This document provides information from an ultrasound training course on various techniques for imaging intracranial vessels through different acoustic windows of the skull. It discusses techniques such as transorbital, temporal, and foramen magnum windows. It also covers topics like diagnosing intracranial occlusions and stenoses, grading carotid artery stenosis, diagnosing carotid dissections, assessing collateral flow, and evaluating bypass graft patency. The document discusses the use of transcranial Doppler in patients after decompressive craniectomy. It also reviews perfusion imaging with ultrasound contrast and experimental evidence for sonothrombolysis.
Bedside Ultrasound in Neurosurgery Part 1/3Liew Boon Seng
This document provides an overview of ultrasound training in neurosurgery. It introduces various applications of ultrasound in neurosurgery such as fetal neurosonograms, cranial ultrasonography of newborns, assessing ventricular shunt patency, spinal ultrasound in infants, and transcranial insonation of blood vessels. It also summarizes techniques for different types of Doppler imaging and discusses pathologies that can be detected using ultrasound like intraventricular hemorrhage.
Bedside Ultrasound in Neurosurgery Part 3/3Liew Boon Seng
Ultrasound can be used to assess intracranial dural arteriovenous fistulas (DAVF) and carotid cavernous fistulas (CCF). For DAVF, ultrasound shows increased velocities in feeding arteries and decreased resistance indices, allowing assessment before and after treatment. For CCF, ultrasound reveals abnormal mosaic flow in the cavernous sinus and engorged veins with reversed flow. It can monitor hemodynamic changes and treatment response in a noninvasive manner. Ultrasound is also useful for assessing cerebral veins and sinuses, and can diagnose temporal arteritis by identifying hypoechoic wall thickening and stenoses in temporal arteries.
This document discusses hydrocephalus, including:
- Hydrocephalus is an abnormal buildup of cerebrospinal fluid in the brain, which can increase pressure and cause neurological symptoms.
- There are two main types - obstructive, caused by blockages in the flow of cerebrospinal fluid, and communicating, caused by issues with absorption of fluid.
- Common causes of obstructive hydrocephalus include aqueductal stenosis, tumors, cysts, and hemorrhages. Communicating hydrocephalus can result from subarachnoid hemorrhages.
- Normal pressure hydrocephalus is a type of communicating hydrocephalus where patients experience gait, memory, and
The document discusses various vascular emergencies that can be diagnosed using ultrasound. It outlines tools like ultrasound, CT, MR and DSA that can be used and highlights advantages of ultrasound like being readily available, portable, and having good temporal resolution. It describes acute conditions like ruptured aortic aneurysm, acute carotid thrombosis, carotid and vertebral dissections, pseudoaneurysms, acute limb ischemia and graft failure. For each condition, it provides ultrasound findings, diagnostic criteria and treatment options. It emphasizes the importance of prompt diagnosis, accurate assessment and timely intervention in managing vascular emergencies.
Ultrasonography provides several advantages in clinical neurology. It can be used to assess neurovascular structures like arteries and veins, detect abnormalities associated with movement disorders like increased substantia nigra hyperechogenicity in Parkinson's disease, and evaluate peripheral nerves for entrapment neuropathies. Ultrasonography techniques like duplex ultrasonography and transcranial Doppler allow visualization of vessel structures, plaque composition, and blood flow velocities to diagnose vascular diseases, monitor treatment, and detect vasospasm. Transcranial Doppler is also used to evaluate movement disorders, cerebral circulation in stroke and brain injury, and support a diagnosis of brain death. Peripheral nerve ultrasonography examines cross-sectional area, echogenicity,
This document provides an overview of various vascular lesions of the brain. It discusses arteriovenous malformations (AVMs), dural arteriovenous fistulas, carotid-cavernous fistulas, cavernomas, capillary telangiectasias, venous angiomas, aneurysms, and other conditions. For each type of lesion, it describes characteristics, imaging appearance, clinical presentation, and treatment options. Magnetic resonance imaging and cerebral angiography are important diagnostic tools. Treatment may involve surgery, endovascular procedures, or radiosurgery depending on the specific lesion.
Collateral blood flow is important for sustaining brain tissue after an occlusion of major arteries to the brain. There are three principal pathways for collateral circulation: extracranial-intracranial communications, the circle of Willis, and leptomeningeal anastomoses. Several imaging techniques can provide insight into collateral flow, such as digital subtraction angiography, CT angiography, magnetic resonance angiography, and trans-cranial Doppler. Therapies aimed at augmenting cerebral blood flow in acute stroke have included plasma expanders, vasodilators, and induced hypertension to potentially increase collateral flow.
Neonatal sonography of the brain is an essential part of newborn care, particularly for preterm and unstable infants. It allows for portable, low-cost, and radiation-free evaluation of the brain for hemorrhages, abnormalities, and other issues like hydrocephalus. Standard imaging planes include coronal and sagittal views of the brain and ventricles. Key indications for neurosonography in newborns include detection of intraventricular hemorrhage in preterm infants and evaluation of periventricular leukomalacia, a common ischemic injury. Neurosonography is also used to identify other issues like cystic lesions, tumors, and hydrocephalus.
Bedside Ultrasound in Neurosurgery Part 1/3Liew Boon Seng
This document provides an overview of ultrasound training in neurosurgery. It introduces various applications of ultrasound in neurosurgery such as fetal neurosonograms, cranial ultrasonography of newborns, assessing ventricular shunt patency, spinal ultrasound in infants, and transcranial insonation of blood vessels. It also summarizes techniques for different types of Doppler imaging and discusses pathologies that can be detected using ultrasound like intraventricular hemorrhage.
Bedside Ultrasound in Neurosurgery Part 3/3Liew Boon Seng
Ultrasound can be used to assess intracranial dural arteriovenous fistulas (DAVF) and carotid cavernous fistulas (CCF). For DAVF, ultrasound shows increased velocities in feeding arteries and decreased resistance indices, allowing assessment before and after treatment. For CCF, ultrasound reveals abnormal mosaic flow in the cavernous sinus and engorged veins with reversed flow. It can monitor hemodynamic changes and treatment response in a noninvasive manner. Ultrasound is also useful for assessing cerebral veins and sinuses, and can diagnose temporal arteritis by identifying hypoechoic wall thickening and stenoses in temporal arteries.
This document discusses hydrocephalus, including:
- Hydrocephalus is an abnormal buildup of cerebrospinal fluid in the brain, which can increase pressure and cause neurological symptoms.
- There are two main types - obstructive, caused by blockages in the flow of cerebrospinal fluid, and communicating, caused by issues with absorption of fluid.
- Common causes of obstructive hydrocephalus include aqueductal stenosis, tumors, cysts, and hemorrhages. Communicating hydrocephalus can result from subarachnoid hemorrhages.
- Normal pressure hydrocephalus is a type of communicating hydrocephalus where patients experience gait, memory, and
The document discusses various vascular emergencies that can be diagnosed using ultrasound. It outlines tools like ultrasound, CT, MR and DSA that can be used and highlights advantages of ultrasound like being readily available, portable, and having good temporal resolution. It describes acute conditions like ruptured aortic aneurysm, acute carotid thrombosis, carotid and vertebral dissections, pseudoaneurysms, acute limb ischemia and graft failure. For each condition, it provides ultrasound findings, diagnostic criteria and treatment options. It emphasizes the importance of prompt diagnosis, accurate assessment and timely intervention in managing vascular emergencies.
