Neuroradiology Flashcards
Which of the following branches of the internal carotid artery is directly related to the aneurysm shown?
A. Anterior choroidal artery
B. Posterior communicating artery
C. Anterior cerebral artery
D. Meningohypophyseal Trunk
E. Middle cerebral artery
Posterior communicating artery
The cerebral angiogram image shows a lateral projection of an internal carotid artery injection. The black arrow indicates the aneurysm. Distal flow can be seen into the posterior communicating artery. The anterior choroidal artery branches off the internal carotid artery distally to the posterior communicating branch point. Variants can occur in which the posterior communicating and anterior choroidal arteries either appear fused or emanate from a single trunk. The meningohypophyseal trunk arises from the cavernous segment of the internal carotid artery. The middle and anterior cerebral arteries are both distal to the location of the aneurysm.
Which of the following is the most likely diagnosis for the patient with the findings in the angiograms shown?
A. Spinal arteriovenous malformation
B. Spinal cavernous malformation
C. Spinal arteriovenous fistulas
D. Spinal hemangioblastoma
E. Spinal aneurysm
Spinal arteriovenous malformation
Spinal arteriovenous malformations (AVMs) are characterized by arteriovenous shunting with a true nidus. They account for 25% of spinal vascular lesions. A spinal hemangioblastoma has a densely enhancing nidus with associated dilated arteries and prominent draining veins are characteristic of a hemangioblastomas. Spinal cavernous malformations are occult on angiogram. Spinal arteriovenous fistulas (spinal AVFs) are characterized by abnormal communication and shunting of blood from an artery to a vein of the spine that bypasses the capillary bed. Unlike brain aneurysms, spinal aneurysms tend to be very small and are almost never recognized on an MRI.
A spinal angiogram is usually necessary for diagnosis. The vast majority are fusiform, likely dissecting, aneurysms of the proximal intradural portion of the radiculomedullary or radiculopial artery. The former is an artery which supplies the anterior spinal arterial system, the latter supplies posterior spinal system.
The angiogram shown was obtained during evaluation of a 35-year-old man with headaches. The best management for this lesion is:
A. Coil Embolization
B. Radiosurgery
C. Particle Embolization
D. Observation
E. Open surgical excision
Observation
The cerebral angiogram shows a developmental venous anomaly, or a venous angioma. These may occur alone or in association with other vascular malformations such as cavernous malformations. Venous angiomas are typically incidental findings and are usually asymptomatic. The natural history of these lesions is also generally benign, and associated bleeding risk is typically attributed to associated co-occurring vascular malformations. As a result, most practitioners advocate for conservative management. When encountered intraoperatively, venous angiomas should be spared, as occlusion or thrombosis can result in ischemic complications.
Open surgical excision, embolization, and radiosurgery are all typically not used to treat developmental venous anomalies. However, if the developmental venous anomaly were found to be associated with an arteriovenous malformation or cavernous malformation, excision or treatment of the vascular malformation should spare the developmental venous anomaly in order to prevent venous infarction.
A 24-year-old woman is being evaluated for a six-week history of pulsatile tinnitus and headaches. She has no history of serious illness and takes no medication. Neurological examination shows no abnormalities. Arterial (Figure 1) and venous phases (Figure 2) of her right internal carotid angiogram are shown. Which of the following is the most likely diagnosis?
A. Developmental venous anomaly
B. Venous sinus thrombosis
C. Anterior cerebral artery embolus
D. Middle fossa meningioma
E. Posterior communicating artery aneurysm
Developmental venous anomaly
The angiograms show lateral projections of an internal carotid injection in the arterial and venous phases. On the venous phase, the “caput medusae sign” can be seen in the frontal region, with multiple smaller veins draining into a larger collecting vein, which then drains into the superior sagittal sinus. This sign is characteristic of a developmental venous anomaly, which is common incidental finding.
The other options are not seen on these cerebral angiogram images.
A 51-year-old woman reports progressive difficulty walking since she was involved in a motor vehicle collision six months ago. On neurological examination, she has bilateral weakness of her legs, clonus, and hyperreflexia. After MR imaging is inconclusive, she undergoes CT myelography for further evaluation. The thoracic MR imaging (Figure 1) and x-ray film (Figure 2) shown are most consistent with which of the following?
A. Meningioma
B. Arachnoid cyst
C. Epidural lipomatosis
D. Hydromyelia
E. Herniated ventral cord
Arachnoid cyst
Spinal arachnoid cysts are relatively uncommon and may be either intradural (type III meningeal cyst) or extradural (type IA meningeal cyst). Epidural lipomatosis refers to an excessive accumulation of fat within the spinal epidural space resulting in compression of the thecal sac. Meningiomas would not have the same density of CSF as seen in Figure 1 &2. Herniated ventral cord on imaging shows absence of CSF flow ventral to the herniated cord and a normal CSF flow pattern dorsal to the cord, this can be distinguished from arachnoid cyst especially on myelogram. A hydromyelia is the dilatation of the central canal of the spinal cord, and thus the lesion is lined by ependymal.
An otherwise healthy 18-year-old man with shunted hydrocephalus from neonatal meningitis is brought to the emergency department after falling off his bicycle. He was wearing a helmet. His Glasgow Coma Scale score is 15. The shunt series x-ray film shown was obtained before he developed progressive headaches leading to vomiting. The deterioration in this patient is most likely the result of which of the following?
A. Ventriculoperitoneal shunt dysfunction of valve
B. Traumatic brain injury
C. Ventriculoperitoneal shunt dysfunction of ventricular catheter
D. Ventriculoperitoneal shunt dysfunction from discontinuity
E. Ventriculoperitoneal shunt dysfunction from infection
Ventriculoperitoneal shunt dysfunction from discontinuity
The shunt series depicts discontinuity of the distal catheter, likely secondary to trauma, now causing ventriculoperitoneal shunt failure. The patient’s headaches and emesis are likely secondary to increased intracranial pressure. In general, shunt series x-rays have relatively low sensitivity in detecting shunt abnormalities. They are thought to be more useful specifically in suspected mechanical causes of shunt failure, as with trauma.
