Division of Clinical Radiology, Christian Medical College, Vellore, India.
Department of Orthopaedic Surgery, Christian Medical College, Vellore, India.
Haemophilia. 2021 May;27(3):488-493. doi: 10.1111/hae.14303. Epub 2021 Mar 29.
Early detection of bleeding into a joint is crucial in patients with haemophilia. This study was designed to evaluate the sensitivity of ultrasonography (USG) and magnetic resonance imaging (MRI) to detect the presence of blood in small concentrations in a simulated model to mimic joint bleeding.
Different concentrations of blood in plasma, varying from 0.1% to 45%, were collected in 10-ml plastic syringes and imaged using 12 and 18 MHz USG transducers and with 1.5T and 3T MRI scanners, at different intervals of time following dilution. The images were scored for the presence of blood by four experienced radiologists who were blinded to the concentration of blood.
Within the first 2 h, the 18 MHz transducer was able to detect blood consistently up to 0.5%, whereas the 12 MHz transducer could consistently identify blood up to 1.4%. After the first 12 h, both transducers were able to detect blood up to 0.5% concentration. However, at concentrations below 0.5%, there was discordance in the ability to detect blood, with both transducers. There was no correlation between the signal intensities of MRI images and concentration of blood, at different time intervals, irrespective of the magnetic field strength.
Detection of blood using the USG is dependent on variables such as the concentration of blood, frequency of the transducer used and timing of the imaging. As the concentration of blood decreases below 0.5%, the discordance between the observers increases, implying that the detection limit of USG affects its reliability at lower concentrations of blood. Caution is urged while interpreting USG imaging studies for the detection of blood in symptomatic joints.
在血友病患者中，及早发现关节内出血至关重要。本研究旨在评估超声（USG）和磁共振成像（MRI）在模拟模型中检测小浓度血液存在的敏感性，以模拟关节出血。
将不同浓度（0.1%至 45%）的血液收集在 10 毫升塑料注射器中，并使用 12 和 18 MHz USG 换能器以及 1.5T 和 3T MRI 扫描仪进行成像，在稀释后不同时间间隔进行成像。四名经验丰富的放射科医生对图像进行评分，以评估血液的存在情况，这些医生对血液浓度不知情。
在最初的 2 小时内，18 MHz 换能器能够始终如一地检测到 0.5%以下的血液，而 12 MHz 换能器则能够始终如一地识别出 1.4%以下的血液。在最初的 12 小时后，两种换能器都能够检测到 0.5%以下的血液浓度。然而，在低于 0.5%的浓度下，两种换能器在检测血液的能力上存在不一致性。在不同的时间间隔内，MRI 图像的信号强度与血液浓度之间没有相关性，无论磁场强度如何。
使用 USG 检测血液取决于血液浓度、使用的换能器频率和成像时间等变量。随着血液浓度降至 0.5%以下，观察者之间的不一致性增加，这意味着 USG 的检测限会影响其在较低血液浓度下的可靠性。在解释有症状关节的 USG 成像研究以检测血液时，应谨慎行事。
