The document discusses various presacral lesions that can be seen on imaging. It describes the anatomy of the presacral space and then covers conditions with osteochondral origin like giant cell tumor and Ewing sarcoma. Neurogenic conditions such as neurofibromas, schwannomas, and perineural cysts are also discussed. Other lesions mentioned include dural ectasia and anterior myelomeningoceles. For each condition, the document provides details on clinical features, imaging appearance on modalities like CT and MRI, and examples of imaging findings.
Intracranial chordomas are rare, slow-growing tumors that arise from remnants of the embryonic notochord in the skull base. They typically present as soft tissue masses originating in the clivus with associated bone destruction. MR imaging and CT are effective in diagnosing and monitoring these tumors. Treatment involves surgical resection followed by radiation therapy, which provides the best outcomes for patients with intracranial chordomas.
Skull base tumors & perineural spread radiology pptDr pradeep Kumar
Skull base tumors & perineural spread radiology ppt This powerpoint presentation includes important anatomy and important pathology of skull base lesion with its imaging feature as well as its ct mri image. This will help alot. this will help for radiology resident as well as ent .
Meningeal Based Intracranial Masses Beyond MeningiomaDr Varun Bansal
Dural based masses other than meningioma ( which is the most common dural based intracranial mass) their appearance on imaging modalities such as CT and MRI.
An aneurysmal bone cyst is a benign bone tumor characterized by blood-filled cavities separated by bone or fibrous tissue. It most commonly affects long bones in people under 30 years old. This case report describes a rare aneurysmal bone cyst located in the cervical spine of a 13-year-old girl who presented with neck pain. Imaging showed an osteolytic lesion of the C2 spinous process. The cyst was surgically excised and pathology confirmed the diagnosis. Following halo cast immobilization, the girl recovered with no recurrence at her 2-year follow-up.
The document discusses various primary spinal cord tumors. It describes the most common types of tumors including ependymomas, astrocytomas, gangliogliomas, and hemangioblastomas. For each tumor type, it provides details on location, imaging characteristics such as signal on T1 and T2 MRI sequences, enhancement patterns, and associated findings like cysts. It emphasizes that the essential criterion for identifying an intramedullary spinal tumor is cord expansion visible on MRI. Contrast enhancement is also seen in most tumors but may be absent.
An aneurysmal bone cyst is a benign bone tumor characterized by blood-filled cavities separated by bone and fibrous tissue. It most commonly affects children and young adults near the metaphysis of long bones. The cause is unknown but believed to involve a vascular malformation that results in bone erosion and expansion. Diagnosis is made based on imaging showing an expansile lytic lesion with septations and sometimes fluid-fluid levels, and confirmed with histology. Treatment involves curettage, bone grafting, and sometimes embolization or radiation for difficult cases. Recurrence rates after treatment are around 20-30%.
Presentation1, radiological imaging of chest wall tumour.Abdellah Nazeer
1. The document discusses various tumors that can occur in the chest wall, dividing them into benign and malignant lesions.
2. It provides details on specific tumor types including their demographics, imaging appearance on x-ray, CT and MRI, and pathological characteristics.
3. Examples of tumors covered include lipoma, liposarcoma, hemangioma, schwannoma, neurofibroma, and malignant peripheral nerve sheath tumors among others. Imaging findings that help differentiate between benign and malignant lesions are also highlighted.
Intracranial chordomas are rare, slow-growing tumors that arise from remnants of the embryonic notochord in the skull base. They typically present as soft tissue masses originating in the clivus with associated bone destruction. MR imaging and CT are effective in diagnosing and monitoring these tumors. Treatment involves surgical resection followed by radiation therapy, which provides the best outcomes for patients with intracranial chordomas.
Skull base tumors & perineural spread radiology pptDr pradeep Kumar
Skull base tumors & perineural spread radiology ppt This powerpoint presentation includes important anatomy and important pathology of skull base lesion with its imaging feature as well as its ct mri image. This will help alot. this will help for radiology resident as well as ent .
Meningeal Based Intracranial Masses Beyond MeningiomaDr Varun Bansal
Dural based masses other than meningioma ( which is the most common dural based intracranial mass) their appearance on imaging modalities such as CT and MRI.
An aneurysmal bone cyst is a benign bone tumor characterized by blood-filled cavities separated by bone or fibrous tissue. It most commonly affects long bones in people under 30 years old. This case report describes a rare aneurysmal bone cyst located in the cervical spine of a 13-year-old girl who presented with neck pain. Imaging showed an osteolytic lesion of the C2 spinous process. The cyst was surgically excised and pathology confirmed the diagnosis. Following halo cast immobilization, the girl recovered with no recurrence at her 2-year follow-up.
The document discusses various primary spinal cord tumors. It describes the most common types of tumors including ependymomas, astrocytomas, gangliogliomas, and hemangioblastomas. For each tumor type, it provides details on location, imaging characteristics such as signal on T1 and T2 MRI sequences, enhancement patterns, and associated findings like cysts. It emphasizes that the essential criterion for identifying an intramedullary spinal tumor is cord expansion visible on MRI. Contrast enhancement is also seen in most tumors but may be absent.
An aneurysmal bone cyst is a benign bone tumor characterized by blood-filled cavities separated by bone and fibrous tissue. It most commonly affects children and young adults near the metaphysis of long bones. The cause is unknown but believed to involve a vascular malformation that results in bone erosion and expansion. Diagnosis is made based on imaging showing an expansile lytic lesion with septations and sometimes fluid-fluid levels, and confirmed with histology. Treatment involves curettage, bone grafting, and sometimes embolization or radiation for difficult cases. Recurrence rates after treatment are around 20-30%.
Presentation1, radiological imaging of chest wall tumour.Abdellah Nazeer
1. The document discusses various tumors that can occur in the chest wall, dividing them into benign and malignant lesions.
2. It provides details on specific tumor types including their demographics, imaging appearance on x-ray, CT and MRI, and pathological characteristics.
3. Examples of tumors covered include lipoma, liposarcoma, hemangioma, schwannoma, neurofibroma, and malignant peripheral nerve sheath tumors among others. Imaging findings that help differentiate between benign and malignant lesions are also highlighted.
This document describes two cases:
1. Autoimmune pancreatitis, which is a unique form of pancreatitis caused by autoimmune disease. It commonly affects men aged 40-65 and presents with obstructive jaundice and abdominal pain. Imaging shows swelling of the pancreas and narrowing of the pancreatic and bile ducts. Treatment involves steroids.
2. Chordoma, a rare bone tumor originating from embryonic remnants. It most commonly affects the sacrum and skull base. Imaging shows a destructive lytic bone lesion and soft tissue mass. It is locally aggressive but slow growing. Treatment involves surgery and radiation therapy.
