History
A 32-year-old female patient, suffering from bilateral symptomatic breast hypertrophy with severe ptosis (grade 3) after breastfeeding within the past eight years, was scheduled for a reduction mammaplasty. Prior to surgery, a CT angiography (CTA) was performed, using an ultra-high resolution (UHR) scan mode with a dual-source photon-counting detector (PCD) CT, NAEOTOM Alpha®, to assess the dominant blood supply of the nipple-areola complex (NAC) and its vascular sources.
Diagnosis
CTA images revealed a symmetrical pattern of a single source artery on both sides. The dominant arteries branched off the internal thoracic arteries at the first intercostal space on the right and at the second intercostal space on the left, supplying blood to the NAC region. Virtual monoenergetic images (VMI) displayed at 50 keV showed increased contrast enhancement and improved visualization of the terminal arteries for the NAC. These images were used to create three dimensional (3D) images with cinematic volume rendering technique (cVRT). Different presets were applied to demonstrate the anatomical relationship between the arteries and the bones, as well as the muscles and the fatty tissues, matching the surgical position of the patient. The rendering results were projected for holographic localization and the arteries were pre-operatively marked on the patient’s body.
The patient underwent a successful reduction mammaplasty and pedicled nipple-areola reconstruction with a satisfactory outcome.
Fig. 1: cVRT images show a symmetrical pattern of a single source artery on both sides. The dominant arteries branch off the internal thoracic arteries at the first intercostal space on the right and at the second intercostal space on the left, supplying blood to the NAC region. The anatomical relationship between the arteries and the bones (Fig. 1a), the muscles (Fig. 1b), and the fatty tissues (Fig.1c), is demonstrated using different presets, and matching surgical position of the patient.
Comments
Macromastia, aka breast hypertrophy, is a medical condition characterized by an excessive growth of breast size, imposing physical and psychological challenges to the patients. There is no lasting non-operative treatment for symptomatic breast hypertrophy and its precise etiology remains elusive. [1] Surgical treatment by reduction mammaplasty has been recognized in the guidelines as the best approach to symptomatic relief and constitutes the most common therapy. [2] However, postoperative functional loss or even necrosis of the NAC, resulting from injuries of the arteries during the operation, may occur due to the complexity of the blood supply. An incidence rate of up to 13% has been reported. [3] Studies have shown that the blood supply pattern of the NAC is highly variable among individuals and even between the right and left breast of the same person. The source artery can be single or multiple, with a symmetrical or asymmetrical pattern. In some cases, the dominant artery may not be visualized, when the detectable diameter threshold is set to beyond 1.0 mm. [3] It is therefore important to have CTA images with a high resolution for a better understanding of the NAC blood supply to achieve a successful, individualized design of the reduction mammaplasty.
This case was performed with a dual source PCD-CT, NAEOTOM Alpha, which provides energy-resolved CT data at improved spatial resolution with inherent spectral information, without electronic noise. [4] These advanced techniques contribute to the improvement of imaging the details of the small terminal arteries to the NAC. The individual detector pixels of the PCD are defined by a strong electric field, instead of physical separation applied with the conventional energy-integrating detector (EID) CT, resulting in small subpixels without loss of radiation dose efficiency. The UHR mode therefore features a fine collimation of 120 x 0.2 mm and high in-plane resolution. In addition, spectral information is available at a slice width of 0.4 mm, to display VMIs at a low keV level (50 keV in this case), thus improving contrast enhancement. The absence of the electronic noise prompts a potential dose reduction (4.5 mGy in this case) while retaining optimal image quality.
As shown in this case, pre-operative CTA imaging facilitates a comprehensive understanding of the primary blood supply in the NAC region, and is thus a useful tool in the assistance of surgical planning for reduction mammaplasty. The UHR images acquired with PCD-CT demonstrate the potential of improving the vascular details at a reduced radiation dose.
Examination Protocol
