Abstract: Techniques and systems for non-contrast enhanced magnetic resonance angiography and venography (MRAV) are described. For example, within one cardiac cycle of a subject, a single shot acquisition of non-suppressed arterial MR signals and a single shot acquisition of non-suppressed venous MR signals are employed. Radio frequency (RF) saturation pulses may be applied to one or more slabs such that MR signals indicative of venous blood that flows into the arterial imaging slice are substantially suppressed and MR signals indicative of arterial blood that flows in the venous imaging slice are substantially suppressed. The RF saturation pulses and the single shot acquisitions may be timed such that one or more of the single shot acquisitions occur during substantially steady state inflow of blood into the respective imaging slice. In this manner, k-space data may be acquired from arterial specific and venous specific imaging slices occurring within a single cardiac cycle.

Abstract: Techniques and systems for non-contrast enhanced magnetic resonance angiography and venography (MRAV) are described. For example, within one cardiac cycle of a subject, a single shot acquisition of non-suppressed arterial MR signals and a single shot acquisition of non-suppressed venous MR signals are employed. Radio frequency (RF) saturation pulses may be applied to one or more slabs such that MR signals indicative of venous blood that flows into the arterial imaging slice are substantially suppressed and MR signals indicative of arterial blood that flows in the venous imaging slice are substantially suppressed. The RF saturation pulses and the single shot acquisitions may be timed such that one or more of the single shot acquisitions occur during substantially steady state inflow of blood into the respective imaging slice. In this manner, k-space data may be acquired from arterial specific and venous specific imaging slices occurring within a single cardiac cycle.

Abstract: An image reconstruction method includes reconstructing an initial composite image of a subject using a conventional reconstruction method. The initial composite image employs the best information available regarding the subject of the scan and this information is used to constrain the reconstruction of a highly undersampled or low SNR image frames. This highly constrained image reconstruction is repeated a plurality of iterations with the reconstructed image frame for one iteration being used as the composite image for the next iteration. The reconstructed image frame rapidly converges to a final image frame.

Abstract: A method for measuring the apparent transverse relaxation time (“T*2”) and apparent diffusion coefficient (“ADC”) of a hyperpolarized gas in a single breath-hold and consequently, with a single dose of the hyperpolarized gas contrast agent, is provided. The method employs a multiple-echo projection acquisition based pulse sequence. Individual images are reconstructed from data acquired during each of the individual echo times. Subsequently, T*2 and ADC are calculated using these reconstructed images. Furthermore, the method produces images indicative of ADC that have isotropic resolution, allowing for more reliable image registration. The inter-echo spacing and diffusion weighting b-value are varied during the pulse sequence employed when practicing the present invention; thus, a significant separation between the effects of diffusion and T*2 decay on the detected MR signals is possible. This separation allows for reliable measurements of these two parameters from a single echo-train.

Abstract: An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. Drive circuitry for each pair of opposing conductive legs includes a current balun that maintains substantially equal and opposite currents in the two conductive legs. Terminal susceptance elements are used to maintain maximum currents and minimum voltage at the midpoints of the conductive legs. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

Abstract: A method for measuring the apparent transverse relaxation time (“T2*”) and apparent diffusion coefficient (“ADC”) of a hyperpolarized gas in a single breath-hold and consequently, with a single dose of the hyperpolarized gas contrast agent, is provided. The method employs a multiple-echo projection acquisition based pulse sequence. Individual images are reconstructed from data acquired during each of the individual echo times. Subsequently, T2* and ADC are calculated using these reconstructed images. Furthermore, the method produces images indicative of ADC that have isotropic resolution, allowing for more reliable image registration. The inter-echo spacing and diffusion weighting b-value are varied during the pulse sequence employed when practicing the present invention; thus, a significant separation between the effects of diffusion and T2* decay on the detected MR signals is possible. This separation allows for reliable measurements of these two parameters from a single echo-train.

Abstract: An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. One set of conductive leg pairs is tuned to operate at the Larmor frequency of 13C and another set is tuned to operate at the Larmor frequency of 1H. Drive circuitry operates the RF coil assembly to produce 1H spin magnetization which is transferred to 13C magnetization by the nuclear overhauser effect and to acquire MR data from the 13C spins. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

Abstract: An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. One set of conductive leg pairs is tuned to operate at the Larmor frequency of 13C and another set is tuned to operate at the Larmor frequency of 1H. Drive circuitry operates the RF coil assembly to produce 1H spin magnetization which is transferred to 13C magnetization by the nuclear overhauser effect and to acquire MR data from the 13C spins. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

Abstract: An image reconstruction method includes reconstructing an initial composite image of a subject using a conventional reconstruction method. The initial composite image employs the best information available regarding the subject of the scan and this information is used to constrain the reconstruction of a highly undersampled or low SNR image frames. This highly constrained image reconstruction is repeated a plurality of iterations with the reconstructed image frame for one iteration being used as the composite image for the next iteration. The reconstructed image frame rapidly converges to a final image frame.

Abstract: A television set is energized by electricity generated by an exercise cycle. The bicycle may be used to charge a battery which in turn operates the T.V. set or the exercise cycle can turn a generator which directly operates the set. The device is particularly useful in limiting the amount of "junk" T.V. watched by children.