RESUMO
Breast augmentation is considered one of the most commonly performed procedures by aesthetic plastic surgeons, representing 16 % of all global plastic surgery procedures in 2020. Given the fact that thoracic trauma comprises over 20 % of trauma worldwide, it is unsurprising that there is potential for overlap between these two patient populations. Here, we present the case of a 59-year-old patient who had undergone bilateral breast augmentation over 10 years prior to presentation. They arrived as a highest-level trauma activation after being a helmeted cyclist struck by a motor vehicle resulting in significant left-sided thoracic trauma. Following stabilization in the trauma bay, CT imaging of the thorax demonstrated multifocal left pulmonary contusions and lacerations, multiple left-sided rib fractures (ribs 2-12), a small left pneumothorax, and left-sided subcutaneous emphysema. Imaging also demonstrated the presence of bilateral breast implants with the left implant appearing irregular in shape with the retropectoral space corresponding to the implant capsule having evidence of significant free air (capsular pneumatosis) concerning for acute traumatic rupture of the capsule. While undergoing surgical stabilization of her left-sided rib fractures, one of her ribs was noted to have violated the posterior wall of the breast capsule. Upon implant removal, the implant was found to have ruptured with tears in the shell corresponding to patient's rib fractures. This case represents a rare and unexpected complication of traumatic rib fractures; mainly the traumatic rupture of a silicone breast implant, which was identified by the presence of capsular pneumatosis on CT imaging. Presence of this rare radiographic sign (capsular pneumatosis) in the setting of a patient who has undergone breast augmentation should raise concern for possible implant rupture and capsule violation, even in the absence of external signs of penetrating injury.
RESUMO
Increasingly, the advent of multislice CT scanners, volume CT scanners, and total body spiral acquisition modes has led to the use of Multi Planar Reconstruction and 3D datasets. In considering 3D resolution properties of a CT system it is important to note that both the in-plane (x,y) and z-axis (slice thickness) influence the visual-ization and detection of objects within the scanned volume. This study investigates ways to consider both the in-plane resolution and the z-axis resolution in a single phantom wherein analytic or visualized analysis can yield information on these combined effects. A new phantom called the "Wave Phantom" is developed that can be used to sample the 3D resolution properties of a CT image, including in-plane (x,y) and z-axis information. The key development in this Wave Phantom is the incorporation of a z-axis aspect of a more traditional step (bar) resolution gauge phantom. The phantom can be examined visually wherein a cutoff level may be seen; and/or the analytic analysis of the various characteristics of the waveform profile by including amplitude, frequency, and slope (rate of climb) of the peaks, can be extracted from the Wave Pattern using mathematical analysis such as the Fourier transform. The combined effect of changes in in-plane resolution and z-axis (thickness), are shown, as well as the effect of changes in either in-plane resolu-tion, or z-axis thickness. Examples of visual images of the Wave pattern as well as the analytic characteristics of the various harmonics of a periodic Wave pattern resulting from changes in resolution filter and/or slice thickness, and position in the field of view are shown. The Wave Phantom offers a promising way to investigate 3D resolution results from combined effect of in-plane (x-y) and z-axis resolution as contrasted to the use of simple 2D resolution gauges that need to be used with separate measures of z-axis dependency, such as angled ramps. It offers both a visual pattern as well as a pattern amenable to analytic analysis using Fourier Transform methods, and is believed to offer an image quality test closer to the diagnostic task where the 2D image has the hidden third (z) axis effects.