An aneurysmal bone cyst is a benign, expansile bone lesion characterized by blood-filled cavities separated by bone or fibrous tissue with osteoclast giant cells. Most patients are under 20 years old, with common locations in the long bones of the lower extremities. The etiology is unknown but may involve genetic translocations. Imaging shows an expansile, osteolytic lesion with possible fluid-fluid levels. Treatment involves preoperative embolization, curettage with bone grafting, or complete resection to prevent the 20-30% recurrence rate associated with partial resection.
An aneurysmal bone cyst is a benign, expansile bone lesion characterized by blood-filled cavities separated by bone or fibrous tissue with osteoclast giant cells. Most patients are under 20 years old, with common locations in the long bones of the lower extremities. The etiology is unknown but may involve genetic translocations. Imaging shows an expansile, osteolytic lesion with possible fluid-fluid levels. Treatment involves preoperative embolization, curettage with bone grafting, or complete resection to prevent the 20-30% recurrence rate associated with partial resection.
Congenital neck mass radiology pk final is very good power point presentation for radiologist, radiology resident, student and even ent surgeon or resident doctor.. Every disease of neck lesion is properly describe with multi usg, ct and MRI images. this will help a lot. thanks.
MRI is an accurate method for evaluating brachial plexus injuries and other pathologies. It can identify lesions in the supraclavicular, retroclavicular, and infraclavicular regions. Common non-traumatic causes seen on MRI include inflammatory plexitis, nerve sheath tumors, Pancoast tumors, and metastases. Traumatic injuries are classified as preganglionic or postganglionic. Preganglionic injuries often involve nerve root avulsions while postganglionic injuries stretch or rupture nerve roots, cords, and trunks. MR neurography and diffusion-weighted imaging provide improved visualization of the brachial plexus.
This document provides a summary of imaging features of lesions in the anterior skull base region, including sinonasal neoplasms such as squamous cell carcinoma, adenocarcinoma, esthesioneuroblastoma, malignant melanoma, and lymphoma. Key imaging findings discussed include tumor appearance on CT and MRI, characteristics of bone and soft tissue involvement, and distinguishing features between lesion types. Imaging plays an important role in diagnosis and surgical planning for anterior skull base pathology.
Lytic lesions of the skull can have many potential etiologies ranging from normal variants to neoplastic lesions. Imaging plays an important role in the evaluation and diagnosis of lytic skull lesions. CT and MRI are often used to characterize the lesions and assess bone and soft tissue involvement. The differential diagnosis depends on factors like the patient's age, lesion characteristics such as appearance, location and whether it is solitary or multiple. Common etiologies include metastases, multiple myeloma, epidermoid cysts, hemangioma and fibrous dysplasia among others. A thorough clinical history and imaging findings are needed to establish the correct diagnosis.
1. The document discusses various head and neck masses and their imaging appearance on CT and MRI.
2. Key neck masses discussed include lymph nodes, tonsillar abscesses, benign mixed tumors, minor salivary gland malignancies, and squamous cell carcinoma of the nasopharynx and oropharynx.
3. Important imaging findings for differentiating benign from malignant lesions are described.
CT and MR imaging are useful for evaluating the spleen. CT typically shows splenic tissue with homogeneous attenuation of 40-60 HU. The spleen normally enhances heterogeneously after intravenous contrast. MR also evaluates the spleen using T1- and T2-weighted sequences. Infectious processes like abscesses, tuberculosis, and Pneumocystis carinii can involve the spleen. Abscesses may contain fluid, gas, or septations. Tuberculosis can cause irregular low attenuation areas or infarcts. Pneumocystis carinii causes focal low attenuation lesions and calcifications. Other conditions like cysts, inflammatory pseudotumors, and fluid collections associated with pancreatitis can also occur in the spleen
This document discusses aneurysmal bone cyst (ABC), beginning with its definition as a benign, expansile bone lesion containing blood-filled cystic cavities. It describes ABC's unknown etiology, most common locations in long bones of younger patients, and presentations of pain, swelling or fracture. Imaging findings include expansile lytic lesions on x-ray, and fluid-fluid levels on MRI. Treatment involves preoperative embolization and curettage with bone grafting. ABC's differential diagnosis and potential for recurrence after treatment are also summarized.
The document discusses various types of orbital tumours and pathologies. It describes three main intraorbital spaces - intraconal, conal and extraconal - and examples of pathologies that can occur in each space. It provides details on orbital lymphoma, rhabdomyosarcoma, orbital metastasis and dermoid cysts. For each condition, it outlines clinical features, location in the orbit, radiological features on CT and MRI such as signal characteristics, enhancement patterns and appearance. Common primary cancers that metastasize to the orbit are also listed.
Tips, Pearls and Pitfalls of Spinal Cord MRIWafik Bahnasy
- Many neurological disorders simultaneously or consecutively affect the brain and spinal cord, however most neurologist find their comfort zone in attending the diagnosis via the brain access.
- This concept resulted in lagging of spinal cord imaging researches compared to brain ones and consecutive underestimation of the opportunity of an important tool sometimes essential to reach a definite diagnosis.
MRI of Spine and very easy details of spssuserc66686
The document discusses various neurological conditions that can be seen on CT and MRI imaging of the brain and spine. It provides examples of imaging findings for tumors such as meningiomas, medulloblastomas, ependymomas, glioblastomas, and metastases. It also reviews imaging appearances of conditions like cerebral abscesses, multiple sclerosis, cavernomas, spinal tuberculosis, and spondylitis. Key distinguishing radiological features of different lesions are highlighted.
Benign bone tumors can be classified based on their location, rate of growth, perioseal reaction, and matrix mineralization. Common cartilage tumors include osteochondroma, enchondroma, chondroblastoma, chondromyxoid fibroma, and fibrocartilaginous mesenchymoma. Osteochondroma is characterized by a cartilage-capped bony projection and most commonly affects the distal femur, proximal humerus, proximal tibia and proximal femur. Enchondroma forms mature hyaline cartilage and typically affects the small tubular bones of the hands and feet. Chondroblastoma presents before skeletal maturity with a sclerotic border and scattered calcifications. Treatment
This document discusses imaging modalities used for head and neck cancers including radiography, ultrasound, CT, MRI, nuclear scans and PET CT/PET MR. It describes the anatomy visualized by each modality and indications for their use. Key points covered include ultrasound criteria for evaluating lymph nodes, advantages and disadvantages of CT and MRI, and basics of interpreting various tissue types on imaging studies. The neck is divided into spaces and triangles and relevant anatomy of each area is outlined.
