20° oblique projection

Last revised by Andrew Murphy ◉ on 23 Mar 2023

Citation, DOI, disclosures and article data

Citation:

Skandhan A, Murphy A, Sheikh Y, et al. 20° oblique projection. Reference article, Radiopaedia.org (Accessed on 03 Oct 2023) https://doi.org/10.53347/rID-28221

DOI:

https://doi.org/10.53347/rID-28221

Permalink:

https://radiopaedia.org/articles/28221

rID:

28221

Article created:

15 Mar 2014, Avni K P Skandhan ◉

Disclosures:

At the time the article was created Avni K P Skandhan had no recorded disclosures.

View Avni K P Skandhan's current disclosures

Last revised:

23 Mar 2023, Andrew Murphy ◉

Disclosures:

At the time the article was last revised Andrew Murphy had no financial relationships to ineligible companies to disclose.

View Andrew Murphy's current disclosures

Revisions:

8 times, by 5 contributors - see full revision history and disclosures

Systems:

Breast

Sections:

Radiography

Tags:

breast, mammographic views, refs

Synonyms:

20° MLO
20° Mediolateral oblique view
20° Mediolateral oblique projections
20° oblique view

20° oblique projection is a troubleshooting projection used in mammography, especially in young women and in follow-up patients.

Technique

The C-arm is turned approximately 20° for a superomedial-inferolateral oblique. With the patient's feet pointing towards the unit and her torso turned slightly outward with the lateral portion of the ipsilateral breast closer to the unit, the breast is placed on the image receptor. The contralateral arm should remain at her side, and the ipsilateral hand may grip the lower aspect of the image receptor. Raise the C-arm so that posterolateral tissue comes to rest on the image receptor. Relax the shoulders to better image the upper outer quadrant. To successfully open the glandular structures, try to flatten the breast. Gently pull the breast outward and forward and apply compression.

Clinical application

demonstrates the entire glandular island with less superimposition than the two projection mammograms
useful for visualizing the upper outer quadrant of the breast
preferred position in a follow-up patient of young age
useful as a third projection when seeking further evidence about a possible abnormality imaged on the MLO projection
useful as a third view for both the unaffected and the affected breasts in patients who have had breast cancer, as these patients have an increased risk of either developing another carcinoma in the unaffected breast or of recurrence in the affected breast