1
Q
What does the high-voltage generator do?
A
It provides power to the x-ray tube in one of three ways: single-phase, three-phase, or high-frequency power.
2
Q
What are the three primary parts of a high-voltage generator?
A
The high-voltage transformer, filament transformer, and rectifiers.
3
Q
What does the high-voltage transformer do?
A
It is a step-up transformer — it increases the voltage on the secondary side compared to the primary side.
4
Q
What is the function of a rectifier?
A
A rectifier allows current to flow in only one direction, converting AC to DC.
5
Q
What are the two basic types of generators in terms of power phases?
A
Single-phase and three-phase generators.
6
Q
What happens in a half-wave rectified single-phase generator?
A
Half of the current is wasted or suppressed, producing one pulse every 1/60 of a second (60 pulses per second).
7
Q
How many pulses per second are produced in full-wave rectification? (Single phase)
A
120 pulses per second (2 pulses every 1/60 of a second).
8
Q
How efficient is full-wave rectification compared to half-wave rectification?
A
It is twice as efficient.
9
Q
What is a visible difference between half-wave and full-wave rectification waveforms?
A
Half-wave has gaps in the waveform, while full-wave has no gaps.
10
Q
How is power delivered in a three-phase generator?
A
Through three separate power lines that overlap phases, so the voltage never falls to zero.
11
Q
What are the advantages of three-phase power?
A
Shorter exposure times, Reduced motion blur, Less heat produced, Higher quality x-ray beam (more penetrability)
12
Q
How many pulses per second occur in a full-wave rectified three-phase system?
A
360 pulses per second.
13
Q
What type of rectification does single-phase power produce?
A
Half-wave or full-wave rectification.
14
Q
What is the main drawback of single-phase power?
A
The voltage waveform drops near zero, producing low-energy, low-penetrability x-rays — not ideal for diagnostic imaging.
15
Q
Why is three-phase power more efficient?
A
It combines multiple voltage waveforms that maintain a nearly constant high voltage.
16
Q
Are more modern machines single-phase power or three-phase power?
A
Three-phase power
(Does not require as high technique)
17
Q
Why are tube loading charts important?
A
They prevent thermal overloading and potential tube damage by indicating safe exposure conditions.
18
Q
What is a tube rating chart?
A
A chart that shows the safe or unsafe tube capacity in terms of heat load for specific technical factors (kVp, mA, and time).
19
Q
What do the axes and curves represent on a tube rating chart?
A
X-axis: exposure time (seconds), Y-axis: tube current (mA), Curves: specific kVp values.
20
Q
How do you determine if an exposure is safe using the chart?
A
If the intersection of mA and time is below the kVp curve → Safe. If the intersection is above the kVp curve → Unsafe.
21
Q
What do fluoro towers (II) have that x-ray tubes don’t?
A
The ability to zoom in
22
Q
When was the early fluoroscope made and by whom?
A
1896, Thomas Edison and Clarence Dally
23
Q
What sort of goggles were produced in the 40s to help fluoroscopists?
A
Red goggles to help the doctor adapt to seeing in the dark. Didn’t prevent radiation from reaching the eyes
24
Q
In an image intensifier (II) tube, each incident x-ray that interacts with the input phosphor results in what?
A
A large number of light photons at the output phosphor
25
A
Glass envelope
26
B
Focal point
27
C
Output phosphor
28
D
Anode
29
E
Electrostatic lenses
30
F
Electrons
31
G
Photocathode
32
H
Input phosphor
33
What is fluoroscopy?
Fluoroscopy allows imaging of movement of internal structures in real time.
34
What is image intensification?
A process where exit radiation from the body is converted into visible light by the input phosphor, then into electrons by the photocathode, focused by electrostatic lenses, and accelerated to the output phosphor to create a brighter image.
35
What is image-intensified fluoroscopy?
Dynamic imaging in which exit radiation is converted to light and then to an electronic signal displayed on a monitor.
36
What is brightness gain?
The overall increase in image brightness, a product of flux gain × minification gain.
37
What is flux gain?
The increase in light intensity at the output phosphor due to acceleration of electrons.
