Unit 2 (CNS & CT)

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Unit 2 (CNS & CT)
2013-03-03 19:28:12
Procedures IV

Unit 2: Central Nervous System and CT
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  1. medical term for "brain"
  2. medical term for "spinal cord"
    medula spinalis
  3. the outer portion of the brain:
    gray matter (cortex)
  4. the inner portion of the brain:
    white matter
  5. the three divisions of the brain:
    • cerebrum (telencephalon, largest part)
    • cerebellum
    • brain stem (continuous with spinal cord)
    • A. cerebrum
    • B. diencephalon (thalamus & hypothalamus)
    • C. midbrain (mesencephalon)
    • D. spinal cord
    • E. pons
    • F. medulla oblongata
    • G. cerebellum
  6. divides the cerebrum into right and left hemispheres:
    longitudinal fissure
  7. a double fold of duramatter that connects to the crista gali:
    falx cerebri
  8. stem-like portion that joins the cerebrum to the pons and cerebellum:
  9. parts of the forebrain:
    • cerebrum
    • diencephalon
  10. parts of the midbrain:
    • diencephalon
    • brain stem
    • pons
    • medulla oblongata
  11. parts of the hindbrain:
    • pons
    • medulla oblongata
    • cerebellum
  12. composed of structures located near the midline of the brain:
    • diencephalon
    • (includes thalamus & hypothalamus)
  13. nerve fiber that connects the right and left hemisphere:
    corpus callosum
  14. an endocrine gland located in the hypophyseal fossa of the sella turcica:
    hypophysis cerebri (pituitary gland)
  15. the third ventricle is surrounded by:
    the cerebral hemispheres
  16. inferior to the diencephalon is the:
    hypophysis cerebri (pituitary gland)
  17. largest part of the hindbrain:
  18. median constricted area that seperates the
    hemispheres of the cerebellum:
  19. separates cerebellum from cerebrum:
    transverse cleft
  20. describe the appearance of the cerebellum:
    a laminated appearance due to the many transverse fissures
  21. tissue between the fissures of the cerebellum:
  22. upper position of hindbrain where the cerebrum, cerebellum, and medulla come together:
  23. Between the pons and spinal cord, the lower portion of the hindbrain:
  24. the inner portion of the spinal cord:
    a gray cellular substance
  25. the outer portion of the spinal cord:
    a white fibrous substance
    • A. gray cellular substance
    • B. white fibrous substance
    • C. posterior nerve root
    • D. anterior nerve root
    • E. pons
    • F. medulla oblongata
    • G. spinal cord
    • H. conus medullaris
    • I. cauda equina
  26. at what vertebral level does the spinal cord end?
    around L1-L2 interspace
  27. the spinal cord connects to the medulla oblongata at the level of:
    the foramen magnum (great hole)
  28. the pointed area where the spinal cord ends:
    conus medullaris
  29. a fibrous strand that extends from the conus medullaris and attaches the cord to the upper coccygeal segment:
    filum terminale
  30. there are _______ pairs of spinal nerves, and each pair arises from:
    • 31
    • two roots at the side of the spinal cord
  31. where the nerves extend inferiorly through the vertebral canal below the termination of the spinal cord:
    cauda equina
  32. protective membranes that cover the brain and spinal cord:
  33. the highly vascular inner sheath that adheres closely to the underlying brain and cord structures:
  34. the delicate, avascular central sheath that resembles a spider web:
  35. the outermost, fibrous protective sheath of the spinal cord:
  36. nicknames for the pia and the dura meninges:
    • pia - tender mother
    • dura - hard or tough mother
  37. the epidural space is between:
    the subdural space is between:
    the subarachnoid is between:
    • epidural: between the periosteum of the bone and the duramatter
    • subdural: between the dural and the arachnoid
    • subarachnoid: between the arachnoid and the pia
    • A. spinal cord
    • B. pia mater
    • C. subarachnoid space
    • D. arachnoid mater
    • E. dura mater
    • F. vertebra
  38. widened areas of the subarachnoid space:
  39. the widest space of the subarachnoid space:
    cisternae cerebellomedularis (cisterna magna)
  40. describe the shape and location of the cisternae cerebellomedularis (cisterna magna):
    triangular in shape and at posterior–superior part of subarachnoid space between the base of cerebellum and dorsal surface of the medulla oblongata
  41. the ______________ is continuous with the ventricles.