Ultrasonography provides several advantages in clinical neurology. It can be used to assess neurovascular structures like arteries and veins, detect abnormalities associated with movement disorders like increased substantia nigra hyperechogenicity in Parkinson's disease, and evaluate peripheral nerves for entrapment neuropathies. Ultrasonography techniques like duplex ultrasonography and transcranial Doppler allow visualization of vessel structures, plaque composition, and blood flow velocities to diagnose vascular diseases, monitor treatment, and detect vasospasm. Transcranial Doppler is also used to evaluate movement disorders, cerebral circulation in stroke and brain injury, and support a diagnosis of brain death. Peripheral nerve ultrasonography examines cross-sectional area, echogenicity,
This document provides an overview of various vascular lesions of the brain. It discusses arteriovenous malformations (AVMs), dural arteriovenous fistulas, carotid-cavernous fistulas, cavernomas, capillary telangiectasias, venous angiomas, aneurysms, and other conditions. For each type of lesion, it describes characteristics, imaging appearance, clinical presentation, and treatment options. Magnetic resonance imaging and cerebral angiography are important diagnostic tools. Treatment may involve surgery, endovascular procedures, or radiosurgery depending on the specific lesion.
Collateral blood flow is important for sustaining brain tissue after an occlusion of major arteries to the brain. There are three principal pathways for collateral circulation: extracranial-intracranial communications, the circle of Willis, and leptomeningeal anastomoses. Several imaging techniques can provide insight into collateral flow, such as digital subtraction angiography, CT angiography, magnetic resonance angiography, and trans-cranial Doppler. Therapies aimed at augmenting cerebral blood flow in acute stroke have included plasma expanders, vasodilators, and induced hypertension to potentially increase collateral flow.
Neonatal sonography of the brain is an essential part of newborn care, particularly for preterm and unstable infants. It allows for portable, low-cost, and radiation-free evaluation of the brain for hemorrhages, abnormalities, and other issues like hydrocephalus. Standard imaging planes include coronal and sagittal views of the brain and ventricles. Key indications for neurosonography in newborns include detection of intraventricular hemorrhage in preterm infants and evaluation of periventricular leukomalacia, a common ischemic injury. Neurosonography is also used to identify other issues like cystic lesions, tumors, and hydrocephalus.
Arteriography and interventional radiologyMilan Silwal
Angiography involves the radiologic examination of blood vessels after injection of iodinated contrast medium. Arteriography specifically examines arteries, while venography examines veins. Techniques include non-invasive ultrasound and MRI, minimally invasive CT or MRI with contrast, and invasive catheterization. Catheters and guide wires are used to access vessels and inject contrast medium. Potential complications include contrast reactions, embolism, infection, and vessel damage. Indications for arteriography include evaluating congenital anomalies, aneurysms, stenoses, arteritis, trauma, embolism, vascular malformations, fistulas, hemorrhage, and masses.
Non traumatic Subarachnoid hemorrhage (SAH)Milan Silwal
The document discusses imaging of non-traumatic subarachnoid hemorrhage (SAH). The most common cause of SAH is the rupture of a saccular aneurysm, usually located in the circle of Willis. CT and MRI are used to diagnose and locate SAH, while CT angiography, MR angiography, and conventional angiography can identify aneurysms. Complications of SAH like hydrocephalus and cerebral ischemia are also discussed. Perimesencephalic and convexal SAH represent patterns of non-aneurysmal SAH with different etiologies and prognoses.
It's helpful in understanding various aspects of revascularization procedures, with good illustrations, easy to learn, no complexity, easy language, conclusion added, short descriptions
- Transcranial Doppler (TCD) ultrasonography uses 2MHz probes to visualize intracranial vasculature non-invasively and measure blood flow velocities. It was introduced in 1982 and can monitor the middle cerebral artery, anterior cerebral artery, internal carotid artery, and other vessels.
- TCD is useful for evaluating stroke, cerebral vasospasm, intracranial stenosis, emboli, aneurysms, and raised intracranial pressure. It has good correlation with angiography and can detect stenosis with high sensitivity and specificity. Hemodynamic changes and collateral flow patterns can also be assessed.
- Monitoring emboli with TCD has helped identify the
Trans-cranial Doppler (TCD) ultrasonography is used to evaluate blood flow velocities in the basal intracerebral arteries. It was introduced in 1982 and has since been used for applications like detecting vasospasm after subarachnoid hemorrhage, monitoring stroke risk in sickle cell disease, and as a supplementary test for confirming brain death. TCD uses acoustic windows to insonate arteries like the middle cerebral artery, assessing flow parameters like peak systolic velocity to evaluate stenosis or vasomotor reactivity. It can also detect embolic signals and changes in flow patterns associated with conditions like atrial fibrillation or cerebral circulatory arrest.
Renal artery Doppler and renal transplantMilan Silwal
Renal Doppler study is a non-invasive test used to evaluate renal arteries and veins. It provides both anatomic and physiologic information about conditions like renal artery stenosis. A normal renal artery Doppler waveform shows low resistance flow with rapid systolic upstroke and continuous diastolic flow. The study requires knowledge of renal anatomy and optimization of imaging parameters. Both anterior and flank scanning approaches are used to visualize the entire length of renal arteries from origin to hilum.
Details of Cerebrospinal Fluid special reference to cell count and alteration of CSF Hydrodynamics explained in brief and Different Diagnostic parameters to Hydrocephalus
This document provides an overview of how to systematically analyze a head CT scan. It begins with identifying patient information and scan parameters. It then describes how to examine different regions of the brain from midline structures outward, including ventricles, cisterns, brain parenchyma, sulci, sinuses, bones, and soft tissues. Key things to evaluate for in each region are discussed, such as midline shift, masses, hemorrhages, fractures, and more. Two case examples are then presented to demonstrate application of the approach.
This document discusses CT imaging techniques for evaluating acute stroke. It describes CT perfusion imaging which uses a contrast agent bolus to evaluate cerebral blood flow, cerebral blood volume, and mean transit time. These perfusion values can identify the ischemic core with very low blood flow as well as the penumbra of salvageable tissue at risk for infarction. CT angiography is also discussed for evaluating vessel occlusion in thromboembolic stroke.
This document provides an overview of CT and MRI indications, techniques, findings, and interpretations for various brain pathologies. It discusses stroke imaging including early signs of ischemia on CT and advantages of MRI diffusion weighted imaging. It also covers trauma, infections, tumors and white matter diseases. Key points include sensitivity of imaging modalities for acute vs. chronic hemorrhage, importance of excluding hemorrhage for thrombolysis, and assessing penumbra on perfusion studies.
The document provides information on CSF nuclear imaging, including:
1. The physiology and anatomy of CSF circulation and production in the brain ventricles.
2. Radiopharmaceuticals used for CSF imaging like radiolabeled serum albumin and DTPA, and their properties.
3. Clinical applications of CSF imaging like evaluating CSF circulation in cisternography for hydrocephalus and detecting CSF leaks.
1) The document discusses imaging protocols for acute ischemic stroke, including non-contrast CT (NCCT), CT angiography (CTA), MRI, and thrombectomy procedures.
2) NCCT can help identify hemorrhage as a contraindication to thrombolysis and detect early ischemia. CTA can demonstrate thrombi to guide thrombolysis or thrombectomy and assess vessel occlusion, core infarction, and collaterals.
3) MRI is more sensitive than CT for acute stroke, detecting most infarcts by 24 hours. Diffusion-weighted imaging (DWI) is most sensitive in the first few hours. Perfusion imaging assesses penumbra.
