How do we unlock fetal cardiac MRI?

The clinical gold standard for cardiac gating is applying an Electrocardiogram. However, this can not be applied for the fetus during MR imaging. We have developed a unique solution to detect the fetal cardiac movement to create a gating signal for the MRI based on Doppler ultrasound.

The core of smart-sync is the battery powered and wirelessly connected Sensor Box. It is used together with a fetal ultrasound transducer that is specifically designed for the challenge of a reliable fetal heartbeat detection during MRI examinations.


A unique algorithm is applied on the Doppler ultrasound signal of the fetal heart that allows precise gating for uncompromised image quality. smart-sync can be integrated into any MRI system with the included Connector Box.

How to use smart-sync?


Fetal Transducer
specifically designed for the demanding challenge of a reliable fetal heartbeat detection

As the position of the fetal heart is always different the heart must be located with the ultrasound transducer by the user. The standard to locate the fetal heart is by listening to the heartbeat.

To optimize the workflow we have developed unique MRI safe headphones that allows this standard procedure within the MRI environment. Once the heart is located the transducer is fixed with a belt.

smart-sync creates a gating signal that is sent wirelessly to the MRI.

What can I do with smart-sync?

Standard CINE Balanced SSFP Imaging

CINE SSFP Sequences are clinical standard to evaluate cardiac function. With smart-sync you can use all cardiac MRI sequences that need cardiac gating. This includes morphological and functional imaging in four chamber view and short axis with several slices as shown in examples below. ​

Four Chamber View @ 1.5T

Short Axis View @ 1.5T 

Visualisation of the Aorta

Healthy fetus in week 35

Healthy fetus in week 35

Short axis stack @ 1.5T 

Standard SSFP

Healthy fetus in week 38

2D and 4D flow velocimetry phase-contrast MRI

Flow measurements are clinical routine for adult imaging. With smart-sync blood flow measurements can now also be clinical routine for fetal MRI. All clinical available phase contrast MRI Sequences can be used as known from daily routine, including 4D flow.

2D phase.png

2D phase contrast MRI

4D Flow imaging @ 1.5T

Healthy fetus in week 38

in week 30 @ 1.5T

4D Flow imaging @ 1.5T

Healthy fetus in week 38


Schoennagel BP, Yamamura J, Kording F, Fischer R, Bannas P, Adam G, et al. Eur Radiol 2019;29:4169–76.

Tavares de Sousa M, Hecher K, Yamamura J, Kording F, Ruprecht C, Fehrs K, et al. Ultrasound Obstet Gynecol 2019;53:669–75.

Kording F, Yamamura J, Tavares De Sousa M, Ruprecht C, Hedström E, Aletras AH, et al.  J Cardiovasc Magn Reson 2018;20:1–10.

Kording F, Schoennagel BP, Sousa MT De, Fehrs K.  Magn Reson Med Sci 20 2018:1–10.