Presentation1, radiological imaging of trigeminal schwanoma.Abdellah Nazeer
The document discusses trigeminal schwannomas, which are slow-growing tumors composed of schwann cells that occur along the trigeminal nerve. It provides details on the epidemiology, clinical presentation, and radiographic features of trigeminal schwannomas. Specifically, it notes that trigeminal schwannomas most commonly present in the third to fourth decades of life and typically manifest as trigeminal nerve dysfunction. Radiographically, they often have a dumbbell appearance on MRI when extending between compartments, and demonstrate enhancement following contrast administration. The document includes several images showing examples of trigeminal schwannomas along different segments of the nerve.
This presenation includes anatomy and pathology of intraconal conal and extraconal orbital pathology. this presenation dealsimaging feature of different pathology. Thanks.
This document discusses various cystic neck masses that can be seen on imaging. It describes the imaging appearance and characteristics of common cystic lesions such as thyroglossal duct cysts, branchial cleft cysts, lymphangiomas, dermoid/epidermoid cysts, thymic cysts, laryngoceles, ranulas, cystic metastatic lymph nodes, and neurogenic tumors. It provides details on the ultrasound, CT, and MRI features that can help differentiate these lesions. Rare vascular causes of cystic neck masses like arteriovenous malformations are also mentioned.
The vertebral column consists of 33 vertebrae separated by intervertebral discs. A typical vertebra has a vertebral body and arch enclosing the vertebral foramen through which the spinal cord passes. The spinal cord has 31 pairs of spinal nerves and is composed of gray and white matter. It transmits sensory information up the posterior columns and motor commands down tracts like the corticospinal tract. Injuries can cause syndromes like complete transection with bilateral deficits or Brown-Sequard with unilateral deficits depending on the location and extent of damage.
The document describes the various cerebrospinal fluid (CSF) filled spaces, or cisterns, within the subarachnoid space. It details both supra-tentorial and infra-tentorial cisterns, providing their locations, contents such as vessels and cranial nerves, and anatomical relationships. Key cisterns mentioned include the cistern of the lamina terminalis, chiasmatic cistern, interpeduncular cistern, prepontine cistern, cisterna magna, and cerebellopontine angle cistern. The cisterns form a interconnected network facilitating CSF circulation within the subarachnoid space.
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Semelhante a pre sacral lesion sept5.pptx RADIOLOGY
This document describes two cases:
1. Autoimmune pancreatitis, which is a unique form of pancreatitis caused by autoimmune disease. It commonly affects men aged 40-65 and presents with obstructive jaundice and abdominal pain. Imaging shows swelling of the pancreas and narrowing of the pancreatic and bile ducts. Treatment involves steroids.
2. Chordoma, a rare bone tumor originating from embryonic remnants. It most commonly affects the sacrum and skull base. Imaging shows a destructive lytic bone lesion and soft tissue mass. It is locally aggressive but slow growing. Treatment involves surgery and radiation therapy.
An aneurysmal bone cyst is a benign, expansile bone lesion characterized by blood-filled cavities separated by bone or fibrous tissue with osteoclast giant cells. Most patients are under 20 years old, with common locations in the long bones of the lower extremities. The etiology is unknown but may involve genetic translocations. Imaging shows an expansile, osteolytic lesion with possible fluid-fluid levels. Treatment involves preoperative embolization, curettage with bone grafting, or complete resection to prevent the 20-30% recurrence rate associated with partial resection.
An aneurysmal bone cyst is a benign, expansile bone lesion characterized by blood-filled cavities separated by bone or fibrous tissue with osteoclast giant cells. Most patients are under 20 years old, with common locations in the long bones of the lower extremities. The etiology is unknown but may involve genetic translocations. Imaging shows an expansile, osteolytic lesion with possible fluid-fluid levels. Treatment involves preoperative embolization, curettage with bone grafting, or complete resection to prevent the 20-30% recurrence rate associated with partial resection.
Congenital neck mass radiology pk final is very good power point presentation for radiologist, radiology resident, student and even ent surgeon or resident doctor.. Every disease of neck lesion is properly describe with multi usg, ct and MRI images. this will help a lot. thanks.
MRI is an accurate method for evaluating brachial plexus injuries and other pathologies. It can identify lesions in the supraclavicular, retroclavicular, and infraclavicular regions. Common non-traumatic causes seen on MRI include inflammatory plexitis, nerve sheath tumors, Pancoast tumors, and metastases. Traumatic injuries are classified as preganglionic or postganglionic. Preganglionic injuries often involve nerve root avulsions while postganglionic injuries stretch or rupture nerve roots, cords, and trunks. MR neurography and diffusion-weighted imaging provide improved visualization of the brachial plexus.
This document provides a summary of imaging features of lesions in the anterior skull base region, including sinonasal neoplasms such as squamous cell carcinoma, adenocarcinoma, esthesioneuroblastoma, malignant melanoma, and lymphoma. Key imaging findings discussed include tumor appearance on CT and MRI, characteristics of bone and soft tissue involvement, and distinguishing features between lesion types. Imaging plays an important role in diagnosis and surgical planning for anterior skull base pathology.
Lytic lesions of the skull can have many potential etiologies ranging from normal variants to neoplastic lesions. Imaging plays an important role in the evaluation and diagnosis of lytic skull lesions. CT and MRI are often used to characterize the lesions and assess bone and soft tissue involvement. The differential diagnosis depends on factors like the patient's age, lesion characteristics such as appearance, location and whether it is solitary or multiple. Common etiologies include metastases, multiple myeloma, epidermoid cysts, hemangioma and fibrous dysplasia among others. A thorough clinical history and imaging findings are needed to establish the correct diagnosis.
1. The document discusses various head and neck masses and their imaging appearance on CT and MRI.
2. Key neck masses discussed include lymph nodes, tonsillar abscesses, benign mixed tumors, minor salivary gland malignancies, and squamous cell carcinoma of the nasopharynx and oropharynx.
3. Important imaging findings for differentiating benign from malignant lesions are described.
CT and MR imaging are useful for evaluating the spleen. CT typically shows splenic tissue with homogeneous attenuation of 40-60 HU. The spleen normally enhances heterogeneously after intravenous contrast. MR also evaluates the spleen using T1- and T2-weighted sequences. Infectious processes like abscesses, tuberculosis, and Pneumocystis carinii can involve the spleen. Abscesses may contain fluid, gas, or septations. Tuberculosis can cause irregular low attenuation areas or infarcts. Pneumocystis carinii causes focal low attenuation lesions and calcifications. Other conditions like cysts, inflammatory pseudotumors, and fluid collections associated with pancreatitis can also occur in the spleen
This document discusses aneurysmal bone cyst (ABC), beginning with its definition as a benign, expansile bone lesion containing blood-filled cystic cavities. It describes ABC's unknown etiology, most common locations in long bones of younger patients, and presentations of pain, swelling or fracture. Imaging findings include expansile lytic lesions on x-ray, and fluid-fluid levels on MRI. Treatment involves preoperative embolization and curettage with bone grafting. ABC's differential diagnosis and potential for recurrence after treatment are also summarized.
