Noninvasive assessment of implant capsules.

The assessment of implant capsular contracture has been imprecise and vulnerable to observer bias. Attempts to measure capsules with instruments that measure implant deformability are influenced by surrounding breast tissue, subcutaneous fat, and skin. Xeromammography, B-mode ultrasound, and CT were employed in an effort to provide a noninvasive and accurate method of capsule assessment. Through two study phases, implants were placed bilaterally in a total of 21 rabbits. At 4 months, animals underwent radiologic assessment and were then sacrificed for direct implant capsule measurements. Mammographic measurements, more than ultrasound-derived measurements, strongly correlated with laboratory measures of capsular dimensions and deformability. Cross-table lateral mammographic views were more informative than traditional views, providing measures of diameter and height that both strongly correlated with laboratory measurements. CT is theoretically the most accurate method to assess contracture, but it is impractical because of expense and time requirements. The results indicate that radiologic assessment, in particular by xeromammography, of implant capsules is accurate, practical, and noninvasive. Mammography strongly correlates with laboratory measures of implant capsular contracture and therefore could be used in the clinical setting to assess capsular contracture.