4) For severe strokes,
This document discusses different techniques for angiography of the head and neck, including digital subtraction angiography (DSA), CT angiography (CTA), and MR angiography (MRA). DSA uses image subtraction to visualize contrast-filled blood vessels. CTA uses a CT scan after injection of contrast media. MRA is non-invasive and does not require contrast, using magnetic fields to visualize blood flow. The document provides details on the protocols, advantages, and images produced for each angiography technique of the head and neck vasculature.
Carotid ultrasound is used to detect plaque buildup in the carotid arteries, which can harden or rupture over time and increase the risk of stroke. Plaque can narrow the arteries and reduce blood flow to the brain. Ruptured plaque can also form blood clots, which may block or partially block the carotid artery and cause a stroke if pieces of plaque or clots break off and travel to the brain. Carotid ultrasound is recommended for those who have had a stroke or mini-stroke, have an abnormal carotid bruit sound, blood clots in the carotid arteries, or a dissection in the carotid artery wall. Ultrasound images show normal versus abnormal carotid arteries, including plaque buildup, ulcerations
This document summarizes a seminar presentation on ultrasonography for diagnosing hydrocephalus. It begins with an introduction that defines hydrocephalus and reviews ventricular anatomy. It then presents a case study of a pregnant patient with severe hydrocephalus and spinal bifida. The procedure, images, and report of the ultrasound exam are described. The summary discusses diagnostic features of hydrocephalus on ultrasound and differential diagnoses. Management options are also reviewed.
1) The document discusses imaging of cerebral ischemia from acute stroke to chronic disorders. Imaging provides valuable information about disease progression, diagnosis, treatment selection and monitoring over time.
2) Several imaging modalities such as CT, MRI, CTA and CTP can be used to evaluate brain parenchyma integrity, vascular disease severity, and changes in tissue metabolism and perfusion over the acute, subacute and chronic phases of ischemia.
3) Choosing the appropriate imaging modality depends on the specific clinical question and can help guide management decisions by providing insight into disease mechanisms and monitoring progression.
Digital subtraction angiography (DSA) is the gold standard for evaluating the cerebral vasculature. It involves injecting iodinated contrast material into arteries and using subtraction techniques to visualize vessels. The normal anatomy includes the circle of Willis and branches of major arteries. Variants are common. DSA is used to diagnose conditions like aneurysms and arteriovenous malformations. Newer digital systems provide 3D reconstruction and less radiation exposure compared to older techniques. DSA remains an important tool for interventional procedures and treatment planning of complex vascular lesions of the brain.
This presentation includes stroke and infarct latest defination an pathophysiology and CT MRI imaging features and management . This presntation help alot. Thanks
This document discusses various imaging modalities for stroke, focusing on their ability to assess the 4 P's: parenchyma, pipes, perfusion, and penumbra. CT techniques like non-contrast CT, CTA, and CTP can quickly detect hemorrhage, visualize vessels for clots, and assess perfusion/penumbra. MRI techniques like DWI, PWI, MRA provide highly sensitive visualization of acute ischemia and perfusion abnormalities to identify the ischemic core and penumbra. Imaging plays a crucial role in the early diagnosis and management of stroke by establishing the diagnosis, guiding therapy decisions, and identifying salvageable brain tissue.
The document provides an overview of brain anatomy and physiology for nurses. It describes the three main parts of the brain - the hindbrain, midbrain, and forebrain. It details the lobes of the cerebrum including the frontal, parietal, occipital, and temporal lobes. It discusses the composition of the brain including neurons, glial cells, cerebrospinal fluid, and blood vessels. Key structures like the ventricles, basal ganglia, and brainstem are also outlined. The document aims to educate nurses on the basic structure and function of the human brain.
This document outlines guidelines for the insertion and management of external ventricular drains (EVDs). EVDs are used to temporarily drain cerebrospinal fluid from the brain ventricles to relieve pressure. The document describes the indications for EVD placement, types of EVD systems, insertion procedure, and guidelines for drain positioning, monitoring drainage amounts and characteristics, obtaining samples, administering medications, and removing the drain. Key steps include accurately positioning the drain system based on the patient's ventricle height, monitoring hourly drainage amounts and qualities, and following aseptic technique for procedures involving the drain port.
Arteriography and interventional radiologyMilan Silwal
Angiography involves the radiologic examination of blood vessels after injection of iodinated contrast medium. Arteriography specifically examines arteries, while venography examines veins. Techniques include non-invasive ultrasound and MRI, minimally invasive CT or MRI with contrast, and invasive catheterization. Catheters and guide wires are used to access vessels and inject contrast medium. Potential complications include contrast reactions, embolism, infection, and vessel damage. Indications for arteriography include evaluating congenital anomalies, aneurysms, stenoses, arteritis, trauma, embolism, vascular malformations, fistulas, hemorrhage, and masses.
Non traumatic Subarachnoid hemorrhage (SAH)Milan Silwal
The document discusses imaging of non-traumatic subarachnoid hemorrhage (SAH). The most common cause of SAH is the rupture of a saccular aneurysm, usually located in the circle of Willis. CT and MRI are used to diagnose and locate SAH, while CT angiography, MR angiography, and conventional angiography can identify aneurysms. Complications of SAH like hydrocephalus and cerebral ischemia are also discussed. Perimesencephalic and convexal SAH represent patterns of non-aneurysmal SAH with different etiologies and prognoses.
It's helpful in understanding various aspects of revascularization procedures, with good illustrations, easy to learn, no complexity, easy language, conclusion added, short descriptions
- Transcranial Doppler (TCD) ultrasonography uses 2MHz probes to visualize intracranial vasculature non-invasively and measure blood flow velocities. It was introduced in 1982 and can monitor the middle cerebral artery, anterior cerebral artery, internal carotid artery, and other vessels.
- TCD is useful for evaluating stroke, cerebral vasospasm, intracranial stenosis, emboli, aneurysms, and raised intracranial pressure. It has good correlation with angiography and can detect stenosis with high sensitivity and specificity. Hemodynamic changes and collateral flow patterns can also be assessed.
- Monitoring emboli with TCD has helped identify the
Trans-cranial Doppler (TCD) ultrasonography is used to evaluate blood flow velocities in the basal intracerebral arteries. It was introduced in 1982 and has since been used for applications like detecting vasospasm after subarachnoid hemorrhage, monitoring stroke risk in sickle cell disease, and as a supplementary test for confirming brain death. TCD uses acoustic windows to insonate arteries like the middle cerebral artery, assessing flow parameters like peak systolic velocity to evaluate stenosis or vasomotor reactivity. It can also detect embolic signals and changes in flow patterns associated with conditions like atrial fibrillation or cerebral circulatory arrest.
Renal artery Doppler and renal transplantMilan Silwal
Renal Doppler study is a non-invasive test used to evaluate renal arteries and veins. It provides both anatomic and physiologic information about conditions like renal artery stenosis. A normal renal artery Doppler waveform shows low resistance flow with rapid systolic upstroke and continuous diastolic flow. The study requires knowledge of renal anatomy and optimization of imaging parameters. Both anterior and flank scanning approaches are used to visualize the entire length of renal arteries from origin to hilum.
Details of Cerebrospinal Fluid special reference to cell count and alteration of CSF Hydrodynamics explained in brief and Different Diagnostic parameters to Hydrocephalus
This document provides an overview of how to systematically analyze a head CT scan. It begins with identifying patient information and scan parameters. It then describes how to examine different regions of the brain from midline structures outward, including ventricles, cisterns, brain parenchyma, sulci, sinuses, bones, and soft tissues. Key things to evaluate for in each region are discussed, such as midline shift, masses, hemorrhages, fractures, and more. Two case examples are then presented to demonstrate application of the approach.