38
What is minification gain?
The increase in brightness resulting from the smaller output phosphor size compared to the input phosphor.
39
What happens in magnification mode?
Voltage to electrostatic focusing lenses increases, tightening the electron stream and shifting the focal point, magnifying the image.
40
What are the pros and cons of magnification mode?
It improves visualization of small structures but increases patient radiation dose.
41
What is shape distortion (pincushion effect)?
Unequal magnification or distortion caused by inaccurate focusing of electrons at the photocathode edges.
42
What is vignetting?
Loss of brightness around the periphery of the image.
43
What causes image noise?
Insufficient x-ray quantity, leading to a grainy or noisy image.
44
How is the image from the output phosphor displayed on a monitor?
It is converted to an electrical (video) signal by a television camera.
(television monitor converts electric signal into visible image)
45
What are the two main types of television cameras?
Camera tube and Charge-Coupled Device (CCD)
46
What is a camera tube?
Vacuum tube with electron gun and photoconductive target
47
What is a Charge-Coupled Device (CCD)
Semiconductor that generates and stores electrical charge when stimulated by light
48
What are the advantages of CCDs?
Greater light sensitivity
No geometric distortion
Smaller size
49
What are CRT monitors?
Older display monitors using an electron gun to scan a phosphor layer; can display only 1–2 line pairs per mm.
50
What are LCD monitors?
Monitors containing a liquid crystal layer between polarizing layers; thinner and more modern than CRTs.
51
What are plasma monitors?
Monitors with pixels filled with neon and xenon gases, similar in design to LCDs.
52
What are common fluoroscopic recording systems?
Cassette spot filming (increases patient dose)
Film/photospot cameras
Videotape/DVD recording
53
What is digital fluoroscopy?
Image-intensified fluoroscopy with an analog-to-digital converter (ADC) and computer for digital processing.
54
What does an ADC do?
Converts the video signal into digital data (bits) for computer processing, storage, and postprocessing.
55
What improvements come with newer digital fluoroscopy systems?
Use of flat panel detectors (no camera tube or ADC needed)
Lighter and more compact design
Less electronic noise
Better contrast resolution and higher DQE (detective quantum efficiency)
56
What are the two main types of flat-panel detectors?
Cesium iodide amorphous silicon (indirect capture)
Amorphous selenium (direct capture)
57
Do flat panel detectors reduce the patient's dose?
Yes, by as much as 50%
58
What is continuous fluoroscopy?
X-ray exposure is constant and uninterrupted; produces 30 frames per second and increases patient dose.
59
What is pulsed fluoroscopy?
X-ray exposure occurs in pulses with gaps between exposures, lowering patient dose; frame rate can vary.
60
Which mode reduces radiation exposure?
Pulsed fluoroscopy.
61
How can radiation exposure be minimized?
Use intermittent or pulsed fluoroscopy
Operate in the lowest pulsed mode (less frequent) and/or lower dose (less technique)
Apply time, distance, and shielding principles
62
What are the exposure limits at the tabletop?
With ABC: ≤ 10 R/min (88 mGy/min)
Without ABC: ≤ 5 R/min (44 mGy/min)
63
What are the minimum source-to-skin distances (SSD)?
Stationary unit: ≥ 38 cm (15 in)
Mobile unit: ≥ 30 cm (12 in)
64
What does the fluoroscopic system resolution test evaluate?
It tests the system’s ability to display fine details — both small (high-contrast) and large (low-contrast) objects.
65
What is the purpose of the fluoroscopic automatic brightness control (ABC) performance test?
To evaluate image quality when exposure parameters such as dose rate, pulsed mode, and field of view (FOV) are changed.
Maintains overall appearance of intensified image (contrast and brightness)
66
What does the fluoroscopic phantom image quality test assess?
The overall quality of the displayed image, checking for image distortion or image lag.
67
What is the purpose of the fluoroscopic exposure rate test?
To measure the intensity of the x-ray beam during fluoroscopy.
68
What does the fluoroscopic alignment test ensure?
That the x-ray beam is properly aligned with the center of the image intensifier, within 2% of the SID.
