Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Exposure Technique
Quality
| Question | Answer |
|---|---|
| anatomically programmed technique | A method that uses pre-set exposure factors based on anatomical structures. |
| automatic exposure control (AEC) | A system that automatically adjusts radiation exposure to produce quality images. |
| backup time | The maximum time the AEC system will allow for exposure before terminating. |
| body mass index (BMI) | A measure of body fat based on height and weight. |
| calipers | Tools used to measure the thickness of body parts for exposure calculations. |
| comparative anatomy | The study of similarities and differences in the anatomy of different species. |
| contrast medium | A substance used to enhance the contrast of structures in imaging. |
| density controls | Settings that adjust the overall darkness of the radiographic image. |
| detectors | Devices that measure the amount of radiation reaching the image receptor. |
| exposure adjustment | Modifications made to exposure settings based on patient or technique factors. |
| exposure technique charts | Guidelines that provide recommended exposure settings for various conditions. |
| extrapolated | The process of estimating values beyond the known range based on existing data. |
| fixed kVp/variable mAs technique chart | A chart that maintains a constant kVp while varying the mAs for different exposures. |
| ionization or ion chamber | A type of detector that measures radiation by ionizing gas within a chamber. |
| mAs readout | A display showing the milliampere-seconds used during the exposure. |
| minimum response time | The shortest time interval in which an AEC system can respond to radiation. |
| optimal kVp | The ideal kilovoltage peak setting for achieving the best image quality. |
| phototimers | Devices that measure radiation exposure and terminate the exposure automatically. |
| variable kVp/fixed mAs technique chart | A chart that allows for varying kVp while keeping mAs constant for exposures. |
| AEC radiation detectors | Devices that measure the amount of radiation transmitted through the patient, terminating the exposure time when a predetermined amount of radiation has been detected. |
| Phototiming | The use of an AEC device that employs photomultiplier tubes or photodiodes, though the term is often incorrectly used today. |
| Ionization chambers | A type of AEC system that uses a hollow cell containing air to create ionizations that are converted into an electrical signal. |
| Solid-state detectors | Devices used in modern AEC systems to measure radiation exposure and convert it into an electrical signal. |
| Radiation-measuring devices | Detectors that measure the amount of radiation transmitted through the patient, allowing the radiographer to select the combination of detectors to use. |
| Exit-type devices | AEC devices, like phototimers, where the detectors are positioned behind the image receptor, measuring radiation after it exits the IR. |
| Entrance-type devices | AEC devices, like ionization chambers, where the detectors are positioned in front of the image receptor, measuring radiation before it enters the IR. |
| Light paddles | Detectors used in phototimer systems that produce visible light when radiation interacts with them, which is then converted into electricity. |
| Photodiode | A solid-state device that converts visible light energy into electrical energy, used in phototimer AEC systems. |
| Electrical signal | The output generated by AEC systems when a sufficient amount of radiation is detected, used to terminate the exposure. |
| Remnant radiation | Radiation that exits the patient and is measured by the AEC detectors. |
| Ion pairs | Pairs of ions created in an ionization chamber that generate an electrical current proportional to the x-ray exposure. |
| Amplified signal | The electrical signal that is sent to the x-ray generator to end the exposure, created from the ion pairs in an ionization chamber. |
| Calibration | The process by which service personnel set the predetermined level of radiation for AEC systems to meet departmental standards. |
| Image receptor (IR) | The device that captures the radiation exposure to create an image in radiography. |
| Sensing area | The part of the ionization chamber that receives remnant radiation and creates ionizations. |
| Timer circuit | The electronic component connected to the ionization chamber that controls the exposure time based on the detected radiation. |
| Charge | The electrical output generated by the AEC system in proportion to the radiation exposure received. |
| Departmental standards | The quality benchmarks set by a radiology department that AEC systems must meet through calibration. |
| X-ray generator | The device that produces x-rays for imaging, which receives signals from the AEC system to terminate exposure. |
