ROC151 Test 1

EMR contains:

- Patient's identification -Ordered and planned procedures -Treatment data -Physician notes -Lab work

Benefits of CT Simulation (lots)

-The ability to outline critical structures and view these structures in three dimensions -The ability to delineate the target volume and lymph nodes in the patient's treatment position -Optimal beam placement -Beam's eye view (BEV) display allows anatomy to be viewed from the perspective of the radiation beam -Allows manipulation of data/images without patient being present -Boost fields can be planned without patient present -CT simulation allows field shaping electronically at the graphic display station -The calculation of dose distribution• Construction of digital reconstructed radiographs (DRRs)

Essential components of a CT scanner are

1. CT Gantry 2. Patient table 3. Intercom 4. Computer with Array processer 5. High voltage generator

What are the 3 steps of CT image formation:

1. Data acquisition 2. Image reconstruction 3. Image display

A creatinine level of greater than ________ for women and greater than _______ for men may be an early sign that the kidneys are not working well.

1.2 & 1.4

Typical kVp settings range from ______ to ______.

100-140

It was in the late _______ and early ________ that a type of CT scanner specifically for radiation therapy was attempted

1970's......1980's

In what year did a a physicist/engineer named _____________ first demonstrated CT imaging.

1973, Godfrey Hounsfield

What is the most common size used for image matrix?

512x512

What is normal eGFR levels?

90 or above An eGFR below 60 is a sign that the kidneys are not working well.

Which of the following is the window width on a CT image? A) The range of numbers displayed on a CT image B) The number of columns and rows of pixels demonstrated on an image C) An unwanted image characteristic D) The central Hounsfield unit of all the CT numbers displayed on an image

A) The range of numbers displayed on a CT image

In multi-slice CT, as the pitch increases, the z-gap _____ and image quality _____ . A) increases; decreases B) decreases; increases C) increases; increases D) decreases; is unaffected

A) increases; decreases

Ghosting refers to _____ artifacts. A) motion B) cupping C) ring D) static

A) motion

1. When setting scan parameters, it is best to review both an AP and Lateral topogram? A) true B) false

A) true

When setting scan parameters, it is best to review both an AP and Lateral topogram. A) true B) false

A) true You need to check both AP and Lat to make sure all needed anatomy is included.

The tube rotates once around a stationary table. The table is then moved a small increment and the tube rotates again. (slice by slice scanning) is also known as: A. Conventional CT scanners B. Sprial/helical CT scanners

A. Conventional CT scanners

_______________ uses preprocessed raw data (data actually collected by scanner) A. Reconstruction B. Reformatting

A. Reconstruction

Abdominal cavity is part of the A. Ventral cavities B. Dorsal cavities

A. Ventral cavities

The Hounsfield unit of 0 would represent what? A. Water B. Bone C. Muscle D. None of the above

A. Water

Who developed the mathematics used to construct the CT images?

Alan Cormack

___________ is a(n) finite set of instructions used by computers to compute a desired result

Algorithm

What organization developed DICOM?

American College of Radiology (ACR)

Collimators: 1) Reduce scatter radiation 2) Restrict the path of the x-ray beam 3) Minimize the x-ray dose to the patient A) 1 & 3 B) 1,2, & 3 C) 1 & 2 D) 2 & 3

B) 1,2, & 3

The spleen is located in which region of the abdominal cavity? A) Hypogastric B) Left hypochondriac C) Left iliac D) Right hypochondriac

B) Left hypochondriac

1. Partial volume averaging can be improved by using: A) smaller pixel sizes. B) a smaller SFOV. C) thinner slice thicknesses.

B) a smaller SFOV. EX: Bone and fat in the same pixel- computer averages both densities. If we scan a smaller SFOV we will have a smaller number of pixels in the view of the anatomy.

The z-axis refers to the ______ plane. A) coronal B) axial C) sagittal D) oblique

B) axial

What is the effect of increased image noise? A) increased contrast resolution B) decreased contrast resolution C) improved image quality D) A and C are correct.

