Radiographic Image Formation and Density Answers PDF

Radiographic Image Formation and Density Answers 1. What is the primary function of intensifying screens in radiography? A. To protect the film from light B. To enhance image contrast C. To sandwich the film for processing D. To reduce the required exposure time Answer: To reduce the...

Radiographic Image Formation and Density Answers 1. What is the primary function of intensifying screens in radiography? A. To protect the film from light B. To enhance image contrast C. To sandwich the film for processing D. To reduce the required exposure time Answer: To reduce the required exposure time (D) Intensifying screens reduce the radiation dose needed by converting X-rays into visible light, which then exposes the film. 2. When examining denser parts of the body, which of the following best describes grid usage? A. Grids are ineffective in digital image acquisition B. Grids increase the amount of secondary radiation produced C. Focused grids are designed to function best at a specific distance D. Grids should always be used regardless of body density Answer: Focused grids are designed to function best at a specific distance (C) Focused grids are intended for optimal performance at specific distances to minimize secondary radiation. 3. What factor is NOT considered when selecting the mAs for exposure in radiography? A. Kilovoltage settings B. Type of image-acquisition device C. Grid factor D. Patient age Answer: Patient age (D) Patient age is not a factor in the direct selection of mAs; rather, the focus is on equipment and exposure settings. 4. How can one effectively handle grid cut-off during radiographic procedures? A. Maintain proper beam angulation relative to the grid lines B. Avoid using grids entirely when examining thick body parts C. Position the grid at any angle to the X-ray beam D. Use grids with fewer than 50 lines per centimeter Answer: Maintain proper beam angulation relative to the grid lines (A) Proper angulation of the beam in relation to the grid lines is critical to prevent grid cut-off. 5. Which statement about digital image capture is true? A. It requires a specific exposure to produce an image B. It is solely dependent on the grid factor in use C. A wide range of exposures will generally result in an acceptable image D. A limited range of exposures results in poor image quality Answer: A wide range of exposures will generally result in an acceptable image (C) Digital image acquisition methods like CR can tolerate a wide range of exposures, offering flexibility in radiography. 6. What is subject contrast primarily influenced by? A. Region of the body under examination B. Type of imaging technology used C. Patient's age D. Size of the examination room Answer: Region of the body under examination (A) Subject contrast varies based on the anatomical features of the body region being examined. 7. Which of the following factors contributes to subjective contrast? A. Ambient lighting B. Kilovoltage settings C. Film fog D. Radiopaque contrast agents Answer: Ambient lighting (A) Subjective contrast is affected by viewing conditions such as ambient lighting. 8. What is the relationship between magnification and focus-to- object distance (FOD)? A. Magnification is inversely proportional to FOD B. Increased FOD results in decreased magnification C. Distance does not affect magnification D. Higher magnification can be achieved without altering FOD Answer: Increased FOD results in decreased magnification (B) Increasing the focus-to-object distance generally results in lower magnification. 9. Which of the following does NOT affect radiographic (objective) contrast? A. Exposure settings B. Image-acquisition device C. Observer's visual perception D. Scattered radiation Answer: Observer's visual perception (C) Radiographic contrast is a measure of the differences in image density and is not influenced by the observer's perception. 10. What type of unsharpness is caused by the geometry of the X- ray source? A. Photographic unsharpness B. Absorption unsharpness C. Geometric unsharpness D. Motion unsharpness Answer: Geometric unsharpness (C) Geometric unsharpness occurs due to the non-point nature of the X-ray source affecting image clarity. 11. What does radiographic contrast measure? A. Differences in measured image density B. Quality of contrast media used C. Ambient lighting conditions D. Observer's fatigue levels Answer: Differences in measured image density (A) Radiographic contrast is defined as the differences in image density between specific parts of the radiographic image. 12. Which factor is least likely to affect image sharpness in radiography? A. Geometric alignment of film and object B. Development process of the film C. Movement of patient D. Type of contrast agent used Answer: Type of contrast agent used (D) The type of contrast agent used is less likely to influence the sharpness of the image compared to other factors such as movement and alignment. 13. Which of the following best defines subjective contrast? A. Measurable difference in image density B. Effects of scattered radiation on image quality C. Observer's personal appreciation of contrast D. Alteration of film development time Answer: Observer's personal appreciation of contrast (C) Subjective contrast is based on how individuals perceive contrast in an image, influenced by various factors such as fatigue and lighting. 