    subarachnoid space
  42. the subarachnoid space communicates with the ventricles by way of the:
    median aperture and lateral aperture
    • A. subarachnoid space
    • B. fourth ventricle
    • C. medulla oblongata
    • D. lateral ventricle
    • E. third ventricle
    • F. cerebellum
    • G. cisterna cerebellomedularis
    • H. median aperture
  43. alternate names for the median aperture and the lateral aperture:
    • median aperture: foramen of magendie
    • lateral aperture: foramen of lusckka
  44. where are the median and lateral apertures located?
    between the cisterna magna and the fourth ventricle
  45. where is cerebrospinal fluid contained?
    in the ventricles of the brain and the subarachnoid space
  46. an area they sometimes stick to enter the subarachnoid space:
    cisterna magna
  47. fibrous membrane that covers bones except at articular surfaces:
  48. two spaces that do not communicate with the ventricular system and are potential sites of hemorrhaging:
    • subdural
    • epidural
  49. the __________ space has a thin film of fluid, and the ___________ space is wider and filled with CSF.
    • subdural
    • subarachnoid
  50. results from bleeding between the dura and the skull, usually caused by tearing of the middle menigeal artery in the temporal region:
    • epidural (extradural) hematoma
    • signs of trouble usually arise within a few hours of injury, when the person loses consciousness after a brief period of responsiveness
  51. results from bleeding that develops between the dura and the arachnoid:
    subdural hematoma
  52. which hematoma is more often a slow bleed from a tear in a vein?
    subdural hematoma
  53. a chronic subdural hematoma may occur in what type of patient? 
    an elderly person, in whom brain atrophy allows more space for a hematoma to develop
  54. a tear in the arachnoid can:
    it can allow CSF to leak into the subdural space creating additional pressure
  55. name the two layers of the dura at cranial level:
    • endosteal (outer)
    • meningeal (inner)
  56. the endosteal and meningeal layers of the dura are fused together, except for spaces that are called __________ which are large venous blood channels.
    venous sinuses
  57. lines the cranial bones, serving as periosteum to their inner surface:
    the endosteal layer of the dura
  58. protects the brain, supports blood vessels, and has four partitions (for support and protection of various parts of the brain):
    the meningeal layer of the dura
  59. list the four divisions of the meningeal layer of the dura:
    • falx cerebri
    • falx cerebelli
    • right and left tentorium cerebelli
    • sellar diaphragm
  60. runs through the interhemispheric fissure and provides support for the cerebral hemispheres:
    falx cerebri
  61. seperates the cerebrum from the cerebellum:
    right and left tentorium cerebelli
  62. lower portion of the dura mater:
    dural sac
  63. dura extends below the spinal cord to the level of:
    the 2nd sacral segment
  64. what structures create CSF?
    choroid plexuses
  65. a water cushion protecting the brain and spinal cord from physical injury:
    CSF (cerebrospinal fluid)
  66. the ventricles all contain:
  67. located on each side of the MSP in the inferior and medial part of the cerebal hemispheres:
    right and left lateral ventricles
    • A. anterior horn
    • B. body of lateral ventricle
    • C. third ventricle
    • D. posterior horn
    • E. fourth ventricle
    • F. inferior horn
    • G. interventricular foramen (foramen of monro)
  68. give the names of the central, anterior, posterior,and inferior portions of the right and left lateral ventricles:
    • central portion: body
    • anterior: frontal horn
    • posterior: occipital horn
    • inferior: temporal horn
  69. each lateral ventricle is connected to the third ventricle by a channel called the:
    • interventricular foramen
    • (aka foramen of monro)
  70. describe the appearance of the 3rd ventricle:
    a slitlike cavity that is somewhat quadrilateral in shape
  71. the 3rd ventricle also connects posteroinferiorly with the 4th ventricle by means of a passage known as:
    • the cerebral aqueduct
    • (aka aqueduct of sylvius)
  72. diamond shaped cavity of the hindbrain that lies anterior to the cerebellum and posterior to the pons and upper portion of the medulla:
    4th ventricle
  73. the pointed end of the 4th ventricle is continuous with the:
    central canal of the medulla oblongata
  74. the 4th ventricle communicates with the __________ via median and lateral apertures.