B) decreased contrast resolution

1. The shift method can avoid potential errors in patient positioning because the isocenter and patient markings are placed while the patient is in the scan position. A) true B) false

B) false

A patient with a creatinine level of 1.6 can safely receive IV contrast. A) true B) false

B) false

One advantage of reformatting is that image detail is increased A) true B) false

B) false; decreased

Image noise can be reduced by: A) decreasing mAs. B) increasing slice thickness. C) decreasing pixel size. D) A and C are correct.

B) increasing slice thickness

1. Adverse reactions to iodinated contrast administration most commonly appear: A) immediately after administration. B) within 3 minutes of administration. C) within 30 minutes of administration. D) within 3 hours of administration.

B) within 3 minutes of administration.

The Hounsfield unit of +1000 would represent what? A. Water B. Bone C. Muscle D. None of the above

B. Bone

What would be a cause of a ring artifact? A. Metal object B. Detector not working C. Patient motion D. Slow scan

B. Detector not working

An increase of kVp will ______ image density A. Lower B. Double C. Triple

B. Double

________________ is rearranging the image data set and data is manipulated to show image in different planes A. Reconstruction B. Reformatting

B. Reformatting

The gantry rotates around the patient continuously in one direction while the table moves inward as it scans. (volume scanning) is also known as: A. Conventional CT scanners B. Sprial/helical CT scanners

B. Sprial/helical CT scanners

1) The first commercial CT scanner was available during the: A) 1990s B) 1980s C) 1970s D) 1960s

C) 1970s

Spatial resolution can be increased by using: 1) larger-size detectors. 2) a smaller pixel size. 3) thinner slice thicknesses. A) 1 and 2 B) 1 and 3 C) 2 and 3 D) 1, 2 and 3

C) 2 and 3 Smaller detector size does increase spatial resolution but we cannot control this. We have control over pixel size and slice thickness. Thin slices have better spatial resolution.

1. CT scanner x-ray tube voltages range from _____ to _____ kilovolts (kV). A) 60; 100 B) 80; 120 C) 90; 140 D) 100; 160

C) 90; 140

1) As the display field of view increases, the resulting radiation dose to the patient: A) decreases B) increases C) is not affected

C) is not affected

As the display field of view increases, the resulting radiation dose to the patient: A) decreases B) increases C) is not affected

C) is not affected- it is how it is displayed on the monitor. The image has already been produced we are just changing how we look at it so it does not affect dose.

1) A pitch of _____ results in the highest dose to the patient. A) 1 B) 2 C) less than 1 D) Pitch does not affect patient dose.

C) less than 1

A pitch of _____ results in the highest dose to the patient. A) 1 B) 2 C) less than 1 D) Pitch does not affect patient dose.

C) less than 1 - more slices so more dose to patient

Which of the following factors decreases contrast resolution? A) smaller field of view B) smaller matrix size C) smaller pixel size D) higher mAs

C) smaller pixel size

What year was the first tomographic imaging system created? A. 1895 B. 1930 C. 1920 D. 1985

C. 1920

__________ test is a blood test that measures how well your kidneys filter waste from your blood and how well your kidneys are functioning. A. BUN B. Creatine C. eGFR D. CMP

C. eGFR

What vertebra corresponds with the mastoid tip?

C1

____________ is the element of imaging that provides visual evidence of the all important differential absorption rates of various body tissues

Contrast

What are the two most important concepts in imaging?

Contrast and Density

Which of the following cross-sectional orientations of an abdomen can be directly scanned in CT? 1) Sagittal 2) Coronal 3) Transverse A) 1 & 3 B) 1 only C) 2 only D) 3 only

D) 3 only

1. Which of the following is the window level on a CT image? A) The range of numbers displayed on a CT image B) The number of columns and rows of pixels demonstrated on an image C) An unwanted image characteristic D) The central Hounsfield unit of all the CT numbers displayed on an image

D) The central Hounsfield unit of all the CT numbers displayed on an image

1. Partial volume averaging occurs when: A) similar tissue types share the same voxel. B) cardiac studies are performed. C) metal objects are present within the patient or the patient's clothing. D) detector elements fail.

D) detector elements fail.