14. What term refers to the difference in density between structures of interest within an image? A. Optical density B. Image density C. Subjective contrast D. Contrast Answer: Contrast (D) Contrast is essential for distinguishing details in a radiographic image. 15. How is subject contrast defined in the context of radiographic imaging? A. A personal perception of density differences B. The difference in optical density on processed film C. The measurement of radiation exposure D. The feature of the object under examination Answer: The feature of the object under examination (D) Subject contrast is directly related to the characteristics of the structures being imaged. 16. What happens to X-rays as they pass through the body? A. They are all absorbed regardless of structure B. They are attenuated by different amounts based on tissue characteristics C. They travel in curved paths to detect anomalies D. They become concentrated at a single point for clearer imaging Answer: They are attenuated by different amounts based on tissue characteristics (B) Different tissues and structures attenuate X-rays at varying rates, affecting image quality. 17. In radiographic imaging, what is the term for the amount of signal detected in the image receptor? A. Radiographic contrast B. Signal attenuation C. Patient density D. Optical density Answer: Optical density (D) Optical density represents how much blackening occurs in the radiographic image. 18. Which type of imaging captures images digitally using systems like computed radiography? A. Direct radiography B. Optical density imaging C. Photographic emulsion D. Analog imaging Answer: Direct radiography (A) Digital systems such as direct radiography enhance image capture and processing. 19. What does image density refer to in radiographic terminology? A. The total mass of a patient's body B. The amount of signal detected in the imaging detector C. The thickness of the tissue being imaged D. The amount of X-ray exposure used Answer: The amount of signal detected in the imaging detector (B) Image density signifies how dark or light an area appears on a radiograph based on signal reception. 20. What characterizes a low-contrast image? A. High density differences between structures B. Little difference in density between structures C. Greater optical density overall D. Enhanced visibility of small details Answer: Little difference in density between structures (B) Low-contrast images do not effectively separate different anatomical structures. 21. Which factor does NOT influence subject contrast in radiographic imaging? A. Duration of the X-ray exposure B. Atomic number of the materials C. Thickness of the tissue D. Density of the structures Answer: Duration of the X-ray exposure (A) Subject contrast is influenced by the physical properties of the object being imaged, not exposure time. 22. What effect does increasing focal spot size have on geometric unsharpness? A. Has no effect on unsharpness B. Only affects the exposure time C. Increases geometric unsharpness D. Decreases geometric unsharpness Answer: Increases geometric unsharpness (C) Increasing the focal spot size leads to greater geometric unsharpness. 23. Which of the following methods can help reduce movement unsharpness during an exposure? A. Increasing exposure time B. Adjusting film distance C. Using a shorter exposure time D. Using higher mAs with lower kVp Answer: Using a shorter exposure time (C) Using a shorter exposure time can help reduce movement unsharpness. 24. Which of the following exposure factors directly determines the amount of radiation used? A. Kilovoltage B. Exposure time in seconds C. Focus-to-film distance D. Milliampere seconds (mAs) Answer: Milliampere seconds (mAs) (D) Milliampere seconds (mAs) indicates the intensity or amount of radiation being used. 25. What is the preferred kilovoltage range used in diagnostic radiography for most examinations? A. 50 kVp to 120 kVp B. 100 kVp to 150 kVp C. 25 kVp to 50 kVp D. 150 kVp to 200 kVp Answer: 50 kVp to 120 kVp (A) The normal range of kilovoltages used in diagnostic radiography is 50 kVp to 120 kVp. 26. Why is a kilovoltage of 120 kVp often used in chest radiography? A. For a higher contrast image B. To minimize the thermal stress on the X-ray tube C. To penetrate the body's density effectively D. To reduce the exposure time Answer: To penetrate the body's density effectively (C) High-kVp techniques, like those used in chest radiography, are employed for effective penetration of body density. 27. What is the standard focus-to-film distance (FFD) used in most radiographic examinations? A. 100 cm B. 50 cm C. 75 cm D. 150 cm Answer: 100 cm (A) Most radiographic examinations are carried out with a focus-to-film distance of 100 cm. 28. How does increasing the kilovoltage affect exposure time? A. Does not affect exposure time B. Only affects image sharpness C. Decreases exposure time D. Increases exposure time Answer: Decreases exposure time (C) Increasing the kilovoltage allows the milliampere seconds to be reduced, thus decreasing exposure time. 29. What type of imaging technology uses computed radiography (CR) and direct digital radiography (DDR)? A. Magnetic resonance imaging B. Digital imaging C. Conventional film/screen technology D. Fluoroscopy/fluorography Answer: Digital imaging (B) Digital imaging includes techniques such as computed radiography (CR) and direct digital radiography (DDR).