This document discusses CT imaging techniques for evaluating acute stroke. It describes CT perfusion imaging which uses a contrast agent bolus to evaluate cerebral blood flow, cerebral blood volume, and mean transit time. These perfusion values can identify the ischemic core with very low blood flow as well as the penumbra of salvageable tissue at risk for infarction. CT angiography is also discussed for evaluating vessel occlusion in thromboembolic stroke.
This document provides an overview of CT and MRI indications, techniques, findings, and interpretations for various brain pathologies. It discusses stroke imaging including early signs of ischemia on CT and advantages of MRI diffusion weighted imaging. It also covers trauma, infections, tumors and white matter diseases. Key points include sensitivity of imaging modalities for acute vs. chronic hemorrhage, importance of excluding hemorrhage for thrombolysis, and assessing penumbra on perfusion studies.
The document provides information on CSF nuclear imaging, including:
1. The physiology and anatomy of CSF circulation and production in the brain ventricles.
2. Radiopharmaceuticals used for CSF imaging like radiolabeled serum albumin and DTPA, and their properties.
3. Clinical applications of CSF imaging like evaluating CSF circulation in cisternography for hydrocephalus and detecting CSF leaks.
1) The document discusses imaging protocols for acute ischemic stroke, including non-contrast CT (NCCT), CT angiography (CTA), MRI, and thrombectomy procedures.
2) NCCT can help identify hemorrhage as a contraindication to thrombolysis and detect early ischemia. CTA can demonstrate thrombi to guide thrombolysis or thrombectomy and assess vessel occlusion, core infarction, and collaterals.
3) MRI is more sensitive than CT for acute stroke, detecting most infarcts by 24 hours. Diffusion-weighted imaging (DWI) is most sensitive in the first few hours. Perfusion imaging assesses penumbra.
4) For severe strokes,
This document discusses different techniques for angiography of the head and neck, including digital subtraction angiography (DSA), CT angiography (CTA), and MR angiography (MRA). DSA uses image subtraction to visualize contrast-filled blood vessels. CTA uses a CT scan after injection of contrast media. MRA is non-invasive and does not require contrast, using magnetic fields to visualize blood flow. The document provides details on the protocols, advantages, and images produced for each angiography technique of the head and neck vasculature.
Carotid ultrasound is used to detect plaque buildup in the carotid arteries, which can harden or rupture over time and increase the risk of stroke. Plaque can narrow the arteries and reduce blood flow to the brain. Ruptured plaque can also form blood clots, which may block or partially block the carotid artery and cause a stroke if pieces of plaque or clots break off and travel to the brain. Carotid ultrasound is recommended for those who have had a stroke or mini-stroke, have an abnormal carotid bruit sound, blood clots in the carotid arteries, or a dissection in the carotid artery wall. Ultrasound images show normal versus abnormal carotid arteries, including plaque buildup, ulcerations
This document summarizes a seminar presentation on ultrasonography for diagnosing hydrocephalus. It begins with an introduction that defines hydrocephalus and reviews ventricular anatomy. It then presents a case study of a pregnant patient with severe hydrocephalus and spinal bifida. The procedure, images, and report of the ultrasound exam are described. The summary discusses diagnostic features of hydrocephalus on ultrasound and differential diagnoses. Management options are also reviewed.
1) The document discusses imaging of cerebral ischemia from acute stroke to chronic disorders. Imaging provides valuable information about disease progression, diagnosis, treatment selection and monitoring over time.
2) Several imaging modalities such as CT, MRI, CTA and CTP can be used to evaluate brain parenchyma integrity, vascular disease severity, and changes in tissue metabolism and perfusion over the acute, subacute and chronic phases of ischemia.
3) Choosing the appropriate imaging modality depends on the specific clinical question and can help guide management decisions by providing insight into disease mechanisms and monitoring progression.
Digital subtraction angiography (DSA) is the gold standard for evaluating the cerebral vasculature. It involves injecting iodinated contrast material into arteries and using subtraction techniques to visualize vessels. The normal anatomy includes the circle of Willis and branches of major arteries. Variants are common. DSA is used to diagnose conditions like aneurysms and arteriovenous malformations. Newer digital systems provide 3D reconstruction and less radiation exposure compared to older techniques. DSA remains an important tool for interventional procedures and treatment planning of complex vascular lesions of the brain.
This presentation includes stroke and infarct latest defination an pathophysiology and CT MRI imaging features and management . This presntation help alot. Thanks
This document discusses various imaging modalities for stroke, focusing on their ability to assess the 4 P's: parenchyma, pipes, perfusion, and penumbra. CT techniques like non-contrast CT, CTA, and CTP can quickly detect hemorrhage, visualize vessels for clots, and assess perfusion/penumbra. MRI techniques like DWI, PWI, MRA provide highly sensitive visualization of acute ischemia and perfusion abnormalities to identify the ischemic core and penumbra. Imaging plays a crucial role in the early diagnosis and management of stroke by establishing the diagnosis, guiding therapy decisions, and identifying salvageable brain tissue.
The document provides an overview of brain anatomy and physiology for nurses. It describes the three main parts of the brain - the hindbrain, midbrain, and forebrain. It details the lobes of the cerebrum including the frontal, parietal, occipital, and temporal lobes. It discusses the composition of the brain including neurons, glial cells, cerebrospinal fluid, and blood vessels. Key structures like the ventricles, basal ganglia, and brainstem are also outlined. The document aims to educate nurses on the basic structure and function of the human brain.
This document outlines guidelines for the insertion and management of external ventricular drains (EVDs). EVDs are used to temporarily drain cerebrospinal fluid from the brain ventricles to relieve pressure. The document describes the indications for EVD placement, types of EVD systems, insertion procedure, and guidelines for drain positioning, monitoring drainage amounts and characteristics, obtaining samples, administering medications, and removing the drain. Key steps include accurately positioning the drain system based on the patient's ventricle height, monitoring hourly drainage amounts and qualities, and following aseptic technique for procedures involving the drain port.
Neurological Conditions and Diseases (During Development)Liew Boon Seng
No associated symptoms
- Not aggravated by routine physical activity
- Not associated with nausea or vomiting
- Bilateral and non-pulsating
- Family history of tension headaches
This document discusses classifications and surgical methods for treating spinal injuries. It covers injuries of the cervical, thoracolumbar, and lumbar spine. For the cervical spine, it describes techniques for fractures of C1-C2 including traction, fusion, and screw fixation. For the thoracolumbar spine, it recommends a posterior approach using pedicle screws and plates or rods, and only using anterior fusion for large defects. It stresses the importance of careful technique and handling to avoid neurological complications.
Current concepts in management of metastatic brain tumourLiew Boon Seng
1) Brain metastases occur in 25% of cancer patients and are most commonly diagnosed from lung cancer, breast cancer, and melanoma. Surgery is the preferred treatment for single, accessible brain metastases while radiosurgery and whole brain radiation therapy are options for multiple metastases.
2) Surgical resection provides the best chance of survival and neurological function for carefully selected patients with single brain metastases. Factors such as the patient's overall health, tumor size and location, and control of the primary cancer help determine treatment.
3) While whole brain radiation can effectively treat multiple brain metastases, it carries risks of neurocognitive side effects. Combined treatment with surgery or radiosurgery followed by whole brain radiation may improve outcomes
Three key points about space occupying lesions of the brain:
1. Space occupying lesions include neoplasms like meningiomas and gliomas, infections like abscesses, and vascular lesions like aneurysms and hemorrhages.
