All (20358)
Notes (10000)
note
Ratios
Updated 502d ago
0.0(0)
note
ratio
Updated 392d ago
0.0(0)
note
Ratio Analysis
Updated 953d ago
0.0(0)
note
Financial-ratios
Updated 453d ago
0.0(0)
note
financial ratios
Updated 393d ago
0.0(0)
note
Profit
Updated 520d ago
0.0(0)
note
RATIOS MOB
Updated 714d ago
0.0(0)
note
Financial Ratio
Updated 412d ago
0.0(0)
note
Financial Ratio
Updated 713d ago
0.0(0)
note
Financial Ratios
Updated 461d ago
0.0(0)
note
financial ratios
Updated 141d ago
0.0(0)
Flashcards (10000)
flashcards
FAR Ratios
27
Updated 21m ago
0.0(0)
flashcards
reporting profit
6
Updated 3h ago
0.0(0)
flashcards
Accounting 1 Topic 10 Ratios
21
Updated 3h ago
0.0(0)
flashcards
Financial Ratios (W10)
28
Updated 5h ago
0.0(0)
flashcards
Quiz 3 Study Guide – Digital Radiography ⸻ Preprocessing vs Postprocessing • Preprocessing = happens before the image is displayed • Corrects raw data from the detector • Examples: flat-field correction, dead pixel correction • Postprocessing = happens after image acquisition • Adjusts image appearance • Examples: brightness, contrast, edge enhancement ⸻ Postprocessing Domains Spatial Domain • Works with pixel location • Affects detail/resolution • Example: smoothing, edge enhancement Intensity Domain • Works with pixel brightness values • Affects contrast • Example: windowing, LUT Frequency Domain • Works with patterns (frequencies) in the image • Separates noise vs detail • Example: filtering (remove noise or enhance edges) ⸻ Histogram Analysis What the Histogram Represents • Graph of pixel intensity distribution • X-axis = brightness (black → white) • Y-axis = number of pixels ⸻ Types of Histogram Analysis • Type 1 • Simple exams (extremities) • Single peak • Type 2 • Two main tissue types (chest) • Two peaks • Type 3 • Complex anatomy (abdomen) • Multiple peaks • Neural (AI-based) • Uses pattern recognition instead of fixed shapes ⸻ Construction of Histogram 1. Image acquired 2. Exposure field recognized 3. Pixels analyzed 4. Histogram created from pixel values ⸻ Histogram Analysis Errors • Wrong body part selected • Collimation too wide/narrow • Artifacts (prosthetics, shielding) • Multiple exposures on one plate 👉 Leads to incorrect brightness/contrast ⸻ Look-Up Table (LUT) • Converts pixel values → visible grayscale • Controls contrast and brightness appearance • Different LUTs = different exam types ⸻ Dynamic Range Compression (DRC) • Reduces wide exposure range into visible range • Helps see both dark & light areas ⚠️ Effects: • Can reduce contrast • Can hide pathology if overused ⸻ Smoothing • Reduces noise • Makes image look softer • ↓ spatial resolution ⸻ Edge Enhancement • Increases sharpness • Highlights borders • Can increase noise/artifacts ⸻ SNR vs CNR • SNR (Signal-to-Noise Ratio) • Signal vs background noise • Higher = cleaner image • CNR (Contrast-to-Noise Ratio) • Difference between structures vs noise • Higher = better visibility of anatomy ⸻ Dose Creep & Exposure Index (EI) • Dose creep • Gradual increase in exposure over time • Happens because images still look good even at higher dose • Exposure Index (EI) • Indicates how much radiation reached detector • Used to monitor proper exposure ⸻ Segmentation • Identifies area of interest • Removes background from analysis • Important for accurate histogram ⸻ Grid Line Suppression • Removes visible grid lines digitally • Prevents moiré patterns ⸻ Kernels • Mathematical filters applied to image • Types: • Smooth (reduce noise) • Sharp (increase detail) ⸻ Postprocessing Controls (Tech Can Adjust) • Window level (brightness) • Window width (contrast) • Magnification • Edge enhancement • Smoothing ⸻ Sequence of Preprocessing Events 1. Exposure detection 2. Analog → digital conversion 3. Flat-field correction 4. Dead pixel correction 5. Exposure field recognition 6. Histogram creation 7
44
Updated 15h ago
0.0(0)
flashcards
Police Radio Codes
66
Updated 17h ago
0.0(0)
flashcards
Amendments Rolling Assessment
21
Updated 23h ago
0.0(0)
Users (358)