    subarachnoid space
  75. radiologic examination of the central nervous system structures within the vertebral canal such as the spinal cord and its nerve root branches:
  76. what occurs during a myelogram?
    contrast is put into the subarachnoid space (only) by spinal puncture and the spinal cord and nerve roots are outlined by injecting contrast
  77. pathologies visualized with myelography (6):
    • herniated disk
    • bone fragments
    • tumor
    • cysts
    • spinal cord swelling from an injury
    • narrowing of subarachnoid space
  78. name the two areas of puncture for myelography:
    • L2-3 or L3-4 interspace (much more common)
    • cisterna cerebellomedullaris
  79. contrast used to better visualize nerve root branches:
    • water-soluble
    • (dense contrast can cover up anatomy)
  80. give the history of contrast usage on myelograms:
    • first used: pantopaque (oily, nonwater soluble contrast)
    • in the 70s: metrizamide (water soluble contrast absorbed very fast by the body)
    • today: non-ionic
  81. list the non-ionic agents used in myelography:
    • iohexol (ex. omnipaque)
    • iopamidol
    • ioversol
  82. how is the contrast for a myelogram commonly administered?
    • intrathecal injection into the subarachnoid space of L3-L4 or L4-L5.
    • (since the cord ends at L1-L2, and you don’t want to stick cord)
  83. describe water-soluble vs. oil-based contrast in terms of how much is needed in myelogram procedures:
    • C & L spine: 9-12cc of w-s and 12-15cc of o-b 
    • T spine: 12cc w-s and 25-30cc o-b
  84. contrast is in the ______ on post myelogram studies.
    thecal sac
  85. though rarely used, negative agents for a myelogram are:
    • air
    • oxygen
  86. how do positive and negative contrast movements differ in a myelogram?
    • gas and opaque contrasts move in opposite directions
    • air rises
    • opaque dye moves down
  87. name some contraindications for a myelogram:
    • blood in the cerebrospinal fluid  
    • arachnoiditis
    • increased intracranial pressure
    • previous LP performed within two weeks (risk of extravasation of contrast)
  88. name some things that should be done when prepping for a myelogram procedure:
    • explain the details of the myelogram to the patient
    • consent form
    • one hour before exam, a sedative is given if needed
    • patient needs to be well hydrated
    • use aseptic technique
  89. during a myelogram, what must be done when the patient is in the trendelenburg position and why?
    • head extended
    • compresses the cisterna magna and keeps contrast from flowing into the head
  90. be familiar with the injection process to the lumbar area:
    • dr fluoros and marks the center location on the back of the pt
    • after marking site, pt is put in position for puncture
    • pt is prone with pillow under stomach or lateral with spine flexed
    • shave area
    • clean skin with antiseptic solution
    • dry area with gauze pad and drape 
    • local anesthetic is given with the 2cc syringe and 22 or 23 gauge needle
    • spinal needle is inserted through skin into subarachnoid space
  91. be familiar with the myelogram process after needle is placed:
    • if needle is in place, CSF will flow back through needle  
    • a sample can be taken and sent to the lab
    • CSF should be allowed to flow back and not drawn out
    • contrast is now administered in an amount equal to the amount of CSF taken out
  92. be familiar with the myelogram process after the contrast is administered:
    • after the injection, the spinal needle is removed
    • as the column of contrast medium travels through the spinal column, it is observed fluoroscopically
    • the direction of its flow is controlled by varying the angulation of the table
    • spot radiographs are taken at the level of any blockage or distortion in the outline of the contrast column
  93. be familiar with the injection process to the cervical area:
    • pt can be seated or prone with head flexed to place the external occipital protuberance in line with the spinous processes
    • shave area
    • clean skin with antiseptic solution
    • dry area with gauze pad and drape
    • local anesthetic is given with the 2cc syringe and 22 or 23 gauge needle
    • spinal needle is inserted through skin into cisterna magna
    • when needle is in place, position table to prevent media from entering ventricular system
    • remove needle and extend neck to compress cisternal cavity
  94. list some qualities of water-soluble media used today for myelograms that make it desirable:
    • mixes well with CSF
    • absorbed easily
    • non-toxic
    • inert (non-reactive)
    • good radiopacity
  95. positioning used for projections taken during a myelogram procedure:
    • prone or supine
    • anterior or posterior obliques
    • pt. moved from trendelenburg to erect to help flow of contrast move throughout canal
    • (for oil-based contrast, only prone positions were possible due to the needle remaining)
  96. for a myelogram, crosstable lateral radiographs are obtained with:
    • grid-front cassettes or a stationary grid
    • must be closely collimated
  97. a rapid, noninvasive form of radiography that produces sectional images and was first introduced in the 70s:
  98. for a CT head, what alignment is used?