1. Which of the following is not a common contrast injection reaction? A) pain at the injection site B) metallic taste C) flushed feeling in the pelvis D) dyspnea

D) dyspnea

The Hounsfield unit of -1000 would represent what? A. Water B. Bone C. Muscle D. Air

D. Air

Clarity or the measure of detail in a CT image A. Contrast B. Noise C. Dose D. Spatial resolution

D. Spatial resolution

___________ is the standard image format to transfer information between the imaging devices and the treatment planning computer.

DICOM (Digital Imaging and Communications in Medicine)

What are 3 internal aspects of the gantry of the CT scanner?

Detector array, x-ray tube, generator

TRUE or FALSE: If window width is narrowed, lower contrast and less sharper images in the shades of grey as a result.

FALSE greater contrast or sharper images in the shades of gray as a result.

TRUE or FALSE If someone has a BUN level of 23, it is a good indicator that the kidneys are functioning properly.

FALSE; A normal BUN level is between 7 and 20. As kidney function decreases, the BUN level can rise.

TRUE or FALSE The asthenic habitus exhibits a short, wide trunk; great body weight; and a heavy skeletal framework. The abdomen is long with great capacity, the alimentary tract is high, and the stomach is almost thoracic.

FALSE; Hypersythenic

TRUE or FALSE Barium sulfate is water soluble

FALSE; barium sulfate is NOT water soluble

TRUE or FALSE One advantage of reformatting is that image detail is increased.

FALSE; decreased

CT number is also known as what?

Hounsfield units (because Godfrey Hounsfield originally demonstrated CT imaging in 1973)

What is a disadvantage to reformatting?

Image detail decreases

Images seen on the screen are a display of cells in rows and columns called the __________ ___________.

Image matrix

The splenic flexure is located in which quadrant?

LUQ

Why did it take so long for the CT technology to make its way to Radiation Therapy?

Lack of high quality digitally reconstructed radiographs (DRRs) Limited treatment planning systems that did not allow for interactive definition of target volumes and dose calculations

Who was the first to depict cross-sectional anatomy and studied animals to determine internal anatomy?

Leonardo Da Vinci (Born on the April 15, 1452)

___________ is a specialized technique that uses injected dyes to help visualize the lymphatic system

Lymphangiography; Lymphatic vessels are visualized as white areas

TRUE or FALSE The therapist normally has to pre-set the scanning parameters, this includes setting the kVp and mA's.

Most scanners have 'pre-set' scanning parameters that take into account what is being imaged, so therapists do not have to adjust kVp and mAs.

PACS stands for what? When was it available?

Picture archiving system, available in the 1990's

__________ __________ is a scanning method in which the scanner is triggered to acquire an image set at a specific point of respiration while letting the patient breathe freely during the scan.

Prospective axial

hepatic flexure is located in which quadrant?

RUQ

SFOV is smaller or larger than the aperture of the gantry?

SMALLER

Thenar

The fleshy part of the hand at the base of the thumb

Volar

The sole of the foot or palm of hand

To minimize beam hardening artifacts __________ _________ should be used.

Thin slices. Beam hardening artifacts are seen as dark bands often near bone.

_________________ refers to any imaging method in which the patient's tissues are visualized by 'cutting' them into sections.

Tomography

-100 to +100 represents what?

Water, soft tissue, and fat

__________ ____________ is the range of numbers displayed or the contrast on a CT image.

Window Width (WW)

__________ ____________ represents the central HU of all the CT numbers within the WW.

Window level (WL)

What part of the CT scanner is used to reconstruct the CT images a. High voltage generator b. CT gantry c. Computer with array processor d. all of the above

c. Computer with array processor

TRUE or FALSE Ipsilateral means on the opposite side of the body.

false (contralateral)

What is pitch?

is the distance traveled by the couch during one x-ray tube rotation.

What controls the contrast of an image?

kVp

What controls the quantity of x-rays produced?

mAs

peritoneum

membrane that lines the abdominal cavity

Imaginary horizontal line goes through...

midline through the umbilicus (navel)

Imaginary vertical line goes through....

midline through the xiphoid process

A small pixel size creates better spatial resolution, however the image is ________.

noisy

Kidneys are located in the ______________ area.

retroperitoneum

To minimize star artifacts....

surgical clips or metal objects should be removed or avoid metal objects within the FOV

Superior

toward the head

Rostral

toward the nose