The document discusses various types of orbital tumours and pathologies. It describes three main intraorbital spaces - intraconal, conal and extraconal - and examples of pathologies that can occur in each space. It provides details on orbital lymphoma, rhabdomyosarcoma, orbital metastasis and dermoid cysts. For each condition, it outlines clinical features, location in the orbit, radiological features on CT and MRI such as signal characteristics, enhancement patterns and appearance. Common primary cancers that metastasize to the orbit are also listed.
Tips, Pearls and Pitfalls of Spinal Cord MRIWafik Bahnasy
- Many neurological disorders simultaneously or consecutively affect the brain and spinal cord, however most neurologist find their comfort zone in attending the diagnosis via the brain access.
- This concept resulted in lagging of spinal cord imaging researches compared to brain ones and consecutive underestimation of the opportunity of an important tool sometimes essential to reach a definite diagnosis.
MRI of Spine and very easy details of spssuserc66686
The document discusses various neurological conditions that can be seen on CT and MRI imaging of the brain and spine. It provides examples of imaging findings for tumors such as meningiomas, medulloblastomas, ependymomas, glioblastomas, and metastases. It also reviews imaging appearances of conditions like cerebral abscesses, multiple sclerosis, cavernomas, spinal tuberculosis, and spondylitis. Key distinguishing radiological features of different lesions are highlighted.
Benign bone tumors can be classified based on their location, rate of growth, perioseal reaction, and matrix mineralization. Common cartilage tumors include osteochondroma, enchondroma, chondroblastoma, chondromyxoid fibroma, and fibrocartilaginous mesenchymoma. Osteochondroma is characterized by a cartilage-capped bony projection and most commonly affects the distal femur, proximal humerus, proximal tibia and proximal femur. Enchondroma forms mature hyaline cartilage and typically affects the small tubular bones of the hands and feet. Chondroblastoma presents before skeletal maturity with a sclerotic border and scattered calcifications. Treatment
This document discusses imaging modalities used for head and neck cancers including radiography, ultrasound, CT, MRI, nuclear scans and PET CT/PET MR. It describes the anatomy visualized by each modality and indications for their use. Key points covered include ultrasound criteria for evaluating lymph nodes, advantages and disadvantages of CT and MRI, and basics of interpreting various tissue types on imaging studies. The neck is divided into spaces and triangles and relevant anatomy of each area is outlined.
Presentation1, radiological imaging of trigeminal schwanoma.Abdellah Nazeer
The document discusses trigeminal schwannomas, which are slow-growing tumors composed of schwann cells that occur along the trigeminal nerve. It provides details on the epidemiology, clinical presentation, and radiographic features of trigeminal schwannomas. Specifically, it notes that trigeminal schwannomas most commonly present in the third to fourth decades of life and typically manifest as trigeminal nerve dysfunction. Radiographically, they often have a dumbbell appearance on MRI when extending between compartments, and demonstrate enhancement following contrast administration. The document includes several images showing examples of trigeminal schwannomas along different segments of the nerve.
This presenation includes anatomy and pathology of intraconal conal and extraconal orbital pathology. this presenation dealsimaging feature of different pathology. Thanks.
This document discusses various cystic neck masses that can be seen on imaging. It describes the imaging appearance and characteristics of common cystic lesions such as thyroglossal duct cysts, branchial cleft cysts, lymphangiomas, dermoid/epidermoid cysts, thymic cysts, laryngoceles, ranulas, cystic metastatic lymph nodes, and neurogenic tumors. It provides details on the ultrasound, CT, and MRI features that can help differentiate these lesions. Rare vascular causes of cystic neck masses like arteriovenous malformations are also mentioned.
Semelhante a pre sacral lesion sept5.pptx RADIOLOGY (20)
The vertebral column consists of 33 vertebrae separated by intervertebral discs. A typical vertebra has a vertebral body and arch enclosing the vertebral foramen through which the spinal cord passes. The spinal cord has 31 pairs of spinal nerves and is composed of gray and white matter. It transmits sensory information up the posterior columns and motor commands down tracts like the corticospinal tract. Injuries can cause syndromes like complete transection with bilateral deficits or Brown-Sequard with unilateral deficits depending on the location and extent of damage.
The document describes the various cerebrospinal fluid (CSF) filled spaces, or cisterns, within the subarachnoid space. It details both supra-tentorial and infra-tentorial cisterns, providing their locations, contents such as vessels and cranial nerves, and anatomical relationships. Key cisterns mentioned include the cistern of the lamina terminalis, chiasmatic cistern, interpeduncular cistern, prepontine cistern, cisterna magna, and cerebellopontine angle cistern. The cisterns form a interconnected network facilitating CSF circulation within the subarachnoid space.
This document provides an overview of the gross anatomy of the brain as seen on MR imaging. It describes the central sulcus, ventricular system, limbic system, and white matter. It then details the axial, sagittal, and coronal views of the brain and lists over 100 structures and their 3D localization within the brain.
The document discusses various congenital anomalies of the pancreas including annular pancreas, pancreas divisum, ectopic pancreatic tissue, horseshoe pancreas, and variations in pancreatic ductal anatomy. It describes the embryological development of the pancreas and defines important anatomical structures such as the pancreatic ducts. Imaging features of different pancreatic anomalies on modalities like CT, MRI, ERCP, and ultrasound are provided.
CT guided FNAC is a simple and minimally invasive technique for obtaining tissue samples from complex lung lesions for diagnosis. A study of 28 patients found CT guided FNAC to have a sensitivity of 80% and specificity of 100% for diagnosing malignancy. Complications occurred in 3 patients (12.5%) and were minor and self-resolving. CT guided FNAC is shown to be an effective and safe outpatient procedure for evaluating pulmonary nodules and masses.
CT guided FNAC is a simple and effective technique for diagnosing complex pulmonary lesions. In a study of 28 patients, CT guided FNAC had a sensitivity of 80% and specificity of 100% for diagnosing malignancy. CT scanning alone had sensitivity of 75% and specificity of 83.3% for malignancy. Complications occurred in 3 patients (12.5%) and were minor and resolved with conservative treatment. The study concluded that CT guided FNAC is a highly sensitive and specific technique for characterizing pulmonary lesions.
Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by non-caseating granulomas. It most commonly affects the lungs, presenting radiographically as bilateral hilar lymphadenopathy in 50% of cases and pulmonary nodules in 30-50% of cases. Other involved organs include the eyes, skin, and heart. On CT, it demonstrates enlarged lymph nodes and pulmonary nodules distributed along the bronchovascular bundles. Late stage disease can develop pulmonary fibrosis. Sarcoidosis can also involve bones, presenting as cystic lesions in the hands. Neurosarcoidosis manifests as leptomeningeal enhancement or intracranial masses.
