CT Tutor Test 1 Wrong Answers

Question 1

Cone beam artifacts are related to the advances found in multi-row scanners because:

Answer 1

The traditional filtered back projection method of reconstruction cannot handle image formation with a beam collimation greater than 20mm

Question 2

The system that consists of a secure network for transmission of patient information, a CT scanner, multiple workstations for interpreting and reviewing images and storage archived is called:

Answer 2

PACs

Question 3

SFOV (or scan field of view) controls the diameter of the data acquired and is determined by

Answer 3

The detector array

Question 4

The positioning system that assumes the patient is in the supine position is called:

Answer 4

Patient coordinate system

Question 5

The technology that allowed the smaller, high-frequency generator to be located inside the CT gantry:

Answer 5

Slip ring technology

Question 6

The main purpose of filtered backprojection is

Answer 6

To create artifact free images

Question 7

What is the normal range for adult blood urea nitrogen (BUN) levels?

Answer 7

5-20 mg/dL

Question 8

As the section (slice) width is increased the collimation is decreased.

True

False

Answer 8

True

Collimation determines slice width, the greater the collimation the smaller the slice width.

Question 9

Answer 9

Lymphoma

Question 10

Which of the following symptoms would be exhibited in a patient experiencing shock?

Rapid, shallow breath

Cyanosis

Tachycardia

All of the above

Answer 10

All of the above

Question 11

Of the following x-ray interactions between the x-ray beam and the patient which results in the most patient dose?

Photoelectric effect

Bremsstrahlung

Compton scatter

Characteristic

Answer 11

Photoelectric effect

The photoelectric interaction results in the complete absorption of the energy from the incident x-ray photon within the patient’s body.

Question 12

The type of image reconstruction used in the first-generation prototype CT scanner was _____________.

Convolution method

Fourier transform

Back-projection

Iterative technique

Answer 12

Iterative technique

Question 13

With cupping artifacts, CT numbers are higher at the edges of the image and lower in the center.

True

False

Answer 13

true

There is less beam hardening at the edges of the image hence higher CT numbers and the radiation path are longer to the center of the image which causes a low number in the center.

Question 14

Parotid gland

Submandibular gland

Sublingual gland

Salivary gland

Answer 14

Submandibular gland

Question 15

If the filter at the aperture of the x-ray tube removed even more low energy x-ray photons which of the following would result?

An increase in partial volume artifacts.

A decrease in partial volume artifacts.

An increase in beam hardening artifacts.

A decrease in beam hardening artifacts.

Answer 15

A decrease in beam hardening artifacts.

Removing more of the low energy x-ray photons results in higher energy in the incident x-ray beam. This will decrease the amount of beam hardening artifacts due to the removal of the low energy x-ray photons.

Question 16

When administering intravenous iodinated contrast media what type of infection control technique is required?

Surgical asepsis

Enteric precautions

Medical asepsis

Droplet isolation

Answer 16

Surgical asepsis

Question 17

The average density of a solitary pulmonary nodule indicates it is benign when it falls within the following ranges…

15-30 Hounsfield units

50-80 Hounsfield units

125-145 Hounsfield units

175-200 Hounsfield units

Answer 17

175-200 Hounsfield units

Researchers feel pulmonary nodules appearing on CT examinations of the lungs can be considered benign if their average density is more than +164 Hounsfield units. The closer to +200 Hounsfield units the more certain the benign diagnosis is accurate.

Question 18

Internal jugular vein

Internal carotid artery

External carotid artery

Common carotid artery

Answer 18

Common carotid artery

Question 19

When completing a CT examination for the post-myelogram of the lumbar spine in an adult patient, which of the following would be an acceptable range for contrast volume for the intrathecal injection?

1-3 mL

5-9 mL

12-14 mL

18-22 mL

Answer 19

12-14 mL

The injection rate should not exceed approximately 17 mL in an adult patient, keeping the total dose of iodine below 3 grams. The most common range of injection during post-myelographic CT is 12-14 mL in an adult patient.

Question 20

The acetabulum is formed by which of the following pelvic bones?

1. Pubis
2. Ischium
3. Ilium

Answer 20

1, 2, and 3

Question 21

The direction of the streaks that result from the edge gradient effect is perpendicular to the direction of the sharp density difference interface.

True

False

Answer 21

False

The edge gradient effect results from structures that have sharp edges and great density differences from neighboring tissues such as the interface of air and contrast media or bone and soft tissue. The resulting streak artifacts appear parallel to the direction of the sharp density difference interface due to the incorrect attenuation information that is collected and misinterpreted during the reconstruction process.

Question 22

Aneurysm

Embolus

Thrombus

Abdominal neurogenic tumor

Answer 22

Thrombus

Question 23

Transverse sinus

Sigmoid sinus

Straight sinus

Inferior sagittal sinus

Answer 23

Straight sinus

Question 24

The normal range of respiratory rate in a child is…

Answer 24

20 to 30 breaths per minute

Question 25

Of the following types of contrast material which may be used during a CT examination of the chest? Iopamidol barium sulfate Diatrizoate meglumine All of the above

Answer 25

All of the above Lopamidol is a non-ionic contrast media. Diatrizoate meglumine is an ionic contrast media. Barium sulfate contrast in the form of a paste is used to outline the esophagus.

