THROMBIN GENERATION BY MAGNET RESONANCE IMAGING

• Published in: Hemostasis laboratory Vol. 6; no. 1; p. 129
• Main Authors: Stief, Thomas, Seyfer, Perla, Völker, Maximilian, Donges, Janine, Klingmüller, Volker
• Format: Journal Article
• Language: English
• Published: Hauppauge Nova Science Publishers, Inc 01.01.2013
• Subjects: Coagulation; NMR; Nuclear magnetic resonance; Risk factors; Ultrasonic imaging
• ISSN: 1941-8493; 2374-0795

Surface energy can trigger intrinsic coagulation. So, ultrasound has to be considered a pathophysiologic risk factor for the generation of elevated concentrations of systemically circulating micro-thrombi. The present work aimed to answer the question if also magnet resonance imaging (MRI; magnet resonance tomography = MRT) is an intrinsic coagulation trigger, using the ultra-sensitive, ultra-specific recalcified coagulation activity assay (RECA). 1 ml samples of pooled normal platelet poor citrated plasma in 1 ml polypropylene cups were exposed to MRT (SIEMENS MAGNETOM ClinScan syngo MR B15) for 0-13 min at 23°C. Then the RECA was performed: 50 μl plasma were incubated in duplicate with 5 μl 250 mM CaCl^sub 2^ in high quality polystyrene microwells (Brand®781600). After 0-25 min coagulation reaction time (CRT) 100 μl 2.5 M arginine, pH 8.6, 0.16 % Triton X 100® were added. After 3 min 25 μl 1 mM HD-CHG-Ala-Arg-pNA in 1.25 M arginine, pH 8.7, were added and the increase in absorbance with time ΔA/t was determined by a microtiter plate photometer with a 1 mA resolution (PHOmo). Within the first 4 min of MRT exposure there was no significant increase in recalcified thrombin generation. The maximal thrombin generation, which was 33fold higher than the control thrombin generation (4 mIU/ml) at 0 min MRT exposure, was reached after 7 min of MRT exposure. Within 1 min after the thrombin peak the thrombin generation decreased by about 50%, within 3 min after the thrombin peak the amount of thrombin generation was again similar as at 0 min MRT exposure. MRT has to be considered as a risk factor for the development of a critical change of normal intravascular coagulation to slightly pathologic or to pathologic (NIC[arrow right]pre-PIC[arrow right]PIC). Patients with additional risk factors for the generation of systemic micro-thrombi should be protected by low-molecular-weight-heparin (LMWH) and the exposure time to MRT should be as short as possible.