The ventricular catheter and valve appear to be intact and connected to the proximal portion of the distal catheter. Shunt infection would be unlikely as the cause of shunt failure, particularly given the history of a traumatic event. Although TBI and post-concussive symptoms can include headaches and emesis, structural VP shunt issues should be suspected and addressed as the etiology of this patient’s symptoms.
The non-contrast CT scans shown are obtained from a 65-year-old man. Which of the following is the most likely cause of these findings?
A. Stroke
B. Low grade glioma
C. Arachnoid cyst
D. Trauma
E. Subdural hygroma
Stroke
The CT findings are consistent with gliotic brain tissue following a right MCA stroke. A low grade glioma would also be hypodense or isodense on CT but would have mass effect features and would not be limited to a vascular territory. Long term sequelae of trauma can be a mix of gliosis and encephalomalacia although this can be a vascular geography it often to more global and along the convexity or hemispheric cortically. Arachnoid cysts are extremely well circumscribed, with an imperceptible wall, and displace adjacent structures, additionally on CT they should have the same density of CSF. Subdural hygroma radiographically appears as a crescentic near-CSF density/signal accumulation in the subdural space that does not extend into the sulci and rarely exerts significant mass-effect.
On the lateral view internal carotid artery angiogram shown, the arrow is pointing to which of the following arteries?
A. Anterior choroidal artery
B. Ophthalmic artery
C. Meningohypophyseal trunk
D. Posterior choroidal artery
E. Posterior communicating artery
Anterior choroidal artery
The angiogram shows an artery that appears to branch from the cavernous segment of the internal carotid artery on lateral projection. The artery appears to ultimately supply the tentorium cerebelli and then courses upward, which are hallmarks of the artery of Bernasconi and Cassinari, also known as the marginal (or medial) tentorial artery. In this angiogram image, the artery appears secondarily enlarged due to the vascular malformation.
The anterior choroidal artery is a branch of the communicating segment of the internal carotid artery, as is the posterior communicating artery. The inferior hypophyseal artery, like the artery of Bernasconi and Cassinari, is a branch of the meningohypophyseal trunk, but supplies the pituitary gland.
A 2-year-old male infant is a passenger in a motor vehicle collision. A CT scan of the head shows no abnormalities. A CT scan of the cervical spine at C3 reveals the findings demarcated by the arrows in the image shown. Neurological examination shows no abnormalities. It should be explained to the family and emergency department staff that the findings indicated by the arrows represent which of the following?
A. Traumatic fractures
B. Iatrogenic fracture lines
C. Synchondroses
D. Congenital abnormalities
E. Vasculature in bone
Synchondroses
Synchondroses are primary cartilaginous joints mainly found in the developing skeleton, but a few also persist in the mature skeleton as normal structures or as variants. These are the sites of ossification centers for certain areas in the skeleton; they can be misinterpreted as traumatic fractures, congenital abnormalities and vasculature of the bone.
An 8-year-old boy has a tender, immobile, soft mass on his scalp. A CT scan is shown. The histopathology of this lesion is most likely to be which of the following?
A. Osteoma
B. Eosinophilic granuloma
C. Epidermoid cyst
D. Hemangioma
E. Osteoblastoma
Eosinophilic granuloma
Eosinophilic granulomas are solitary or multiple punched out lytic lesions without sclerotic rim. They often have a double contour or beveled edge appearance may be seen due to asymmetrical involvement of the inner and outer tables (hole within a hole) sign. Epidermoid cysts refer to epidermoid cysts that occur in the diploë of the skull, non-enhancing hypodense lesion with sharply demarcated bony defects and zones of calcifications; it may alter the outer and/or inner tables of the skull. Osteomas appear as very radiodense lesions, similar to the normal cortex. Osteoblastomas are often demonstrated as predominantly lytic and have internal matrix mineralization. Hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They appear as a lobulated mass with the same density to the adjacent muscles and exhibiting a vivid and homogeneous contrast enhancement.
A 75-year-old man is evaluated because of a six-month history of headaches. A CT scan (bone windows) of the head is shown. Which of the following is the most likely diagnosis?
A. Paget’s disease
B. Multiple myeloma
C. Osteoma
D. Hyperostosis frontalis interna
E. Fibrous dysplasia
Paget’s disease
Paget’s disease of the skull can have classic appearances including osteoporosis circumscripta, cotton wool appearance, diploic widening and Tam o’ Shanter sign. Osteoporosis circumscripta are large, well-defined lytic lesions involving the inner aspect of the outer table of the skull (stage one) with a preserved inner table. Cotton wool is the term for the mixed lytic and sclerotic lesions of the skull. Diploic widening describes when both inner and outer calvarial tables are involved, with the former usually more extensively affected. Tam o’ Shanter sign is when there is platybasia and basilar invagination with the appearance of the skull falling over the facial bones, like a Tam o’ Shanter hat. Hyperostosis frontalis interna occurs when there is thickening of the internal table of the frontal bone. Fibrous dysplasia usually affects the outer table more prominently. Multiple myeloma is defined as numerous, well-circumscribed, lytic bone lesions, punched out lucencies
sometimes termed ‘raindrop skull’ and can have endosteal scalloping. Osteomas are benign mature bony growths, seen almost exclusively in bones formed in membrane (e.g. skull).
The 3D CT scan of the skull shown in Figure 1 is obtained from a 4-month-old girl. An intraoperative photograph is shown (Figure 2). Premature closure of which of the following cranial sutures is most likely in this patient?
A. Sagittal suture synostosis
B. Lambdoid suture synostosis
C. Metopic suture synostosis
D. Unilateral coronal suture synostosis E. Bilateral coronal suture synostosis
Metopic suture synostosis
Metopic suture synostosis results in trigonocephaly, the resulting shape can best be assessed from a top view again, which will reveal a somewhat triangular form of the head. Sagittal suture synostosis results in scaphocephaly, the Greek derived word ‘scaphocephaly’ is boat-head, which is the shape seen standing above the child looking downward at the top of the head. Unilateral coronal suture synostosis also known as anterior plagiocephaly, results in a skew head. Lambdoid suture synostosis also known as posterior plagiocephaly, results in a skew head but posteriorly. Brachycephaly, or a “short head,” is the result of a closure of both the coronal sutures, recessed frontal bones and a flattened occiput.
