Center of Plastic, Hand and Reconstructive Surgery, University Hospital Regensburg, Regensburg, Germany.
Clin Hemorheol Microcirc. 2011;48(1):105-17. doi: 10.3233/CH-2011-1405.
The immediate evaluation of microvascular tissue flaps with respect to microcirculation after transplantation is crucial for optimal monitoring and outcome. The purpose of our investigation was to evaluate the clinical value of contrast-enhanced ultrasound (CEUS) and contrast-enhanced MRI (ceMRI) for monitoring the integrity of tissue flaps in plastic surgery.
To this end, we investigated 10 patients (47 ± 16 a) between postoperative day 7 and 14 who underwent flap surgery in order to cover tissue defects in various body regions. For CEUS we utilized the GE LOGIQ E9 equipped with a linear transducer (6-9 MHz). After application of 2.4 ml SonoVue, the tissue perfusion was detected in Low MI-Technique (MI < 0.2). The perfusion curves were quantitatively analyzed using digital video sequences (QONTRAST, Bracco, Italy) regarding peak % and relative blood flow (RBF). Furthermore, we investigated all tissue flaps using contrast-enhanced MRI (Magnetom Symphony TIM, Siemens) with a 3D-VIBE sequence and a time resolution of 7s. Thus, the transplants were completely captured in all cases. As perfusion parameters, the positive enhancement integral (PEI) as well as the maximum intensity projection time (MIP-time) were collected. For comparison of both applications, all parameters were displayed in color-coded resolution and analyzed by three independent readers. Depending on the flap thickness, 1-3 regions of interest (ROI) were investigated. Each ROI measured 1 × 3 cm.
The subcutaneous ROI-1 showed a significantly lower rating regarding RBF in the ceMRI compared to CEUS (Mann-Whitney Rank-Sum test, p < 0.05). ROI-2 and -3 did not show any significant differences between the two applications. The frequency distribution showed good accordance in both modalities. Both imaging techniques detected 1 partial flap necrosis within the random area of cutaneous and subcutaneous layers, 1 hematoma as well as 1 insufficient perfusion over all tissue layers. After subsequent reoperation, graft loss could be prevented.
At present, both technologies provide an optimal assessment of perfusion in cutaneous, subcutaneous and muscle tissue layers, whereby the detection of fatty tissue perfusion is currently more easily detected using CEUS compared to ceMRI.
移植后立即评估微血管组织瓣的微循环对于最佳监测和结果至关重要。我们的研究目的是评估对比增强超声（CEUS）和对比增强磁共振成像（ceMRI）在监测整形外科组织瓣完整性方面的临床价值。
为此，我们调查了 10 名患者（47 ± 16 a），他们在术后 7 至 14 天接受了皮瓣手术，以覆盖各种身体部位的组织缺损。对于 CEUS，我们使用配备线性换能器（6-9 MHz）的 GE LOGIQ E9。应用 2.4 ml SonoVue 后，在低 MI 技术（MI < 0.2）下检测组织灌注。使用数字视频序列（QONTRAST，Bracco，意大利）对灌注曲线进行定量分析，以获得峰值 %和相对血流（RBF）。此外，我们使用对比增强磁共振成像（Magnetom Symphony TIM，Siemens）对所有组织瓣进行了研究，使用 3D-VIBE 序列和 7s 的时间分辨率。因此，在所有情况下都完全捕获了移植体。作为灌注参数，收集阳性增强积分（PEI）和最大强度投影时间（MIP-time）。为了比较两种应用，所有参数均以彩色分辨率显示，并由三位独立读者进行分析。根据皮瓣厚度，对 1-3 个感兴趣区域（ROI）进行了研究。每个 ROI 测量为 1×3cm。
皮下 ROI-1 的 RBF 在 ceMRI 中明显低于 CEUS（Mann-Whitney 秩和检验，p<0.05）。ROI-2 和 -3 两种应用之间无显著差异。两种成像技术的频率分布在两种模态中均具有良好的一致性。两种成像技术均检测到 1 例随机皮瓣和皮下层的部分皮瓣坏死，1 例血肿以及所有组织层的灌注不足。随后进行的再次手术可防止移植物丢失。
目前，这两种技术都可以对皮肤、皮下和肌肉组织层的灌注情况进行最佳评估，其中 CEUS 比 ceMRI 更易于检测到脂肪组织的灌注。
