Abstract: To generate a magnetic resonance angiograph, a patient is injected with a contrast-enhancing agent (210). An ellipsoidal central portion of k-space (300) and a first surrounding region (310) are continuously sampled (220). A portion of each central data set (300, 310) is reconstructed (230) into a low-resolution volume and maximum-intensity-projected (240) onto a line. The maximum intensity projection (240) is processed (250) in order to detect the arrival of the contrast enhancing bolus within a volume of interest. Upon detection of the arrival of the bolus, the acquisition of a high-resolution magnetic resonance angiograph is triggered (260) in which higher phase encode portions (310, 420) of k-space are sampled. The central data set (300) along with the higher phase encode views (310, 420) are reconstructed (290) into a high-resolution magnetic resonance angiogram.

Abstract: A diagnostic imaging system (100, 200) and method generates a plurality of temporally resolved volume image representations (130, 132, . . . , 134). A time course projection processor (140, 240) temporally collapses the volume image representations. A spatial projection processor (146, 246) performs a maximum or minimum intensity process along rays through voxels of a three-dimensional image representation. By sequentially temporally collapsing and maximum or minimum intensity projecting, in either order, the plurality of temporally resolved volume image representations is reduced to a two-dimensional temporally collapsed and spatially projected image representation (148, 248). In preferred embodiments, the present invention is directed to angiography, and more preferably to magnetic resonance angiography.

Abstract: A non-rectangular central kernel (200, 400, 500) of magnetic resonance image data is collected and stored in an acquired data memory (44). A non-rectangular peripheral portion (210, 410, 510) of magnetic resonance image data adjacent the central kernel (200) is collected and stored in the acquired data memory (44). A phase correction data value set (54) is generated from at least a portion of the central and peripheral data value sets. A synthetic conjugately symmetric data set (220, 420, 520) is generated (60) from the peripheral data set and phase corrected (60) using the phase correction data value set (54). Unsampled corners of k-space are zero filled. The central, peripheral, and conjugately symmetric data sets are combined (80) to form a combined data set. The combined data'set is Fourier transformed (82) to form an intermediate image representation (84), which may be exported for display (90) or used for a further iteration.

Abstract: A black blood magnetic resonance angiogram is produced by exciting dipoles (52) and repeatedly inverting the resonance (541, 542, . . . ) to produce a series of magnetic resonance echoes (561, 562, . . . ). Early echoes (e.g., (561, . . . , 568)) are more heavily proton density weighted than later echoes (e.g., (569, . . . , 5616)), which are more heavily T2 weighted. The magnetic resonance echoes are received and demodulated (38) into a series of data lines. The data lines are sorted (60) between the more heavily proton density weighted data lines and T2 weighted data lines which are reconstructed into a proton density weighted image representation and a T2 weighted image representation. The proton density weighted and T2 weighted image representations are combined (90) to emphasize the black blood from the T2 weighted images and the static tissue from the proton density weighted image. The combination processor (90) scales (92) the PDW and T2W images to a common maximum intensity level.

Abstract: A black blood magnetic resonance angiogram is produced by exciting dipoles (52) and repeatedly inverting the resonance (541, 542, . . . ) to produce a series of magnetic resonance echoes (561, 562, . . . ). Early echoes (e.g., (561, . . . , 568)) are more heavily proton density weighted than later echoes (e.g., (569, . . . , 5616)) which are more heavily T2 weighted. The magnetic resonance echoes are received and demodulated (38) into a series of data lines. The data lines are sorted (60) between the more heavily proton density weighted data lines and T2 weighted data lines which are reconstructed into a proton density weighted image representation and a T2 weighted image representation. The proton density weighted and T2 weighted image representations are combined (90) to emphasize the black blood from the T2 weighted images and the static tissue from the proton density weighted image. The combined image is a black blood magnetic resonance angiogram.