Question 26

In reviewing a CT examination of a chest, the technologist notices a board or flat tabletop beneath the patient. This indicates what type of CT study? Invasive General survey Radiation planning Quantitative

Answer 26

Radiation planning CT scans are used to localize an area of malignant pathology for radiation therapy treatment. During this type of CT scan, the patient must be positioned exactly the same as the position used during the radiation treatment.

Question 27

The units of Sv and rem are used to measure

Answer 27

any kind of ionizing radiation

Question 28

used to measure specifically x-ray radiation

Answer 28

rad and Gy

Question 29

Of the following areas of the head, which commonly become calcified due to pathology and the aging process? 1. Pineal gland 2. Choroid plexus 3. Thalamus

Answer 29

1 and 2 only

Question 30

What is the primary reason iodine is the most common material used in radiopaque contrast media? Viscosity Radiolucency Osmolality High atomic number

Answer 30

High atomic number

Question 31

A patient has a prior history of lymphoma. Of the following sets of slice widths and spacing, which would be best for a CT scan of the abdomen and pelvis? 3 x 3 mm 5 x 15 mm 10 x 15 mm 10 x 30 mm

Answer 31

10 x 15 mm CT scans of the abdomen and pelvis may be performed with spacings of 15-20mm when using an aperture size of 10mm. If warranted, contiguous scans may be performed on specific areas of interest.

Question 32

Ascending aorta Left subclavian artery Aortic arch Aorta

Answer 32

Aortic arch

Question 33

normal BUN

Answer 33

8-23 mg/dL.

Question 34

Which of the following can be accurately demonstrated during a CT study of the abdomen without the use of iodinated contrast media? 1. Appendicitis 2. Renal stone 3. Diverticulitis 4. renal cyst

Answer 34

1, 2 and 3 only

Question 35

Outpocketings of the wall of the colon are commonly associated with \_\_\_\_\_\_\_\_\_\_\_\_. Polyps Intussusception Diverticulitis Diverticulosis

Answer 35

Diverticulosis Diverticulosis causes the presence of small pouch-like openings in the colon wall. Diverticulitis is the inflammation of the diverticula.

Question 36

A type of renal mass often seen in pediatric patients developing from immature kidney cells is termed… von Hippel-Lindau disease Wilm's tumor Krudenberg's tumor Ewing's sarcoma

Answer 36

Wilm's tumor

Question 37

Once the x-ray beam passes through an object the intensity of the beam to a detector is called the… Ray Transmitted intensity Incident intensity Primary beam

Answer 37

Transmitted intensity

Question 38

the amount of energy that passes through the patient onto a detector.

Answer 38

transmitted intensity

Question 39

The term ____________ describes a contrast material that does not dissociate into charged particles within a solution. Neutral Non-ionic Osmolar Ionic

Answer 39

Non-ionic

Question 40

What is the name of fibrous connective tissue that binds the kidneys in the retroperitoneum? Fascia of Camper Gerota's fascia Cooper's ligament Linea alba

Answer 40

Gerota's fascia

Question 41

Water-soluble based oral contrast (gastroview) should not be used when?

Answer 41

The patient has ascites

Question 42

Hyoid bone Thyroid gland Epiglottis Laryngeal vestibule

Answer 42

Epiglottis

Question 43

What is adult normal respiration?

Answer 43

12-25 breaths per minute

Question 44

The flow rate for a biphasic technique for a spiral CT study of the liver would include the which of the following sets? 2 mL/sec for 50 mL during the superior half of the liver 3 mL/sec for 50 mL followed by 1.5 mL/sec for 100 mL 2 mL/sec for 100 mL with scanning during both peak enhancement and the equilibrium phase 3 mL/sec for 150 mL with a 90 second delay before scanning

Answer 44

3 mL/sec for 50 mL followed by 1.5 mL/sec for 100 mL ## Footnote A biphasic contrast injection of the liver should include a complete scan of the liver before the onset of equilibrium to avoid hepatic lesions from being obscured. A biphasic injection has a rapid initial flow rate followed by a slower injection rate.

Question 45

Slice thickness is governed by the

Answer 45

smallest single detector element.

Question 46

Stomach Spleen Liver Pancreas

Answer 46

Stomach

Question 47

What is an average scan delay on a portal-venous phase abdomen? 20-40 seconds 40-70 seconds 2-5 minutes 6-8 minutes

Answer 47

40-70 seconds

Question 48

What is an average scan delay on a arterial phase abdomen? 20-40 seconds 40-70 seconds 2-5 minutes 6-8 minutes

Answer 48

20-40 seconds

Question 49

What is an average scan delay on a equalibrium phase abdomen? ## Footnote 20-40 seconds 40-70 seconds 2-5 minutes 6-8 minutes