A 16-year-old girl with polyostotic fibrous dysplasia is evaluated because of a mildly tender expanding right frontal scalp mass. A CT scan of the head is shown in Figure 1. An intraoperative photograph of the mass is shown in Figure 2. Pathology shows blood-filled cavernous spaces separated by fibrous septa surrounded by fibroblasts, histiocytes, and multi-nucleated giant cells, but not endothelium. Which of the following is the most likely diagnosis?
A. Epidermoid cyst
B. Osteoblastoma
C. Aneurysmal bone cyst
D. Hemangioma
E. Calcified cephalohematoma
Aneurysmal bone cyst
The imaging shows an aneurysmal bone cyst. On imaging these are sharply defined, expansile osteolytic lesions, with thin sclerotic margins. The occurrence of a concomitant fibrous dysplasia and aneurysmal bone cysts in calvarium is exceedingly rare, but there is a report that a secondary form of aneurysmal bone cysts may arise from a disruption in the osseous circulation caused by a primary lesion. Cephalohematoma occurs when pressure on the fetal head ruptures small blood vessels when the head is compressed against the maternal pelvis during labor or pressure from forceps or a vacuum extractor used to assist the birth. As blood accumulates, the periosteum lifts away from the skull. On imaging it can appear as double skull sign as over time, the outer rim may develop calcification, and the bulge may feel harder as the collected blood calcifies. Epidermoid cysts refer to cysts that occur in the diploë of the skull, non-enhancing hypodense lesion with sharply demarcated bony defects and zones of calcifications; it may alter the outer and/or inner tables of the skull. Osteoblastomas are often demonstrated as predominantly lytic and have internal matrix mineralization. Hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They appear as a lobulated mass with the same density to the adjacent muscles and exhibiting a vivid and homogeneous contrast enhancement.
A 56-year-old man presents to the office for evaluation of recurrent symptoms. Neurological examination and cranial MR imaging studies show no abnormalities. Dynamic angiography has been performed as part of his work up, with Figure 2 showing rightward rotation of the patient’s head. Which of the following is the most likely symptomatology associated with the angiograms shown?
A. Lower extremity paresthesia
B. Epigastic rising sensation
C. Fluent aphasia
D. Gerstmann syndrome
E. Syncope
Syncope
The angiogram shows diminished caliber of the vertebral artery at C2 upon head rotation, indicative of rotational vertebral artery syndrome, or Bow hunter’s syndrome. This syndrome comprises of symptomatic vertebrobasilar insufficiency due to neck and head rotation, due to compression of the vertebral artery. Reduced blood flow can therefore result in syncope or presyncope symptoms. Other associated symptoms can include vertigo.
The other symptoms are less likely to occur from vertebrobasilar insufficiency. Fluent aphasia would likely occur from an infarct of the dominant lobe MCA territory. Epigastric rising sensation is a typical symptom of temporal lobe seizures. Gerstmann syndrome is associated with a lesion of the dominant inferior parietal lobule.
In the lateral view angiogram shown, the segment of the internal carotid artery located between the two black lines is referred to as which of the following?
A. cervical segment
B. petrous segment
C. lacerum segment
D. clinoid segment
E. communicating (terminal) segment
**petrous segment
**
The petrous segment, or C2, of the internal carotid, is that which is inside the petrous part of the temporal bone. This segment extends until the foramen lacerum. The petrous portion classically has three sections: an ascending, or vertical, portion; the genu, or bend; and the horizontal portion.
In a patient with hydrocephalus treated previously with a ventriculoperitoneal shunt, contrast enhancement of the ventricular walls on CT scan is most often the result of
A. Subependymal giant cell astrocytoma B. Hydrocephalus
C. Choroid plexus carcinoma
D. Primary CNS lymphoma
E. Ventriculitis
Ventriculitis
Ventriculitis is inflammation, usually due to infection (meningitis), of the ependymal lining of the cerebral ventricles – enhancing on post contrast imaging. Primary CNS lymphoma characteristically is identified as a CT hyperdense enhancing supratentorial mass that is parenchyma but can be associated with the ventricle. Hydrocephalus would cause dilation of the ventricles but should not marked by enhancement post contrast. Subependymal giant cell astrocytomas are classically located at the foramen of Monro, and the tumor arises when a subependymal nodule transforms into subependymal giant cell astrocytomas over a period of time. Choroid plexus carcinomas are markedly enhancing intraventricular tumors, usually arising in the trigone of a lateral ventricle and invading adjacent brain parenchyma.
The pathology of the diagnostic cerebral angiogram shown is most likely which of the following?
A. Dural metastases
B. Venous varix
C. Meningioma
D. Supraorbital cell mucocele
E. Dural AVF
Dural AVF
Dural arteriovenous fistulas (dAVF) are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They present variably with hemorrhage or venous hypertension. Meningioma and metastases may have increased blood flow but would not cause this degree of shunting or abnormal drainage. Venous varices are developmental and are usually within the parenchyma. Supraorbital cell mucocele is not a vascular lesion and would not demonstrate abnormal blood flow on an angiogram.
Extraosseous calcium within the spinal canal is most likely to appear within a(n)
A. meningioma
B. abscess
C. lymphoma
D. lipoma
E. metastasis
meningioma
Spinal meningiomas are the second most common intradural spinal tumor behind schwannomas, accounting for about 25-45% of all spinal neoplasms. Meningiomas are the most common type of tumor presenting with intraspinal calcification, although gross calcifications are seen in 1-5% of cases. Schwannomas can also present with calcification and adjacent bone erosion.
Calcifications are not commonly seen in intraspinal lipomas, lymphomas, metastases, or infections.
An 18-year-old man is referred to the office because of a three-month history of nocturnal back pain. A CT scan of the spine is shown. Which of the following is the most likely diagnosis?