2. Signs and symptoms vary depending on the location and size of the lesion but can include headaches, seizures, nausea/vomiting, and neurological deficits.
3. Neuroimaging with CT or MRI is important for diagnosis and helps characterize lesions, while lumbar puncture and blood tests help evaluate for other potential causes like infections.
Applied Surgical Anatomy of the Brain and Spinal CordLiew Boon Seng
The document summarizes key anatomy related to the spinal cord and scalp. It describes the layers of the scalp from superficial to deep. It then discusses the skull vault and base, identifying several surface landmarks. It details the anatomy of the spinal cord, including its length, weight, segments, internal configuration of grey and white matter, and surrounding meninges. Finally, it lists the objectives which are to identify brain and spinal cord anatomy and relate it to surgical procedures and surface markings.
Neurological Conditions and Diseases (At birth)Liew Boon Seng
This document discusses various neurological conditions and diseases that can cause macrocephaly in infants and children. It describes conditions present at birth such as caput succedaneum, subgaleal hemorrhage, cephalohematoma, osteopetrosis, subdural hematomas, benign enlargement of the subarachnoid space, megalencephaly, vein of Galen aneurysm, and hydrocephalus. Hydrocephalus and its causes, clinical presentation, assessment, treatments including shunts, and complications are discussed in detail. Posthemorrhagic hydrocephalus as a consequence of intraventricular hemorrhage is also outlined.
CSF Shunt Infection: Diagnosis and TreatmentLiew Boon Seng
Ventricular shunt infection is a common complication of CSF shunting with an incidence rate of 8.5-15%. Risk factors include young age, prior revisions, and prolonged surgery time. Early infections are usually caused by skin flora like Staphylococcus epidermidis. Diagnosis involves CSF analysis showing pleocytosis and low glucose, along with culture of infected hardware. Treatment consists of removing the infected shunt and replacing it with a new shunt after the CSF is sterile, while administering intravenous antibiotics for 10-14 days. Prognosis depends on the organism, underlying pathology, and adequacy of treatment to prevent complications like cerebritis, abscesses, or recurrent infections.
This document discusses various medical and surgical management strategies for different types of hydrocephalus and associated conditions. It covers:
1) Medical management of hydrocephalus using diuretics and steroids to decrease CSF production.
2) The history of surgical drainage methods for hydrocephalus dating back to Hippocrates. Modern methods include ventriculostomies, shunt placements in various cavities, and endoscopic procedures.
3) Complications associated with different surgical procedures and how newer endoscopic techniques are improving outcomes compared to traditional shunting.
4) Specific guidelines for treating different causes of hydrocephalus like TB meningitis, hematocephalus, and congenital cases
Cranial surgery involves procedures to access and treat conditions within the skull and brain. The main types discussed are burr holes, craniotomies, and craniectomies. Craniotomies provide larger access than burr holes and are used for procedures like tumor removal, hemorrhage evacuation, and repairing vascular structures. Craniectomies involve removing a piece of skull that is later reconstructed. Additional topics covered include cranial procedures for vascular conditions like aneurysms, skull base surgery, and treating tumors, infections, hydrocephalus and more. Precise techniques and equipment are needed to perform surgeries near vital structures in the brain.
Neuropsychiatric manifestations of head injurySantanu Ghosh
This document summarizes a presentation on neuropsychiatric aspects of head injury. It begins with an introduction discussing the prevalence of head injuries. It then covers the history of understanding head injuries, comparative diagnostic classifications, epidemiology, types and pathophysiology of head injuries including acute and chronic behavioral consequences. The presentation also discusses clinical features such as cognitive impairment, personality changes, mood disorders, anxiety, aggression and psychosis. It concludes with discussing prognosis and predictors of outcome following head injury.
This document discusses Doppler ultrasound of the carotid arteries. It begins with an introduction describing how carotid artery disease can cause strokes and how ultrasound is used to diagnose stenosis to determine surgical candidates. It then describes the anatomy of the carotid arteries and outlines the normal ultrasound appearance. Key points of a carotid ultrasound exam are described including using grayscale, color Doppler, power Doppler and spectral analysis. Different types of carotid plaques are defined as well as how they appear ultrasonographically. Methods for evaluating stenosis and differentiating true from pseudo-spectral broadening are also covered.
Transcranial color coded duplex ultrasonography in routine cerebrovascular di...Marcela84
Transcranial color-coded duplex ultrasonography (TCCS) allows visualization of basal cerebral arteries through the intact skull. TCCS can identify arteries by location relative to brainstem structures and flow direction. It is useful for diagnosing intracranial vascular diseases. TCCS provides better visualization of vessel anatomy compared to transcranial Doppler and allows measuring the angle of insonation. TCCS is useful in clinical settings like stroke units for diagnosing conditions like stenosis, occlusion, vasospasm, and collateral circulation.
This document provides an overview of carotid artery ultrasound evaluation. It describes the normal anatomy of the carotid arteries and their branches. The protocol for a carotid ultrasound examination is outlined, including patient positioning, transducer selection, scanning sequences, and evaluation of stenosis. Key anatomical structures are defined, such as the intima-media complex. Non-atherosclerotic diseases that can involve the carotid or vertebral arteries, such as fibromuscular dysplasia, dissection, vasospasm, and aneurysms are also reviewed. The limitations of carotid ultrasound are noted.
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.
This document provides an overview of carotid Doppler ultrasound. It begins with the anatomy of the carotid arteries and their branches. It then discusses the technique of carotid Doppler ultrasound, including instrumentation, examination protocol, and interpretation of ultrasound findings. It provides details on evaluating the internal carotid, external carotid, and vertebral arteries for stenosis or occlusion. The document also covers characterizing carotid plaques and differentiating true findings from artifacts.
1. The document discusses the anatomy and epidemiology of carotid atherosclerotic disease. It describes the anatomy of the aortic arch and its branches, including the common, external, and internal carotid arteries.
2. Pathophysiology sections cover the development of atherosclerosis in the carotid bulb and mechanisms by which plaques can cause TIAs or strokes via embolization and hypoperfusion.
3. Evaluation and management are discussed, including use of carotid duplex ultrasound, CTA, MRA, and angiography to diagnose stenosis. Medical management focuses on risk factor modification including smoking cessation and diabetes control.
Transcranial Doppler (TCD) uses ultrasound to evaluate blood flow velocity in the brain's intracranial arteries. It is a noninvasive technique that uses probes placed on the head to transmit ultrasound pulses through thin parts of the skull and detect the Doppler shift of reflected signals from moving blood. TCD allows evaluation of conditions like stenosis, occlusion, vasospasm, and collateral flow. It can be used to monitor blood flow during surgery or in intracranial hemorrhage. Interpretation requires identifying vessels based on depth, direction of flow, and spatial relationships to other vessels. The vertebrobasilar system can be more difficult to evaluate due to anatomical variability.
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.
This document provides an overview of performing a normal carotid artery Doppler study. It discusses the anatomy of the carotid arteries and examines protocol, including using high-frequency transducers, color Doppler, and analyzing Doppler spectral waveforms. The appearance of normal carotid artery walls and blood flow characteristics are described. Tips are provided for differentiating the external and internal carotid arteries. The document references sources for further information on vascular ultrasonography techniques and carotid artery anatomy.
