Contrast-enhanced magnetic resonance angiography (CE-MRA) was first introduced for clinical studies approximately 20 years ago. Early work provided 3-4 mm spatial resolution with acquisition times in the 30-second range. Since that time there has been continuing effort to provide improved spatial resolution with reduced acquisition time, allowing high resolution 3D time-resolved studies. The pu...

Magnetic resonance angiography (MRA) is increasingly used to evaluate arterial and venous diseases. Although the resolution of MRA is not as high as that of conventional angiography, it is sufficient to evaluate pathologic conditions in the larger vascular structures of most parts of the body. It is especially useful in patients who cannot tolerate the risks of iodinated contrast agents or arte...

An attempt is made for improvement of secret image invisibility in circulation images with dyadic wavelet based data hiding with run-length coded secret images of which location of codes are determined by random number. Through experiments, it is confirmed that secret images are almost invisible in circulation images. Also robustness of the proposed data hiding method against data compression o...

PURPOSE We propose a compressed-sensing (CS) technique based on magnitude image subtraction for high spatial and temporal resolution dynamic contrast-enhanced MR angiography (CE-MRA). METHODS Our technique integrates the magnitude difference image into the CS reconstruction to promote subtraction sparsity. Fully sampled Cartesian 3D CE-MRA datasets from 6 volunteers were retrospectively under...

The critical issue for coronary MRA is to account for multiple sources of motion while maintaining a high spatial resolution and high temporal resolution acquisition. Under optimal circumstances, the spatial resolution of coronary MRA is 700-900 microns for in plane resolution, but slice thickness z-axis) remains at 2-3 mm. This is considerably greater than the 300 micron resolution available f...

BACKGROUND AND PURPOSE We have developed PC HYPRFlow, a comprehensive MRA technique that includes a whole-brain CE dynamic series followed by PC velocity-encoding, yielding a time series of high-resolution morphologic angiograms with associated velocity information. In this study, we present velocity data acquired by using the PC component of PC HYPRFlow (PC-VIPR). MATERIALS AND METHODS Ten h...

OBJECTIVES The goal of the present study was to develop a strategy for three-dimensional (3D) volume acquisition along the major axes of the coronary arteries. BACKGROUND For high-resolution 3D free-breathing coronary magnetic resonance angiography (MRA), coverage of the coronary artery tree may be limited due to excessive measurement times associated with large volume acquisitions. Planning ...

Data hiding method based on steganography improving secret image invisibility through replacing Least Significant Bit: LSB with run-length coded Image is proposed. Although, the proposed method is based on Discrete Wavelet Transformation: DWT, run-length coded secrete image is embedded in the LSB of the high frequency component before reconstruction of the image for opening to the public for im...

Background The aim for ultrahigh field coronary MR angiography (MRA) is to convert the benefit of increased signal-tonoise ratio (SNR) to improved spatial resolution and thereby better vessel edge sharpness (VES), while vessel conspicuity is preserved. Furthermore, black blood coronary MRA has been shown to be an alternative technique to detect arterial remodeling in patients with coronary arte...

Introduction Recently, the intravascular MR contrast agent gadofosveset trisodium has been clinically approved for use in the European market. The contrast agent has a high reversible affinity to human serum albumin, which leads to a prolonged presence in the blood stream. The prolonged intravascular contrast allows acquiring high-resolution MRA data sets during steady state, but optimized imag...