Chapter 18

Match each tissue with the correct CT number range.(Use each choice only once.) - Muscle a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

a. +50 pg. 697: See table 18.2 +50 (gray)

MATCHING Select the correct lettered portion of the brain.(Use each choice only once.) - Cerebrum a. A b. B c. C d. D e. E f. F

a. A pg. 689: see figure 18.16

Which one of the following pitch ratios represents undersampling? A) 1:1 B) 2:1 C) 0.5:1 D) 0.7:1

B) 2:1 Pg. A 2:1 pitch increases the risk that pathology may be missed as a result of undersampling of the anatomy.

How many pairs of cranial nerves are found in the brain? A) 10 B) 12 C) 14 D) 7

B) 12 pg. 691: see table 18.1

Which of the following is not a major cranial nerve? A) Olfactory B) Vagus C) Sensory D) Abducens

C) Sensory pg. 691: see table 18.1

What is the pitch for the following parameters: couch movement of 10 mm/second and slice thickness per 360° rotation of 20 mm? A) 0.5:1 B) 2:1 C) 1:2 D) 1:1.5

A) 0.5:1 Pg. 697: see example (10 mm/second) / (20 mm/second) = 0.5

Typical slice thickness for a spine CT range is usually no greater than _____ mm. A) 3 B) 7 C) 10 D) 15

A) 3 Pg. 705: 2 to 3mm slices

What specifically do the CT detectors measure? A) Attenuation B) Patient dose C) Primary radiation D) Scatter radiation

A) Attenuation pg. 696: Any CT image is composed of a large number of pixels that represent various degrees of attenuation, depending on the anatomic density of the tissue in the voxel that is being represented. Each vote in the tissue slice is assigned a number by the computer that is proportional to the degree of X-ray attenuation.

Which structure of the neuron carries electric impulses away from the cell body? A) Axon B) Dendrite C) Nerve cell D) Multipolar neuron

A) Axon Pg. 684: Dendrites are the processes that conduct impulses toward the neuron cell body. An axon is a process that leads away from the cell body.

Which of the following structures is not part of the brainstem? A) Cerebellum B) Midbrain C) Pons D) Medulla

A) Cerebellum : pg. 685: the brainstem is comprised of midbrain, pons, and medulla. pg. 689: the hindbrain consists of the cerebellum, pons, and medulla.

Which of the following structures filters the blood to produce CSF? A) Choroid plexus B) Arachnoid granulations C) Arachnoid villi D) Ventricles

A) Choroid plexus pg. 687: CSF is formed in the lateral ventricles in specialized capillary beds called choroid plexus.

What is the name for the enlarged regions of the subarachnoid space? A) Cisterns B) Subdural space C) Centrum semiovale D) Optic chiasma

A) Cisterns pg. 688: various large areas within the subarachnoid space or system are called cisterns.

What is the name of the deep fissure that separates the two cerebral hemispheres? A) Longitudinal fissure B) Central sulcus C) Posterior, central sulcus D) Falx cerebri

A) Longitudinal fissure pg. The cerebrum is partially separated by a deep longitudinal fissure in the MSP. This tissue divides the cerebrum into right and left cerebral hemispheres.

Which layer of the meninges is located closest to the brain? A) Pia mater B) Dura mater C) Epidural mater D) Arachnoid mater

A) Pia mater pg. 685: the innermost membrane is the pia matter.

Which of the following structures is attached to the roof of the third ventricle? A) Pineal gland B) Pituitary gland C) Fourth ventricle D) Lateral recess

A) Pineal gland Pg. 68: the pineal gland is attached to the roof of the posterior part of the third ventricle directly above the cerebral aqueduct.

Which aspect of the forebrain serves as an interpretation center for pain, temperature, and touch? A) Thalamus B) Hypothalamus C) Pons D) Cerebellum

A) Thalamus pg. 689: Thalamus serves as the interpretation center for certain sensory impulses, such as pain, temperature, and touch, and for certain emotions and memory.