This document outlines Dr. Sulav Pradhan's presentation on vascular territories of the brain and different types of strokes. It discusses the role of imaging modalities like CT, CT angiography, MRI, diffusion weighted imaging, and perfusion imaging in evaluating acute ischemic strokes. It describes the appearance of ischemic brain tissue on different sequences over time and how these modalities are used to distinguish irreversible infarcted tissue from potentially salvageable penumbra.
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 provides guidelines for performing and interpreting a carotid Doppler ultrasound study. It describes optimal patient positioning and transducer selection. All carotid arteries should be thoroughly imaged using B-mode, color Doppler, power Doppler, and spectral Doppler. Limitations and techniques to avoid are outlined. Proper scanning techniques including Doppler settings, sample volume placement, and angle correction are explained. Normal carotid artery waveform patterns are demonstrated. Indications for carotid ultrasound and common carotid pathologies like plaque and stenosis are described.
Advances in CT technology allow for higher resolution imaging with multi-slice CT scanners. This provides benefits for visualizing complex anatomy, diseases, and evaluating vasculature non-invasively with techniques like CT angiography. Additional applications enabled by high resolution volumetric data include virtual bronchoscopy and colonoscopy which provide endoluminal views to evaluate airways and the colon with benefits over conventional scopes. While CT involves ionizing radiation, doses are addressed with new technologies and some procedures may replace more invasive options, proving new CT applications are of increasing clinical value.
Echocardiography is a versatile imaging technique used to evaluate cardiac anatomy and function. It utilizes ultrasound to obtain standard 2D views of the heart from different windows including parasternal, apical, subcostal, suprasternal, and right parasternal. Doppler echocardiography, including color Doppler, assesses cardiac valves, chambers, and blood flow. Echocardiography is useful for diagnosing conditions such as valvular disease, heart failure, and congenital heart defects.
Echocardiography uses ultrasound to produce images of the heart. Sound waves are sent through a transducer and reflected off structures in the heart. These echoes are converted into pictures that are displayed on a monitor. Different modalities include M-mode, 2D, Doppler, and 3D echocardiography. Views are obtained by positioning the transducer in various locations on the chest or esophagus to visualize cardiac structures from different angles. Echocardiography is used to evaluate cardiac structure and function as well as hemodynamics.
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.
- Diffusion-weighted MRI is more sensitive than non-contrast CT for distinguishing acute ischemic stroke from other conditions, as it can detect ischemia earlier. It shows hyperintensity on DWI and hypointensity on the ADC map in the acute setting.
- MRI can also identify chronic cerebrovascular pathology better than CT. However, CT is more readily available, less costly, and does not require removing metal/electronics from patients.
- Multimodal CT and MRI, combining perfusion, angiography, and diffusion images, can identify the ischemic core and penumbra. This helps determine if patients may benefit from reperfusion therapies in the acute period.
This document discusses a study that used dynamic CT angiography to evaluate enhancement patterns in the aorta and endoleaks after endovascular aneurysm repair (EVAR). The study found that maximum endoleak enhancement occurred at 22 seconds after contrast injection, while the highest endoleak detection rate was at 27 seconds. Conventional biphasic CT is insufficient for endoleak detection. Dynamic CT allowed detection of a 45% endoleak rate compared to typical rates of 20-30% and can help optimize EVAR follow-up imaging protocols.
Echocardiography in intervention cardiologyRubayet Anwar
Echocardiography can be used to guide various cardiac interventions and procedures. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) are commonly used to guide percutaneous procedures like pericardiocentesis, balloon mitral valvuloplasty, and ablation procedures. Intracardiac echocardiography (ICE) provides high-quality images and is used for transseptal punctures and atrial fibrillation ablation. Echocardiography helps with catheter placement and rules out complications. It is also used to identify coronary artery disease by detecting retrograde flow in occluded vessels and "mosaic flow" patterns in stenotic vessels.
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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.
10 Benefits an EPCR Software should Bring to EMS Organizations Traumasoft LLC
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5-hydroxytryptamine or 5-HT or Serotonin is a neurotransmitter that serves a range of roles in the human body. It is sometimes referred to as the happy chemical since it promotes overall well-being and happiness.
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2. Orbital Window
• Transorbital Doppler sonography is used for investigating the OphA
and the carotid siphon.
• The patient is in the supine position, and the vessels are identified
by the depth of insonation and direction of blood flow.
• Flow towards the probe is assumed to come from the OphA or C4
segment of the internal carotid artery (ICA; lower carotid siphon),
whereas the upper carotid siphon (C2 segment of the ICA) leads to
Doppler signals being directed away from the probe.
• Transorbital ultrasound is assumed to
be safe when the lowest emission
energies are used, and the insonation
time is as short as possible.
• For safety reasons, the use of echo
contrast agents is prohibited.
4. Temporal Bony Window
• The posterior coronal plane
depicts the PCA, distal
basilar artery (BA), M2 and
M3 MCA, and horizontal
segment of the petrosal part
of the ICA.
• Transtemporal insonation is performed using axial and coronal
planes.
• The axial mesencephalic plane depicts the midbrain, which is
hypoechogenic and shaped like a butterfly, the sphenoidal (M1) and
insular (M2) parts of the MCA, A1 ACA, the terminal segment (C1)
of the ICA, and postcommunicating (P2) PCA
• The anterior coronal plane shows M1 MCA, A1 ACA, C1 ICA, parts
of the carotid siphon, and C5 ICA.
5. Temporal Bony Window
• With advancing age, and especially in postmenopausal women, the temporal
bone window becomes smaller or may even disappear, and the frequency of
ultrasonic detection of intracranial vessels decreases.
• Consequently, vascular structures located in the periphery of the insonation
field, such as the petrosal part, C5 and the siphon of the ICA, A2 ACA, M3
and M2 MCA, P3 PCA, the straight-, and transverse sinus will be missed in
older patients.
• The temporal window is better in men than women, and in white compared
to black and Asiatic patients
• Temporal squama thickness of 2.7mm was associated with a good window,
and values of 5.0mm permitted just a partial transcranial study
• 1-MHz probes increase the diagnostic yield of transcranial ultrasound in
patients presenting with absent or insufficient temporal bone windows at
transtemporal insonation with 2-MHz probes.
7. Foramen Magnum Window
• Transforaminal (transnuchal) insonation is performed
with an axial scanning plane, and allows the distinction of
the atlas loop (V3) and the intracranial segment (V4) of
both vertebral arteries (VA), and the BA
9. Intracranial Occlusion
• TCD diagnosis of intracranial cerebral artery occlusion is
established by the absence of Doppler signals in a
cerebral artery of a patient with an appropriate acoustic
window proven by the detection of at least one ipsilateral
cerebral artery.
• TCCDS diagnosis of intracranial occlusion is based on
the absence of color and spectral Doppler signals in the
occluded vessel, whereas the adequate insonation
window can also be demonstrated by depicting adjacent
intracranial veins or structures
10. Intracranial cerebral artery stenosis
• It is not possible to differentiate cerebral artery narrowing due to a
vasospasm and stenosis as well as embolic from atherosclerotic
stenoses.
• Vasospasm and stenoses due to cerebral embolism typically
recanalize within days, weeks, or months.
• In contrast, atherosclerotic stenoses are assumed to show no
recanalization.
14. Intracranial cerebral artery stenosis
Transtemporal color duplex
sonography with an axial plane shows
a 50% stenosis of the sphenoidal
segment of the middle cerebral
artery with increased intrastenotic
flow velocities (a),
and decreased flow velocities and
pulsatility distal to the stenosis (b).