    axial orientation: gantry angle 20-25 degrees to the OML
  99. what is best viewed on a coronal orientation for a CT head?
    • sella turcica
    • facial bones
    • sinuses
  100. describe the slices taken during a CT head:
    • lowest slice: upper cervical/foramen magnum and the roof of the orbits are seen (posterior fossa)
    • 12-14 slices taken
    • slice thickness may vary: typically 8-10mm with 3-5mm slices through the posterior fossa
  101. name pathologies viewed on a pre-infusion CT head (4):
    • assessment of dementia
    • craniocerebral trauma
    • hydrocephalus
    • infarcts
  102. name pathologies viewed on a post-infusion CT head (6):
    • primary neoplasms
    • metastatic disease
    • arteriovenous malformations (AVM)
    • multiple sclerosis
    • seizure disorders
    • bilateral isodense hematomas
  103. what is CT most useful for demonstrating (9)?
    • size, location, and configuration of mass lesions
    • surrounding edema
    • cerebral ventricular or cortical sulcus enlargement
    • shifting of ML structures
    • hematomas
    • aneurysms
    • ischemic or hemorrhagic strokes
    • acute infarcts
    • trauma situations (contusions, subarachnoid hemorrhage, fracture evaluation)
  104. in a CT head, how do an ischemic and a hemorrhagic stroke appear different?
    • ischemic stroke appears to be a dark area
    • hemorrhagic stroke appears to be a white area
  105. what is a CT spine useful for?
    • vertebral column hemangiomas
    • lumbar spinal stenosis
    • r/o fractures of cervical spine, especially for axis, atlas, and lower cervical and upper thoracic
    • distinguish neural compression by soft tissue from compression by bone
    • postoperatively, to assess surgical procedure
  106. the myelographic procedure is usually followed by:
    • a CT exam of the spine
    • (within four hours, preferably within one)
    • (generally limited to specific regions of the spine and performed while contrast agent is still within subarachnoid space)
  107. be familiar with the specifics of a CT Myelography (CTM):
    • 1.5 – 3 mm slices
    • gantry parallel to the plane of the intervertebral disk
    • demonstrates size, shape, and position of the spinal cord and nerve roots
    • useful with compressive injuries or in determining the extent of dural tears resulting in extravasation of the CSF
  108. magnetic resonance imaging (MRI) is not a valuable tool for:
    • osseous bone abnormalities of the skull
    • intra-cerebral hematomas
    • subarachnoid hemorrhage
  109. name pathologies viewed by MRI:
    • multiple sclerosis
    • spinal cord compression
    • paraspinal masses
    • post-radiation therapy changes in spinal cord tumors
    • metastatic disease
    • herniated disks
    • congenital anomalies of spine
    • middle and posterior fossa abnormalities
    • acoustic neuroma
    • pituitary tumors
    • primary and metastatic neoplasms
    • hydrocephalus
    • AVM
    • brain atrophy
  110. name contraindications to MRI:
    • (related to the use of the magnetic field:)
    • pacemakers
    • ferromagnetic aneurysm clips
    • metallic spinal fusion rods
  111. what is the imaging modality of choice in the diagnosis of multiple sclerosis?