Which of the following is not one of the cerebral nuclei or basal ganglia? A) Thalamus B) Caudate nucleus C) Lentiform nucleus D) Claustrum

A) Thalamus pg. 689: cerebral nuclei (basal ganglia) are paired collections of gray matter deep within each cerebral hemisphere. There are four specific areas of these cerebral nuclei: 1. caudate nucleus 2. lentiform nucleus 3. claustrum 4. amygdaloid nucleus

____ controls the brightness of an image within a certain range. A) Window level B) Window width C) Voxel D) CT number

A) Window level Pg. 709: see "Terminology"

Hemianopia is a condition defined as: A) blindness occurring in half of the visual field in each eye. B) an iron deficiency producing intracranial bleeding. C) a congenital tumor in the thalamus. D) an abnormal collection of CSF in the cranial ventricles.

A) blindness occurring in half of the visual field in each eye. pg. 692: Hemianopia causes blindness or defective vision in only half of the visual field of each eye.

On the average, how much CSF is formed daily? A) 100 mL B) 150 mL C) 400 mL D) 500 mL

B) 500 mL pg. 687: CSF is formed in the lateral ventricles in specialized capillary beds called choroid plexus, which filter the blood to form CSF. Although 500 mL of CSF is formed daily, only about 140 mL of CSF is present within and around the entire CNS.

What is the chief disadvantage of CT colonography over conventional endoscopy? A) Cost B) Inability to biopsy or remove polyps C) Bowel preparation required D) Time consuming procedure

B) Inability to biopsy or remove polyps

Which of the following pathologic indications would NOT apply to head CT? A) Subdural hematoma B) Multiple sclerosis C) Aneurysm D) Brain atrophy

B) Multiple sclerosis Pg. 701: See pathologic indications

Which of the following is not a major division of the brain? A) Forebrain B) Posterior brain C) Hindbrain D) Midbrain

B) Posterior brain pg. 685: the brain can be divided into 3 general areas: (1) forebrain, (2) midbrain, and (3) hindbrain.

The two divisions of the central nervous system include the brain and: A) meninges. B) spinal cord. C) spinal nerves. D) neurons.

B) Spinal cord pg. 64: the CNS includes the brains and spinal cord

Which meningeal space contains cerebrospinal fluid (CSF)? A) Subdural space B) Subarachnoid space C) Pia space D) Cerebral fluid space

B) Subarachnoid space Pg. 658: Beneath the arachnoid membrane, between the arachnoid and the pia matter, is a wide space termed the subarachnoid space. The subarachnoid spaces of the brain and spinal cord normally are filled with CSF.

Which medium serves as the baseline for CT numbers? A) Air B) Water C) Muscle D) Fat

B) Water pg. 697: The baseline for CT numbers is water, which is assigned the CT number value of 0.

Hydrocephalus is caused by: A) blockage of the cranial blood vessel. B) blockage of the drainage of CSF. C) trauma to the head. D) congenital abnormality.

B) blockage of the drainage of CSF pg. 688: any blockage along the pathway leading from the ventricles to the subarachnoid space may cause excessive accumulation of CSF within the ventricles, a condition known as hydrocephalus.

Which of the following structures is a white brain matter structure? A) Basal ganglia B) Cerebral cortex C) Centrum semiovale D) Thalamus

C) Centrum semiovale pg. 690: white matter consists of myelinated axons, centrum semiovale, and corpus callosum.

A condition caused by an abnormal amount of CSF in the ventricles is termed: A) cerebral atrophy. B) hydrocephalus. C) pneumoencephalos. D) encephalitis.

B) hydrocephalus pg. 688: any blockage along the pathway leading from the ventricles to the subarachnoid space may cause excessive accumulation of CSF within the ventricles, a condition known as hydrocephalus.

A technique used to view vessels demonstrated in CTA is termed: A) windowing. B) maximum intensity projection. C) multiplanar reconstruction. D) volume scanning.

B) maximum intensity projection. Pg. 709: see "Terminology"

Visual centers in the brain are located in the ____ lobe of the cerebrum. A) parietal B) occipital C) insula D) frontal

B) occipital pg. 692: visual centers are located in the cortex of the occipital lobes in the cerebrum

A predetermined procedure is the definition for: A) procedure. B) protocol. C) scan parameter. D) technique.

