Department of Medicine, University of California San Diego, San Diego, CA, USA.
Radiology Service, VA San Diego Healthcare System, San Diego, CA, USA.
J Thromb Haemost. 2018 Mar;16(3):490-499. doi: 10.1111/jth.13930. Epub 2018 Jan 19.
Essentials The best imaging modality for joint blood detection in hemophilia is unknown. Blood appearance and detection thresholds were studied with ultrasound and conventional MRI. Ultrasound is sensitive to low volume and concentration of blood, whereas conventional MRI is not. The findings establish the validity of ultrasound for rapid bleed detection in hemophilia care.
Background There is increasing demand for musculoskeletal ultrasound (MSKUS) to detect hemophilic joint bleeding, but there is uncertainty regarding blood detection concentration thresholds or if magnetic resonance imaging (MRI) is more accurate. Aims Compare the sensitivity of blood detection by MSKUS and MRI. Methods Increasing blood concentrations in plasma were imaged with MSKUS and MRI 1-2 h, 3-4 days and 7 days after blood withdrawal in vitro, and after injection into cadaveric pig joints. Additionally, effusions in the joints of two patients with hemophilia joints were imaged, followed by aspiration. MSKUS was performed using an 8-18-MHz linear transducer; MRI was performed at 3T using T1-weighted and T2-weighted fat-suppressed sequences. Images were reviewed by a hematologist certified in MSKUS and a musculoskeletal radiologist. Results MSKUS permitted the detection of blood in vitro and in pig joint spaces at concentrations as low as 5%, demonstrated by the presence of echogenic signals that were absent with plasma alone. In contrast, no differences between fluids were discernible on the T1-weighted or T2-weighted MRI images. Results were confirmed in the two patients with hemophilia. Blood clots demonstrated varying and dynamic echogenicity patterns over time and, using MRI, were visualized best with T2 sequences. Conclusion MSKUS is extremely sensitive in detecting low concentrations of intra-articular blood and in discriminating between bloody and non-bloody fluid, whereas conventional MRI is not. These observations demonstrate the advantages of MSKUS over MRI in detecting intra-articular blood, and show that MSKUS is ideal for rapid bleed detection in the clinic.
探讨关节血液检测的最佳成像方式。方法：采用超声和常规 MRI 检测血液外观和检测阈值。超声对低体积和低浓度的血液敏感，而常规 MRI 不敏感。结果：在体外采血后 1-2 小时、3-4 天和 7 天以及注射到尸体猪关节后，超声和 MRI 均可检测到血液浓度的增加。此外，还对 2 例血友病关节积液患者进行了超声检查，随后进行了抽吸。采用 8-18MHz 线性探头进行超声检查；MRI 采用 3T，采用 T1 加权和 T2 加权脂肪抑制序列。由经过 MSKUS 认证的血液学家和肌肉骨骼放射科医生对图像进行评估。结果：MSKUS 可在体外和猪关节空间检测到低至 5%的血液浓度，表现为存在超声信号，而单独使用血浆则不存在这些信号。相比之下，T1 加权和 T2 加权 MRI 图像上无法分辨两种液体之间的差异。在 2 例血友病患者中得到了验证。凝血块在不同时间表现出不同和动态的回声强度模式，而 T2 序列最适合显示 MRI 上的血液。结论：MSKUS 非常敏感，可以检测到关节内低浓度的血液，并且可以区分血液和非血液液体，而常规 MRI 则不能。这些观察结果表明，MSKUS 在检测关节内血液方面优于 MRI，并且表明 MSKUS 非常适合在临床上快速检测出血。
