Johan Samuel Van Den Brink

Transmit SENSE: Transmit SENSE

The idea of using parallel imaging to shorten the acquisition time by the simultaneous use of multiple receive coils can be adapted for the parallel transmission of a spatially‐selective multidimensional RF pulse. As in data acquisition, a multidimensional RF pulse follows a certain k‐space trajectory. Shortening this trajectory shortens the pulse duration. The use of multiple transmit coils, each with its own time‐dependent waveform and spatial sensitivity, can compensate for the missing parts of the excitation k‐space. This results in a maintained spatial definition of the pulse profile, while its duration is reduced. This work introduces the concept of parallel transmission with arbitrarily shaped transmit coils (termed “Transmit SENSE”). Results of numerical studies demonstrate the theoretical feasibility of the approach. The experimental proof of principle is provided on a commercial MR scanner. The lack of multiple independent transmit channels was addressed by combining the excitation patterns from two separate subexperiments with different transmit setups. Shortening multidimensional RF pulses could be an interesting means of making 3D RF pulses feasible even for fast T  2* relaxing species or strong main field inhomogeneities. Other applications might benefit from the ability of Transmit SENSE to improve the spatial resolution of the pulse profile while maintaining the transmit duration. Magn Reson Med 49:144–150, 2003.

Implications of SENSE MR in routine clinical practice

Sensitivity encoding (SENSE) uses multiple MRI receive coil elements to encode spatial information in addition to traditional gradient encoding. Requiring less gradient encodings translates into shorter scan times, which is extremely beneficial in many clinical applications. SENSE is available to routine diagnostic imaging for the past 2 years. This paper highlights the use of SENSE with scan time reduction factors up to 6 in contrast-enhanced MRA, routine abdominal imaging, mammography, cardiac and neuro imaging. It is shown that SENSE has opened new horizons in both routine and advanced MR imaging.

MR System Operator: Recommended Minimum Requirements for Performing MRI in Human Subjects in a Research Setting

This article is intended to provide guidelines for the minimum level of safety and operational knowledge that an MR system operator should exhibit in order to safely perform an MR procedure in a human subject in a research setting. This article represents the position of the International Society for Magnetic Resonance in Medicine (ISMRM) regarding this important topic and was developed by members of this societys MR Safety Committee. J. Magn. Reson. Imaging 2015;41:899–902.

Scheduling in MRI Scans processing

In this chapter we present a new approach to reduce the examination time of MRI systems. The time reduction is accomplished by dividing MRI scans into segments, which are intermixed to reduce the MRI examination time. The intermixing algorithms are based on a scheduling framework. First, the concept of multiple scan sets (ExamCards) is introduced. Then an explicit definition of the algorithms for different duty cycle limitations is presented. Next, the results of application of the algorithms to the Philips Healthcare routine examinations are provided. Finally, the MRI experiments that employs this time reduction approach are described. These algorithms are robust with respect to MRI hardware changes, thus they can be utilized to improve overall evolvability of the MRI system.