The document describes various signs seen on imaging of the respiratory system. It defines signs such as the signet ring sign seen on CT scans of the lungs, the finger-in-glove appearance seen in allergic broncho-pulmonary aspergillosis, and the continuous diaphragm sign seen in pneumomediastinum where air outlines the entire diaphragm. It also provides details on other signs like the halo sign associated with hemorrhagic nodules, the reversed halo sign, and tree-in-bud appearance seen in conditions like tuberculosis.
1. The document defines and describes solitary pulmonary nodules, providing details on measurements, characteristics, and imaging features that help determine if a nodule is benign or malignant.
2. Malignant nodules are more likely to be larger in size, irregular or spiculated in shape, located in the upper lobes, and demonstrate rapid growth. Benign nodules often have fat, calcification, or show long-term stability.
3. Guidelines are provided for follow-up of solid versus subsolid nodules based on size, with smaller or stable nodules requiring less frequent follow-up, and suspicious nodules warranting further evaluation including PET scans or biopsy.
Esophageal webs are thin mucosal membranes that project into the esophageal lumen, causing constriction. They more commonly occur in the cervical esophagus near the cricopharyngeus muscle. Associations include Plummer-Vinson syndrome, graft-versus-host disease, and gastroesophageal reflux disease. On barium swallows, esophageal webs appear as smooth tapered concentric narrowing in the cervical esophagus.
The parathyroid glands are located posterior to the thyroid gland in the neck. Parathyroid adenomas, the most common cause of primary hyperparathyroidism, enhance vividly on arterial phase CT then wash out rapidly on delayed phase with low attenuation on non-contrast images. Localizing the adenoma precisely with 4D CT guides focused surgical treatment through a small incision. The characteristic enhancement pattern and morphology help identify ectopic adenomas located during fetal development in the mediastinum.
This document provides an overview of brain anatomy including:
1. It describes the MRI appearance of different brain tissues and structures including white matter, fat, CSF, and gray matter on different sequences.
2. It then covers the sulcal and gyral anatomy of the brain, describing the lobes, major sulci like the central sulcus and sylvian fissure, and how they can be identified.
3. The anatomy of each lobe is then covered in more detail including the surfaces and sulci that make up the frontal, parietal, occipital, and temporal lobes.
Osteomyelitis is an infection of bone that is usually caused by bacteria entering through the bloodstream or direct inoculation via injury. It can be acute, subacute, or chronic. Common symptoms include fever, pain, and swelling near the infected bone. Diagnosis involves blood tests, imaging like x-rays, MRI, and bone scans, and bone/blood cultures. Treatment consists of antibiotics tailored to the identified bacteria as well as possible surgical drainage of abscesses.
This document discusses primary retroperitoneal neoplasms, which arise outside of major retroperitoneal organs. It notes that 70-80% of retroperitoneal masses are malignant in nature. The document then categorizes and describes several specific types of solid neoplastic masses that can occur in the retroperitoneum, including mesodermal neoplasms (such as liposarcomas and leiomyosarcomas), neurogenic tumors, and others. For each type of mass, it provides details on prevalence, appearance on CT and MRI scans, characteristics, associated syndromes, and other relevant clinical information.
1. The goals of first trimester ultrasound include visualization of the gestational sac, identification of embryonic demise, determination of gestational age, and early diagnosis of fetal anomalies.
2. A normal intrauterine gestation will demonstrate a gestational sac, yolk sac, embryo, amnion, and cardiac activity on ultrasound. Measurement of the mean sac diameter, crown-rump length, and biometric measurements can be used to estimate gestational age.
3. Absence of cardiac activity along with signs of bleeding have a high probability of embryonic demise. Criteria such as large sac size without visualizing fetal structures indicate a poor pregnancy outcome.
This document discusses Legg-Calve-Perthes disease, which is avascular necrosis of the femoral head that occurs in children. It begins by describing the etiology as an ischemic episode affecting the capital femoral epiphysis, though the exact cause is unknown. The stages of the disease are then outlined based on radiographic appearance, from initial avascular necrosis to revascularization and bone remodeling. Complications including deformities of the femoral head and neck are also summarized. The document provides detailed information on the radiographic signs and classifications systems used to evaluate the progression and prognosis of Legg-Calve-Perthes disease.
X-ray grids are devices used to remove scattered radiation from radiographic images. They consist of alternating strips of lead and transparent material. Grids work by absorbing most of the multidirectional scattered radiation while allowing the directional primary radiation to pass through. Grid performance is evaluated based on primary transmission, Bucky factor, and contrast improvement factor. Proper grid selection and positioning are important to avoid grid cutoff and increased patient radiation dose. Moving grids eliminate grid line artifacts but have some disadvantages.
This document discusses fluoroscopy, including conventional fluoroscopy units and modern fluoroscopic units. It describes the key components of a fluoroscopic unit, including the image intensifier, vidicon camera, and TV monitor. It also discusses factors that influence fluoroscopic image quality such as radiation dose rates, image resolution both vertically and horizontally, and techniques to reduce image noise like frame averaging.
A fluoroscope uses x-rays and a fluorescent screen to enable direct observation of internal organs. It consists of an x-ray tube, table, and image intensifier. The image intensifier converts x-rays into visible light images and amplifies them for viewing. It works by accelerating photoelectrons emitted from a photocathode onto a phosphor screen, producing light photons and gaining brightness. Newer generations of image intensifiers use additional electron multiplication for higher sensitivity. Fluoroscopy provides real-time moving images for procedures while fluorography captures still diagnostic images.
Diffusion MRI measures the random thermal motion of water molecules in tissues. It provides unique contrast based on differences in water diffusion between normal and abnormal tissues. Diffusion is restricted in cellular tissues and areas of restricted diffusion appear bright on diffusion-weighted images and dark on apparent diffusion coefficient maps. Diffusion MRI is useful for early detection of cerebral ischemia, differentiating between cystic and solid lesions, and evaluating white matter abnormalities and tumors. It has numerous clinical applications including stroke evaluation and characterization of brain lesions.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills MN
By harnessing the power of High Flux Vacuum Membrane Distillation, Travis Hills from MN envisions a future where clean and safe drinking water is accessible to all, regardless of geographical location or economic status.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
2. • The presacral space is an extraperitoneal potential space
between the upper two-thirds of the rectum and the sacrum.
• Anteriorly - rectum and mesorectal fascia,
Superiorly -peritoneal reflection of the rectosigmoid colon,
Inferiorly -rectosacral/Waldeyer's fascia, levator ani
Posteriorly -presacral fascia, sacrum, and coccyx
Laterally - iliac vessels and ureters.