| Ionization Chamber | A device that becomes ionized when exposed to radiation, creating an electrical charge that travels to the timer circuit. |
| Entrance Type AEC | An AEC system where the x-ray exposure is measured just before entering the image receptor. |
| Radiographic Study | An examination performed using an AEC device to determine the appropriate exposure to the image receptor. |
| Manual Exposure Technique | A method used by radiographers to adjust exposure settings based on knowledge of the mAs readout. |
| Subject Contrast | The difference in density between various tissues in an image, which is influenced by the selected kVp. |
| Kilovoltage Peak (kVp) | The voltage applied across the x-ray tube, which affects the quality and penetrating power of the x-ray beam. |
| High kVp Imaging | Used for chest imaging to visualize widely varying tissues, resulting in lower subject contrast. |
| Low kVp Imaging | Results in high subject contrast, not typical for chest imaging, and indicates significantly more radiation exposure. |
| Exposure Time | The duration for which the x-ray beam is active, which is shorter with higher kVp values. |
| Radiographic Unit | The equipment used to perform radiographic studies, which may include an mAs readout display. |
| Radiation Exposure | The amount of radiation measured by the ionization chamber before it reaches the image receptor. |
| Oblique Exposures | Radiographic positions that may require manual technique adjustments based on mAs readout. |
| AEC Detector | Devices located in front of the image receptor that measure radiation exposure in an AEC system. |
| Radiographic Image | The visual representation created from the x-ray exposure, which can vary based on kVp and mAs settings. |
| Exposure Adjustments | Changes made by the radiographer to the exposure settings based on the mAs readout and image quality. |
| Digital Imaging | A method of imaging where contrast can be manipulated by computer, but kVp should still be selected for optimal visualization. |
| Patient Radiation Exposure | The total amount of x-ray exposure received by the patient, which can be reduced with higher kVp settings. |
| Radiographic Techniques | Methods and settings used by radiographers to achieve optimal imaging results. |
| Electrical Charge | The result of ionization in the ionization chamber, which is proportional to the radiation exposure. |
| kVp and AEC response | The radiographer must set the kVp as needed to ensure adequate penetration and enhance the subject contrast for the part examined. |
| Low kVp | A low kVp requires more exposure time to reach the predetermined amount of exposure. |
| High kVp | A high kVp decreases the exposure time to reach the predetermined amount of exposure and reduces the overall radiation exposure to the patient. |
| Kilovoltage selection | Using a higher kVp with AEC decreases the exposure time and the overall mAs needed to produce a diagnostic image, significantly reducing patient exposure. |
| mA and AEC response | If the radiographer can set the mA when using AEC, it will inversely affect the time of exposure for a given procedure. |
| Increasing mA | Increasing the mA decreases the exposure time to reach the predetermined amount of exposure. |
| Decreasing mA | Decreasing the mA increases the exposure time to reach the predetermined amount of exposure. |
| Minimum response time with modern AEC systems | Minimum response time is usually longer with AEC systems than with other types of radiographic timers (i.e., other types of radiographic timers usually are able to produce shorter exposure times than AEC devices). |
| Setting backup time | The backup time may be set by the radiographer or automatically controlled by the radiographic unit. |
| Function of backup time | Backup time serves as a safety mechanism when AEC is not used properly or is not functioning properly. |
| Maximum backup time | If the backup time is automatically controlled, it should terminate at a maximum of 600 mAs when equipment is operated at or above 50 kVp. |
| Operator oversight | The backup time might be reached as a result of operator oversight when an AEC examination is conducted at the upright unit and the radiographer has set the control panel for a table unit. |
| Patient exposure protection | The backup time protects the patient from receiving unnecessary exposure and protects the x-ray tube from reaching or exceeding its heat-loading capacity. |
| Pediatric patients and AEC | With pediatric patients and other patients who cannot or will not cooperate with the radiographer, AEC devices may not be the technology of choice. |
| Increasing mA for quicker exposure | Typically, the radiographer increases the mA so that the time of exposure terminates more quickly. |