69
What is the purpose of the patient dose monitoring system calibration test?
To check that dose monitoring systems (such as DAP meters) are functioning correctly.
70
What does the digital monitor performance test evaluate?
It assesses the display characteristics of the monitor to ensure accurate image presentation.
71
A
TV camera
72
B
Cine camera
73
C
Light photons
74
D
Output phosphor
75
E
Anode
76
F
Electrostatic lenses
77
G
Electrons
78
H
Photocathode
79
I
Input phosphor
80
J
X-rays
81
K
X-rays
82
L
Under-table x-ray tube
83
M
Image intensifier
84
N
Spot-film camera
85
How does the mA used in image intensified fluoroscopy compare to the mA used in radiographic mode?
II fluoro is low (0.5-5 mA) compared to radiographic mode (50-1200 mA).
This is to increase fluoro time (s)
86
How is dose monitored?
Air Kerma specifies the intensity of x-rays at a given point in the air at a known distance from the x-ray source
87
What are common dose displays in fluoro that are put in PT charts?
DAP (Dose area product)
KAP (Kerma area product)
88
What's the difference between HL7 and DICOM?
They are both international standards for sharing electronic health information, but:
HL7 is text
DICOM is images
89
On a server based network, is each computer considered "equal"?
NO!
90
What is a network protocol?
An agreed upon set of rules that data uses to move through a network
91
What does MIMPS stand for?
Medical Image Management and Processing System
92
What does PACS stand for?
Picture Archiving and Communication System
93
What device stores the historic image data to be viewed along with current studies?
Archive server
94
What is an advanced image manipulation that allows multiple images to join as one?
Stitching
95
What MIMPS/PACS architecture involves a central place where all the images are stored?
Client/server
96
What are common uses for imagers in a PACS environment?
Education
Referrals
Court cases
Workers Comp
97
What does RAID stand for?
Redundant array of independent disks
98
What is a MOD disk (magneto optical) an example of?
Long term storage device
99
What device will scan an analog x-ray film into MIMPS/PACS?
Film digitizer
100
What is a network?
Two or more objects sharing resources and information (interconnected computers, terminals, servers as well as printers, scanners, barcode readers)
101
What are the two major categories of network classifications?
LAN (local area network) and WAN (wide area network)
102
What is a local area network (LAN)?
Small area networked with a series of cables or wireless access points
103
What is a wide area network (WAN)?
Large area network that spans a large area (computers are NOT physically attached...they use telephone lines and satellite links)
104
Are LAN or WAN more costly?
WAN.
Communication links are often owned by separate company
105
Are LAN or WAN faster?
LAN
106
Are PACS workstations in a radiology read room considered LAN or WAN?
LAN
107
Can larger networks (WAN) be composed of interconnected LANs ?
Yes
108
How is network type determined?
1. By the role computers play in operation of the network
2. Which computer controls the network operation
109
What are typical component role classifications of networks?
Peer to peer
Server or client based
110
What characterizes a peer-to-peer network?
All computers are equal, each controls its own information, and it is inexpensive and simple. Popular for homes and small offices.
111
What is a server-based network?
A centralized server controls operations and file storage for client computers.
112
How does a server-based network operate?
Client requests a file → server sends entire file → client processes → returns updated file.
113
Are PACS systems often peer to peer or server based?
Server based.
114
What is a client-based network?
Server processes data and returns only the results, reducing network load.
115
What is a server?
A computer that manages resources, applications, files, and network tasks.
116
What is a thin client?
A device that requests services/resources from a server (e.g., PCs, printers).
117
What is a thick client?
A computer capable of independent processing; used for high-level tasks like 3D imaging.
118
What is coaxial cable?
Sturdy cable with a central wire and braided shield; resistant to interference.
119
What is twisted-pair wire?
Four twisted pairs of copper wires with RJ-45 connectors; most common in LANs.
120
What is fiberoptic cable?
Glass threads transmitting data rapidly but fragile and expensive.
121
What are advantages of wireless networks?
Mobility and convenience.
122
What affects wireless performance?