B) protocol. Pg. 709: see "Terminology"

Which of the following pitch ratios is considered to be oversampling? A) 2:1 B) 3:1 C) 0.5:1 D) 1:1

C) 0.5:1 Pg. 697: A 0.5:1 ratio would increase patient dose because of oversampling of the anatomy. smaller pitch = more tissue sampled due to more overlap

Approximately ____ of all head CTs generally require intravenous contrast media. A) 10% to 30% B) 30% to 50% C) 50% to 90% D) None of the above; all require contrast media.

C) 50% to 90% Pg. 700: it is estimated hat 50% to 90% of all head CT scans require an intravenous injection of contrast medium.

CT fluoroscopy can obtain and display partially reconstructed images at a rate of _____ images per second. A) 1 to 3 B) 6 to 8 C) 8 to 12 D) 20 to 25

C) 8 to 12 Pg. 708: Partially reconstructed images can be obtained and displayed at the rate of 8 to 12 images per second.

What is the major advantage of volume CT over standard CT imaging? A) Generates less tube heat units B) Allows cardiovascular scanning because of shorter scanning times C) Allows a volume of tissue to be examined rather than individual slices only D) Requires less dose be given to the patient

C) Allows a volume of tissue to be examined rather than individual slices only pg. 694

What is the name of the passageway from the third to fourth ventricle? A) Foramen of Monro B) Interventricular foramen C) Cerebral aqueduct D) Foramen of Luschka

C) Cerebral aqueduct pg. 687: the cavity of the third ventricle connects posterioinferiorly with the fourth ventricle through a passage known as the cerebral aquaduct.

What is the name of the white brain structure that connects the two cerebral hemispheres? A) Central sulcus B) Falx cerebri C) Corpus callosum D) Insula

C) Corpus callosum Pg. 686: the corpus callosum, located deep within the longitudinal fissure, consists of an arched mass of transverse fibers (white matter) connecting the two cerebral hemispheres.

What is the name of the channels located between the cranium and dura mater that contain blood? A) Subdural space B) Epidural space C) Dural mater sinuses D) Subarachnoid space

C) Dural mater sinuses Pg. 685: The outer layer of the dura matter s tightly fused to the inner layer, except for spaces that are provided for large venous blood channels called venous sinuses, or dura matter sinuses.

Which of the ventricles is located directly superior to the cistern cerebellomedullaris? A) Lateral B) Third C) Fourth D) Second

C) Fourth Pg. 687: see figure 18.10 - the diamond shaped froth ventricle connects

Which generation of CT scanner first used a fixed ring of detectors? A) Second B) Third C) Fourth D) None of the above

C) Fourth pg. 693: fourth generation scanners possessed a fixed ring of 4800 or more detectors, which completely surrounded the patient in a full circle within the gantry.

Which of the following structures is not part of the hindbrain? A) Cerebellum B) Pons C) Hypothalamus D) Medulla

C) Hypothalamus pg. 689: the hindbrain consists of the cerebellum, pons, and medulla.

The common lumbar puncture site is located at the vertebra level of: A) T12-L1. B) L1-2. C) L3-4. D) L4-5.

C) L3-4. Pg. 684: a commons lumbar puncture site is between L3 and L4.

At what vertebral level is the tapered, terminal part of the spinal cord found? A) Lower border of T10 B) L4-5 joint space C) Lower border of L1 D) S1-2

C) Lower border of L1 pg. 684: the conus medullaris is the distal tapered ending of the spinal cord at the lower level f L1

Along with the posterior pituitary gland and the infundibulum, what other structure or region is associated with the hypothalamus? A) Thalamus B) Olfactory nerve C) Optic chiasm D) Falx cerebri

C) Optic chiasm pg. 689: Three significant structures associated with the hypothalamus are the infundibulum, posterior pituitary gland, and the optic chiasm.

What controls the actual slice thickness on multislice CT scanners? A) Filament of x-ray tube B) Postpatient collimator C) Size of the detector row used D) Prepatient collimator

C) Size of the detector row used pg. 695: The slice thickness on modern multi detector CT units is determined by the size of the detector row used.

