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Learn how to think in three dimensions when viewing mammograms, understand descriptive terminology, recognize moving abnormalities, and approximate lesion location. Develop a consistent viewing routine to improve breast tissue analysis.
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CHAPTER 9 Thinking in Three Dimensions
THINKING THREE DIMENSIONALLY • Each views is two dimensional • Combining two views creates a three-dimensional image • Numerous overlapping tissues • Medial structures over lateral • Superior structures over inferior • Each quadrant appears differently
CONSISTENT VIEWING • Develop a routine of viewing • Conforming to same method will familiarize to breast tissue distribution • Established format helps to recognize patterns of pathology • Work with your radiologist
DESCRIPTIVE TERMINOLOGY • Quadrants • UOQ (upper outer quadrant) • UIQ (upper inner quadrant) • LOQ (lower outer quadrant) • LIQ (lower inner quadrant) • Clock-time • Subareolar • Periareolar
MAMMOGRAPHIC SUPERIMPOSITION • Each view is a summation of tissue • It is possible to demonstrate an area free of superimposition of other glandular islands or one quadrant free of another
“MOVING” ABNORMALITIES • Nipple is only fixed reference point in breast • Centrally located structures should remain constant • A lesion’s relationship to the nipple will change from view to view • Understanding how a lesion “moves” will help in obtaining correct projection
“MOVING” ABNORMALITIES Three rules • When comparing MLO projection to true lateral, medial lesion will move up on the lateral view • When comparing MLO projection to true lateral, lateral lesion will move down on the lateral view • A central lesion will show no or little movement from MLO to true lateral
APPROXIMATING LOCATION • Determine whether lesion is medial or lateral to the nipple and its distance from nipple on CC projection • Determine whether lesion is superior or inferior to the nipple and its distance from nipple on MLO projection • A lesion will not change distance from nipple
APPROXIMATING LOCATION Common Errors • Superior and inferior cannot be determined from CC • Medial or lateral cannot be determined from MLO • Superior lesion may be in UOQ or UIQ • If nipple is excessively rotated, lesion may appear to be moving