Radiology of the Breast: Technique Selection

TECHNIQUE SELECTION

As with other organ systems, the task of the referring physi-cian with regard to breast imaging is to determine which patients may benefit from these studies and which are the appropriate studies to order. To do this, the physician first categorizes the patient as asymptomatic or symptomatic.

Asymptomatic patients: As a group, these patients will benefit from routine screening mammography performed ac-cording to published national guidelines. A particular patient may require an individualized program for specific reasons: for example, a 30-year-old asymptomatic woman whose mother died of breast cancer at age 35 may justifiably begin yearly screening mammography. (2) Symptomatic patients: These are women who have any of the following signs or symptoms: a new or enlarging breast lump, skin changes (primarily dimpling), nipple retraction, eczematoid nipple changes, bloody or serous nipple discharge, and focal pain or tenderness. Diagnostic mammography is indicated in these patients. If the patient is under 35 years of age, the examina-tions may be differently tailored than for older patients. Con-sultation with the breast imager may be helpful in determining a suitable evaluation plan in any patient for whom the usual guidelines are not helpful.

If a diagnostic study is needed, a standard two-view mam-mogram is obtained first. The need for further studies will be determined by the results of the mammogram. Whether ul-trasonography or another modality is needed is best decided by the person interpreting the films, provided that he or she has the necessary clinical information available. For example, it is imperative that the location and description of a sus-pected mass be made known to the radiologist so that a spe-cific search can be made for a lesion.

Also, knowledge of prior surgery, inflammation, or trauma to the breast is a requirement for accurate image in-terpretation. The different disease processes may have over-lapping appearances on breast images, and refining the differential diagnosis therefore depends on accurate breast physical examination and the patient’s history.

When it has been determined that an abnormality is pres-ent, then the decision as to whether close follow-up, needle biopsy, or excision is warranted is best made by integrating the image-based diagnosis and clinical considerations. Good communication between the radiologist and the referring physician is needed to optimize management of breast lesions.

Patient Preparation

For the mammogram, two-piece clothing is most convenient as the patient will need to undress from the waist up. Patients should not apply antiperspirant to the breast or axilla be-cause it may cause artifacts.

Mammography is generally limited to ambulatory, cooper-ative patients because of the difficulties in proper positioning and because mammography units are not portable. If a debili-tated patient has a palpable mass, then ultrasound would be a reasonable first step, followed by bedside needle aspiration or biopsy if the mass is solid. Screening mammography in markedly debilitated patients rarely has clinical utility.

Patients for whom stereotactic biopsy is being considered should be able to lie in prone position without moving for about 1 hour.

Conflict with Other Procedures

Coordinating with other techniques is an infrequent problem with breast imaging. One situation that does occasionally cause difficulty occurs in the patient with a palpable mass that is aspirated with a needle prior to imaging. Aspiration of a simple cyst may cause bleeding into the lesion. Subsequent ultrasonography then shows a complex lesion with debris or some apparently solid elements, rather than a simple cyst. A complex lesion requires more aggressive management than does a simple cyst. Therefore, imaging is best performed prior to aspiration.