improves image quality in many clinical applications, it can decrease axial resolution compared to fundamental frequency imaging due to the narrowed signal bandwidth.
This presentation includes stroke and infarct latest defination an pathophysiology and CT MRI imaging features and management . This presntation help alot. Thanks
stroke FOAM Acute central nervous system injury with abrupt onsetDr Aya Ali
Acute central nervous system injury with abrupt
onset
Mechanism:
• Interruption of blood flow(Ischemic Stroke)
or
• Bleeding into or around the brain(Hemorrhagic
stroke)
This document discusses the evolution and advances in coronary CT angiography (CCTA) technology and its role in the assessment of coronary artery disease (CAD). Key points include:
- CCTA has advanced from early CT scanners with 4-minute scan times to modern multi-detector scanners that can image the entire heart in a single heartbeat.
- CCTA provides information on coronary artery anatomy, plaque characteristics, and has prognostic value when assessing coronary artery calcium scoring.
- CCTA has good accuracy for detecting CAD compared to invasive coronary angiography, especially for ruling out disease, though its role in asymptomatic patients is still unclear.
- CCTA is useful for evaluating coronary anomalies, bypass grafts,
Imaging in ischemic stroke18 11-15 finalNeurologyKota
This document provides information on imaging techniques used in the diagnosis and management of ischemic stroke. It discusses the advantages of different tests such as CT, CT angiography, CT perfusion, MRI, MR angiography, and diffusion weighted imaging at various time points after stroke onset. CT without contrast is useful initially to distinguish between ischemic and hemorrhagic stroke. Advanced imaging such as CT and MR perfusion can identify tissue at risk of infarction. Diffusion weighted MRI is highly sensitive and specific for acute ischemia. Together, imaging plays a key role in the evaluation and treatment of patients with ischemic stroke.
This document provides information on imaging techniques used in the diagnosis and management of ischemic stroke. It discusses the advantages of different tests such as CT, CT angiography, CT perfusion, MRI, MR angiography, and diffusion weighted imaging at various time points after stroke onset. CT without contrast is useful in the hyperacute period to distinguish between ischemic and hemorrhagic stroke. Advanced imaging such as CT and MR perfusion can identify tissue at risk of infarction. Diffusion weighted imaging is highly sensitive and specific for acute ischemia. Together, imaging plays a key role in the evaluation and treatment of patients with ischemic stroke.
This document discusses neurosonology and transcranial Doppler ultrasound (TCD). It defines neurosonology as ultrasonic imaging of the brain and neural structures. TCD provides noninvasive, real-time measures of blood flow in the brain's basal arteries. The document outlines the clinical applications of TCD, including monitoring cerebral vasospasm after subarachnoid hemorrhage, detecting intracranial stenosis, monitoring acute ischemic stroke, and screening for stroke risk in children with sickle cell disease. TCD is a useful tool for diagnosing and managing various cerebrovascular disorders.
This document discusses neurosonology and transcranial Doppler ultrasound (TCD). It defines neurosonology as ultrasonic imaging of the brain and neural structures. TCD provides noninvasive, real-time measures of blood flow in the brain's basal arteries. The document outlines the clinical applications of TCD, including monitoring cerebral vasospasm after subarachnoid hemorrhage, detecting intracranial stenosis, assessing acute ischemic stroke, and screening for stroke risk in children with sickle cell disease. TCD is a useful tool for diagnosing and monitoring various cerebrovascular disorders.
This document provides an overview of imaging in acute stroke. It discusses the goals of imaging evaluation for acute stroke which are to establish a diagnosis, guide treatment, assess location and size of involved territory, rule out hemorrhage and mimics, and obtain information about vasculature and perfusion. CT is the first-line test and can detect early signs of stroke within 6 hours. MRI, including DWI, is very sensitive for acute ischemia. CT angiography and perfusion can assess vessels, blood flow, and the ischemic penumbra. Different territories are discussed along with imaging findings and the physical basis of signs seen on various sequences.
This document provides information about intracranial pressure (ICP) monitoring. It defines ICP and normal ranges, and discusses the historical understanding of cerebrospinal fluid circulation dating back to the 18th century work of Magendie. It also summarizes the Monroe-Kelly doctrine which established the concept of a fixed intracranial volume. The document reviews various techniques for ICP monitoring including invasive methods like external ventricular drains and fiberoptic monitors as well as non-invasive options like MRI, ultrasound, and optic nerve sheath diameter measurement. Key aspects of ICP waveform analysis are also summarized.
1. Imaging plays an important role in the evaluation and management of patients with acute stroke.
2. Different imaging modalities such as CT, CT angiography, CT perfusion, MRI, MR angiography, and MR perfusion have benefits for assessing the brain parenchyma, vasculature, perfusion, and identifying potentially salvageable penumbral tissue.