15. Carotid Artery Stenosis
Longitudinal US image of right common carotid
artery ( C ) and internal carotid artery ( I ) showed
a large heterogeneous plaque at the origin
of the internal carotid artery with calcified and
fibrolipoid components( arrows ).
Longitudinal color Doppler US images showed a
heterogeneous plaque with apparent severe luminal
narrowing ( arrows ) at internal carotid artery origin.
Note color aliasing at the point
of maximal stenosis ( arrow)
16. Carotid Artery Stenosis
Power Doppler US images showed a
heterogeneous plaque with apparent
severe luminal narrowing ( arrows ) at
internal carotid artery origin.
Duplex Doppler image showed a
peak systolic velocity of 418 cm/s at
the point of maximal stenosis. This
velocity represents severe stenosis
(more than 70 %).
17. Carotid Artery Stenosis
Two centimeter distal to the stenosis, duplex
Doppler showed a peak systolic velocity of 82
cm/s, within normal limits, but with turbulent
flow features.
Digital angiography con firmed a severe stenosis
in the proximal internal carotid artery ( arrow ).
An endovascular stent was placed.
18. Carotid Artery Stenosis
Measurement of fibrous cap thickness in a carotid atheromatous plaque by
a new semi-automatic system. Fibrous cap is defined as the hyperechoic
structure existing between two anechoic surroundings (blood and lipid
core).
19. Carotid Artery Stenosis
Schematic examples of intra-arterial angiographic measurements for the degree
of stenosis for different configurations of ICA lesions. N ‘NASCET method’; E ‘ECST
method
NASCET method describes
predominantly the hemodynamic
significance of ICA stenosis (relation
of the inflow to outflow diameter)
1/3
ESCT method reflects more the
amount of atherosclerotic
tissue at the stenosed segment
1/2
20. Carotid Artery Stenosis
Nonstenotic ICA plaque without
hemodynamic changes, plaque
length is about 15mm, plaque
thickness 3.9 mm;
approximately 60–70%
ICA stenosis
approximately 90% ICA
stenosis
proximal ICA occlusion
The upper panel shows
longitudinal color
Doppler-assisted duplex
imaging where right is
proximal
The bottom left panel
shows the transverse
view of the narrowest part
of the stenosis and cross-
sectional luminal area
reduction measurement
The bottom right panel
displays the Doppler shift
recording and
spectrum analysis, the
maximum peak systolic shift
is given in kilo Hertz (kHz).
21. Carotid Artery Dissection
Longitudinal color Doppler ultrasound of the right
internal carotid artery demonstrating a low-reflective
intramural hematoma ( arrows ) compressing the true
lumen of the internal carotid artery 2 cm cranially from
the bulb. These findings are strongly suggestive of
internal carotid artery dissection with intramural
hematoma.
Color and spectral Doppler ultrasound of
internal carotid artery immediately
proximal to the lesion shows a high-
resistance triphasic waveform.
22. Carotid Artery Dissection
Spectral Doppler at the point of
maximal lumen stenosis shows
a very high peak systolic velocity (4
m/s).
Digital angiography confirmed an irregular
stenosis ( arrowheads ) starting 2 cm distal
to the carotid bulb.
23. Carotid Artery Dissection
Color duplex sonography (power Doppler imaging) with
longitudinal (a) and axial (b) planes
shows a spontaneous dissection of the cervical internal carotid artery.
•Luminal narrowing and the hypoechogenic and thickened vessel wall (white
arrows) begin distal to the carotid bulb.
•The unequivocal depiction of the border between the vessel wall and the
lumen including the presence of an intimal reflex (arrowheads) suggests that
mural thickening is mainly due to a wall hematoma and not an intraluminal
thrombus.
24. Cross-Flow through the Circle of
Willis
• Crossflow through the anterior communicating artery
was diagnosed in the presence of reversed flow in the
ACA located on the side of the obstructed carotid artery.
• If this ACA was missed, decrease of flow velocity in the
homolateral MCA during digital compression of the
contralateral common carotid artery was used for
diagnosis.
• The corresponding sensitivity was 98%, specificity 100%,
PPV 100%, and NPV 98%.
• Ultrasound contrast agents increase the detection rate of
Willisian collaterals compared to nonenhanced TCCDS
25. Extracranial-Intracranial Bypass
• Catheter- and MR-based angiography are typically used to evaluate
the postoperative bypass patency.
• Short-term effects of ECIC bypass on cerebral hemodynamics have
been investigated with various neuroradiologic techniques, including
positron-emission tomography (PET), single-photon emission CT
(SPECT), and xenon-enhanced CT scanning, these modalities are
complicated, expensive, time consuming, and invasive because
they expose patients to radiation, making them ill suited for use in
the outpatient setting or for long-term routine follow-up of ECIC
bypass.
• The ipsilateral STA mean blood flow velocity is a highly sensitive
parameter to predict regional cerebral blood flow (rCBF) in the
ipsilateral middle cerebral artery (MCA) territory at 14 days after
ECIC bypass in patients with internal carotid artery occlusion or
middle cerebral artery stenosis.
26. Transcranial Doppler Sonography
In Underwent Decompressive
Craniectomy For Traumatic Brain
Injury
• Cerebral blood flow (CBF) velocity by means of
transcranial Doppler sonography (TCD) can be
performed in patients post decompressive craniectomy
for traumatic brain injury
27. Transcranial Doppler Sonography
In Underwent Decompressive
Craniectomy For Traumatic Brain
Injury
Transcranial Doppler spectral waveforms obtained from the right middle cerebral artery of patient
A, before decompressive craniectomy, the cerebral circulation was characterized by reduced blood flow
velocity and high pulsatility index (PI) (18 cm/s and 7.09, respectively).
Note that during the diastolic phase, the blood flow velocity decreases continuously reaching zero value,
and straight away, there is a reversion of flow direction (see arrow).
This finding can indicate the presence of critical intracranial hypertension with a severe impairment of
cerebral blood flow.
B, immediately after surgery, the blood flow was restored to a unidirectional pattern, with more acceptable
flow dynamics in terms of flow velocity and PI (65 cm/s and 0.92, respectively).
28. Acute Stroke: Perfusion Imaging
• Ultrasound perfusion imaging of the human brain is a new semi-
invasive bedside technique based on the detection of ultrasound
contrast agent (UCA) in the brain tissue to evaluate brain perfusion.
• Current UCAs consist of microbubbles composed of a gas that is
associated with various types of shells for stabilization.
• Because of their small size, they can pass through the
microcirculation several times, thus representing optimum blood
pool tracers.
• Multiple pulse technologies receive contrast-agent-specific signals
in the fundamental frequency band (so-called nonlinear fundamental
signals) with a higher sensitivity than conventional single-pulse
approaches.
• As a measure of energy impinging on the tissue, the mechanical
index (MI) is defined as the peak pressure of a longitudinal
ultrasound wave propagating in a uniform medium divided by the
square root of the center frequency of the transmitted ultrasound
pulse
29. Acute Stroke: Perfusion Imaging
a Follow-up CT, 48 h after symptom onset, of a 67-
year-old woman suffering from middle cerebral artery
occlusion.
Ultrasound perfusion imaging (Harmonic imaging
1.8/3.6 MHz, MI 1.6, 2.4 ml SonoVueTM bolus
injection, investigation depth 10 cm, frame rate 0.67
Hz) was performed 2.5 h after symptom onset.
b Contrast image with area of reduced contrast
enhancement in the middle cerebral artery territory.