Distance, wall composition, and thickness.
123
What is a Network Interface Card (NIC)?
Provides the physical connection between a computer and the network medium.
124
What is a network hub?
A simple device that sends incoming data to all connected devices.
125
What is a network switch?
Sends data only to the intended device, reducing traffic and increasing efficiency.
126
What is a network bridge?
Connects network segments and directs data appropriately.
127
What does a router do?
Directs data to intended targets across networks using different protocols.
128
What is an IP address?
Four groups of numbers (0–255) identifying network and device location.
129
What is a network protocol?
An agreed-upon set of rules for data transmission.
130
What is a data packet?
A piece of data containing destination address, source address, sequence number, and error info.
131
What is the OSI model?
A 7-layer communication model; understanding usually focuses on bottom 4 layers.
132
What is topology?
Physical layout of connected devices.
133
How does a bus topology work?
All devices share one wire; a break disrupts the entire network.
134
How does a ring topology work?
Devices pass messages around a circle in one direction.
135
What is a token ring?
A token circulates; only the device holding the token can transmit.
136
What characterizes a star topology?
All devices connect to a central hub/switch; most common topology.
137
Why is mesh topology used?
Provides multiple interconnecting paths and redundancy; used by the Internet.
138
What is DICOM?
Digital Imaging and Communications in Medicine—universal standard for medical image exchange.
139
Who developed DICOM?
ACR (American College of Radiology) and NEMA.
140
What does DICOM 3.0 improve?
Uses TCP/IP, strict image headers, conformance statements, and open development standards.
141
What are SOPs?
Service–Object Pairs defining the functions a device can perform.
142
What is a UID?
Globally unique identifier for study, series, and image.
143
What compression does DICOM support?
JPEG lossless (2:1), common in hospitals.
144
What is modality worklist?
Allows patient demographics to be pulled from RIS automatically.
145
What does HL-7 stand for?
Health Level 7.
146
What is HL-7 used for?
Communication between HIS and RIS; supports clinical and administrative data.
147
What does HIS contain?
Full patient medical information, billing, and orders.
148
What does RIS contain?
Radiology-specific data: scheduling, reports, and imaging information.
149
What are the three main components of PACS?
Image acquisition, display workstations, and archive servers.
150
What is soft copy?
Digital images viewed on a monitor.
151
What is a display workstation?
Any computer used to view a digital medical image.
152
What is DICOM?
Universally accepted standard for exchanging medical images and data.
153
What is workflow?
The step-by-step process of completing an exam from order entry to final report.
154
What is the archive server in PACS?
The “file room” that stores all current and historical image data.
155
What is a major inefficiency of film-based workflow?
Waiting for film processing, hanging films, and retrieving old film jackets.
156
How does PACS improve workflow?
Electronic worklists, instant image access, fast report turnaround, no film retrieval delays.
157
What is prefetching?
The system retrieving historic images automatically for comparison.
158
What defines a client-server PACS system?
Images stored on a central archive; workstations request images as needed.
159
Major advantage/disadvantage of client-server PACS systems?
Advantage: Any exam is available anywhere without intervention. Disadvantage: Archive server is a single point of failure.
160
What defines a distributed PACS system?
Images sent directly to designated reading and review stations; stored locally.
161
Main advantage/disadvantage of distributed PACS systems?
Advantage: Reading continues even if the archive server is down. Disadvantage: Worklist and image distribution errors can cause user confusion.
162
What defines a web-based PACS system?
Images and software load through a web browser; thin-client design.
163
Major advantage/disadvantage of web-based PACS system?
Advantage: Accessible from almost any computer; good for teleradiology. Disadvantage: Performance limited by network bandwidth.
164
What are the four main types of PACS workstations?
Radiologist reading station, physician review station, technologist QC station, and file-room workstation.
165
Why are LCD monitors preferred?
High resolution, low heat, brighter image, and less maintenance.
166
Does mammography or cross-sectional imaging require more resolution?
Mammo needs 5K (5-megapixel). Cross sectional only needs 1K.
167
What is the purpose of a QC workstation?
