Architectural Distortion

Presentation and Presenting Images

( ▶ Fig. 103.1, ▶ Fig. 103.2, ▶ Fig. 103.3, ▶ Fig. 103.4)

A 54-year-old female presents for tomosynthesis-directed stereotactic biopsy of an area of architectural distortion seen on the craniocaudal (CC) tomosynthesis movie only.

103.2 Key Images

( ▶ Fig. 103.5, ▶ Fig. 103.6, ▶ Fig. 103.7, [ ▶ Fig. 103.8,] ▶ Fig. 103.9)

103.2.1 Breast Tissue Density

The breasts are heterogeneously dense, which may obscure small masses.

103.2.2 Imaging Findings

There are no prior mammograms available for comparison. The imaging of the right breast is normal (not shown). There is an asymmetry with possible associated architectural distortion (circle) seen in the posterior depth of the left breast on the CC digital breast tomosynthesis (DBT) movie only. This finding is seen on ▶ Fig. 103.1, ▶ Fig. 103.2, ▶ Fig. 103.3, and ▶ Fig. 103.4. The patient is not positioned well and the amount of retroglandular fat (line) is limited ( ▶ Fig. 103.5). Biopsy was recommend but repeat imaging with better positioning and adequate retroglandular fat ( ▶ Fig. 103.6 and ▶ Fig. 103.7) was performed on the day of the biopsy. The repeat craniocaudal (CC) and the mediolateral oblique (MLO) images ( ▶ Fig. 103.8 and ▶ Fig. 103.9) do not reveal a persistent architectural distortion. No suspicious lesions are seen; therefore, the biopsy was canceled.

The posterior nipple line (PNL in ▶ Fig. 103.5 and ▶ Fig. 103.7) is the line drawn posterior and perpendicularly from the nipple toward the pectoral muscle on the mammogram.

Repeat CC and lateromedial (LM) tomosynthesis movies ( ▶ Fig. 103.6 and ▶ Fig. 103.9) on the day of biopsy do not reveal a persistent architectural distortion. No suspicious lesions are seen.

103.3 BI-RADS Classification and Action

Category 1: Negative

103.4 Differential Diagnosis

Summation artifact: This finding resolves on the tomosynthesis movie consistent with a pseudomass or summation artifact. The biopsy was aborted.
Developing asymmetry: There are no prior mammograms or tomosynthesis imaging for comparison, so one cannot ascertain if this finding has increased in conspicuity or size. This finding does not persist on repeat mammography or DBT imaging.
Invasive lobular carcinoma: Invasive lobular carcinomas have been shown to be better seen on one view, usually the CC view. This finding is not seen on repeat DBT imaging.

103.5 Essential Facts

DBT helps imagers to identify true mass lesions and to dismiss pseudomasses or summation artifacts.
The detection of lesions obscured by overlapping breast tissue is a limitation of conventional mammography.
DBT eliminates the effects of overlapping breast tissue, thus reducing callbacks and biopsies; however, an improperly positioned breast on DBT can create a pseudolesion. The pseudolesion in this case almost resulted in a biopsy.

103.6 Management and Digital Breast Tomosynthesis Principles

The factors that affect the image quality of mammography are positioning, compression, optimum exposure, sharpness, noise, and contrast. Exposure, sharpness, noise, and contrast have been eliminated with technological advances.
Positioning and compression are dependent upon the patient and technologist working together as a team.
Making certain that the patient is appropriately positioned can reduce many artifacts seen with mammography.
Appropriate positioning is just as important with DBT as with conventional mammography.
In this case, the amount of retroglandular fat (line) included on the CC tomosynthesis movie is about three times greater on the repeat tomosynthesis movie than on the initial movie ( ▶ Fig. 103.5 and ▶ Fig. 103.7).

103.7 Further Reading

[1] Popli MB, Teotia R, Narang M, Krishna H. Breast positioning during mammography: mistakes to be avoided. Breast Cancer (Auckl). 2014; 8: 119‐124 PubMed