CONTENTS – Osteochondral tissue from the sacrum and
coccyx,
Neural tissue from the cauda equina and branches of the
sacral plexus, and
Mesenchymal tissue from adjacentorgans, as well as
surrounding Connective tissue , Blood and Lymphatic
vessels.
5. GIANT CELL TUMOR
• most common sacral tumors after chordoma
• 2nd–4th decades, F>M
• locally aggressive, lytic, destructive, expansile lesion, often in an eccentric
location
• commonly involve both sides of the midline and may extend across the
sacroiliac joints
6. CT - osteolytic or radiolucent lesion , soft-tissue mass within the bone; usually no
surrounding sclerosis (80-85%) , the mass may have a thin sclerotic rim
MR –
• T1
○ low to intermediate signal (solid component)
○ low signal rim
• T2: heterogeneous high signal with areas of low signal intensity due to hemosiderin
or fibrosis
• T1 C+ (Gd): solid components will enhance
7. Giant cell tumor. (a) Lateral radiograph shows a lytic lesion involving S1 and S2. (b) Sagittal T2-weighted MR image
shows that the lesion has heterogeneous signal intensity. (c) Axial contrast-enhanced T1-weighted MR image shows
that the lesion demonstrates intense enhancement. (d) Axial CT image obtained with bone window settings clearly
shows lytic bone destruction.
8. EWING SARCOMA
• Three to ten percent of all primary Ewing sarcomas occur in the spine, but metastatic involvement
is more common
• Ages Group - 5 and 30
9. • Aggressive, demonstrating permeative bone lysis, osseous expansion, or sclerosis
• lamellated (onion skin) periosteal reaction
• Associated soft-tissue masses are common
• MRI - T1: low to intermediate signal
T1 C+ (Gd): heterogeneous but prominent enhancement
T2: heterogeneously high signal, may see hair on end low signal striations
IMAGING
10. T2-weighted images (Fig 3).
• Radiation and chemotherapy are the standard treatments for patients
Ewing sarcoma in two patients. (a, b) Coronal contrast-enhanced T1- weighted (a) and sagittal T2-
weighted (b) MR images show a large heterogeneous presacral mass with intermediate to high signal
intensity at T2-weighted imaging and heterogeneous enhancement
12. Plain radiograph –
o lytic (50%)
o intralesional calcifications: ~70% (rings and arcs calcification or popcorn
calcification), characteristic chondroid matrix
o endosteal scalloping: affecting more than two-thirds of the cortical thickness
o moth-eaten appearance or permeative appearance in higher grade tumors
CT –
o attenuation of the non-mineralized portion is often lower than that of muscle due to the
relatively high water content of hyaline cartilage
IMAGING
13. MRI –
o T1: low to intermediate signal.
o T2: very high intensity in non-mineralized/calcified portions - the cartilage is a
hydrophilic tissue with high water content
o gradient echo/SWI: blooming of mineralized/calcified portions.
o T1 C+ (Gd) :
■ enhancement can be septal and peripheral rim-like corresponding to fibrovascular
septation between lobules of hyaline cartilage - rings and arcs enhancement
pattern
■ most demonstrate heterogeneous moderate to intense contrast enhancement.
14. Chondrosarcoma in a patient with multiple hereditary exostoses. (a) Axial radiograph of the pelvis
shows multiple osteochondromas (arrowheads). An area of increased opacity is also seen in the lower
sacrum, with areas of faint calcification. (b, c) Coronal T2- weighted (b) and sagittal contrast-
enhanced T1-weighted (c) MR images show a large presacral mass with increased signal intensity at
T2-weighted imaging and intense contrast enhancement.
16. NEUROFIBROMAS
• benign neural tumors
• Neurofibromas most often occur in isolation, although multiple tumors may occur in
patients with neurofibromatosis type 1 (NF1)
17. Imaging
CT –
o well-defined hypodense mass low attenuation lower than that in adjacent soft tissues
o minimal or no contrast enhancement
o may resemble lymphadenopathy
MRI –
o T1: hypointense
o T2 : hyperintense
■ target sign
● a hyperintense rim (myxoid material ) and central area of a low signal (dense
central area of collagenous stroma ) may be seen
● although this sign is highly suggestive of neurofibroma, it is occasionally also
seen in schwannomas and malignant peripheral nerve sheath tumors
■ fascicular sign
o T1 C+ (Gd): heterogeneous enhancement
18. Plexiform neurofibroma in two patients. (a) Axial CT image shows an area of low attenuation in the sacral
plexus, a characteristic finding of plexiform neurofibroma. (b) Sagittal T2-weighted MR image obtained in
another patient shows the target sign (arrows) in the sacral plexus, a finding characterized by an area of
high signal intensity with a central area of low signal intensity that is suggestive of plexiform neurofibroma
19. SCHWANNOMAS
• benign nerve sheath tumors
• peak incidence in the 5th to 6th decades
• When they occur in patients with neurofibromatosis type 2 (NF2), schwannomas
usually present by the 3rd decade
• Multiple schwannomas are characteristic of neurofibromatosis type 2
• large mass, and they may remodel or erode through the sacral bone
20. • well-circumscribed masses which displace adjacent structures without direct invasion
• cystic and fatty degeneration is common
• calcification is rare
CT –
o heterogeneous presacral soft-tissue mass, with or without calcifications.
o intense contrast enhancement
o adjacent bone remodeling with smooth corticated edges
MR –
o T1: isointense or hypointense
o T1 C+ (Gd): intense enhancement
o T2: heterogeneously hyperintense, cystic degenerative areas may be present, especially in larger
tumors
o T2*: larger tumors often have areas of hemosiderin
Imaging
21. Schwannoma in two patients. (a) Axial T2-weighted MR image shows a high-signal-intensity presacral mass
with scattered cystic areas. (b) Sagittal contrast-enhanced T1-weighted MR image shows that the mass
demonstrates heterogeneous enhancement. (c) Axial contrast-enhanced CT image in another patient shows a
heterogeneously enhancing presacral mass.
22. PERINEURAL CYSTS
• CSF-filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root
sheath)
• most commonly occur at the level of the second and third sacral nerve roots
• cyst wall is continuous with the arachnoid and dura, and the cyst cavity occupies the space
between the perineurium and endoneurium
• may be congenital or traumatic
• Stenosis of the ostium of the nerve root sheath allows cerebrospinal fluid (CSF) to flow in with
arterial pulsation and restricts outflow
23. CT –
o cystic mass that is isoattenuating relative to CSF at the neural foramina
o Bone remodeling and enlargement of the neural foramina may be seen, a result of
increased CSF pressure
o Because communicate with CSF, perineural cysts fill with contrast material at CT
myelography
MRI –
o T1: low signal
o T2:
■ high signal
■ will show chemical shift at fat-fluid boundary with epidural fat
o T1 C+: no enhancement
o DWI/ADC: facilitated diffusion ~3000 x 10-6 mm2/s
Imaging
24. A peri-neural cyst at the level of S2 segment lateralizing to right with smooth
scalloping of the related bony skeleton and mild effacement of the related right
sided sacral nerve roots
25. DURAL ECTASIA
• ballooning or widening of the dural sac which can result in posterior vertebral scalloping and is
associated with herniation of nerve root sleeves.