| Long minimum response time issue | If the minimum response time is longer than the amount of time needed to terminate the preset exposure, it results in an increased amount of radiation reaching the IR. |
| Excessive wait for exposure | The table detectors are forced to wait for an excessively long time to measure enough radiation to terminate the exposure. |
| Radiographic timers | Other types of radiographic timers usually are able to produce shorter exposure times than AEC devices. |
| Monitoring backup time | To minimize patient exposure, the backup time should be neither too long nor too short. |
| Increment in exposure adjustment | A common increment is 25%, meaning that the predetermined exposure level can be either increased or decreased from normal. |
| Radiographic image A | Produced using 81 kVp and the center automatic exposure control (AEC) detector, and 0 exposure adjustment. |
| Radiographic image B | Produced using 81 kVp and the center AEC detector, and +3 exposure adjustment. |
| Radiographic image C | Produced using 81 kVp and the center AEC detector, and -3 exposure adjustment. |
| Quantum noise | The displayed image demonstrates less quantum noise than image A for image B and more quantum noise than B for image C. |
| AEC calibration | Routinely using plus or minus exposure adjustments to produce an acceptable image indicates that a problem exists, possibly a problem with the AEC calibration. |
| Detector selection | Selection of the detectors to be used for a specific examination is critical when using an AEC system. |
| Multiple detectors | AEC systems with multiple detectors typically allow the radiographer to select any combination of one, two, or three detectors. |
| Five AEC detectors | Radiographic equipment can also be purchased with five AEC detectors, which provide greater flexibility in imaging a wide variety of patients. |
| Expected exposure time | The time anticipated for the AEC system to terminate the exposure under normal conditions. |
| Excessive exposure | Setting the backup time appropriately protects the patient and tube from excessive exposure if a problem occurs. |
| Image quality | The radiographer must monitor the exposure indicator along with image quality to determine whether over- or underexposure has occurred. |
| Displayed brightness | The computer adjusts the displayed brightness, which may not visually indicate overexposure. |
| Radiographer's role | It is important for the radiographer to monitor the exposure indicator along with image quality. |
| Practical experience | Common sense and practical experience should also serve as guidelines for the radiographer. |
| Underexposure | Insufficient radiation exposure resulting in an image that is too light or lacks detail. |
| Overexposure | Excessive radiation exposure resulting in an image that is too dark or has loss of detail. |
| Central Ray (CR) | The central beam of radiation directed at the area of interest during imaging. |
| Radiographic Interest | The specific anatomical structures that need to be visualized in the final image. |
| Posteroanterior (PA) Chest Radiograph | A type of chest X-ray where the X-ray beam enters from the back and exits through the front. |
| Exposure Indicator | A numerical value that reflects the amount of radiation exposure received by the image receptor. |
| Proper Centering | The accurate positioning of the anatomical area of interest over the selected detectors. |
| Radiographic Procedure Textbooks | Books that provide guidelines and recommendations for performing various radiographic examinations. |
| Anatomic Structures | The specific parts of the body that are being imaged or examined. |
| Radiographic Equipment | The machinery and tools used to perform radiographic imaging. |
| Radiographers | Healthcare professionals trained to perform radiographic imaging and ensure quality control. |
| Thoracic Spine | The part of the spine located in the chest region, which can affect imaging if not properly centered. |
| Soft Tissue and Ribs | Anatomical structures that can obscure the view of the spine if improperly centered during imaging. |
| Long Exposure | An unusually extended exposure time that can occur if detectors are not properly exposed to radiation. |
| Radiographic Image Quality | The clarity and detail of the image produced, which can be affected by exposure settings and detector selection. |
| Computer Adjusted Brightness | The modification of image brightness by a computer to enhance visibility, regardless of actual exposure. |
| Excessive Radiation Exposure | A situation where the patient or image receptor is subjected to more radiation than necessary. |
| Patient centering | Accurate centering of the area of interest over the detectors is critical to ensure proper exposure to the IR. |
