title: Post-processing central k-space subtraction for high-resolution arterial peripheral MR angiography.
abstract: Peripheral MR angiography requires high resolution and arterial contrast. Neither can be obtained simultaneously due to the short arterial phase of the contrast agent. To improve temporal resolution, keyhole imaging was developed, which combines high resolution and arterial k-spaces at the time of image acquisition. Here, a related approach is introduced for image post-processing in the Fourier domain. It is demonstrated that simple substitution of the central k-space with low-resolution data leads to severe distortion. Hence, a dedicated calculation scheme is necessary for composite k-space post-processing. A solution is presented for high-resolution arterial peripheral MR angiography that uses subtraction of venous intensities from the central high-resolution k-space. The calculations in the Fourier domain do not require interpolations between the different resolutions. High-resolution steady-state MR angiography, which exhibits contrast-enhanced arteries and veins at an isotropic resolution of 0.65 mm, and standard resolution arterial first-pass MR angiography were combined to obtain images with the resolution of the steady-state images and arterial contrast. Numerical simulations on software phantoms are presented. The operation of the method is demonstrated in five patients.
authors.affiliation: Institute of Medical Informatics, Charité University Medicine Berlin, Berlin, Germany. egbert.gedat@charite.de
authors.forename: Egbert
authors.initials: E
authors.lastname: Gedat
authors.forename: Mojgan
authors.initials: M
authors.lastname: Mohajer
authors.forename: Rainer
authors.initials: R
authors.lastname: Kirsch
authors.forename: Bernd
authors.initials: B
authors.lastname: Frericks
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction / Q000379:methods; D001157:Arterial Occlusive Diseases / Q000473:pathology*; D016477:Artifacts; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D005583:Fourier Analysis; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D007866:Leg / Q000098:blood supply; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D016491:Peripheral Vascular Diseases / Q000473:pathology*; D019047:Phantoms, Imaging; D011446:Prospective Studies; D012984:Software
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D005682:Gadolinium; C109932:gadofosveset trisodium