• defective microfibrils weaken the dural sac, usually in the lumbosacral spine, where CSF
pressure is greatest, which leads to incompetence
• Dural ectasia is present in 56%–65% of patients with Marfan syndrome
26. • widening of the interpediculate distance and posterior vertebral body scalloping
• Widening of the dural sac, dilatation of the nerve root sleeves, and scalloping of the posterior
vertebral bodies may be seen in the lumbosacral spine
Dural ectasia in a patient with Marfan syndrome. Axial contrast-enhanced CT images obtained with
bone (a) and soft-tissue (b) window settings show dural ectasia with bone remodeling in the sacral
foramina.
27. ANTERIOR MYELOMENINGOCELES
• Anterior myelomeningoceles occur when the dural sac herniates through a defect in the anterior
surface of the sacrum
• Dural sac is composed of both the outer dura and the inner arachnoid membranes, and it
contains CSF and, occasionally, neural elements
• manifest in the 1st decade of life
• Currarino triad, which comprises an anorectal malformation, a sacrococcygeal osseous defect,
and a presacral mass. The associated presacral mass may be a teratoma, anterior sacral
meningocele, dermoid cyst, hamartoma, or enteric duplication cyst and is autosomal dominant
in more than 50% of patients.
• classic clinical presentation of headache during valsalva owing to increased cerebrospinal fluid
(CSF) pressure transmitted via the connection between the meningocele and subdural space
28. Imaging
pelvic radiographs - unilateral anterior sacral defect may be seen with a rounded, concave border
with scalloping/destruction of the surrounding bone, often referred to as the “scimitar sign”
CT - Osseous defects, such as vertebral body scalloping, hypoplasia, and aplasia, may accompany
an anterior sacral meningocele and are best assessed at CT
MRI - the signal intensity of the content within the meningocele should parallel the CSF signal on
all sequences
• Biopsy and aspiration should not be performed, given the risk of introduction of pathogens
directly into the spinal meninges, which can result in meningitis.
29. Well defined, rounded defect in the lower
sacrum with a huge fluid collection in the
pelvis communicating with the spinal thecal
sac - typical of a sacral meningocoele.
MRI confirms the CT findings indicating that the
huge fluid collection in the pelvis is connected to the
thecal sac and is not the bladder or other pathological
cyst.
30. A 17-year-old-male with anterior
sacral meningocele.
Sagittal T2 weighted image showing
a sacral defect (black arrow) and a
small anterior cystic mass with
demonstrable direct communication
with the dural sac (white arrow).
31. PARAGANGLIOMAS
• neuroendocrine neoplasms that arise from the paraganglia, accessory organs of the
peripheral nervous system
• Typically, spinal paragangliomas are intradural, extramedullary lesions located in the
region of the cauda equina and filum terminale
• more common in men,
32. • Paragangliomas are highly vascular tumors that demonstrate an intense, early blush at
angiography that persists into the late arterial and early venous phases
• well-circumscribed mass that is isointense on T1-weighted MR images and iso- to hyperintense
on T2-weighted
• Hemorrhage is common, and a low-signal-intensity rim (the cap sign) may be seen. Intense
enhancement is seen on contrast-enhanced images, and flow voids are common
33. Paraganglioma in a pregnant woman. Axial (a) and sagittal (b) T2-weighted MR images
show a large presacral mass that is iso- to hyperintense with a hypointense rim, a finding
known as the cap sign.
34. CHORDOMAS
• most common primary sacral tumor
• from notochordal rests and are limited to the clivus, spine, and sacrum on the basis of their cell
of origin
• typically located in the midline or paramedian region
• most common in the 4th–7th decades of life
35. • Chordomas are destructive lytic lesions that may extend across the sacroiliac joints
• Calcification is common in sacrococcygeal lesions
• large presacral soft-tissue component is present, with soft tissues extending into the sacral canal.
CT
o centrally located
o well-circumscribed
o destructive lytic lesion, sometimes with marginal sclerosis
o expansile soft-tissue mass soft-tissue mass is often disproportionately large relative to the
bony destruction
o irregular intratumoral calcifications (thought to represent sequestra of normal bone rather
than dystrophic calcifications)
o moderate enhancement
low to intermediate signal intensity on T1-weighted MR images and high signal intensity on T2-
weighted variable, often only moderate, contrast enhancement
36. Chordoma. (a) Axial contrastenhanced CT image shows a homogeneous mass anterior to the distal
sacrum and coccyx. (b) Sagittal T2-weighted MR image shows the hyperintense mass. (c) Axial
contrast-enhanced T1-weighted MR image shows that the mass demonstrates only mild enhancement.
38. HEMANGIOMAS
• most common soft-tissue abnormality
• most common tumors in infants and usually appear within the 1st week of life
• three times more common in girls
39. Imaging
• intermediate signal intensity on T1-weighted MR images and high signal intensity and flow
voids on T2-weighted images
• On T2-weighted images, clusters of high-signal-intensity lobules indicate cystic vascular spaces
that contain stagnant blood.
• Areas of increased signal intensity on T1- and T2- weighted images correlate with haemorrhage
and areas of fat deposition.
• Phleboliths are common and appear as low-signal-intensity foci on both T1- and T2-weighted
images.
40. Perirectal hemangioma in two patients. (a) Sagittal short inversion time inversion-recovery MR image
shows a perirectal mass with heterogeneous high signal intensity. (b) Axial contrast-enhanced T1-weighted
MR image shows that the mass demonstrates heterogeneous enhancement. (c) Axial contrast enhanced CT
image obtained in another patient shows phleboliths, a typical finding of perirectal hemangioma.
42. • CT - they typically appear as a hypovascular mass that contains macroscopic fat with areas of
soft-tissue attenuation interspersed
• T1-weighted MR imaging, the fatty areas have high signal intensity that drops out when fat is
suppressed.
Imaging
43. Myelolipoma.
(a) Axial contrast-enhanced CT
image shows a well-circumscribed
presacral mass with macroscopic
fat.
(b, c) Axial (b) and sagittal
(c) T1-weighted MR images show that
the areas of fat demonstrate increased
signal intensity.
(d) Sagittal T1-weighted fat-
suppressed MR image shows dropout
of signal intensity in the areas of fat.
