The mirror image artifact can also occur with Doppler system. This means that an image of a vessel and a source of Doppler shifted echoes can be duplicated on the opposite side of a strong reflector such as bone. The duplicated vessel containing flow could be misinterpreted as additional vessel. A mirror image of a Doppler spectrum can be appear on the opposite side of the baseline when, indeed, flow is unidirectional and should appear only on one side of the baseline. This is an electronic duplication of spectral information. It can occur when receiver gain is set too high causing overloading in the receiver and cross talk between the two flows channels or with gain where the receiver has difficulty determining the sign of the Doppler shift. It can also occur when Doppler angle is near 90 o. Here the duplication is usually legitimate and this is because beams are focused and not cylindrical in shape. Thus, portions of the beam can experience flow toward while other portions can be experience flow away.
A prerequisite for optimal utilization of ultrasound in obstetrics and gynecology is an in depth knowledge of the principles and limitations of the dynamics technique. It is important to appreciate that the appearance of the Doppler images is influenced by the operational setting of the equipment that must be taken into account for any reable interpretation. Only persons with sufficient training and education should perform diagnostic ultrasound. One major reason for so many conflicting and controversial results in the ultrasound literature originates from technique complexity and rather limited education in physics and technique. With all artifacts, it is important not to let a superficial knowledge cause trouble. Once the cause and nature of an artifact are understood, it is important not to misinterpret a real lesion as a miss the true pathologic. This can happen, particularly with pelvic masses such as leiomaymas with poor through transmission in which the deep wall is not well seen. If there is also an artifact situated near where the deep wall would be, the actual mass might be dismissed as simply an artifact. One must pay attention at all times not only to identify artifacts but also not to let them interfere with the identification of true lesions. While the more common artifacts seen on ultrasound imaged frequency ignored and appreciated as such as, it is certainly interesting to know why they occur, on the other hand, the usefulness of the artifacts cannot be underestimated. Occasionally, the identification of an artifact may prevent the novice from making an important error in diagnosis or management. An appreciation and understand of how to avoid artifacts can help even the more experienced practitioner decide weather a structure is real. It is also important not to ignore real pathology under the assumption that it is caused by artifact.
A prerequisite for optimal utilization of ultrasound in obstetrics and gynecology is an in depth knowledge of the principles and limitations of the dynamics technique. It is important to appreciate that the appearance of the Doppler images is influenced by the operational setting of the equipment that must be taken into account for any reable interpretation. Only persons with sufficient training and education should perform diagnostic ultrasound. One major reason for so many conflicting and controversial results in the ultrasound literature originates from technique complexity and rather limited education in physics and technique. With all artifacts, it is important not to let a superficial knowledge cause trouble. Once the cause and nature of an artifact are understood, it is important not to misinterpret a real lesion as a miss the true pathologic. This can happen, particularly with pelvic masses such as leiomaymas with poor through transmission in which the deep wall is not well seen. If there is also an artifact situated near where the deep wall would be, the actual mass might be dismissed as simply an artifact. One must pay attention at all times not only to identify artifacts but also not to let them interfere with the identification of true lesions. While the more common artifacts seen on ultrasound imaged frequency ignored and appreciated as such as, it is certainly interesting to know why they occur, on the other hand, the usefulness of the artifacts cannot be underestimated. Occasionally, the identification of an artifact may prevent the novice from making an important error in diagnosis or management. An appreciation and understand of how to avoid artifacts can help even the more experienced practitioner decide weather a structure is real. It is also important not to ignore real pathology under the assumption that it is caused by artifact.
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