| mAs | The applied milliampere-seconds that radiographers must evaluate when using the AEC device. |
| AEC device | Automatic Exposure Control device that adjusts exposure based on the detected radiation. |
| Detector size | The size and shape of the detectors manufactured within an AEC system is fixed and cannot be adjusted. |
| Compensating issues | Refers to the AEC system's ability to adjust for changes in patient thickness. |
| Excessive bowel gas | Can compromise abdominal examinations using AEC, causing premature termination of exposure. |
| Positive contrast media | An additive pathological condition that can cause excessive exposure when superimposing the detector. |
| Destructive pathological conditions | Can cause underexposure of the area of radiographic interest. |
| Radiation exposure level | The level necessary to terminate the exposure is reached almost immediately if a portion of the detector is directly exposed to the primary beam. |
| Detector combination | The selection of this must adequately cover the patient's anatomic area of interest. |
| Radiographic procedure | The process that may require careful consideration of AEC use based on patient size and anatomy. |
| Recalibration | May be necessary for AEC systems that do not adequately compensate for changes in patient thickness. |
| Image brightness | May be adjusted by the computer, but errors in AEC use may not be visually apparent. |
| Patient exposure | Can be increased due to overexposure, affecting the safety and quality of the imaging process. |
| Inappropriate exposure to the IR | Occurs when the anatomic area over the detector does not represent the anatomic area of interest. |
| Foreign object | An item that can obstruct the anatomic area over the detector, affecting image quality. |
| AEC | Automatic Exposure Control; a system that automatically adjusts exposure based on detected radiation levels. |
| Patient variability | Factors related to the patient that affect the time of exposure reaching the IR and image quality. |
| Pathology | A condition that can affect the exposure time and image quality. |
| Collimation | The process of restricting the size of the x-ray field to minimize scatter radiation. |
| Scatter radiation | Radiation that is deflected from its original path, which can interfere with exposure measurement. |
| Image receptor variations | Different types of image receptors (IRs) that cannot be easily interchanged after AEC calibration. |
| Quality Control Testing | Essential procedures to maintain the proper functioning of the AEC system. |
| Milligray (mGy) | A unit of measurement for radiation exposure that can be evaluated during quality control checks. |
| Pixel brightness levels | The displayed levels on an image that can be measured to assess exposure consistency. |
| Exposure adjustment controls | Controls that may be used to modify exposure in certain imaging circumstances. |
| Technique chart | A manual technique determined for radiographic exposure based on specific parameters. |
| Excessive collimation | May result in an extremely long exposure time due to insufficient radiation reaching the detector. |
| Insufficient collimation | May lead to excessive scatter reaching the detectors, causing premature termination of exposure. |
| Upright Bucky | A type of imaging device that may utilize AEC with two outer detectors. |
| 120 kVp | A specific kilovolt peak setting used in radiographic imaging. |
| 400 mA | A specific milliampere setting used in radiographic imaging. |
| Homogeneous patient-equivalent phantom | A model used to simulate patient characteristics for testing AEC performance. |
| Technique factors | Parameters such as mA and kVp that can be varied to assess AEC performance. |
| mGy | Milligray, a unit of measurement for radiation dose. |
| IR | Imaging receptor, a device that captures the image produced by radiation. |
| kVp | Kilovoltage peak, the maximum voltage applied across the x-ray tube. |
| mA | Milliamperage, a unit of measurement for the current in the x-ray tube. |
| CR | Computed radiography, a digital imaging process using phosphor plates. |
| Image contrast | The difference in brightness between different areas of an image. |
| Excessive scatter | Unwanted radiation that degrades image quality by reducing contrast. |
| Posteroanterior (PA) | A type of radiographic view where the x-ray beam enters from the back and exits through the front. |
| Detector | A device that captures the x-ray image, can be digital or film-based. |
| Flat-panel detector | A type of digital imaging receptor that captures images electronically. |
| Diagnostic image | An image that provides sufficient quality for accurate diagnosis. |
| Efficiency of imaging department | The effectiveness of the department in producing quality images in a timely manner. |