A. Osteoblastoma
B. Osteoid osteoma
C. Osteosarcoma
D. Osteomyelitis
E. Osteopetrosis
Osteoid osteoma
Spinal osteoid osteomas usually affect the posterior elements. Osteoid osteoma is composed of three concentric parts: a nidus, which is a meshwork of dilated vessels, osteoblasts, osteoid, and woven bone that may have a central region of mineralization; a fibrovascular rim; and surrounding reactive sclerosis. CT will show the nidus and the surrounding lucency. The sclerotic reaction can also be well assessed. Osteoblastomas are rare bone-forming tumors that may be locally aggressive. They are larger (>1.5-2 cm) and tend to affect the axial skeleton more often than their histologic relative, osteoid osteoma. Osteosarcomas have medullary and cortical bone destruction a permeative or moth-eaten appearance with aggressive periosteal reaction often described as a sunburst type. Osteomyelitis is often of the vertebral body, affecting lumbar more than thoracic more than cervical vertebral bodies. Osteomyelitis can be seen with periosteal reaction/thickening and focal bony lysis or cortical loss. Osteopetrosis typically presents with “rugger jersey” spine with dense posterior appendages.
Which of the following structures is indicated by the arrow on the lateral projection angiogram shown?
A. Superior middle cerebral vein
B. Sigmoid sinus
C. Vein of Labbe
D. Transverse sinus
E. Vein of Trolard
Vein of Labbe
Vein of Labbe is the largest venous channel on the lateral surface of the brain that crosses the temporal lobe between the sylvian fissure and the transverse sinus. It courses posteroinferiorly from the mid-Sylvian fissure connecting the superficial middle cerebral vein to the anterolateral portion of the transverse sinus.
Occlusion of the artery depicted in the angiogram shown would result in which of the following neurological deficits?
A. Loss of lower extremity vibratory sensation
B. Loss of lower extremity pain sensation
C. Loss of upper extremity strength with preserved lower extremity strength
D. Loss of left arm proprioception
E. Loss of lower extremity proprioception
Loss of lower extremity pain sensation
The angiogram demonstrates a classic hairpin turn of the artery of Adamkiewicz, which provides blood supply to the anterior spinal artery from the thoracolumbar region. Occlusion of this vessel would result in an anterior spinal cord syndrome, which results in lower extremity paresis and loss of pain and temperature sensation below the level of supply.
Central cord syndrome results in greater weakness in the upper versus lower extremities. The posterior columns are spared in anterior spinal cord syndrome, so there would be preservation of proprioception and vibratory sensation.
Which of the following anatomical structures is indicated by the arrow on the axial CT scan shown?
A. Malleus
B. Vestibule
C. Vestibular aqueduct
D. Tympanic segment of facial nerve
E. Cochlea
Tympanic segment of facial nerve
The tympanic segment of the facial nerve lacks the thick surrounding bony architecture of the labyrinthine segment of the facial nerve canal. The tympanic segment of the facial nerve is seen just medial and parallel to the wall of the epitympanum. The cochlea is medial and posterior to the tympanic segment of the facial nerve. The vestibule is posterior to the tympanic segment of the facial nerve. The vestibular aqueduct is a structure of the inner ear. Being part of the osseous labyrinth, it contains the endolymphatic duct and sac and runs from the vestibule in a transverse direction to the long axis of the petrous temporal bone to the posterior cranial fossa. The malleus is the most lateral middle ear ossicle, located between the tympanic membrane and the incus
A 46-year-old man has sudden onset of aphasia and right hemiparesis while in the cardiothoracic intensive care unit of a tertiary care center following open-heart surgery 12 hours ago. History includes antiphospholipid syndrome and four-vessel coronary artery bypass grafting. A non- contrast CT scan of the head shows loss of gray-white differentiation in the left cerebral hemisphere. The patient undergoes emergency cerebral angiography (shown) within two hours of symptom onset. Which of the following is the most appropriate next step in management?
A. Decompressive hemicraniectomy
B. Mechanical thrombectomy
C. Heparin infusion
D. Intra-arterial thrombolysis
E. Intravenous thrombolysis
Mechanical thrombectomy
The symptoms described in the clinical vignette and the accompanying cerebral angiogram demonstrate a left MCA M1 occlusion. In the treatment of acute ischemic stroke, timing is essential
for determining what types of therapy can be offered. In addition, there must be consideration of contraindications to stroke-directed therapies in order to weigh the risks and benefits. In this patient, notable clinical factors would include recent major surgery, antiphospholipid antibody syndrome, and onset of symptoms within 2 hours. Given the patient’s recent major cardiovascular surgery, mechanical thrombectomy would be an optimal treatment for this patient’s large vessel occlusion. While use of tPA after surgery for the treatment of ischemic stroke has been reported in the literature, it carries increased risks of surgical site hemorrhage and bleeding complications. Recent studies have suggested that mechanical thrombectomy may not be inferior to standard medical care with tPA.
Intravenous thrombolysis and intra-arterial thrombolysis would both involve use of fibrinolytics. While these are typically indicated in the acute treatment of ischemic stroke, recent major surgery would be considered a relative contraindication. Decompressive hemicraniectomy would not be indicated at this stage of treating an acute ischemic stroke. While anticoagulation has been used in the treatment of stroke, recent major surgery would also serve as a relative contraindication.
The first sign of ankylosing spondylis on x-ray films is most oen found in which of the following areas?
A. Cervical spine
B. Glenohumeral joints
C. Thoracic spine
D. Lumbar spine
E. Sacroiliac joints
Sacroiliac joints
Ankylosis spondylitis (AS; Marie Strumpell disease) is a chronic, progressive inflammatory spondyloarthropathy affecting the axial skeleton. It is characterized by bilateral sacroiliitis, stiffness of axial joints (ankylosis), and syndesmophytes formation. It is associated with HLA-B27 antigen positivity in 90% of cases.
Sacroiliitis is the required and earliest radiographic manifestation of AS. Pelvic radiographs are thus essential for diagnosis. Sacroiliitis is usually symmetrical and bilateral.
Syndesmophytes are vertical paravertebral ossifications, which can cause the vertebral column to have a “bamboo spine” appearance when disease is diffuse. Classically, back pain and stiffness in inflammatory rheumatic disease is worse in the morning or after long periods of inactivity and improved with exercise. Back pain is usually the first presenting symptom of AS. However, the earliest radiographic changes are not typically in the spine.
