Application of “StatPhantom” Software for Image Quality Evaluation George Davydenko ,

1. Application of “StatPhantom” Software for Image Quality Evaluation George Davydenko , Victor Gurvich, Mark Smekhov

2. StatPhantom - software for image quality evaluation • Enables you to randomly change the position of test elements in the image of any phantom. • Uses statistical technology and computer power to determine probabilities of detail detection. • Delivers reliable, unbiased and rapid quality control results using very simple techniques. • Provides a navigation system allowing to locate a test element by its coordinates or to determine the coordinates of a detected test element. • Allows statistical processing of the image of any phantom with fixed disposition of test elements. • Allows statistical processing of different images of the same or different phantoms simultaneously. • Helps choose optimal physical and technical conditions for diagnostic procedure. • Helps achieve and maintain excellent image quality. • Is ideal for teaching, training and research.

3. StatPhantom Works with various image files: • JPEG • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • GIF • Helps achieve excellent image quality • Can be used for all imaging modalities • DICOM (greyscale, without compression)

4. StatPhantom Provides basic image operations: • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques scaling rotation Brightness adjustment contrast adjustment • Helps achieve excellent image quality • Can be used for all imaging modalities

5. StatPhantom has navigation system which helps to locate test elements • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities test elements labels coordinates of cursor position

6. StatPhantom how to work: step 1 – set one of selection patterns • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality circle (default) • Can be used for all imaging modalities square ellipse rectangle

7. StatPhantom how to work: step 2 – make selection by pressing left mouse button and dragging • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities selection shape was set at Step 1 circle square ellipse rectangle

8. StatPhantom how to work: step 3 – switch to Make selection mode and double click at point which you want to be the center of selection • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities

9. StatPhantom how to work: step 4 – activate pop up menu by clicking right mouse button and add selected fragment to the selection set • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities Select Add selection with test element if fragment contains test element Select Add selection without test element if fragment does not contain test element Set of selections

10. StatPhantom how to work: step 5 – adjust selection set: • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques clicking right mouse button on selection activates context menu • Helps achieve excellent image quality • Can be used for all imaging modalities which enables to change brightness and contrast ofselection or delete it All selections can be deleted by pressing Delete button Order of selections can be randomly changed by pressing Rearrange button. If flag Rotate from Options menu is set they are also rotated at random angle User can save selections into file choosing Save selections from File menu

11. StatPhantom how to work: step 6 – set likelihood of the existence of a test element in selection: • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities Set flag Hide image in View menu if you want to display selections only Select appropriate likelihood for every selection from drop down combo box Set 100 if you are sure test element exists Set 75 if you almost sure test element is in selection Set 0 if you are sure test element isn’t in selection Set 25 if you almost sure test element is not in selection Set 50 if you can say nothing about presence of a test element

12. StatPhantom how to work: step 7 – get results • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities Press Calculate button to get results To see all results of all experiments select item Show results table from View menu Diagnostic preference of observer Probability of true positive answer and its error Probability of true answer and its error To save results in Excel file press Save button To clear table press Clear all To delete some rows from table select them by mouse and press Delete selected rows Signal-to-noise ratio of complete diagnostic system Probability of true negative answer and its error Some results of calculation

13. StatPhantom how to work: step 8 – quality control • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality check item Quality control in Options menu to bring up quality control dialog box • Can be used for all imaging modalities If you activate quality control, then after every calculation Pdet is compared to minimal value of true answer. If it is less, FAILED message pops up, otherwise PASSED message appears Set minimal probability of true answer Set flag if you want to activate quality control

14. StatPhantom Example: compare two images of different quality of the same phantom • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities 1.Higher quality image 2.Lower quality image Selections made from this row

15. StatPhantom Example: compare results • Is ideal for quality control, training and research • Uses simple and reliable statistical techniques • Helps achieve excellent image quality • Can be used for all imaging modalities Fragment from image 1 (higher quality) P(Y/s) = 0.90 P(Y/n) = 0.05 Pdet = 0.93 S/N = 2.93 Fragment from image 2 (lower quality) P(Y/s) = 0.75 P(Y/n) = 0.20 Pdet = 0.78 S/N = 1.52