Abstract: The invention provides methods for diagnosing coronary heart disease in a subject in need thereof comprising administering an admixture comprising CO2 to a subject to reach a predetermined PaCO2 in the subject to induce hyperemia, monitoring vascular reactivity in the subject and diagnosing the presence or absence of coronary heart disease in the subject, wherein decreased vascular reactivity in the subject compared to a control subject is indicative of coronary heart disease. The invention also provides methods for increasing sensitivity and specificity of BOLD MRI.

Abstract: The invention provides methods for diagnosing coronary heart disease in a subject in need thereof comprising administering an admixture comprising CO2 to a subject to reach a predetermined PaCO2 in the subject to induce hyperemia, monitoring vascular reactivity in the subject and diagnosing the presence or absence of coronary heart disease in the subject, wherein decreased vascular reactivity in the subject compared to a control subject is indicative of coronary heart disease. The invention also provides methods for increasing sensitivity and specificity of BOLD MRI.

Abstract: An MR imaging system uses multiple RF coils, for reducing image acquisition time, suitable for chemical exchange saturation transfer (CEST) imaging. Multiple RF (Radio Frequency) coils provide CEST imaging preparation in an anatomical volume by providing multiple interleaved RF pulses. The multiple interleaved RF pulses provide substantially increased RF pulse sequence duty cycle in the multiple RF coils relative to a duty cycle provided by a single coil of the multiple RF coils. The multiple RF coils subsequently provide RF excitation pulses in a reduced anatomical volume using k-space undersampling in an accelerated imaging method using the multiple RF coils and enable subsequent acquisition of associated RF echo data for deriving a CEST image.

Abstract: In a method and apparatus for contrast-enhanced magnetic resonance (MR) angiography of the right coronary artery of a patient, a bolus of MR contrast agent is selected to have a size that will cause the bolus, after injection into the patient, to wash out of right coronary chambers of the heart while still enhancing MR signals from the right coronary artery. The bolus of MR contrast agent is injected into the patient, and MR signals are generated in, and MR signals are obtained from, the patient in a time window after the bolus has washed out of the right coronary chambers and still enhances MR signals in the right coronary artery. An MR image of the right coronary artery is generated using only the MR signals obtained in the time window.

Abstract: In a magnetic resonance imaging method and apparatus, sensitivity encoding (SENSE) with radial sampling trajectories combines the gridding principle with conjugate-gradient least-squares (CGLS) iterative reconstruction. Radial k-space is mapped to a larger matrix by a resealing factor to eliminate the computational complexity of conventional gridding and density compensation. To improve convergence rate of high spatial frequency signals in CGLS iteration, a spatially invariant de-blurring k-space filter uses the impulse response of the system. This filter is incorporated into the SENSE reconstruction as preconditioning. The optimal number of iterations represents a tradeoff between image accuracy and noise over several reduction factors.

Abstract: In a method and apparatus for contrast-enhanced magnetic resonance (MR) angiography of the right coronary artery of a patient, a bolus of MR contrast agent is selected to have a size that will cause the bolus, after injection into the patient, to wash out of right coronary chambers of the heart while still enhancing MR signals from the right coronary artery. The bolus of MR contrast agent is injected into the patient, and MR signals are generated in, and MR signals are obtained from, the patient in a time window after the bolus has washed out of the right coronary chambers and still enhances MR signals in the right coronary artery. An MR image of the right coronary artery is generated using only the MR signals obtained in the time window.

Abstract: In a method and magnetic resonance (MR) imaging apparatus for reducing artifacts due to resonance frequency offsets in a diagnostic MR image, a number of MR scout images of a portion of a subject containing a region of interest (ROI) are generated respectively using different radio frequency (RF) excitation frequencies. Each of the MR scout images has an identifiable image quality in the ROI. The MR scout images are analyzed as to the image quality in the ROI to identify one of the MR scout images having the best image quality in the ROI. An MR diagnostic image is then generated of the portion of the subject containing the ROI, using the RF excitation frequency that was used to generate the MR scout image having the best image quality in the ROI.