Abstract: A sequence controller (40) controls the pulses applied by the radio transmitter (24) and the gradient amplifiers (20) and gradient coils (22) such that each repetition includes a prepreparation sequence segment, such as a presaturation sequence segment and a magnetization transfer contrast correction (MTC) segment, and a plurality of image sequence segments. More specifically, each of the image sequence segments induce resonance, phase and frequency-encode the resonance, and generate one or more views of data, all within a corresponding one of a plurality of slabs or sub-regions (74.sub.1, 74.sub.2, . . .) of an image volume (72). More precisely to the preferred embodiment, the imaging sequence segments interleave the slabs such that resonance is not excited concurrently in adjacent slabs, without exciting resonance and collecting a view in a non-adjacent slab. The views are sorted (80) by slab and stored in corresponding slab data memories (82).

Abstract: When a magnetic resonance imaging sequence is retrieved from memory (58), one of the slice select, phase-encode to read gradient profiles are retrieved for one of the slice select, phase-encode, read gradients. The two gradient profiles have a common field of view if a read gradient or slice thickness if a slice select gradient, but have different motion sensitizations. The reference gradient profile G.sub.1 stored in a memory (52) and the motion sensitized gradient profile G.sub.2 stored in a memory (56) are weighted (60, 62) by weighting functions .alpha..sub.1, .alpha..sub.2 which are selected in accordance with the selected motion sensitivity and a selected one of the field of view or slice thickness. The weighted profiles are combined (64) to generate a motion sensitized gradient with the selected motion sensitivity, field of view or slice thickness.

Abstract: A object handling system is moveable between various diagnostic imaging apparatus for imaging thereby. The handling system has an object handling computer 34 for storing object identification data and imaging data. Selectively linking the object handling computer 34 with a first imaging system provides the first imaging system with access to the object identification data and imaging data for use in the production of diagnostic images thereby. Similarly, the object identification data and imaging data are available to a second imaging system for use in the production of diagnostic images thereby when the object handling computer 34 is selectively linked thereto. The object identification data is associated with the diagnostic images produced by various imaging system for subsequent correlation of the object with the diagnostic images of the object.

Abstract: A magnetic resonance gantry (A) includes a magnet (12) which generates a uniform magnetic field in a thin (under 15 cm thick) imaging volume (10). Gradient coils (30) and radio frequency coils (20) transmit radio frequency and gradient magnetic field pulses of conventional imaging sequences into the imaging volume. A patient support surface (42) moves a patient continuously through the imaging volume as the pulses of the magnetic resonance sequence are applied. A tachometer (52) monitors movement of the patient. A frequency scaler (54) scales the frequency of the RF excitation pulses applied by the transmitter (22) and the demodulation frequency of the receiver (26) in accordance with the patient movement such that the selected slice moves in synchrony with the patient through the imaging volume. The slice select gradient is indexed after magnetic resonance signals to generate a full set of views for reconstruction into a two-dimensional image representation of the slice are generated.

Abstract: A magnetic resonance imaging system (A) examines a region of a patient and generates a plurality of views which are reconstructed (B) into a volumetric image representation and stored in a volume image memory (C). A ray projector (D) projects a plurality of rays (14) from a selectable viewing plane (10) into the volume data and retrieves a plurality of data values that lie along each ray. A maximum intensity projection system (E) selects the brightest pixel along each ray to become the corresponding pixel value of an uncorrected projection angiographic image which is stored in an image memory (F). The uncorrected angiographic image represents blood as bright or white values and non-blood tissues as dark or black values. Noise, some tissue types, regions with fine capillaries, and the like, cause the background non-blood regions of the image to appear hazy or gray rather than black.

Abstract: A magnetic resonance imaging apparatus (A) applies appropriate magnetic fields, magnetic field gradients, and radio frequency pulses across an examination region to generate magnetic resonance signals or views indicative of the properties of a volume of a subject examined in the examination region. The views are reconstructed (B) into voxel values V(x,y,z) and stored in a volumetric image memory (C). A relative angle and position of a viewing plane (10) relative to the image volume are selected. A plurality of rays (14), each corresponding to a pixel P(i,j) of a resultant projection image, are projected from the viewing plane into the volumetric image data. Each ray retrieves a corresponding vector of voxel values V.sub.1, V.sub.2, V.sub.3, . . . V.sub.n. Bright voxel values indicate blood. Dark pixel values indicate non-blood tissue. Intermediate voxel values have a greater uncertainty whether the pixel value represents blood or non-blood tissue.