A CT colonography requires the use of ________ as a contrast medium. A) barium sulfate B) iodinated rectal contrast C) air D) all of the above

C) air Pg. 706: air or CO2 is instilled into the large intestine (demonstrates the intestinal wall).

An undesired feature or density in the CT image not representative of anatomy is a(n): A) CT aberration. B) noise. C) artifact. D) windowing flaw.

C) artifact. Pg. 709: see "Terminology"

Major functions of the cerebellum include: A) regulation of body temperature. B) visual perception. C) coordination, posture, and balance. D) regulation of blood pressure.

C) coordination, posture, and balance. pg. 690: the cerebellum primarily coordinates the important motor functions of the body, such as coordination, posture, and balance.

Prospective electrocardiogram (ECG) gating used during cardiac CT permits the heart to be scanned: A) during maximum cardiac contraction. B) while tricuspid and mitral valves are open. C) during the diastole cycle. D) during the systole cycle.

C) during the diastole cycle. pg. 708: prospective ECG gating = the heart is scanned only during times of least motion n the cardiac cycle (cardiac motion is less during diastole)

Muscular structures seen on a CT image would appear: A) white. B) black. C) gray. D) dark gray.

C) gray. Pg. 697: see table 18.2

How long is the catheter left in place following a percutaneous abscess drainage (PAD) procedure? A) 1 hour B) 6 hours C) 12 hours D) 24 to 48 hours

D) 24 to 48 hours Pg. 709: The catheter is sutured into place, and the abscess drains for approximately 24 to 48 hours.

The success rate for CT percutaneous abscess drainage is reported to be: A) 20%. B) 30%. C) 50%. D) 85%.

D) 85%. Pg. 709: the success rate of CT percutaneous abscess drainage is 85%

Which window widths are CT head scans viewed? A) Soft-tissue window B) Bony window C) Gray and white matter windows D) Both A and B

D) Both A and B pg. 702: Head CT images are viewed with two window settings or window widths. A narrow window width allows optimal visualization of soft tissue and brain, and a wide window width displays optimal bony detail.

What is the name of the tapered, terminal part of the spinal cord? A) Medulla spinalis B) Encephalon C) Axon D) Conus medullaris

D) Conus medullaris pg. 684: the conus medullaris is the distal tapered ending of the spinal cord at the lower level f L1

Which of the following statements is not an advantage of CT (computed tomography) over conventional imaging? A) Can adjust the contrast or gray scale B) Can display anatomy in a series of slices C) Can measure attenuation of specific tissues D) Exposes the patient to less radiation

D) Exposes the patient to less radiation

What is the name of the site where some optic nerve fibers cross in the brain? A) Cisterna magna B) Pons C) Cisterna pontis D) Optic chiasma

D) Optic chiasma pg. 692: within the optic chiasm, some fibers cross to the opposite side, and some remain on the same side.

Which of the following structures is also called the hypophysis? A) Pineal gland B) Pons C) Cerebral peduncles D) Pituitary gland

D) Pituitary gland pg. 689: the pituitary gland, also called the hypophysis...

Which of the following is NOT an advantage of a multislice CT scanner? A) Has fast imaging speed B) Acquires large number of slices rapidly C) Minimizes patient motion D) Reduces patient dose

D) Reduces patient dose

Which of the following conditions may be a contraindication for head CT? A) Epidural hematoma B) Intracranial hemorrhage C) Brain abscess D) Sensitivity to iodinated contrast media

D) Sensitivity to iodinated contrast media

Which one of the following pathologic indications for a head CT is directly related to trauma? A) Hydrocephalus B) Brain atrophy C) Brain abscess D) Subdural hematoma

D) Subdural hematoma Pg. 701: trauma = epidural and subdural hematoma, fracture

Which structure connects the two hemispheres of the cerebellum? A) Falx cerebri B) Tentorium cerebelli C) Basal ganglia D) Vermis

D) Vermis pg. 690: the cerebellum is shaped like a butterfly and consists of right and left hemispheres united by a narrow median strip, the vermis.

The capability to create accurate reconstruction of patient data into alternative planes (coronal, sagittal, three-dimensional) is termed: A) multiple image reconstruction. B) maximum intensity projection. C) algorithmic reconstruction. D) multiplanar reconstruction.

