Abstract: A magnetic resonance (MR) system includes a volume-type radio-frequency (RF) coil assembly having a volume coil with a plurality of ports and a ring coil with a plurality of ports (p?) and which is situated about the volume-type coil. At least one controller is configured to selectively control a first transmit/receive (T/R) radio frequency (RF) channel to generate an output including RF quadrature signals to drive the volume-type coil and to selectively control a second T/R RF channel to generate an output including RF quadrature signals to drive the ring coil.

Abstract: A magnetic resonance system (1) includes at least one radio frequency (RF) transmit coil (6), an RF transmitter (34), an anthropometric unit (28), and an adaptive SAR unit (40). The at least one radio frequency (RF) transmit coil (6) transmits measured RF power to excite and manipulate magnetic resonance in tissues of a subject (57) in an examination region. The RF transmitter (34) controls the amount of transmitted RF power based on a specific absorption rate (SAR) for an imaging sequence. The anthropometric unit (28) determines a mass of a portion of the subject which receives the transmitted RF power based on a determined total mass. The adaptive SAR unit (40) adjusts a selected scan sequence based on the SAR parameters determined from the measured transmitted RF power and a measured reflected power, achieved IB|+I field, the mass of the portion of the subject which receives the transmitted RF power and applicable SAR parameter models stored in a SAR reference unit (46).

Abstract: A radiation therapy planning and follow-up system (10) includes an MR scanner (12) with a first bore (16) which defines an MR imaging region (18) and a functional scanner (26), e.g., a nuclear imaging scanner, or a CT scanner with a second bore (30) which defines a nuclear or CT imaging region (36). The first and second bores (16,30) have a diameter of at least 70 cm, and preferably 80-85 cm. A radiation therapy type couch (90) moves linearly through the MR imaging region (18) along an MR longitudinal axis and the nuclear or CT imaging region (36) along a nuclear or CT longitudinal axis which is aligned with the MR longitudinal axis. The couch positions a subject sequentially in the MR and nuclear or CT imaging regions (18, 36).

Abstract: A magnetic resonance (MR) system may include: a volume-type radio-frequency (RF) coil assembly having a volume coil with a plurality of ports and a ring coil with a plurality of ports (??) and which is situated about the volume-type coil; and at least one controller configured to selectively control a first transmit/receive (T/R) radio frequency (RF) channel to generate an output including RF quadrature signals to drive the volume-type coil and to selectively control a second T/R RF channel to generate an output including RF quadrature signals to drive the ring coil.

Abstract: Coil elements (18) generate a B1 excitation field in an examination region (14), which B1 excitation field is distorted by patient loading (e.g., wavelength effects). Passive shimming elements (22, 24) are disposed between the coil elements and the subject in order to improve the B1 field uniformity. In one embodiment, passive shimming elements include one or more dielectric rods (55) disposed below the subject which generate no substantial MR proton signal and which have a permittivity of at least 100 and preferably greater than 500. In another embodiment, tubes (24) adjacent each coil element are supplied with a dielectric liquid, a thickness of the dielectric liquid between the coil element and the subject adjusting a phase of the B1 field generated by the coil element. Active B1 shimming may be combined with passive shimming elements (22, 24) to effect an improved RF field homogeneity result.

Abstract: A magnetic resonance system (1) includes at least one radio frequency (RF) transmit coil (6), an RF transmitter (34), an anthropometric unit (28), and an adaptive SAR unit (40). The at least one radio frequency (RF) transmit coil (6) transmits measured RF power to excite and manipulate magnetic resonance in tissues of a subject (57) in an examination region. The RF transmitter (34) controls the amount of transmitted RF power based on a specific absorption rate (SAR) for an imaging sequence. The anthropometric unit (28) determines a mass of a portion of the subject which receives the transmitted RF power based on a determined total mass. The adaptive SAR unit (40) adjusts a selected scan sequence based on the SAR parameters determined from the measured transmitted RF power and a measured reflected power, achieved IB|+I field, the mass of the portion of the subject which receives the transmitted RF power and applicable SAR parameter models stored in a SAR reference unit (46).

Abstract: Coil elements (18) generate a B1 excitation field in an examination region (14), which B1 excitation field is distorted by patient loading (e.g., wavelength effects). Passive shimming elements (22, 24) are disposed between the coil elements and the subject in order to improve the B1 field uniformity. In one embodiment, passive shimming elements include one or more dielectric rods (55) disposed below the subject which generate no substantial MR proton signal and which have a permittivity of at least 100 and preferably greater than 500. In another embodiment, tubes (24) adjacent each coil element are supplied with a dielectric liquid, a thickness of the dielectric liquid between the coil element and the subject adjusting a phase of the B1 field generated by the coil element. Active B1 shimming may be combined with passive shimming elements (22, 24) to effect an improved RF field homogeneity result.

Abstract: A multiple modality imaging system (10) includes a MR scanner (12) which defines an MR imaging region (18), a nuclear imaging scanner (26) which defines a nuclear imaging region (34), an CT scanner (36) which defines an CT imaging region (42). Each scanner (12, 26, 36) having a longitudinal axis along which a common patient support (46) moves linearly through the MR, nuclear, and CT imaging regions (18, 34, 42). A marker (130, 140, 150), for use with the system (10), includes a radio-isotope marker (132) which is imageable by the nuclear imaging scanner (26) and the CT scanner (36) surrounded by a flexible silicone MR marker (134) which is imageable by the MR scanner (12) and the CT scanner (36). A calibration phantom (162), for use with the image scanner (10), includes a plurality of the markers (130, 140, 150) supported by a common frame having a known and predictable geometry.

Abstract: A radiation therapy planning and follow-up system (10) includes an MR scanner (12) with a first bore (16) which defines an MR imaging region (18) and a functional scanner (26), e.g., a nuclear imaging scanner, or a CT scanner with a second bore (30) which defines a nuclear or CT imaging region (36). The first and second bores (16,30) have a diameter of at least 70 cm, and preferably 80-85 cm. A radiation therapy type couch (90) moves linearly through the MR imaging region (18) along an MR longitudinal axis and the nuclear or CT imaging region (36) along a nuclear or CT longitudinal axis which is aligned with the MR longitudinal axis. The couch positions a subject sequentially in the MR and nuclear or CT imaging regions (18, 36).