Review images before sending to the radiologist and ensure correct demographics and quality.
168
Why must technologists avoid over-manipulation?
Altering the image too much may misrepresent original diagnostic information.
169
What is the modern role of the file room workstation?
Retrieve or burn CDs of images; correct patient information if permitted.
170
What is a hanging protocol?
Pre-set rules determining how images appear on the monitor.
171
What is cine?
Rapid scrolling through image stacks (commonly CT/MRI).
172
What is window width?
Range of gray values displayed (contrast).
173
What is window level?
Center value of the gray scale range (brightness).
174
What is the purpose of flip/rotate?
Correct anatomic orientation.
175
What’s the risk of using digital markers for L/R?
Legal liability—lead markers must be used.
176
What does ROI measure?
Pixel intensity within a region to determine tissue or fluid characteristics.
177
What is MPR?
Multiplanar reconstruction—creates coronal/sagittal images from axial slices.
178
What is MIP (Maximum intensity projection) used for?
Highlighting high-intensity structures like vessels.
179
What is MinIP (Minimum intensity projection) used for?
Showing air-filled structures.
180
What is VRT (Volume rendering technique)?
Color-coded 3D visualization based on tissue intensity.
181
What does SSD (shaded surface display) show?
3D surfaces of structures above a set threshold.
182
What is stitching?
Combining multiple images into one long image (e.g., scoliosis series).
183
What is an archive in PACS?
The electronic file room and warehouse for all DICOM images and related data.
184
What does the PACS archive control?
Receipt, storage, and distribution of new and historical images.
185
How fast is storage technology advancing?
Storage capacity doubles every 18–24 months while cost per gigabyte continues to drop.
186
What two major categories make up the PACS archive?
Image manager and controller Image storage and server (archive server)
187
What does the image manager contain?
The master archived database (header info only — not actual images).
188
What is stored in the DICOM header?
Patient name, ID, exam date, ordering physician, and location.
189
What is the importance of database mirroring?
If one database goes down, the mirrored copy allows the system to continue running.
190
What are the steps when an exam is processed?
1. Order placed in RIS 2. Images acquired and sent to archive 3. Manager strips header and assigns pointers 4. Database files the data and verifies demographics 5. Query retrieves images via pointers from the archive server
191
What are the storage tiers in a PACS archive?
Short term: online, 3–5 second access Long term: near-line, 1–5 minute retrieval (Some systems have midterm)
192
What is commonly used for short-term storage?
RAID (Redundant Array of Independent Disks).
193
What is RAID?
An array of linked magnetic disks that store and manage image data.
194
Why does striping improve performance?
Multiple disks read simultaneously instead of waiting for a single disk.
195
How does error correction work?
Redundant data allow reconstruction if a disk fails.
196
What is MOD?
Magneto-optical disk; reliable, robust, faster reading; slightly higher cost.
197
Why are DVDs used over CDs?
They hold far more data (up to 17GB vs. 650MB).
198
What is UDO (ultra density optical)?
Next-generation MOD using blue-laser technology; competitive with DVDs.
199
Why is tape used?
Extremely scalable (up to petabytes), low cost.
200
How are tapes stored?
In jukeboxes/libraries with robotic arms.
201
What are disadvantages of tape?
Wear/damage, slower access time.
202
What are the three magnetic disk configurations for long-term storage?
Direct Attached Storage (DAS) Network Attached Storage (NAS) Storage Area Network (SAN)
203
Which is most popular magnetic disk configuration for long term storage in healthcare?
SAN — provides fast response and supports multiple departments.
204
What is an ASP (Application Service Provider)?
A company that provides outsourced archiving and PACS management for a monthly or per-use fee.
205
What is the advantage of ASP?
Offers state-of-the-art hardware/software without the facility purchasing it.
206
Where is short-term archive stored with ASP?
On-site at the hospital.
207
Where is long-term archive stored?
Off-site at the ASP’s remote storage center.
208
What is disaster recovery in PACS?
Creating a complete copy of the archive at a secondary location.
209
What is essential for disaster recovery?
Daily image-manager database backups and a contingency plan.