AS can also affect joints in the knees, hands, shoulders, and chest as the disease progresses. Treatment is with NSAIDs, physical therapy, and eventually disease modifying anti-rheumatic drugs (DMARDs). TNF-alpha blockers are also used as second-line therapy.
A 24-year-old woman in her third trimester is evaluated because of a one-week history of severe headache. Neurological examination is nonfocal. A CT angiogram of the head is shown. Which of the following is the most likely diagnosis?
A. Hypoplasia of sagittal sinus
B. Posterior reversible encephalopathy syndrome (PRES)
C. Dural arteriovenous fistula
D. Normal CT angiogram of head
E. Cerebral venous sinus thrombosis
Cerebral venous sinus thrombosis
Cerebral venous sinus thrombosis can occur during hypercoagulable states or syndromes such as pregnancy as in this case in which the imaging shows an empty delta sign (specific to a superior sagittal sinus thrombosis). Hypoplasia of sagittal sinus can lead to smaller size of the sagittal sinus. Dural arteriovenous fistula appear as abnormally enlarged and tortuous vessels in the subarachnoid space, corresponding to dilated cortical vein. Posterior reversible encephalopathy syndrome (PRES) commonly there is vasogenic edema within the occipital and parietal regions.
A 52-year-old woman is evaluated for neck stiffness and myelopathy. An MR image and CT scan are shown. Which of the following is the most likely diagnosis?
A. Ossification of the posterior longitudinal ligament
B. Meningioma
C. Chondrosarcoma
D. Prostate cancer metastasis
E. Ewing sarcoma
Ossification of the posterior longitudinal ligament
Ossification of the posterior longitudinal ligament (OPLL) is typically an entity seen in patients of Asian descent, although it is seen in all ethnic groups. It is characterized by ossification of the posterior longitudinal ligament. Bones are the most common site of hematogenous metastases of prostate cancer; this is often osteoblastic in nature but starts primarily in the vertebral body. The vast majority (90%) of spinal meningiomas are intradural extramedullary in location. They are most often found in the thoracic spine (80%), and they are isodense or moderately hyperdense mass but are usually contained to 1-3 vertebral bodies and have a dural tail. Chondrosarcomas are malignant cartilaginous tumors that account for ~25% of all primary malignant bone tumors; on imaging they appear as rings and arcs of calcification or popcorn calcification and seems to arise from transverse processes. Ewing sarcomas have an aggressive appearance; common findings include permeative, lamellated (onion skin) periosteal reaction, and sclerosis. Occasionally they can have spiculated (sunburst) or thick periosteal reaction and even bone expansion or cystic
Which of the following arteries is indicated by the arrowhead on the arteriogram shown?
A. Inferior hypophyseal artery
B. Anterior choroidal artery
C. Artery of Bernasconi and Cassinari
D. Posterior communicating artery
E. Posterior choroidal artery
Artery of Bernasconi and Cassinari
The angiogram shows an artery that appears to branch from the cavernous segment of the internal carotid artery on lateral projection. The artery appears to ultimately supply the tentorium cerebelli and then courses upward, which are hallmarks of the artery of Bernasconi and Cassinari, also known as the marginal (or medial) tentorial artery. In this angiogram image, the artery appears secondarily enlarged due to the vascular malformation.
The anterior choroidal artery is a branch of the communicating segment of the internal carotid artery, as is the posterior communicating artery. The inferior hypophyseal artery, like the artery of Bernasconi and Cassinari, is a branch of the meningohypophyseal trunk, but supplies the pituitary gland.
The arrow in the CT scan shown is pointing to which of the following structures?
A. Malleus
B. Internal auditory canal
C. Vestibule
D. Superior semicircular canal
E. Cochlea
Cochlea
The arrow denotes the cochlea. The vestibule is lateral and posterior to cochlea. The malleus is lateral and anterior to cochlea. The internal auditory canal is a bony canal within the petrous portion of the temporal bone that transmits nerves and vessels from within the posterior cranial fossa to the auditory and vestibular apparatus. The superior semicircular canal is oriented in the vertical plane perpendicular (transverse) to the long axis of the petrous temporal bone as it lies under the arcuate eminence on the anterior surface of the petrous temporal bone.
An 8-month-old child is brought to the emergency department because of a swollen right parietal region. Findings on a non-contrast axial CT scan of the brain are shown (Figure 1). Three months later, she returns for follow-up, and an MR image of the head is obtained (Figure 2). Which of the following is the most likely diagnosis?
A. Leptomeningeal cysts
B. Epidermoid cyst
C. Eosinophilic granuloma
D. Metastasis
E. Calvarial birth defect
Leptomeningeal cysts
Leptomeningeal cysts, also known as growing skull fractures, are an enlarging skull fractures that occurs near post-traumatic encephalomalacia. The term cyst is actually a misnomer, as it is not a cyst, but an extension of the encephalomalacia. Eosinophilic granulomas are solitary or multiple punched out lytic lesions without sclerotic rim. Epidermoid cysts are well-circumscribed masses, potential osseous changes include and laminar thinning and scalloping. Metastases to the skull are very common in patients with disseminated skeletal metastatic disease, often lytic in nature. Calvarial birth defects usually resolve and do not progress with time.
The structure indicated by the arrow in the x-ray film shown is most likely associated with which of the following?
A. Subclavian artery thrombosis
B. Miosis and ptosis
C. Dysphagia
D. Dyspnea
E. Upper extremity paresthesias
**Upper extremity paresthesias
**
The x-ray in depicting a cervical rib, or an extra rib that can form above the first thoracic rib. It is a congenital overdevelopment of transverse process of cervical spine vertebra. This can cause development of thoracic outlet syndrome due to pressure on the brachial plexus and/or subclavian artery. Thoracic outlet syndrome can present with neurogenic symptoms of pain radiating into the hand with paresthesias, weakness, and wasting of muscles in the affected limb and hand. Vascular symptoms include coldness, swelling, and bluish discoloration of the limb. Compression of the sympathetic chain may cause Horner’s syndrome, although this is not as common. Operative excision of cervical ribs is indicated in the presence of severe pain, severe muscle wasting, or if there are vascular symptoms. Most cases are not clinically relevant and do not have symptoms. They are discovered incidentally during x-rays and CT scans.
