Artifact reduction in magnetic resonance angiographic images

A method of magnetic resonance angiography (MRA);

• said method comprising:
• placing a subject in a large static magnetic field,
• applying a first selective saturation pulse,
• said first selective saturation pulse being a selective inversion pulse to suppress magnetic resonance signals in selected locations including a location that is being imaged;
• acquiring signals from fresh blood flowing into the location that is being imaged;
• said acquiring step comprising:
• applying a burst of selective RF pulses at a time TI after the application of said first selective saturation pulse,
• applying phase encoding pulses between RF pulses of the burst of selective RF pulses,
• acquiring a gradient echo signal generated due to each of the RF pulses of the burst of selected RF pulses, and
• applying further selective saturation pulses during said time TI to suppress unwanted signals from locations not being imaged.

A method of magnetic resonance angiography (MRA) for imaging blood flow in a portion of the subject, said method of MRA comprising:

• placing the subject in a large static magnetic field,
• supplying a first selective pulse to suppress unwanted magnetic resonance signals in selected locations including a location that is being imaged,
• acquiring signals from fresh blood flowing into the location that is being imaged,
• said acquiring step comprising:
• applying a burst of selective Rf pulses,
• applying phase encoding pulses between the Rf pulses of the burst of selective Rf pulses,
• sampling echo signals after each Rf pulse of the burst of selective pulses, and
• applying further selective saturation pulses to suppress unwanted signals from the location being imaged.

A method of acquiring signals from blood during magnetic resonance imaging of a subject, said method comprising the steps of:

• placing said subject in a homogeneous, static magnetic field,
• applying a selective presaturation RF pulse to saturate tissue in a first section of the subject wherein it is desired to acquire said signals from inflowing blood, while reducing signals from said tissue in said first section,
• applying a selective RF excitation pulse to another section of the subject wherein it is desired to excite spins in said blood,
• sampling an RF gradient echo signal acquired from the blood entering said first section,
• encoding the first section with encoding pulses applied between said presaturation pulse and said excitation pulse,
• eliminating the encoding from the first section with opposite going encoding pulses applied after said excitation RF pulse and prior to acquiring said sampled signal, which leaves said sampled signal encoded and eliminates encoding from the signals from said saturated first section, said signals that are not encoded generating a line along the read out direction in the image, and
• removing the line.