210
What are the types of film digitizers?
Laser Digitizers: Gold standard. Fast (<25 sec). High resolution (up to 5K). Expensive, require maintenance and QC CCD Digitizers: Less expensive. Slower (up to 80 sec). Trouble with extremely light/dark films. Quality now adequate for most radiologists
211
What are the main uses of digitizers?
Teleradiology Comparing outside/old films Film duplication CAD (computer-aided diagnosis)
212
What are imagers?
Film printers
213
Types of film printers/imagers?
Wet Imagers: Use chemicals. High quality. Expensive to maintain. Less common today Dry Imagers: Use heat to develop film. Lower quality. Sensitive to heat/humidity. Convenient (just outlet + network)
214
Why are imagers still used?
PACS downtime backup Surgery, orthopedics, ED Legal cases Teaching Outside physicians who prefer film
215
Why burn images to disk?
Cheaper than film Preferred by many physicians Saves space Images can be manipulated DICOM viewer can be included on the disk
216
What does the high-voltage generator do?
It provides power to the x-ray tube.
217
What are the three types of power used by x-ray generators?
Single-phase, three-phase, and high-frequency power.
218
How many pulses per second does a full-wave rectified single-phase generator produce?
120 pulses per second.
219
How do you calculate the number of dots on a single-phase spinning top test?
120 × exposure time (in seconds).
220
How many pulses per second are produced in a full-wave rectified three-phase generator?
360 pulses per second.
221
How do you calculate the degree of arc on a three-phase spinning top test?
360 × exposure time (in seconds).
222
Which type is older, the single phase generator or three-phase generator?
Single phase is older. The three phase is newer and more common nowadays.
223
Calculate the # of dotts on a single-phase generator:
80 kVp
200 mA
0.5 seconds
0.5 seconds x 120 degrees = 60 dots
224
Calculate the degree of arc on a three-phase generator:
80 kVp
200 mA
0.5 seconds
0.5 seconds x 360 degrees = 180 degree arc
225
What determines if a technique is safe on a tube rating chart?
If the point (mA & time) falls below the kVp curve.
226
What determines if a technique is unsafe on a tube rating chart?
If the point falls above the kVp curve.
227
Is 90 kVp, 175 mA, 0.5 s safe?
No—unsafe.
228
Is 70 kVp, 125 mA, 3 s safe?
Yes—safe.
229
What does fluoroscopy allow?
Imaging of movement of internal structures.
230
What are external artifacts?
Clothing artifacts that can be removed.
231
What are internal artifacts?
Prostheses, pacemakers—cannot be removed.
232
How does image intensification work?
Exit radiation → input phosphor → light → electrons (photocathode) → focused → output phosphor → bright image.
233
What is brightness gain?
Increased brightness at output phosphor; flux gain × minification gain.
234
What is flux gain?
Increase in light intensity due to electron acceleration.
235
What is minification gain?
Increased brightness caused by smaller output phosphor compared to input.
236
What happens in magnification mode?
Voltage to focusing lenses increases, tightening electron beam.
237
What is the benefit of magnification mode?
Better visualization of small structures.
238
What is the drawback of magnification mode?
Increased patient dose.
239
What causes shape distortion (pincushion)?
Curved photocathode surface.
240
What is vignetting distortion?
Loss of brightness around edges of the image.
241
What causes noise in fluoroscopy?
Insufficient x-ray exposure (not enough information is present...grainy).
242
What converts output phosphor light into an electrical signal?
A television camera.
243
What is a CCD?
A light-sensitive semiconductor that stores electrical charge.
244
List advantages of CCDs.
More light-sensitive, No geometric distortion, Smaller size.
245
What do CRT monitors use to scan the image?
An electron gun.
246
What do LCD monitors use?
Liquid crystal layers & polarizers.
247
What do plasma monitors use?
Gas-filled pixels.
248
Name three fluoroscopic recording systems.
Cassette spot filming, Photospot camera, Videotape/DVD.
249
What does digital fluoroscopy add that analog does not?
An ADC and a computer.
250
What replaced image intensifiers in newer systems?