3. Diffusion-weighted MRI is the most sensitive method for detecting acute ischemia within the first few hours, while perfusion imaging can identify tissue at risk of infarction in the ischemic penumbra that may be rescued with reperfusion therapy.
This document provides an overview of neuroradiology with a focus on cerebral ischemia. It discusses the pathophysiology and evolution of ischemic stroke seen on imaging techniques like CT and MRI. Key points covered include the appearance of acute ischemic stroke on non-contrast CT and differences seen on DWI, T1, T2 and FLAIR MRI sequences over time. It also addresses hemorrhagic transformation, evaluation of infarct size using ASPECTS scoring on CT, and the role of CT angiography and perfusion in assessing salvageable brain tissue. Cerebral venous infarction and classification of hemorrhagic transformations are briefly outlined.
1) The document discusses imaging in stroke, focusing on various modalities including CT, CT angiography, CT perfusion, MRI, diffusion weighted imaging, and perfusion weighted imaging.
2) These modalities are used to assess the brain parenchyma, vasculature, perfusion, and penumbra (area of reversible ischemia surrounding the irreversibly damaged core).
3) Identification of the penumbra is especially important as this region may be salvageable with early reperfusion and helps guide treatment decisions.
This document discusses acute ischemic stroke interventions. It provides details on:
- The typical size and duration of untreated ischemic strokes
- How many neurons and synapses are lost each hour and minute of untreated stroke
- Guidelines for emergency evaluation, diagnosis, and imaging of acute ischemic strokes
- Details on different imaging techniques like CT, MRI, CTA, and perfusion imaging
- Guidelines and recommendations for intravenous thrombolysis with rtPA within 3-4.5 hours of stroke onset.
This document discusses interventions for acute ischemic stroke. It summarizes that intra-arterial recanalization can provide good outcomes when performed by experts in high-volume centers. Recent trials show stent retrievers like Solitaire provide high recanalization rates of 80-90% compared to older devices like MERCI. However, case selection using imaging of penumbra is important, and speed of treatment is crucial, as delays can reduce chances of independence. Ongoing randomized trials continue to refine techniques and selection criteria for endovascular stroke interventions.
This document provides an overview of imaging in acute stroke, including CT and MRI. CT is often the initial imaging modality used to rule out hemorrhage. Early CT signs of infarction include hypodensity, obscuration of the lentiform nucleus, and the insular ribbon sign. Diffusion-weighted MRI is the most sensitive sequence for detecting acute ischemia. MRI can identify irreversibly injured tissue as well as potentially salvageable penumbral tissue. CT and MR angiography can detect vessel occlusions. CT perfusion can identify regions of low blood flow and volume that are at risk of infarction. The document reviews imaging findings over time and discusses venous infarcts.
Cardiovascular CT is a valuable tool for evaluating congenital heart disease in children. It provides high spatial and temporal resolution to depict complex anatomy. Key applications include assessing pulmonary blood flow in pulmonary atresia, vascular rings prior to surgery, coronary artery anomalies, and postoperative complications. Careful patient preparation and protocols are needed given pediatric concerns. CT enables simultaneous evaluation of vascular structures, airways, and cardiac function to comprehensively evaluate complex congenital heart disease.
This document discusses how multislice computed tomography (MSCT) can guide percutaneous coronary intervention (PCI). MSCT can help characterize plaque, precisely measure lesion length, and identify the optimal angiographic views for complex lesions like chronic total occlusions. Studies have found higher success rates for CTO recanalization when guided by pre-procedural MSCT. MSCT also aids in evaluating aorto-ostial, bifurcation, and diffuse coronary lesions prior to PCI. While limitations remain, MSCT guidance can improve PCI outcomes for difficult coronary cases not fully defined by invasive angiography alone.
This document discusses computed tomography angiography (CTA) and its applications in cardiology. CTA uses computed tomography to visualize blood vessels throughout the body, including coronary arteries. Coronary CTA can detect plaque buildup in coronary arteries without being invasive. Current multidetector CT systems can acquire high-resolution images of the heart within 20 seconds while the patient holds their breath. Coronary CTA provides diagnostic information but also exposes patients to radiation. It is most useful for evaluating cardiac symptoms in low-to-intermediate risk patients.
Osteoporosis - Definition , Evaluation and Management .pdfJim Jacob Roy
Osteoporosis is an increasing cause of morbidity among the elderly.