Subclavian artery thrombosis and embolization are also possible, although rare. Dyspnea and dysphagia are not commonly associated with cervical ribs.
On the anterior-posterior view internal carotid artery angiogram shown, the arrow is pointing to which of the following arteries?
A. Posterior temporal artery
B. Posterior cerebral artery
C. Anterior temporal artery
D. Anterior choroidal artery
E. Recurrent artery of Heubner
Anterior choroidal artery
At the level of the midbrain the basilar artery bifurcates to form the two posterior cerebral arteries. These anastomose with the middle cerebral arteries and internal carotid arteries via the posterior communicating arteries. They supply the occipital lobes and posteromedial temporal lobes.
Which of the following structures is indicated by the arrow on the vertebral artery angiogram shown?
A. Medial tentorial artery
B. Anterior temporal artery
C. Ophthalmic artery
D. Superior cerebellar artery
E. Posterior communicating artery
Posterior communicating artery
The cerebral angiogram image shows a lateral projection of a vertebral artery injection. The arrow is pointing to flow through the posterior communicating artery, which is directed anteriorly.
The ophthalmic artery is a branch from the internal carotid artery. The medial tentorial artery is a branch from the meningohypophyseal trunk from the cavernous segment of the internal carotid artery. The anterior temporal artery is a branch of the posterior cerebral artery. The superior cerebellar artery branches off of the basilar artery.
A 14-year-old girl is evaluated because of a two-year history of headaches and worsening protrusion of the right forehead. CT scans are shown. Which of the following is the most likely diagnosis?
A. Epidermoid cyst
B. Hemangioma
C. Aneurysmal bone cyst
D. Osteoblastoma
E. Fibrous dysplasia
Fibrous dysplasia
Fibrous dysplasia is a non-neoplastic tumor-like congenital process, manifested as a localized defect in osteoblastic differentiation and maturation, with the replacement of normal bone with large fibrous stroma and islands of immature woven bone. These have ground-glass opacities, well-defined borders with expansion of the bone with intact overlying bone and also endosteal scalloping may be seen. Epidermoid cysts refer to cysts that occur in the diploë of the skull, non- enhancing hypodense lesion with sharply demarcated bony defects and zones of calcifications; it may alter the outer and/or inner tables of the skull. Osteoblastomas are often demonstrated as predominantly lytic and have internal matrix mineralization. Hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They appear as a lobulated mass with the same density to the adjacent muscles and exhibiting a vivid and homogeneous contrast enhancement. Aneurysmal bone cysts demonstrate sharply defined, expansile osteolytic lesions, with thin sclerotic margins.
The normal maximum distance between the anterior aspect of the dens and the posterior arcular surface of the atlas in adults as demonstrated on a roune lateral roentgenogram of the cervical spine is:
A. 7 mm
B. 5 mm
C. 12 mm
D. 3 mm
E. 2 mm
3 mm
The atlantodental interval (ADI) is the horizontal distance between the anterior arch of the atlas and the dens of the axis, used in the diagnosis of atlanto-occipital dissociation injuries and injuries of the atlas and axis. It is the distance (in mm) between the posterior cortex of the anterior arch of the atlas and the anterior cortex of the dens. The normal maximum distance on lateral x-ray imaging is less than 3 mm. In children, the normal distance is < 5mm. On CT imaging, the maximum ADI has been reported as 2 mm in the mid-sagittal plane.
The Rule of Spence is a radiologic method to evaluate the likelihood of injury to the transverse atlantal ligament on an open mouth AP radiograph. As originally described, if the combined projection of the lateral masses of the atlas is more than 7mm beyond the lateral masses of the axis, an injury to transverse ligament is likely.
The normal basion-axis interval (BAI) is < 12mm.
During spinal angiography at the thoracolumbar junction, the artery marked with an asterisk in the figure shown is inadvertently embolized. The patient will most likely experience which of the following postoperative neurological outcomes?
A. Lower extremity paresis
B. Upper extremity paresis
C. No neurologic change
D. Loss of lower extremity vibratory sensation
E. Loss of lower extremity proprioception
Lower extremity paresis
The image shows the classic hairpin turn of the artery of Adamkiewicz, which provides blood supply to the anterior spinal artery. Ultimately, this leads to perfusion of the lower thoracic and lumbar regions of the spine in a watershed territory. As the artery of Adamkiewicz provides perfusion to the anterior spinal cord, and thus embolization would result in anterior spinal cord syndrome, which is characterized by lower extremity paresis and loss of pain and temperature sensation below the level of supply.
With anterior spinal cord syndrome, posterior columns are spared. As a result, preservation of proprioception and vibratory sensation would be expected.
Which of the following is the most likely diagnosis of the lesion in the CT scan (Figure 1) and T2- weighted axial MR image (Figure 2) shown?
A. Multiple myeloma
B. Paget’s disease
C. Fibrous dysplasia
D. Osteoma
E. Hyperostosis frontalis interna
Fibrous dysplasia
Fibrous dysplasia is a non-neoplastic tumor-like congenital process, manifested as a localized defect in osteoblastic differentiation and maturation, with the replacement of normal bone with large fibrous stroma and islands of immature woven bone. They have a ground-glass opacity appearance. Paget’s disease of the skull can have classic appearances including osteoporosis circumscripta, cotton wool appearance, diploic widening and Tam o’ Shanter sign. Osteoporosis circumscripta are large, well-defined lytic lesions involving the inner aspect of the outer table of the skull (stage one) with a preserved inner table. Cotton wool is the term for the mixed lytic and sclerotic lesions of the skull. Diploic widening describes when both inner and outer calvarial tables are involved, with the former usually more extensively affected. Tam o’ Shanter sign is when there is platybasia and basilar invagination with the appearance of the skull falling over the facial bones, like a Tam o’ Shanter hat. Hyperostosis frontalis interna occurs when there is thickening of the internal table of the frontal bone. Multiple myeloma is defined as numerous, well-circumscribed, lytic bone lesions. These punched out lucencies are sometimes termed “raindrop skull” and can have endosteal scalloping. Osteomas are benign mature bony growths, seen almost exclusively in bones formed in membrane (e.g. skull).