| Digital IR | An imaging receptor that captures images in a digital format. |
| Anatomic programming | Another term for anatomically programmed technique. |
| Integrated circuit | A component that controls anatomically programmed techniques by being programmed with exposure factors for different projections and positions of different anatomic parts. |
| Manual exposure techniques | Techniques that require the radiographer to select the kVp and mAs necessary for the radiographic procedure. |
| Patient considerations | Factors related to the patient's condition or anatomy that may affect the choice of exposure technique. |
| Radiation detectors | Devices used in AEC systems to measure the amount of radiation passing through the patient and terminate exposure. |
| Manual exposure technique selection | The process of choosing exposure factors manually based on the radiographer's judgment. |
| Pediatric patient | A patient who is a child, which may require special consideration in exposure techniques due to their smaller anatomy. |
| Distal extremities | The farthest parts of the limbs, which may present challenges in adequately covering AEC detectors. |
| Axial clavicle | A specific projection that may be challenging for the radiographer when using AEC due to centering difficulties. |
| Contrast media | Substances used to enhance the visibility of internal structures in imaging procedures. |
| Diagnostic quality images | Images produced that are clear and detailed enough to allow for accurate diagnosis. |
| Preprogrammed technical factors | Exposure factors that are set in advance for specific anatomic areas and can be adjusted by the radiographer. |
| Radiographic units | Equipment used to perform radiographic imaging, often incorporating both AEC and anatomically programmed techniques. |
| Selection of AEC detectors | The process of choosing which AEC detectors to use for a specific radiographic examination. |
| Lungs PA | A specific radiographic projection for the lungs that results in the selection of 120 kVp and the upright unit. |
| AP | Anteroposterior |
| Technique charts | Pre-established guidelines used by the radiographer to select standardized, manual, or AEC exposure factors for each type of radiographic examination. |
| Radiographic quality | The quality of radiographic images is consistent when using technique charts. |
| AEC detector selection | An additional factor that can be included in the technique chart. |
| Grid use | An additional factor that can be included in the technique chart. |
| SID | Source to image distance, a recommended exposure variable in technique charts. |
| Dynamic range | Digital systems have a wide dynamic range and can compensate for exposure technique errors. |
| Radiological protection | Technique charts should optimize radiation dose to avoid unnecessary exposure to the patient. |
| Individual judgment | The radiographer must continue to use this in properly selecting exposure factors for each patient and type of examination. |
| Unusual circumstances | Technique charts are designed for an average or typical patient and do not account for these. |
| Preprogrammed exposure factors | The radiographer must evaluate the appropriateness of these when using them. |
| Radiographic procedures | Routine use of AEC is recommended for these. |
| Central ray | The area of interest must be adequately centered to this before radiation exposure. |
| Repeat radiographic studies | Technique charts are instrumental in the reduction of these. |
| Exposure variables | Recommended factors such as kVp, mAs, type of IR, grid, and SID that the radiographer consults in technique charts. |
| Mobile radiographic unit | A portable x-ray machine that must have its own technique chart due to differences in radiation output. |
| Exposure factors | Settings such as kVp and mAs that are standardized for consistent image quality. |
| Part thickness measurement | An accurate measurement that determines the selected kVp and mAs values for a radiographic examination. |
| Baseline kVp | The original kVp value predetermined for the anatomic area to be imaged. |
| kVp adjustment | An increase of 2 for every 1 cm (0.4 inch) increase in part thickness in a variable kVp/fixed mAs chart. |
| Grid ratio | The ratio of the height of the lead strips to the distance between them, specified as 10:1 in the example. |
| Focal spot size | The size of the x-ray tube's focal spot, specified as small in the example. |
| Wide exposure latitude | The range of exposures needed to produce a quality digital image, indicating that precise measurement is less critical. |
| Errors in part thickness measurement | Common mistakes made when consulting technique charts that can lead to incorrect exposure factors. |
| Anatomic part | The specific body part being imaged, such as the knee in the example provided. |