Parametric images:
c Pixelwise peak intensity image showing the area
of reduced signal enhancement (dark) in the middle
cerebral artery territory,
d time to peak image showing the dark blue area of
delayed perfusion, invalid data being displayed in
gray,
e area under the curve image, and
f slope image.
30. Sonothrombolysis:
Experimental Evidence
• The combination of ultrasound with thrombolytic agents
may enhance the potential benefit by means of enzyme-
mediated thrombolysis.
• When ultrasound is applied externally through skin or
chest, attenuation will be very low.
• Attenuation, however, is significantly higher if penetration
through the skull is required.
• Attenuation is frequency dependent, with ultrasound
intensity being 10% of the output intensity for diagnostic
frequencies (1 MHz).
• This ratio nearly reverses in the kiloHertz range (500
kHz).
31. Sonothrombolysis:
Experimental Evidence
• Ultrasound insonation is efficient for accelerating
enzymatic thrombolysis within a wide range of
intensities, from 0.5W/cm2 (MI 0.3) to several watts per
square centimeter, particularly in the non focused
ultrasound field.
• Insonation with ultrasound increased tPA-mediated
thrombolysis up to 20% in a static model, while it
enhanced the recanalization rate from 30 to 90% in a
flow model.
• Most studies demonstrated the potential usefulness of
ultrasound for the treatment of arterial or venous
thrombosis.
• Ultrasound may also have pro-thrombic effects.
32. Sonothrombolysis:
Experimental Evidence
Flow rate over time in a tube model. Measurement of recanalization after complete occlusion from a
fibrin clot in different treatment groups:
spontaneously (A), when treating with rt-PA only (B), when treating with rt-PA and ultrasound (1
MHz pulsed wave) (D)*, and (C) when treating with rt-PA and ultrasound (1 MHz pulsed wave)
transcranially (cadaver skull bone). The addition of ultrasound to tPA treatment showed a further
decrease of recanalization time.
33. Application of Ultrasound through
the Skull
• Within 0.25- and 6.0-MHz ultrasound frequencies, the increase of
insertion loss through the skull is not only roughly proportionally
related to an increased intensity, but also directly linked to the
thickness of the diploë and the skull bone
• Ultrasound at low to mid-kiloHertz frequencies and suggest that
only those frequencies may reach the brain and intracranial vessels
with thermally acceptable levels.
The diagram demonstrates the attenuation
of ultrasound through the skull
dependent on the used frequency, showing
the strong reversed correlation between
decrease of intensity and increase of
frequency.
34. Endovascular Application of
Ultrasound
• Miniaturized transducers have also been attached to
catheters for direct endovascular use, offering the
potential of localized ultrasound thrombolysis, while
avoiding attenuation of intensity through the skull and
reducing insonation of the surrounding tissue.
• The potential endovascular use of microcatheters for
acute stroke treatment is limited to specialized centers
and a broader applicability seems unrealistic.
35. Acute Stroke: Therapeutic
Transcranial Doppler Sonography
• Proximal intracranial occlusion is a target for more advanced
reperfusion strategies, among them ultrasound-enhanced
thrombolysis
• High frequencies lead to greater attenuation of ultrasound, lower
frequencies may be harmful due to tissue heating.
• The TRUMBI study, a phase II clinical trial testing the use of low
frequency ultrasound insonation in acute stroke patients treated with
i.v. t-PA, showed a significant increase in hemorrhage, both
symptomatic and asymptomatic
• Phase II randomized controlled trial CLOTBUST (Combined
Lysis of Thrombus in Brain Ischemia using Transcranial Ultrasound
and Systemic TPA), which demonstrated that enhancement of the
thrombolytic activity of tPA could be safely achieved by using higher
frequency (2 MHz) and low intensity (<700 mW/cm2) single element
pulsed-wave ultrasound
36. Acute Stroke: Therapeutic
Transcranial Doppler Sonography
• A phase III trial has been planned for quite some time
and protocols have been published. The problem,
however, is still the lack of an investigator independent
device.
• CLOTBUST-Hands Free Initial Safety Testing of a
Novel Operator-Independent Ultrasound Device in
Stroke-Free Volunteers study published in 2013
showed all subjects were safely insonated with no
adverse effects as indicated by the neurological
examinations during, immediately after the exposure,
and at 24 hours, and no abnormality of the blood brain
barrier was found on any of the MRIs.
37. Acute Stroke: Therapeutic
Transcranial Doppler Sonography
TCDS of the circle of Willis,
showing an occlusion of the MCA-
M1 (left).
Please note the missing Doppler
spectra and the lateral fissure
displayed as an echogenic
structure marked by the arrows in
the detail of the picture showing
the occlusion (middle).
Reconstituted flow after
recanalization with normalized
Doppler spectra (right).
38. Cerebral Aneurysms
• The prime criterion for the diagnosis of an aneurysm is a
color-coded appendix connected with a vessel; additional
criteria are
– (1) a red and a blue zone within the lumen of the aneurysm due
to bidirectional flow within larger aneurysms and
– (2) a circular echogenic structure in B-mode imaging,
demonstrated by fast switching from color-coded mode to B-
mode.
• Aneurysms with thrombosed components appear as an
echogenic, often calcified shell, which surrounds the less
echogenic thrombosed portions.
• The maximum diameter of the color-coded lumen of the
aneurysm should be measured in two planes.
39. Cerebral Aneurysms
Middle cerebral artery aneurysm. Coronal
plane section, insonation through the
temporal bone window: the arrow indicates
a large aneurysm of the middle cerebral
artery with a bicolored zone, which results
from simultaneous inflow and outflow within
the aneurysmal lumen. The echo-intense
small structure in the midline is caused by
the cerebral falx.
40. Cerebral Aneurysms
Basilar artery aneurysm. Transversal
insonation plane, insonation through
the temporal bone window: this figure
demonstrates the circle of Willis with
a giant aneurysm (surrounded by
dotted line) at the top of the basilar
artery compressing the brain stem.
LMCA =Left middle cerebral artery;
LACA = left anterior cerebral artery;
RMCA =right middle cerebral artery;
F = frontal; T = temporal.
41. Cerebral Aneurysms
Thrombosed aneurysm. Transversal
insonation plane, insonation through the
temporal bone window: this figure shows a
particularly thrombosed large aneurysm
(arrows) of the distal segment of the
internal carotid artery. Half of the aneurysm
is occluded by thrombosed (black signal)
and calcified material (bright signal), while
blood flow is detectable in the other half of
the lesion. The bright signal in frontomedial
position to the aneurysm is the base of the
skull (os sphenoidale).
F = Frontal, T = temporal.
43. Cerebral Arteriovenous
Malformations
• Using TCCS, large (4 cm) cerebral arteriovenous
malformations (AVMs) can be depicted by B-mode
imaging as echodense areas interspersed with zones of
lower echo intensity.
• The color-coded illustration of intravascular flow
phenomena allows the distinct identification of the major
feeding vessels, venous drainage, and vascular
convolution of the AVM.
• Information on hemodynamics, such as the blood supply
of the angioma, may be obtained by analysis of the
Doppler spectrum, in addition to color-coded
identification of flow direction.
45. Cerebral Arteriovenous
Malformations
Arteriovenous malformation, transverse.
Transversal insonation through the
temporal bone reveals a large
arteriovenous malformation with convolutes
of arterial and venous vessels in the
temporal lobe and the basal ganglia.
Aliasing phenomena reflect increased
flow velocities in all vessels. The echo-
intense (bright) signal at the bottom of the
figure is caused by the contralateral
temporal bone.