In this document , a brief outline of osteoporosis is given , including the risk factors of osteoporosis fractures , the indications for testing bone mineral density and the management of osteoporosis
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
Integrating Ayurveda into Parkinson’s Management: A Holistic ApproachAyurveda ForAll
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
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TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
3. Perfusion is the ‘’passage of blood, a blood substitute,
or other fluid through a vessel into an organ or tissue”.
CTP is an imaging technique allows functional
evaluation of tissue vascularity.
4. The temporal changes of tissue density
depends on the iodine concentration and
are a reflection of the nature of tissue
vascularity.
So, Perfusion studies are obtained by
monitoring the passage of iodinated
contrast through the cerebral vasculature.
5. • Oncological applications ;brain ,Pancreatic & Rectal tumors:
• Tumor characterization; grading.
• Assisting the therapeutic response, consequently the prognosis.
• Differentiating between recurrent tumor and radiation necrosis.
• Non- oncological applications:
• Acute cerebral Stroke
• To allow qualitative and quantitative evaluation of cerebral perfusion.
• To distinguish infarcted tissue from penumbra.
• Ischaemic Cardiac disease.
• Pancreatitis and pancreatic necrosis.
6.
7.
8.
9. • Stroke: inadequate blood flow of brain cells causing sudden death in a
localized area.
• Caused by blockage of blood flow ( ischemic )or rupture of an artery
(hemorrhagic).
• Neuroimaging plays a vital role in the workup of acute stroke.
• The main goal of CTP is to allow qualitative and quantitative evaluation of
cerebral perfusion and to differentiate the infarct core from the ischemic
penumbra.
10. • Infarcted core; irreversible tissue
ischaemia ( non-salvageable).
• Penumbra; tissue at risk of infarction due
to hypoperfusion (may be salvaged with
early reperfusion)
• In fact re-vascularization of infarcted
core cause hemorrhage .
14. • Repeated acquisitions are obtained at first pass of contrast at ROI ( about 1-2
min), Then, delayed phases ( 2-10 min)
15. • Thick perfusion slap :-
• 16 MDCT: 2.5 cm.
• 64 MDCT: 4 cm.
• 320 MDCT: full brain coverage.
• Contrast :-
• Vol. 40 ml.
• Conc. 370 mg/ml .
• Rate 4 ml/s.
• Dynamic scan: every 2 s.
16. • Scan locations: at the level of basal ganglia:- This
includes vascular areas of the brain that frequently
hypo-perfused at acute stroke cases.
• Choose ROI for :-
• Arterial input: ACA.
• Venous output: SSS.
• Time-attenuation curves for arterial ROI, venous ROI
and each pixel are obtained. This is based on the
principle that transient hyperattenuation is directly
proportional to amount of contrast .
17. • Perfusion parameters are mathematically calculated.
• Color-coded perfusion maps are obtained.
CBV
Cerebral blood volume
CBF
Cerebral blood flow
MTT
Mean transit time
TTP
Time to peak
18.
19. • (CBV): the blood volume passing through the region of interest measured
(ml/100 g).
• (CBF): the blood flow through the tissue of interest per unit of time
measured in (ml/100 g/min).
• (MTT) : the mean time it takes for blood to circulate through capillaries of a
determined region, passing from arterioles to venule measured in seconds.
• (TTP): The time it takes to reach the maximum attenuation value within
artery measures in seconds.
32. • The major limitation is the risk of
exposure to ionizing radiation which
limits its routine use especially in
follow-up studies.
• High radiation dose of CTP (about 3.2
Gy) induces temporary hair loss.
• Low KVp (from 120 to 80) is sufficient
to maximal dose reduction without
affection of diagnostic accuracy.
33.
34.
35.
36.
37. Check list
• Check :-
• Non contrast CT (early findings).
• All 4 CTP series for defects (Cerebral
cortex, basal ganglia and cerebellum).
•Compare CBV to MTT.
• Identify match/ mismatched defects.
•Conclude the core Vs. penumbra (ratio).
38.
39. Case no. 1
56 y old male
patient
presented with
DCL & left
hemiparesis
41. Answer
• CBV: Normal.
• MTT: Prolonged at right temporal lobe along the territory of RT MCA.
• CBF: Decreased at right temporal lobe along the territory of RT MCA.
• TTP: Prolonged at right temporal lobe along the territory of RT MCA.
• Match/ mismatch: mismatched CBV/MTT
• Core/Penumbra: penumbra with no core.
43. Answer
• CBV: decreased at left frontal cortex.
• MTT: Prolonged at left cortical & deep periventricular region.
• CBF: Decreased at left cortical & deep periventricular region.
• TTP: Prolonged at left cortical & deep periventricular region.
• Match/ mismatch: mismatched CBV/MTT
• Core/Penumbra: penumbra with cortical core.