Flat panel detectors (FPDs).
251
Why are FPDs better?
Lighter, Less noise, Higher DQE, Better contrast resolution, Produce digital signal directly.
252
What is continuous fluoroscopy?
Uninterrupted exposure; 30 fps; higher dose.
253
What is pulsed fluoroscopy?
Exposure with gaps; lower dose; adjustable fps.
254
What is the max tabletop exposure with ABC?
10 R/min OR 88 mGy/min.
255
What is the max without ABC?
5 R/min OR 44 mGy/min.
256
What is the minimum SSD for stationary fluoro?
15 inches (38 cm).
257
What is the minimum SSD for mobile fluoro?
12 inches (30 cm).
258
What does the fluoroscopic system resolution test evaluate?
Ability to display small (high-contrast) and large (low-contrast) objects.
259
What does the ABC (automatic brightness control) performance test check?
Image quality as dose rate, pulsed mode, or FOV change.
260
What does the fluoroscopic phantom image quality test evaluate?
Image distortion and image lag.
261
What does the fluoroscopic exposure rate test measure?
Intensity of the x-ray beam.
262
What does the fluoroscopic alignment test ensure?
Beam aligns with center of II within 2% of SID.
263
What does the patient dose monitoring system calibration test check?
Proper function of DAP/dose monitoring systems.
264
What does the digital monitor performance test evaluate?
Display accuracy and performance of the monitor.
265
What is a network?
Two or more devices sharing resources.
266
What is a LAN?
Local area network—small, fast, inexpensive.
267
What is a WAN?
Wide area network—large distances; costly.
268
What is a peer-to-peer network?
All computers equal; each can act as client or server.
269
What is a server-based network?
Central server controls files, operations, and programs.
270
What is a client-based system?
Server processes tasks and returns results; reduces network load.
271
What is a server?
A computer that manages network resources.
272
What is a thin client?
A device that relies on the server to run tasks.
273
What is a thick client?
A computer that can function independently of the network.
274
What provides the physical connection to a network?
Network interface card (NIC).
275
What is DICOM?
The universal imaging exchange standard.
276
What is HL7?
The standard for text-based communication between HIS and RIS.
277
What does PACS stand for?
Picture Archiving and Communication System.
278
What are the three major PACS components?
Acquisition devices, Storage, Display workstations.
279
What is the archive server used for?
Long- and short-term image storage.
280
What is a client/server PACS?
Images stored on a central server; only one user can read a study at a time.
281
What is a distributed PACS?
Images stored locally on reading workstations.
282
What is a web-based PACS?
Images and software accessed through a web browser; network speed is the limiting factor.
283
What is a primary workstation used for?
Radiologist diagnosis.
284
What is a secondary workstation used for?
Technologist review, not diagnosis.
285
What does window level control?
Brightness.
286
What does window width control?
Contrast.
287
What is ROI measurement used for?
Measuring pixel intensity within a selected region.
288
What is short-term storage typically made of?
A RAID array.
289
What is used for long-term storage?
RAID, magnetic disks, tape, or optical media.
290
What is disaster recovery?
Making backup copies stored in a different location.
291
What does a film digitizer do?
Converts analog film to digital data.
292
What does an imager do?
Prints digital images to film.
293
What does a CD burner do?
Stores images on disc with viewing software.
294
What tool is this? How do you know?
Window level (brightness alteration)
Window width (contrast alteration)
295
What tool is this? How do you know?
Annotations (adding text information to image)
296
What tool is this? How do you know?
Flip and rotate (used to flip or rotate images clockwise/counterclockwise)
297
What is this tool used for?
Pan/zoom
Image may be zoomed to desired magnification level or moved to a zoomed central point
298
What tool is this? How do you know?
Magnify (enlarges a square area of an image to quickly see various areas magnified)
299
What tool is this? How do you know?
Measurements (distance and/or angle measurements of structures; ROI determines pixel intensity of certain areas to help determine different tissue or fluid)
300
What provides 360 degree images that can also be used for navigation for procedures? (mobile CT machine). Commonly used for spinal fusions
O-arm
RAD 142
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