Diagnostic ultrasound ( PDFDrive )

790 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
FIG. 21.43 Three-Dimensional or Volume Imaging With Automated Breast Scanner. Spiculations are better demonstrated on the reconstructed
coronal plane (right) than on the serial native (original) plane images.
A B C
FIG. 21.44 Angular Margins Represent Invasion of Carcinoma Into Low-Resistance Pathways. (A) Fat offers little resistance to invasion,
so malignant nodules surrounded by fat can develop angles along any surface (arrows). (B) In lesions surrounded by hyperechoic ibrous tissues,
paths of low resistance are along the periductal tissues (arrowhead) and horizontally along the tissue planes within the ibrous tissue (arrows). (C)
Following Cooper ligaments (arrowheads) down to their base, where they intersect the surface of the nodule, is the best way to detect angles
(arrows) on the surface of malignant solid nodules.
nodules that have a volume of 1 cc or less. As lesions enlarge,
they tend to become parallel (previously termed “wider-than-tall”).
he best of several explanations for this inding is that the orientation
of small carcinomas relects the shape of the TDLUs within
which the carcinoma arose. Most TDLUs lie anteriorly and are
oriented in a not parallel axis. As malignant lesions expand into
the lobar ductal system, which is oriented horizontally within
the breast, they tend rapidly to become parallel (Fig. 21.47).
Given that some carcinomas can have parallel orientation, orientation
alone should not be the distinguishing feature between
benign and malignant.
Duct Extension
Duct extension is a “sot” shape inding that correlates with the
presence of DCIS components of tumor. Duct extension is a part
of the ACR BI-RADS subcategory “Associated Features–Duct
Changes.” 17 Other changes that are part of this subcategory include
ductal dilation, irregularities in caliber and/or arborizaton, and
the presence of an intraductal mass, thrombus, or detritus. Duct
extension correlates with mammographic calciication patterns
that have been applied to components of solid nodules. Duct
extension can best be demonstrated when the scan plane is
oriented parallel to the long axis of the mammary ducts in the
region of the mass. Duct extension usually manifests as a single
projection of solid growth toward the nipple from the main
mass (Fig. 21.48). Additional projections of the solid mass into
multiple small ducts peripherally can also occur. Solid masses
that have long duct extensions tend to have extensive intraductal
DCIS components that increase the likelihood of local
recurrence.