D) multiplanar reconstruction. pg. 698: multiplanar reconstruction (MPR) - volumetric data allow more accurate reconstruction of patient data into alternative planes.

Another term for topogram is: A) CT scan. B) CAT scan. C) MPR. D) scanogram.

D) scanogram. Pg. 709: see "Terminology"

A collection of blood accumulating under the dura mater caused by trauma is termed: A) subarachnoid hemorrhage. B) glioma. C) subdural abscess. D) subdural hematoma.

D) subdural hematoma. pg. 704: a subdural hematoma is a blood clot that forms between the dura mater and the surface of the surface of the brain as a result of damage to the cerebral venous circulation.

True/False: Biopsies can be performed during a CT colonography.

False

True/False: Multislice CT is not recommended for abdomen studies.

False

CT angiography (CTA) does not require the use of intravenous contrast media to demonstrate vascular structures.

False Pg. 707: CT angiography provides the advantage of administering contrast medium intravenously.

True/False: Volume acquisition CT slices cannot be reformatted as 3-D images.

False pg. 696

True/False: Window level (WL) in CT controls the displayed image contrast.

False pg. 697: WL controls image brightness

True/False: CT colonography has eliminated the need for the patient undergoing a bowel prep.

False pg. 706: before the exam is begun the patient must undergo bowel prep to ensure that no fecal debris in the large intestine may obscure anatomy or pathology.

True/False: Most CT systems archive image data on magnetic tape systems.

False pg. 695: image archiving for most CT systems involves the use f digital media that are housed in the PACS archive.

What type of neuron conducts electric impulses toward the cell body? A) Axon B) Dendrite C) Nerve cell D) Multipolar neuron

Pg. 684: Dendrites are the processes that conduct impulses toward the neuron cell body. An axon is a process that leads away from the cell body.

The ratio between the relationship between table speed and slice thickness defines: A) differential absorption. B) pitch. C) voxel. D) display matrix.

Pg. 697: pitch is a ratio that reflects the relationship between table speed and slice thickness.

True/False: Window width controls the displayed image contrast.

True Pg. 697: Window width controls the displayed image contras. Window width refers to the range of CT numbers that are displayed as shades of gray. Wide window width indicates more CT numbers as a group (long scale or low contrast). Narrow window width = high contrast.

True/False: Another term for the insula is the central lobe.

True pg. 686: The fifth lobe termed the insula, or central lobe, is more centrally located.

True/Fasle: The cerebrum is divided into five lobes.

True pg. 686: see figure 18.6 1) frontal lobe 2) parietal lobe 3) Occipital lobe 4) temporal lobe 5) insula central) lobe

True/False: Current multislice CT scanners can acquire up to 320 slices per x-ray tube rotation.

True pg. 694: At the present time, multislice scanners are available that can image 320 slices per x-ray tube.

True/False: Artifacts caused by patient motion are reduced with volume CT scanning as compared with earlier generation scanners.

True pg. 694: advantages of volume CT scanners 1) multiplanar reconstruction (MPR) 2) shorter scan times 3) artifacts reduced

True/False: Submillimeter slice thicknesses are possible with multislice CT scanners.

True pg. 694: submillimeter slice thickness is possible as a result of multislice technology.

True/False: The gantry houses the x-ray tube and the detector array.

True pg. 695: the gantry consists of the X-ray tube, detector array, and collimators.

True/False: The three-dimensional volume of tissue in a slice is called a voxel.

True pg. 696: Each pixel is a 2D representation of the 3D volume of tissue in the CT slice. These 3D tissue volumes are called volume elements, or voxels.

True/False: Glucose and oxygen are able to pass through the blood-brain barrier.

True pg. 700: glucose, oxygen, and certain ions pass readily from the circulatory blood into extracellular fluid and then into brain cells. Brain tissue differs from other tissues in that it possess a natural barrier to the passage of certain substances.

True/False: Oxygen deprivation to the brain for 4 minutes can lead to permanent brain cell injury.

True pg. 700: oxygen must be in constant supply because total oxygen deprivation for 4 minutes can lead to permanent brain cell damage.

