Alanen A, Nummi P
Acta Radiol Diagn (Stockh). 1986 Jul-Aug;27(4):455-8. doi: 10.1177/028418518602700417.
The sonographic appearance of a hematoma may be affected by various factors, including the age of the hematoma. The effect of mechanical motion on the echogenicity and histologic appearance, and on the proton relaxation times T1 and T2 of blood clots, was studied in vitro for up to 21 days. All clots were of similar echogenicity and microscopic appearance during the first 2 days. The minimally disturbed clots were sonolucent from day 4 onwards, whereas moderate mechanical disturbance changed the microscopic structure of the blood clots and caused them to retain their echogenicity. Proton relaxation times T1 and T2 of both minimally disturbed and vigorously manipulated blood samples showed a rapid shortening of T1 and a less marked decrease of T2 between days 1 and 4, which was independent of mechanical motion. The ultrasonic appearance reflected the histologic appearance but not necessarily the age of the clot. The magnetic resonance (MR) parameters T1 and to a lesser extent T2 accurately reflected the age of the clot during the first 6 days. Although relatively gentle motion caused a large change in the ultrasonic appearance of the clots, vigorous shaking did not affect the magnetic resonance appearance of human blood clots.
血肿的超声表现可能受多种因素影响，包括血肿的形成时间。我们在体外研究了机械运动对血凝块的回声性、组织学表现以及质子弛豫时间T1和T2的影响，观察时间长达21天。在最初的2天里，所有血凝块的回声性和微观外观相似。在第4天，受干扰最小的血凝块变得无回声，而中度机械干扰改变了血凝块的微观结构并使其保持回声性。在第1天到第4天期间，受干扰最小和受到剧烈操作的血样的质子弛豫时间T1均迅速缩短，T2的下降则不太明显，这与机械运动无关。超声表现反映了组织学表现，但不一定反映血凝块的形成时间。在最初的6天里，磁共振（MR）参数T1以及程度稍轻的T2能准确反映血凝块的形成时间。尽管相对轻微的运动会使血凝块的超声表现发生很大变化，但剧烈摇晃并不会影响人体血凝块的磁共振表现。