| Projection | The direction of the x-ray beam, specified as AP (anterior-posterior) for the knee example. |
| Measuring point | The specific location on the anatomic part where thickness is measured, such as midpatella for the knee. |
| Tabletop/Bucky | The type of support used for the image receptor, specified as Bucky in the example. |
| Digital IRS | A system that uses digital imaging receptors for radiographic examinations. |
| Part Thickness | The measurement of the anatomical part that must be accurately measured to ensure proper exposure settings. |
| 2-kVp Adjustment | The adjustment of kVp by 2 for every 1-cm (0.5-inch) change in part thickness. |
| Baseline kVp Value | The kVp value that adequately penetrates the anatomic part when using a 2-kVp adjustment. |
| Radiographic Phantoms | Patient-equivalent devices used to experimentally determine the baseline kVp value. |
| Flat-panel IR | A type of image receptor that is flat and used in digital radiography. |
| Anatomic Part: Knee | The specific body part being examined in the radiographic procedure. |
| Projection: AP | Anteroposterior projection; the direction of the x-ray beam from front to back. |
| Measuring Point: Midpatella | The specific location on the knee used for measurement during the radiographic examination. |
| SID: 100 cm (40 inches) | The source-to-image-receptor distance specified for the knee examination. |
| mAs Adjustment | The adjustment of mAs based on variations in part thickness, typically by a factor of 2 for every 4- to 5-cm (1.6- to 2-inch) change. |
| Small Extremities Imaging | Refers to imaging of small body parts such as hands, toes, and feet, where variable kVp may be more effective. |
| Technological Advances in Digital IRS | Improvements in digital imaging systems that challenge the applicability of traditional technique charts. |
| optimal kVp values | The specific kVp settings determined to effectively penetrate an anatomic part without compromising contrast. |
| exponential attenuation | The decrease in intensity of x-rays as they pass through matter, which follows an exponential decay pattern. |
| 4- to 5-cm change in part thickness | A guideline indicating that for every 4- to 5-cm change in thickness, the mAs should be adjusted by a factor of 2. |
| patient groups | Categories formed based on size or weight ranges to standardize exposure techniques. |
| minimal kVp value | The lowest kVp that can adequately penetrate the anatomic part being radiographed. |
| standardized exposure factors | Consistent settings established for imaging specific anatomic areas to ensure quality and accuracy. |
| extreme variation in size | Significant differences in the size of anatomic parts that can affect exposure technique. |
| digital imaging systems | Modern imaging technologies that utilize digital sensors and processing to capture and display images. |
| 10:1 table Bucky grid | A type of grid used in radiography to reduce scatter radiation and improve image quality. |
| exposure technique chart development | The process of creating a systematic guide for selecting exposure settings based on anatomic characteristics. |
| doubling of the mAs | An adjustment made to the mAs when there is a 5-cm (2-inch) increase in part thickness. |
| quality images | Radiographic images that accurately represent the anatomic structures with appropriate contrast and detail. |
| uniform displayed subject contrast | Consistent visibility of structures across different images, ensuring reliable interpretation. |
| extrapolated exposure techniques | Estimated exposure settings derived from established techniques for similar anatomic areas. |
| anatomic part measurement | The process of determining the dimensions of a body part to inform exposure settings. |
| Exposure technique chart | A chart that includes a range of acceptable exposure indicators expected for the anatomic part imaged. |
| 15% rule | A general rule for exposure technique adjustment that suggests a 15% change in kVp will double or halve the exposure. |
| Patient-equivalent phantom | A device used to produce several images by varying the kVp and mAs values during the development of an exposure technique chart. |
| Acceptable images | Images that meet the quality standards after evaluation and are selected based on appropriate kVp values. |
| Pediatric patients | Patients who require lower kVp and mAs values than adults due to their smaller size. |
| Fast exposure times | Exposure times chosen to stop diaphragm motion in pediatric patients who cannot voluntarily suspend their breathing. |
| AEC systems | Automatic exposure control systems that may not be usable for pediatric chest radiography due to small size. |
| Bone density in children | Exposure factors used for the adult skull can be used for pediatric patients aged 6 years and older due to developed bone density. |