A 24-year-old man is brought to the emergency department with a dilated left pupil and a left hemiparesis following a high-speed motor vehicle accident. His initial CT scan is shown. Four hours after admission, the patient dies from other injuries. Which of the following is most likely to be found in the brain at autopsy?
A. Subdural hematoma
B. Epidural hematoma
C. Subdural hygroma
D. Epidural abscess
E. Benign enlargement of the subarachnoid spaces
Epidural hematoma
Epidural hematomas are typically bi-convex (or lentiform) in shape, and most frequently beneath the squamous part of the temporal bone. EDHs are hyperdense, somewhat heterogeneous, and sharply demarcated. Acute subdural hematoma is a crescent-shaped homogeneously hyperdense extra-axial collection that spreads diffusely over the affected hemisphere. Epidural abscesses are extra-axial in location, and they are isodense or hypodense to surrounding brain and are biconvex in shape. Subdural hygroma radiographically appears as a crescentic near-CSF density/signal accumulation in the subdural space that does not extend into the sulci and rarely exerts significant mass-effect. In benign enlargement of the subarachnoid spaces, the CSF space usually follows the gyral contour. Additionally, there is normal ventricular size, no pressure effects on the surrounding brain tissue, and no cerebral atrophy.
An otherwise healthy 28-year-old woman comes to the emergency department because of a two- day history of headache, lethargy, and confusion. She was discharged from the hospital ten days ago after the birth of her second child. Examination shows no focal deficits. A non-contrast CT scan is shown. Which of the following is the most appropriate next step in management?
A. Nonsteroidal anti-inflammatory drug B. Anticoagulation
C. Ventriculostomy
D. Craniotomy
E. Observation
Anticoagulation
The CT scan shows a cerebral sinus thrombosis of the transverse sinus. In the absence of an associated intracerebral hemorrhage, it is recommended to start anticoagulation per the American Heart Association/American Stroke Association. NSAIDS could be used later but will not have any immediate effects. Craniotomy and ventriculostomy are not indicated. Observation in the setting of an acute cerebral sinus thrombosis is not advised.
Which of the following neurological deficits is most likely to result from direct embolization of the artery indicated by the arrow on the angiogram shown?
A. Dysphagia
B. Occipital paresthesia
C. Auricular paresthesia
D. Facial paresthesia
E. Tongue paresis
Dysphagia
The ascending pharyngeal artery supplies the middle and inferior pharyngeal constrictor muscles and the stylopharyngeus which are important in swallowing. Tongue is supplied by lingual artery. Facial artery supplies sensation to portions of the face. Numbness near the ear may be due to embolization of posterior auricular artery. The occipital artery supplies sensation to the posterior scalp/head.
A 40-year-old man has severe, constant pain in the right side of his neck and upper shoulder region. The pain is best relieved by aspirin. Radioisotope study shows uptake at C5 on the right. Axial CT scans are shown. Which of the following is the most likely diagnosis?
A. Osteoblastoma
B. Osteomyelitis
C. Osteopetrosis
D. Osteoid osteoma
E. Osteosarcoma
Osteoid osteoma
Spinal osteoid osteomas usually affect the posteior elements. Osteoid osteoma is composed of three concentric parts, a nidus which is meshwork of dilated vessels, osteoblasts, osteoid, and woven bone that may have a central region of mineralization; fibrovascular rim and surrounding reactive sclerosis. CT will show the nidus and the surrounding lucency. The sclerotic reaction can also be well assessed. Osteoblastomas are rare bone-forming tumors that may be locally aggressive. They are larger (>1.5-2 cm) and tend to affect the axial skeleton more often than their histologic relative, osteoid osteoma. Osteosarcomas have medullary and cortical bone destruction a permeative or moth-eaten appearance with aggressive periosteal reaction often described as a sunburst type. Osteomyelitis is often of the vertebral body, affecting lumbar more than thoracic more than cervical vertebral bodies, and can be seen with periosteal reaction/thickening and focal bony lysis or cortical loss. Osteopetrosis typically demonstrates a “rugger jersey” spine appearance with dense posterior appendages.
The CT scans shown are obtained from a woman with exophthalmos and headaches. Which of the following is the most likely diagnosis?
A. Osteoma
B. Hyperostosis frontalis interna
C. Paget’s disease
D. Fibrous dysplasia
E. Multiple myeloma
Fibrous dysplasia
Fibrous dysplasia is a non-neoplastic tumor-like congenital process, manifested as a localized defect in osteoblastic differentiation and maturation, with the replacement of normal bone with large fibrous stroma and islands of immature woven bone. They have a ground-glass opacity appearance. Paget’s disease of the skull can have classic appearances including osteoporosis circumscripta, cotton wool appearance, diploic widening and Tam o’ Shanter sign. Osteoporosis circumscripta are large, well-defined lytic lesions involving the inner aspect of the outer table of the skull (stage one) with a preserved inner table. Cotton wool is the term for the mixed lytic and sclerotic lesions of the skull. Diploic widening describes when both inner and outer calvarial tables are involved, with the former usually more extensively affected. Tam o’ Shanter sign is when there is platybasia and basilar invagination with the appearance of the skull falling over the facial bones, like a Tam o’ Shanter hat. Hyperostosis frontalis interna occurs when there is thickening of the internal table of the frontal bone. Multiple myeloma is defined as numerous, well-circumscribed, lytic bone lesions. These punched out lucencies are sometimes termed “raindrop skull” and can have endosteal scalloping. Osteomas are benign mature bony growths, seen almost exclusively in bones formed in membrane (e.g. skull).
A 52-year-old man is evaluated because of severe left arm pain. He brings a contrasted CT scan of his cervical spine. The axial image (Figure 1) was obtained at the level designated by the white line in the reconstructed sagittal image (Figure 2). Which of the following physical findings is most likely to be observed when examining this patient?
