N.V. Anisimov1, A.A. Tarasova2, I.A. Usanov3, Yu.A. Pirogov4

1  Lomonosov Moscow State University, Faculty of Fundamental Medicine (Moscow, Russia)

2−4 Lomonosov Moscow State University, Faculty of Physics (Moscow, Russia)

anisimovnv@mail.ru, arina.tarasova99@mail.ru, usanov_i@inbox.ru, yupi937@gmail.com

The problems of registration of weak magnetic resonance (MR) signals in conditions of technogenic interference are considered. Their intensity and temporal activity are analyzed by MRI tomography. To reduce their influence on the result of long-term signal accumulation, it is proposed to save its individual realizations during registration. Then, at the end of registration, it is possible analyze them, identify noisy implementations, edit them, and submit edited copies for summing up instead of noisy ones. An approach that is similar in concept is considered for practical application in MRI – instead of increasing the number of accumulations, it is proposed to increase the number of phase encoding steps. Examples of analysis of interference activity during 23Na MRI scanning of various human organs using various coils are given. The possibility of increasing the information content of MRI data by using apodization for kspace data is shown, and this technique is most effective if the effect of noise occurs when only the peripheral part of this space is filled.

Anisimov N.V., Tarasova A.A., Usanov I.A., Pirogov Yu.A. Registration of weak MRI signals when exposed to radio frequency interference. Electromagnetic waves and electronic systems. 2021. V. 26. № 3. P. 5−10. DOI: https://doi.org/10.18127/j15604128-20210301 (in Russian)

1. Plaksienko V.S., Plaksienko N.E., Plaksienko S.V. Ustroystva priema i obrabotki signalov: Ucheb. posobie dlya vuzov. Pod red. V.S. Plaksienko. M.: Uchebno-metodicheskiy izdatel’skiy tsentr «Uchebnaya literatura». 2004. 376 s. (in Russian)
2. Haacke E.M., Brown R.W., Thompson M.R., Venkatesan R. Magnetic Resonance Imaging: Physical Principles and Sequence Design. Wiley, Hoboken, 1999. Chapter 13, 15.
3. Anisimov N.V., Tarasova A.A., Pavlova O.S., Fomina D.V., Makurenkov A.M., Pavlovskaya G.E., Pirogov Yu.A. MRI Coils Optimized for Detection of 1H and 23Na at 0.5 T. Appl. Magn. Reson. 2021. V. 52(3). P. 221−233.
4. Anisimov N.V., Sadykhov E.G., Pavlova O.S., Fomina D.V., Tarasova A.A., Pirogov Yu.A. Whole Body Sodium MRI at 0.5 Tesla Using Surface Coil and Long Echo Time Sequence. Appl. Magn. Reson. 2019. V. 50(10). P. 1149−1161.
5. Schneider C.A., Rasband W.S., Eliceiri K.W. NIH Image to ImageJ: 25 years of image analysis. Nat. Methods. 2012. V. 9(7). P. 671−675.
6. Parker D.L., Gullberg G.T., Frederick P.R. Gibbs artifact removal in magnetic resonance imaging. Med Phys. 1987. V. 14. P. 640−645.
7. Stobbe R., Beaulieu C. Advantage of sampling density weighted apodization over postacquisition filtering apodization for sodium MRI of the human brain. Magn. Reson. Med. 2008. V. 60. P. 981−986.