| Modification of exposure factors | The adjustment of exposure factors for patients younger than 6 years, including a recommended decrease of kVp by at least 15%. |
| Geriatric patients | Aging patients who may experience physical and psychological changes affecting their ability to follow instructions during imaging. |
| Commitment to technique charts | The necessity for management and staff to use exposure technique charts for consistent production of quality images. |
| Sensitivity to ionizing radiation | Pediatric patients are more sensitive to ionizing radiation and require careful monitoring of exposure indicators. |
| Longer life span | Pediatric patients have a longer life span than adults, making it critical to minimize unnecessary radiation exposure. |
| Skin changes in geriatric patients | Aging patients may have thinner skin that is more easily torn or bruised. |
| Psychological changes in geriatric patients | Changes in the mental state of geriatric patients that may impact their ability to follow instructions during imaging procedures. |
| Enhanced patient care | Providing additional time for imaging procedures, sensitivity to patient comfort, and attention to safety during transport and positioning. |
| Exposure techniques | May need to be decreased for patients who appear thin and frail. |
| mA and exposure time | Should be adjusted to eliminate motion during imaging. |
| Bariatric patients | Bring unique challenges in terms of weight and body diameter, requiring special considerations during imaging. |
| Table weight limit | An important issue to consider when imaging bariatric patients. |
| Aperture diameter | Size of fluoroscopic imaging equipment that must be considered for bariatric patients. |
| kVp and mAs values | Need to be increased for bariatric patients to produce diagnostic images. |
| Grid usage | Important to reduce scatter radiation from reaching the IR, which decreases displayed image contrast. |
| Quadrants imaging | May be necessary for bariatric patients due to the size limitation of the IR. |
| Radiographic projections | Different projections and patient positions often require modification of exposure factors. |
| Oblique position | Requires more exposure than an AP projection due to increased tissue thickness. |
| Casts | Can be made of fiberglass or plaster; fiberglass generally requires no change in exposure factors. |
| Plaster casts | Require an increase in exposure factors compared to imaging the same part without a cast. |
| Splints | Present less challenge for determining exposure factors than casts; inflatable and fiberglass splints do not require an increase in exposure. |
| Wood, aluminum, and solid plastic splints | May require increased exposure factors only if they are in the path of the primary beam. |
| Primary beam | The main beam of radiation used in imaging that can be affected by the presence of splints. |
| Additive diseases | Pathologies that increase the absorption characteristics of the part, making it more difficult to penetrate. |
| Destructive processes | Diseases or conditions that decrease the absorption characteristics of the part, making it less difficult to penetrate. |
| Pulmonary edema | A condition where lung tissues fill with fluids, increasing tissue opacity and requiring an increase in exposure technique. |
| Congestive heart failure (CHF) | A condition that can lead to pulmonary edema, resulting in increased tissue opacity of the lungs. |
| Atelectasis | A significant lung lobe collapse that increases tissue opacity and may require an increase in exposure depending on the degree of collapse. |
| Ascites | A condition characterized by a large collection of fluid in the abdominal cavity, often requiring an increase in kVp and mAs for better image quality. |
| Bowel obstruction | A condition that may lead to large collections of bowel gas, making the abdomen easier to penetrate and potentially requiring less exposure. |
| Osteopetrosis | A bone disorder that creates very dense bones, requiring increased exposure due to its additive condition. |
| Osteoporosis | A condition where bones lose mineralization and mass, making them less dense and requiring a reduction in exposure. |
| 15% change in kVp | The minimum recommended change in kVp when compensating for additive or destructive diseases. |
| Additive Conditions - Abdomen | Includes aortic aneurysm, ascites, and cirrhosis. |
| Destructive Conditions - Abdomen | Includes bowel obstruction and free air. |
| Additive Conditions - Chest | Includes atelectasis, congestive heart failure, malignancy, pleural effusion, and pneumonia. |
| Additive Conditions - Skeleton | Includes hydrocephalus, metastases (osteoblastic), osteochondroma, and Paget's disease (late stage). |