  112. brain stem lesions as small as ___________ can be identified on thin-slice axial MRI images
    3MM in diameter
  113. used for brain and cervical area MRIs:
    head coil
  114. used in MRIs of the spine below the cervical area:
    body coil, in combination with a surface coil
  115. For MRIs, what contrast is used to enhance tumor visualization:
    paramagnetic contrast such as, gadolinium
  116. imaging protocols may include _________ weighted images.
    T-1 and T-2
  117. a noninvasive modality of radiology that began in 1980s that provides detail of the brain, spinal cord, intervertebral disks, and CSF within the subarachnoid space, but is blind to bone:
    MRI (magnetic resonance imaging)
  118. a radiographic procedure in which images are created by the response of loosely bound hydrogen atoms to the magnetic field:
    MRI (magnetic resonance imaging)
  119. angiography is used to:
    • assess vascular supply to tumors
    • demonstrate the relationship between a mass lesion and intra-cerebral vessels
    • illustrate anomalies of a vessel (ex. anneurism, vascular occlusion)
  120. be familiar with the process of an angiogram:
    • a catheter is placed into the vascular system under fluoro, most commonly in the femoral artery
    • the image intensifier must be designed to move around the patient so the patient does not have to move.
    • after the catheter is in place, a nonionic water soluble contrast is injected into the vessels and rapid sequence images are obtained.
  121. —angiographic tubes need a minimum focal spot size of _______ for routine imaging and _______ for magnification.
    • routine: 1.3mm
    • magnification: .3mm
  122. —an angiographic procedure used to assess
    vascular abnormalities within the CNS:
    • arteriosclerosis
    • arteriovenous malformations
    • aneurysms
    • subarachnoid hemorrhage
    • transiet ischemic attacks
    • certain intracerebral hematomas
    • cerebral venous thrombosis
  123. provides a pre-surgical road map and is also performed in combination with interventional techniques to assess the placement of devices before and after the procedures:
    cerebral angiography 
  124. involves the placement of various coils, medications, filters, stents, or other devices to treat a particular problem or provide therapy, and one type involves the introduction of small spheres, coils, or other materials into vessels to occlude blood flow:
    interventional radiology
  125. embolization techniques are often performed to treat:
    • AVMs
    • aneurysms
    • to decrease blood supply to various vascular tumors
  126. used to open occluded vessels by the injection of specialized anticoagulant medications or by the inflation of small balloons within the vessel:
    percutaneous angioplasty
  127. —an examination of individual intervertebral disks where an injection is made into the nucleus pulposis- using double needle entry and water-soluble contrast to diagnose
    internal lesions within a disk for rupture of the nucleus pulposus which can not be demonstrated by myelography:
    • diskography (aka nucleography)
    • —replaced by MRI and CTM
  128. interventional procedures used to treat spinal compression fractures and other pathologies of the vertebral bodies that have not responded to treatment:
    • vertebroplasty
    • kyphoplasty
  129. be familiar with the process of a percutaneous vertebroplasty:
    • the injection of a radiopaque bone cement (polymethyl methacrylate) into a painful compression fracture under fluoro
    • may be performed in the special procedures room or OR with sedation
    • a specialized trocar needle is advanced into the fractured vertrebral body under fluoro
    • intraosseous venography using nonionic contrast media is performed to confirm needle placement
    • the cement is injected, stabilizing fracture fragments and leads to reduction in pain
    • post injection radiographs (AP and lat spine and possible CT)
  130. be familiar with the process of a kyphoplasty:
    • a balloon catheter is used to expand the compressed vertebral body to near its original height before injection of the bone cement
    • inflation of the balloon creates a pocket for the placement of cement
    • can help restore spine to a more normal curvature and reduce hunchback deformities
  131. what are the success rates and risks involved with both vertebroplasty and kyphoplasty:
    • —both procedure successes are measured by the reduction of pain reported by the pt
    • success rates reported to be 80–90%
    • risks to both procedures: leakage of the cement before it hardens, pulmonary embolism, and death (rare, but possible)