44. SOLITARY FIBROUS TUMORS
• slow-growing mass in middle-aged adults
• Solitary fibrous tumors are mesenchymal tumors of fibroblastic or myofibroblastic origin
45. Imaging
CT - well-circumscribed mass with soft-tissue attenuation that typically demonstrates intense
contrast enhancement
Areas of hemorrhage, necrosis, and cystic change may be seen.
MRI - low to intermediate signal intensity on T1- and T2- weighted MR images a result of
fibrous tissue, but areas of myxoid or cystic degeneration may demonstrate high signal intensity
on T2-weighted images.
Hypervascularity with prominent enhancement and flow voids is common.
46. Solitary fibrous tumor.
(a) Axial contrast-enhanced CT image shows a homogeneous mass that is
isoattenuating relative to muscle.
(b) Sagittal T1-weighted MR image shows flow voids (arrows) in the low-signal-
intensity mass.
(c) (c, d) Axial
(c) and coronal
(d) contrast-enhanced T1-weighted MR images show that the mass demonstrates
intense enhancement. (e) Angiogram shows the tumor, which demonstrates
increased vascularity
47. LYMPHOMAS
• CT - lymphomas have soft-tissue attenuation with homogeneous enhancement
• MR imaging, they are characterized by an area of low signal intensity on T1-weighted images
and an area of high signal intensity on T2-weighted images
48. Non-Hodgkin–type B-cell lymphoma. (a) Axial contrast-enhanced CT image shows an abnormal area of
homogeneous enhancement in the rectal and perirectal soft tissues. (b) Positron emission tomographic
(PET)/CT image shows an area of intense uptake that corresponds to the abnormal rectal and perirectal
soft tissues seen at CT
49. GASTROINTESTINAL STROMAL TUMORS
• most commonly occur in older patients and have a slight male predominance
• Gastrointestinal stromal tumors usually involve the outer muscular layer and tend to be
exophytic. When located in the anorectal region, they tend to expand to the rectal wall, resulting
in a focal well-circumscribed mural mass
50. Imaging
• CT - soft-tissue attenuation with a central area of low attenuation resulting from hemorrhage,
necrosis, or cyst formation.
• Peripheral enhancement is common
• MRI - uniform intermediate signal intensity is seen on T1-weighted MR images and an area of
heterogeneous high signal intensity is seen on T2-weighted images, with heterogeneous
enhancement. Extension into the ischiorectal fossa, prostate, or vagina may be present.
51. Gastrointestinal stromal tumor in two patients. (a) Axial contrast-enhanced T1-weighted MR image shows a
perirectal presacral mass that demonstrates intense enhancement. (b) Sagittal T2-weighted MR image in
another patient shows a larger mass with heterogeneous signal intensity.
53. DEVELOPMENTAL CYSTS
• Developmental cysts are the most common congenital condition in the presacral space and
include epidermoid, dermoid, enteric, tailgut (also known as retrorectal cystic hamartoma), and
duplication cysts
• female predilection
• 13% of these cysts may undergo malignant transformation, and for this reason, they are
removed
• its typically manifest during childhood, and they are relatively rare in adults.
• Tailgut cysts are the most common asymptomatic presacral lesions that are incidentally found in
adults
54. • Tailgut cysts are often multiloculated cysts containing mucin and lack a muscular layer, a
differentiating feature from rectal duplication cysts, which can be confirmed on endorectal
ultrasound
• Rectal duplication cysts may be associated with other congenital abnormalities of the anorectal
region and bladder/urethra.
• Sacrococcygeal teratoma is the most common presacral mass in children containing all three
germ-cell lineages.
• Benign mature teratomas tend to be predominantly cystic containing fat, sebum, calcification and
soft tissue from dermoid plugs.
55. • Thin-walled and may be uni- or multilocular.
USG - Internal echoes related to mucoid material or inflammatory debris may be seen.
CT –
o low attenuation , with no associated enhancement, and associated thin calcifications are
rare
o If secondarily infected - thick-walled with surrounding inflammatory change, and they
may contain air if a fistula is present.
MRI –
• hypointense on T1 (although they may be hyperintense if they contain mucoid material),
hyperintense on T2.
• Focal irregular wall thickening with enhancement is suggestive of malignant degeneration
Imaging
56. Rectal duplication cyst. (a) Sagittal T2-weighted MR image shows a large hyperintense presacral cystic
mass. (b) Coronal contrast-enhanced T1-weighted MR image shows a thin area of peripheral
enhancement around the mass.
57. ON IMAGING - CONGENITAL DEVELOPMENTAL CYSTS,
● well defined, unilocular or multilocular, cystic masses ranging from simple to complex in their internal
contents
A 45-year-old-female with tailgut cyst. (a) Axial T2 weighted, (b) fat-saturated pre-contrast and (c) fat-saturated post-contrast
subtraction T1 weighted images (T1WI) through the pelvis showing a presacral multiloculated cystic mass posterior to the
rectum without post-contrast enhancement (arrows in a, c). High signal intensity on pre-contrast T1WI (arrow in b),
suggesting haemorrhage or proteinaceous debris. Surgical resection confirmed tailgut cyst.
58. GERM CELL TUMORS
• occur secondary to disorganization of totipotent primitive neural cells during embryogenesis
• degree of differentiation determines the tumor type, with teratomas, yolk sac tumors, and
embryonal cell carcinomas demonstrating lower degrees of differentiation
• Sacrococcygeal teratoma is the most common presacral germ cell tumor in children and the
most common solid tumor in neonates
59. • Benign teratomas contain only mature tissues, including fluid, fat, calcification, and a small
amount of soft tissue. Benign teratomas are predominantly cystic, with fluid attenuation at CT.
Areas of bone, fat, and calcification may be seen.
• T1-weighted MR imaging, areas that contain fat have high signal intensity, and those that
contain bone and calcifications demonstrate signal void
60. Sacrococcygeal teratoma in two patients. (a) Image from a barium enema study shows widening of the
presacral space. (b, c) Axial (b) and sagittal (c) contrast-enhanced CT images in another patient show a large
multiloculated solid and cystic mass that extends into the sacral canal and foramina. Associated bone
remodeling and destruction are seen
61. • Yolk sac tumors have a more aggressive imaging appearance than teratomas and are
characterized by more heterogeneous soft tissues and areas of hemorrhage and necrosis
• CT, areas of low attenuation with no enhancement are seen, and at T1-weightd MR imaging,
areas of hyperintensity are seen, a finding related to hemorrhage.
• Yolk sac tumors demonstrate heterogeneous contrast enhancement and often invade adjacent
organs.
62. Yolk sac tumor. Axial (a) and sagittal (b) contrast-enhanced CT images show a heterogeneously enhancing
presacral mass that extends into the sacral canal.