| Destructive Conditions - Skeleton | Includes osteoporosis, emphysema, pneumothorax, gout, and metastases (osteolytic). |
| Nonspecific Sites Conditions | Includes abscess, edema, sclerosis, atrophy, emaciation, and malnutrition. |
| Technique selection | The process of choosing exposure factors based on the specific anatomic part and the effect of diseases on that part. |
| Soft tissue technique | A technique that involves decreased mAs to visualize soft tissues that are difficult to radiographically visualize. |
| Positive contrast agents | Substances like barium and iodine that have a high atomic number, absorb more x-rays, and increase attenuation. |
| Negative contrast agents | Substances like air that decrease the attenuation of the x-ray beam and transmit more radiation than surrounding tissue. |
| Radiopaque | Describes positive contrast agents that produce more brightness on the displayed image than adjacent tissues. |
| Radiolucent | Describes negative contrast agents that produce less brightness on the displayed image than adjacent tissues. |
| Detectors in AEC | Devices that measure the amount of radiation exiting the patient and terminate exposure at a preset amount. |
| kVp in AEC | The kilovolt peak selected must penetrate the part and produce the desired subject contrast displayed on the image. |
| mA in AEC | Changing the milliampere affects the exposure time accordingly when using Automatic Exposure Control. |
| Centering the x-ray beam | For AEC to work accurately, the x-ray beam must be centered precisely to the anatomic area of interest. |
| Backup time in AEC | A safety mechanism that prevents the exposure from exceeding a set amount. |
| Attenuation | The reduction in the intensity of the x-ray beam as it passes through matter. |
| Quality of radiographic image | Depends on a multitude of variables including exposure techniques and the use of contrast agents. |
| Visualization of larynx in croup | An example of when a soft tissue technique may be needed for imaging. |
| Foreign body obstruction imaging | A situation where soft tissue techniques are necessary to locate foreign bodies in the throat. |
| Foreign body location in extremities | An instance where a soft tissue technique is applied for imaging in the extremities. |
| Atomic number of barium | 56, indicating its high atomic number as a positive contrast agent. |
| Atomic number of iodine | 53, indicating its high atomic number as a positive contrast agent. |
| Atomic number of air | 8, indicating its low atomic number as a negative contrast agent. |
| Limitations of AEC systems | AEC systems typically allow only one type of IR and have a minimum response time that may be longer than the exposure needed. |
| Quality control in AEC systems | Important for monitoring performance; reproducibility of exposures should result in mR readings within 5% and pixel brightness levels within 30%. |
| AEC devices work by measuring | Radiation leaving the tube, radiation that exits the patient, radiation absorbed by the patient, or attenuation of primary radiation by the patient. |
| Typical number of detectors in AEC system | Typically found in one, two, three, or four configurations. |
| True statement regarding AEC during digital imaging | Adjusting the mA and kVp values affects image brightness. |
| Purpose of the backup timer | To ensure a diagnostic exposure each time AEC is used and limit unnecessary x-ray exposure. |
| Detector selection for right AP shoulder | Right, center, and left detectors should be selected when the patient is supine on the x-ray table. |
| Purpose of anatomically programmed techniques | To present the radiographer with a preselected set of exposure factors. |
| True statement concerning AEC and anatomically programmed techniques | The individual judgment and discretion of the radiographer is still necessary when using these systems. |
| Effect of selecting center detector on PA chest image | Results in appropriate exposure in the lung area. |
| Effect of selecting -2 exposure adjustment on PA chest image | Results in increased quantum noise and increased brightness in the lung area. |
| Special considerations requiring increase in mAs | Contrast media, bariatric patients, plaster casts, and all of the above. |
| Exposure technique system using fixed mAs | Fixed kVp technique uses a fixed mAs regardless of part thickness. |
| Primary goal of an exposure technique chart | To produce quality images consistently. |
| Important condition for technique charts | Equipment must be calibrated to perform properly. |
| Effect of negative contrast agent in gastrointestinal tract | Increased brightness in the area of interest on the displayed image. |
| Patient with congestive heart failure | Considered an additive condition. |
Created by:
user-2019507
Popular Radiology sets