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The __________ referred to the sharpness of structural line recorded in the image.
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Some information is always lost during the process of?
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Imaging
Ch.28 and 29
| The __________ referred to the sharpness of structural line recorded in the image. | Geometric properties. |
| Some information is always lost during the process of? | Image formation |
| ___________ is achieved by maximizing the amount of recorded detail in minimizing the amount of distortion. | Optimal geometric quality. |
| __________ refers to the distinctness or sharpness of the structural lines that make up the recorded image. | Recorded detail |
| The amount of _______ is a result of the relationship among the size of the focal spot, SID and OID. | Geometric unsharpness. |
| A __________ cannot be the exact reconstruction of the anatomic structure. | Radiographic image |
| Manipulating each variable __________________ alters the amount of unsharpness recorded in the image. | Individually or in combination |
| Focal spot size is determined by? | Filament size |
| When you select a focal spot size, you're actually selecting a ___________ that will be energized during x-ray production. | Filament size |
| Small focal sizes are usually ________mm | 0.5 to 0.6 mm |
| Large focal sizes are usually _________mm | 1.0 to 1.2 mm |
| Focal spot size only affects recorded _______ | Detail |
| As focal spot size Increases, unsharpness ________ and recorded detail _______ | Unsharpness increases and recorded detail decreases |
| As focal spot size decreases, unsharpness ________ and recorded detail ________ | Unsharpness decreases and recorded detail increases |
| In general, the smallest focal spot size available should be used in every _______ | Exposure. |
| The exposure is limited with a _________ | Small focal size. |
| When a small focal spot is used, the ________ created during x-ray exposure is concentrated in a small area and could cause tube damage. | Heat |
| You have to weigh the importance of improved recorded detail for a particular exam or anatomic part against the amount of __________ used. | Radiation exposure. |
| ______________ are equipped with safety circuits that prevent an exposure from being make if that exposure will exceed the tube loading capacity for the focal spot size selected. | Modern generators. |
| ____________ made just under the limit over a long period can still jeopardize the life of the x-ray tube. | Repeated exposures |
| Intensity of the x-ray beam is altered when changing the __________ between the source and object or object and receptor, some is the amount of unsharpness recorded on the image. | Distance. |
| Because of the _________________, A geometric relationship exist among the source of x-rays, the object, and the image receptor. | Diverging beam. |
| Increasing the SID, ______ The amount of unsharpness and ________ The amount of recorded detail in the image. | Decreases unsharpness, increases detail. |
| Decreasing the SID, _______The amount of unsharpness and ________The amount of recorded detail in the image. | Increases unsharpness, decreases detail. |
| Increasing that OID, ________ The amount of unsharpness and ________ The recorded detail. | Increases unsharpness, decreases detail |
| Decreasing the amount of OID, ______ The amount of unsharpness and _______ the detail. | Decreases unsharpness, increases detail |
| _____________ distances for SID are used in x-ray to accommodate equipment limitations. | Standard |
| Except for chest and cervical spine exams, a 40 inch or 48 inch SID is the _____ | Standard |
| In addition to the SID, the OID also affects the amount of | Unsharpness |
| Optimal detail is achieved when the OID is _____ | 0 |
| But there is always some ______ created between the area of interest and the image receptor. | Distance |
| As the exit beam leaves the patient, it continues to ______ | Diverge. |
| When _______ is created between the area of interest and the image receptor, they diverging beam records ________ unsharpness within the image | Distance; increased |
| The distance between the area of interest and the image receptor has a greatest effect on the amount of ________ | Geometric unsharpness |
| When possible, the distance between the area of interest and the image receptor should be kept to a ________ | Minimum |
| The distance between the area of interest in the image receptor has a greatest effect on the amount of geometric unsharpness recorded than does | Focal spot size or SID |
| The relationship among the variables of focal spot size and distance can be demonstrated by the geometric unsharpness _______ | Formula |
| Focal spot size X OID / SOD = | Geometric unsharpness |
| Dimensions of the nominal focal spot in millimeters is | Focal spot size |
| The distance between the object ( Area of interest) And the image receptor. | OID |
| The distance between the focal spot (source) and the object (area of interest). | SOD |
| ______ = SID - OID | SOD |
| When calculating the amount of unsharpness, keep the distance in the same units (I.e., inches or centimeters) this will cancel the units and result in | The unsharpness unit in millimeters |
| Motion unsharpness has the most detrimental effect on the ___________ of the radiographic image | Recorded detail |
| Motion of the tube, Port, or image receptor cause a decrease in ______ | Detail |
| Motion needs to be ________ | Eliminated |
| Unsharpness resulting from patient motion is known as | Blur |
| Blur is the most detrimental Factor to maximizing ______ | Detail |
| Unsharpness due to motion is classified as | Voluntary - within the patients control or involuntary - outside the patients control ex. Peristalsis |
| Most motion results from the patient _____ | Moving during an exposure |
| How would you eliminate emotion? | Shorter exposure time, higher mA. Provide clear instructions for the patients. Using physical Immobilization ex. Sandbags, tape. |
| Size distortion/magnification refers to an _____________________ compared to its true or actual size. | Increase in the objects image size |
| Radiographic images of objects are always ______ in terms of the true object size. | Magnified |
| The _______ used (______ and _______) Play an important part in minimizing the amount of size distortion. | Distances (SID and OID). |
| Magnification of the true object will occur because there is always some ______ | OID |
| ______ Is directly related to magnification | OID |
| As OID increases, size distortion ( magnification) _________ | Increases |
| As OID decreases, size distortion _________ | Decreases |
| _______. Also influences the total amount of size distortion represented on an image | SID |
| ________ has the greatest effect on size distortion, _______ is still an important factor to control to minimize size distortion. | OID; SID |
| ________ is inversely related to magnification. | SID |
| As SID increases, size distortion magnification ________ | Decreases |
| Distortion results from the radiographic ________ and either the size magnification or shape of the anatomic part | Misrepresentation |
| When the image is distorted, detail is ______ | Reduced |
| The _______________ indicates how much size distortion is demonstrated. | Magnification factor (MF) |
| SID/SOD= | MF |
| SID - OID= | SOD |
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