Does MRI influence blood coagulation? Poster No.:

C-1726

Congress:

ECR 2014

Type:

Scientific Exhibit

Authors:

P. Seyfer, V. Klingmüller, A. H. Mahnken, M. Völker, T. Stief; Marburg/DE

Keywords:

Vascular, Experimental, MR, Experimental investigations, Blood, Metabolic disorders, Biological effects

DOI:

10.1594/ecr2014/C-1726

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Aims and objectives MRI is often favoured over other diagnostic modalities for its ability to create detailed images using no ionizing radiation. Several studies have shown that surface energy can trigger intrinsic coagulation. The purpose of our study was to analyse the impact of MRI on blood coagulation, using the recalcified coagulation activity assay (RECA), a highly sensitive assay for detecting procoagulant plasma changes.

Methods and materials 1 mL samples of pooled normal plated poor citrated plasma in 1 mL polypropylene cups were exposed to 7 T MRT for 0-13 min at 23° C Fig. 1 on page 2. Afterwards the recalcified coagulation activity assay (RECA) was performed as follows Fig. 2 on page 3: 50 µl pooled normal platelet poor plasma in polystyrene microtiter plates were recalcified with 5 µl 250 mM CaCl2. After 0-30 min coagulation reaction time (CRT) 100 µl 2.5 M arginine, 0.16 % TritonX100 were added to stop coagulation activation. 3 min later 25 µl chromogenic thrombin substrate HD-CHG-Ala-Arg-pNA (Pentapharm, Basel, Switzerland) in 1.25 M arginine, pH 8.7, were added and the increase in absorbance at 405 nm with time (#A/t) was determined by a microtiter plate photometer with a 1 mA resolution (PHOmo; anthos, Krefeld, Germany). The results were standardized by a 0.04 IU/ml thrombin standard (Siemens Healthcare, Munich, Germany) that was identically treated as a plasma sample. Thrombin generation equals thrombin activity minus basal thrombin activity in plasma without CRT. Only the thrombin generations in the ascending part of the CRT vs. thrombin activity curve were considered.

Images for this section:

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Fig. 1: 7 T MRI

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Fig. 2: Recalcified coagulation activity assay (RECA)

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Results No significant increase in recalcified thrombin generation was noticed within the first 4 minutes of MRI exposure (MRIe). The maximum thrombin generation was reached after 7 min of MRIe and was 33fold higher than the control thrombin generation (4 mIU/mL) at 0 min MRIe. Within 1 minute after the thrombin peak the thrombin generation decreased by 50%. Within 3 minutes after the thrombin peak, thrombin generation was similar to the control probe Fig. 3 on page 5. Images for this section:

Fig. 3: Relation between F2-Generation in RECA-20 and MRI (7 Tesla) exposure time.

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Conclusion MRT is a risk factor for triggering intravascular coagulation. In-vivo studies are necessary to detect the effect of MRI on thrombin generation and the advantage of protecting patients by low-molecular-weight-heparin.

Personal information Perla Seyfer, M.D. Department of Diagnostic and Interventional Radiology University Hospital of Marburg Marburg, Germany [email protected]

References 1) Stief TW,Klingmüller V. The ultrasound frequency determines the degree of intrinsic coagulation activation.Blood Coagul Fibrinolysis 2012 Jul;23(5):440-4. 2) Stief TW,Klingmüller V. Diagnostic ultrasound activates pure prekallikrein. Blood Coagul Fibrinolysis 2012 Dec;23(8):781-3. 3) Stief TW. The recalcified coagulation activity. Clin Appl Thromb Hemost 2008 Oct;14(4):447-53 4) Stief TW. Pathological thrombin generation by the synthetic inhibitor argatroban. Hemostasis Laboratory 2009; 2: 83-104 5) Dini L, Abbro L. Bioeffects of moderate-intensity static magnetic fields on cell cultures. Micron.2005;36(3):195-217. 6) Mattsson MO, Simkó M. Is there a relation between extremely low frequency magnetic field exposure, inflammation and neurodegenerative diseases? A review of in vivo and in vitro experimental evidence.Toxi cology.2012 Nov 15;301(1-3):1-12. doi: 10.1016/ j.tox.2012.06.011.

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