A. Ossification of the posterior longitudinal ligament
B. Schwannoma
C. Disc herniation
D. Meningioma
E. Forestier disease
Disc herniation
Disc herniation may contain nucleus pulposus, vertebral endplate cartilage, apophyseal bone/osteophyte and annulus fibrosus, but they frequently are not the same density of surrounding bone. The vast majority of spinal schwannomas are intradural extramedullary in location. They are most frequently seen in the cervical and lumbar regions, far more frequently than in the thoracic spine, they often remodel the bone of the foramen. The vast majority (90%) of spinal meningiomas are intradural extramedullary in location, they are isodense or moderately hyperdense mass, calcification seen in <5%. Ossification of the posterior longitudinal ligament characterized by, as the name suggests, ossification of the posterior longitudinal ligament, primarily seen in cervical spine (75%). Diffuse idiopathic skeletal hyperostosis (DISH), also referred to as Forestier disease, is a common condition characterized by bony proliferation at sites of tendinous and ligamentous insertion of the spine affecting elderly individuals.
Radiographic evidence of increased concavity of the posterior surfaces of several adjacent vertebral bodies can be present in association with
A. Degenerative changes
B. Abdominal aortic aneurysm
C. Intradural spinal mass
D. Metastatic lesion
E. Down Syndrome
Intradural spinal mass
“Scalloping” of vertebral bodies describes an exaggeration of the normal concavity of the posterior surface of the body. The best-known cause for this radiographic appearance is from an intradural lesion causing localized widening of the canal. The lesion is thought to increase the interpediculate distance, increase local intraspinal pressure, and subsequently cause scalloping of the dorsal aspect of adjacent vertebral bodies. Ependymomas of the filum and conus medullaris can often produce scalloping. Other intraspinal masses such as dermoid cysts, epidermoid cysts, and lipomas can also produce scalloping.
Other causes of vertebral body scalloping can include uncontrolled communicating hydrocephalus, connective tissue disorders (e.g., Marfan’s), dural ectasia, NF1, and achondroplasia.
Degenerative changes and metastatic lesions do not typically cause posterior vertebral body scalloping.
Abdominal aortic aneurysms and Down Syndrome are associated with anterior vertebral body scalloping.
Which of the following diseases most often produces radiographically visible intracerebral calcifications?
A. Aspergillosis
B. Toxoplasmosis
C. Coccidioidomycosis
D. Lymphoma
E. Herpes encephalitis
Toxoplasmosis
Toxoplasmosis is caused by T gondii, an intracellular protozoan. It is transmitted to humans by ingestion of cysts in undercooked meat or through direct contact with cat feces. Cerebral toxoplasmosis most commonly presents with headaches and can also present with altered mental status, fevers, and occasionally, seizures.
Congenital toxoplasmosis (transplacental transmission) demonstrates periventricular and cortical calcifications within the infectious lesions. Calcifications are less common in acquired cases. Toxoplasmosis abscesses have a propensity for the basal ganglia, corticomedullary junction, white matter, and periventricular regions. Congenital toxoplasmosis infection produces a triad of hydrocephalus, chorioretinitis, and intracranial calcifications.
Herpes simplex virus (HSV) encephalitis most often invades the brain after reactivation of latent virus that resides in the trigeminal ganglion. CT findings are usually subtle, with areas of lower- attenuation in the temporal lobe and insular cortex. Calcifications are not common.
Coccidioidomycosis can cause fungal meningitis with hematogenous spread from primary pulmonary infection. CT findings can be negative or subtle, with dilated Virchow-Robin spaces and poor visualization of the basal cisterns due to dense exudates. Nodular enhancement can be seen, but lesions are usually not calcified.
CNS lymphoma lesions tend to be more locally infiltrative, with a butterfly-like pattern of enhancement on MRI, diffusion restriction, and a predilection for the basal ganglia and periventricular regions. Calcifications are not common. Lymphomatous lesions also tend to be larger than in toxoplasmosis.
Aspergillosis can cause meningitis and encephalitis in immunocompromised people. It has a predilection for the basal ganglia, thalami, and corpus callosum. Lesions are usually subtle on CT, with varying densities and poor contrast enhancement.
An 18-month-old boy is evaluated because of an asymmetric head shape, which has been stable. He is neurologically intact and has normal facial structure. A CT scan is shown. Which of the following is the most likely diagnosis?
A. Calcified cephalohematoma
B. Osteoblastoma
C. Aneurysmal bone cyst
D. Epidermoid cyst
E. Hemangioma
Calcified cephalohematoma
The CT shows a cephalohematoma. Pressure on the fetal head ruptures small blood vessels when the head is compressed against the maternal pelvis during labor or pressure from forceps or a vacuum extractor used to assist the birth. As blood accumulates, the periosteum lifts away from the skull. On imaging it can appear as double skull sign as over time, the outer rim may develop calcification, and the bulge may feel harder as the collected blood calcifies. The blood then starts to be reabsorbed.
Epidermoid cysts refer to cysts that occur in the diploë of the skull, non-enhancing hypodense lesion with sharply demarcated bony defects and zones of calcifications; it may alter the outer and/or inner tables of the skull. Osteoblastomas are often demonstrated as predominantly lytic and have internal matrix mineralization. Hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They appear as a lobulated mass with the same density to the adjacent muscles and exhibiting a vivid and homogeneous contrast enhancement. Aneurysmal bone cysts demonstrate sharply defined, expansile osteolytic lesions, with thin sclerotic margins.
A 25-year-old man is evaluated because of a 12-month history of headaches. Cranial CT scans are shown. Which of the following is the most likely diagnosis?
A. Osteoblastoma
B. Epidermoid cyst
C. Hemangioma
D. Osteoma
E. Aneurysmal bone cyst
Epidermoid cyst
Epidermoid cysts refer to epidermoid cysts that occur in the diploë of the skull, non-enhancing hypodense lesion with sharply demarcated bony defects and zones of calcifications; it may alter the outer and/or inner tables of the skull. Osteomas appear as very radiodense lesions, similar to the normal cortex. Osteoblastomas are often demonstrated as predominantly lytic and have internal matrix mineralization. Hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They appear as a lobulated mass with the same density to the adjacent muscles and exhibiting a vivid and homogeneous contrast enhancement. Aneurysmal bone cysts demonstrate sharply defined, expansile osteolytic lesions, with thin sclerotic margins.
