Harvard Emergency Ultrasound Fellowship, Division of Emergency Ultrasound, Department of Emergency Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Division of Emergency Ultrasound, Department of Emergency Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Ultrasound Med Biol. 2022 Aug;48(8):1509-1517. doi: 10.1016/j.ultrasmedbio.2022.03.015. Epub 2022 May 5.
Ultrasonographic B-lines are artifacts present in alveolar-interstitial syndromes. We prospectively investigated optimal depth, gain, focal position and transducer type for B-line visualization and image quality. B-Lines were assessed at a single rib interspace with curvilinear and linear transducers. Video clips were acquired by changing parameters: depth (6, 12, 18 and 24 cm for curvilinear transducer, 4 and 8 cm for linear transducer), gain (10%, 50% and 90%) and focal position (at the pleural line or half the scanning depth). Clips were scored for B-lines and image quality. Five hundred sixteen clips were obtained and analyzed. The curvilinear transducer improved B-line visualization (63% vs. 37%, p < 0.0001), with higher image quality (3.52 ± 0.71 vs. 3.31 ± 0.86, p = 0.0047) compared with the linear transducer. B-Lines were better visualized at higher gains (curvilinear: gain of 50% vs. 10%, odds ratio = 7.04, 95% confidence interval: 4.03-12.3; gain of 90% vs. 10%, odds ratio = 9.48, 95% confidence interval: 5.28-17.0) and with the focal point at the pleural line (odds ratio = 1.64, 95% confidence interval: 1.02-2.63). Image quality was highest at 50% gain (p = 0.02) but decreased at 90% gain (p < 0.0001) and with the focal point at the pleural line (p < 0.0001). Image quality was highest at depths of 12-18 cm. B-Lines are best visualized using a curvilinear transducer with at least 50% gain and focal position at the pleural line. Gain less than 90% and image depth between 12 and 18 cm improve image quality.
超声 B 线是肺泡-间质综合征中的伪像。我们前瞻性地研究了最佳深度、增益、焦点位置和换能器类型，以实现 B 线可视化和图像质量。使用线阵和凸阵探头在单一肋间隙评估 B 线。通过改变参数（线阵探头的深度为 6、12、18 和 24cm，凸阵探头的深度为 4 和 8cm）、增益（10%、50%和 90%）和焦点位置（在胸膜线或扫描深度的一半）来获取视频片段。对 B 线和图像质量进行评分。共获得和分析了 516 个片段。与线阵探头相比，凸阵探头提高了 B 线的可视化（63%比 37%，p<0.0001），图像质量也更高（3.52±0.71 比 3.31±0.86，p=0.0047）。在更高增益（凸阵：增益为 50%比 10%，优势比=7.04，95%置信区间：4.03-12.3；增益为 90%比 10%，优势比=9.48，95%置信区间：5.28-17.0）和焦点位于胸膜线时，B 线的可视化效果更好（优势比=1.64，95%置信区间：1.02-2.63）。在增益为 50%时图像质量最高（p=0.02），但在增益为 90%时（p<0.0001）和焦点位于胸膜线时（p<0.0001）图像质量降低。在深度为 12-18cm 时，图像质量最高。使用至少 50%增益和胸膜线焦点位置的凸阵换能器可最佳显示 B 线。增益小于 90%和图像深度在 12-18cm 之间可提高图像质量。