True/False: Special filters can be used during CT fluoroscopy to reduce patient skin dose during biopsies.

True pg. 708: special filters are used to reduce the patients skin dose.

True/False: A lower pitch ratio such as a 2.0:1 ratio with slice overlap leads to a reduced patient dose.

True pg. A 0.5:1 ratio would increase patient dose because of oversampling.

For each function, select the correct cranial nerve. (Use each choice only once.) - Spinal function and some swallowing a .Accessory (XI) b. Hypoglossal (XII) c. Glossopharyngeal (IX) d. Olfactory (I) e. Abducens (VI) f. Optic (II)

a .Accessory (XI) pg. 691: see table 18.1

Match each tissue with the correct CT number range.(Use each choice only once.) - Gray brain matter a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

b. +40 pg. 697: See table 18.2 +40 (gray)

MATCHING Select the correct lettered portion of the brain.(Use each choice only once.) - Thalamus a. A b. B c. C d. D e. E f. F

b. B pg. 689: see figure 18.16

For each function, select the correct cranial nerve.(Use each choice only once.) - Taste and swallowing a .Accessory (XI) b. Hypoglossal (XII) c. Glossopharyngeal (IX) d. Olfactory (I) e. Abducens (VI) f. Optic (II)

b. Hypoglossal (XII) pg. 691: see table 18.1

Match each tissue with the correct CT number range.(Use each choice only once.) - Blood a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

c. +20 pg. 697: See table 18.2 +20 (gray)

MATCHING Select the correct lettered portion of the brain.(Use each choice only once.) - Medulla a. A b. B c. C d. D e. E f. F

c. C pg. 689: see figure 18.16

Match each tissue with the correct CT number range.(Use each choice only once.) - Fat a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

d. -100 pg. 697: See table 18.2 -100 (dark gray to black)

MATCHING Select the correct lettered portion of the brain.(Use each choice only once.) - Pons a. A b. B c. C d. D e. E f. F

d. D pg. 689: see figure 18.16

For each function, select the correct cranial nerve.(Use each choice only once.) - Smell a .Accessory (XI) b. Hypoglossal (XII) c. Glossopharyngeal (IX) d. Olfactory (I) e. Abducens (VI) f. Optic (II)

d. Olfactory (I) pg. 691: see table 18.1

Match each tissue with the correct CT number range.(Use each choice only once.) - Lung tissue a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

e. -200 pg. 697: See table 18.2 -200 (dark gray to black)

For each function, select the correct cranial nerve.(Use each choice only once.) - Eye movement a .Accessory (XI) b. Hypoglossal (XII) c. Glossopharyngeal (IX) d. Olfactory (I) e. Abducens (VI) f. Optic (II)

e. Abducens (VI) pg. 691: see table 18.1

MATCHING Select the correct lettered portion of the brain.(Use each choice only once.) - Cerebellum a. A b. B c. C d. D e. E f. F

e. E pg. 689: see figure 18.16

Match each tissue with the correct CT number range.(Use each choice only once.) - Air a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

f. -1000 pg. 697: See table 18.2 -1000 (black)

MATCHING Select the correct lettered portion of the brain.(Use each choice only once.) - Midbrain a. A b. B c. C d. D e. E f. F

f. F pg. 689: see figure 18.16

For each function, select the correct cranial nerve.(Use each choice only once.) - Vision a .Accessory (XI) b. Hypoglossal (XII) c. Glossopharyngeal (IX) d. Olfactory (I) e. Abducens (VI) f. Optic (II)

f. Optic (II) pg. 691: see table 18.1

Match each tissue with the correct CT number range.(Use each choice only once.) - Cortical bone a. +50 b. +40 c. +20 d. -100 e. -200 f. -1000 g. +1000 or higher

g. +1000 or higher pg. 697: See table 18.2 +1000 or higher (white)

For each function, select the correct cranial nerve.(Use each choice only once.) - Tongue movement, speech, and swallowing a .Accessory (XI) b. Hypoglossal (XII) c. Glossopharyngeal (IX) d. Olfactory (I) e. Abducens (VI) f. Optic (II)

pg. 691: see table 18.1