THE MLO: Never Simple; Sometimes Impossible!

OBJECTIVES

The MLO view is difficult at best; in training we go over it again and again trying to unravel the intricacies of this projection. Then, just when we think we have it right, a patient shows up whose body habitus does not follow any of the rules. There are a few measures we can take to help us in these sometimes frustrating circumstances.

The “WEE MOUSY”

The tiny patient presents some unique problems when come to adequately demonstrating all the tissue in the MLO projection.

• Reduce the angle somewhat for the MLO.
• This patient’s pectoral muscle is usually short and flat (35˚- 45˚).
• Concentrate on the axillary tail and the pectoral for this view.
• If needed do a 90° LM to demonstrate the IMF and inferior breast tissue.

The “14x17”

Who said 24x30 was the largest film size one needs for mammography. The very large patient presents her own set of logistical problems when attempting to capture all the tissue in a precise and organized manner.

• Mark the breast carefully:
• Use nipple markers
• Use superior and inferior markers
• Use your projection markers ALWAYS correctly at the axilla side of the image
• Reduce the angle when acquiring the MLO views to help fight gravity ( up and out can be a very long trip)
• Take your time and map the breast carefully. IT IS VERY EASY TO GET LOST!
• There is nothing sadder (or madder) than a radiologist lost in a large breast
  

MS. PANCAKE

Ms. Pancake is very often the close companion of Mrs. 14X17 and Mme. Pretzel. Her breasts are empty and flaccid. They lay flat and unnoticed against her rib cage. How to handle this flimsy floppy tissue without wrinkles and folds can be a nightmare.

• Use an appropriate size bucky. The pancake breasts tend to spread and spread and spread like flowing water.
• Reduce the angle of the MLO to 30-40˚. This makes the thin floppy tissue easier to control
• Scoop the breast tissue and move it medially toward the sternum
• Flatten the tissue of the breast forward towards the nipple and smooth the wrinkles (don’t pull back toward the shoulder)
• When the MLO is in place and the skin is spread forward; place your hands on the superior and inferior edges of the breast and stretch the tissue flat from top to bottom

The “BANDEAU BATHING SUIT”

The patient with little or no demarcation between her breasts can be a real challenge. The bandeau bathing suit or Uni-Breast leaves little clue as to where the left breast leaves off and the right breast begins. It seems to be impossible to position one breast without the other one getting in the picture or pulling the breast of interest out of place. The answer of course is to work with what you are presented with and not to fight the existing anatomy

• Acquire a reduced angle MLO to demonstrate the anterior breast tissue, the retro mammary space and the posterior fascia.
• The reduced angle MLO may demonstrate a slip of contra lateral breast tissue
• Therefore, if necessary take an additional 90° LM view to open the IMF and demonstrate the inferior breast tissue.

The “PRETZEL”

This is our most delicate and fragile patient. She is elderly, frail, bent, brittle and thin skinned. Her osteoporosis, arthritis, roto-scoliosis, kyphosis and muscular-skeletal woes make this patient a virtual puzzle to image. It seems a daunting task to obtain a CC view free of jaw, skull, shoulder, sternum or ribs. There are a few tricks that will help you and help this most vulnerable patient as well.

• DO NOT fret about getting perfect images on this patient
• Just demonstrate as much as you can without doing any damage
• Acquire SIO or LMO views to accommodate Rotoscoliosis
• Acquire 90° LM views to demonstrate the IMF and the inferior breast tissue
• Use cornstarch or resin powder on your hands to assist with grip and protect the delicate skin
• HANDLE WITH CARE! This patient can break very easily




“PENELOPE THE BODY BUILDER”

Penelope is a very difficult client. She is large and muscular with a thick layer of adipose tissue. Her breasts are very small but she has huge thick pectoral grids and bulky upper arms. Penelope is not very agile and has trouble cooperating with the positioning. What to do, oh what to do? Our best that is all we can do.

• Acquire 1 set of MLO views with a reduced angle 35-45° on 24x30 films to demonstrate the thick unyielding posterior breast tissue against the pectoralis.
• Acquire a 2nd set of 90° LM views on 18x24 films to see the nipple in profile and the anterior breast tissue properly compressed.
• WARNING Penelope often sees herself as delicate. Don't assume she is as sturdy or brave as she appears: She really is a big old Teddy Bear

“PECTORALIS CARNAVATUM” (THE PIDGEON)

Women with this sternal abnormality used to be called “chicken breasted”: Not very politically correct but descriptive. The sternums in woman with this chest configuration have sternal bodies which bow out into a convex curve. The boney protuberance between the breasts seems to crash into the compression paddle long before we get anywhere near the breast tissue. There are again a few simple tricks to work around this thorny problem.

• Acquire a reverse oblique
• Place the sternum against the bucky
• Raise the patient’s arm up over the top of the receptor
• Carefully compress from the lateral side while avoiding the Latissimus Dorsum
• Viola, a near perfect oblique without scraping the paddle over the sternum
• No skin abrasion, no bruising and very little patient discomfort




“PECTORALIS EXCAVATUM” (THE CROSSED HEART)

This sternal malformation has the patient’s sternum and ribs bowing in toward her spine. This presents a challenge to obtaining a good MLO projection. The medial borders of the breasts are pulled together and in toward the sternum with no discernible method of getting the bucky and paddle in-between them. With a little ingenuity we can make this situation less frustrating and more controllable.

• Acquire a SIO or superior/inferior oblique
• Angle the bucky appropriately
• Angle the patient slightly toward the edge of the bucky and more or less wedge the sternal border against the bucky
• Raise the patient’s arm up over the top of the receptor
• Carefully compress from the lateral side while avoiding the Latissimus Dorsum
• Viola, a near perfect oblique capturing most or all of that elusive medial tissue tucked into the sternum.




CONCLUSION

Breast imaging presents a difficult and diverse set of challenges. None of it is easy, especially the MLO projection. These tips are designed to help. Keep them handy, use them liberally.