• Aortic
  • Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging," Japanese Circulation Journal , vol. 64, no. 10, pp. 760-764, 2000. (hindawi.com)
  • time-resolved
  • The advantages of CE-MRA over Computed Tomographic Angiography (CTA), in the assessment of the pulmonary vasculature, are: (1) lack of ionizing radiation, (2) time-resolved imaging for perfusion, and (3) lack of iodinated contrast material. (springer.com)
  • Bley TA, Duffek CC, Francois CJ, Schiebler ML, Acher CW, Mell M, Grist TM, Reeder SB (2010) Presurgical localization of the artery of Adamkiewicz with time-resolved 3.0-T MR angiography. (springer.com)
  • radiation
  • Harms of overuse of CT angiography include radiation exposure and the possibility of finding then seeking treatment for a clinically insignificant pulmonary embolism which ought not be treated. (wikipedia.org)
  • scan
  • Recently, turbo MR angiography with zero-filling interpolation (ZFI) technique has been proposed as a new technique to reduce scan time for the evaluation of cerebrovascular diseases. (ahajournals.org)
  • 7-10 Thus, the ZFI technique allows for high-resolution turbo MR angiography in less scan time. (ahajournals.org)
  • This can be described by: S N R v = π 2 v v e n c S N R {\displaystyle SNR_{v}={\frac {\pi }{\sqrt {2}}}{\frac {v}{v_{enc}}}SNR} where S N R {\displaystyle SNR} is the signal-to-noise ratio of the image (which depends on the magnetic field of the scanner, the voxel volume, and the acquisition time of the scan). (wikipedia.org)
  • This is based on MRI scan, magnetic resonance angiography and CT scan. (wikipedia.org)
  • gradients
  • To measure Δ Φ {\displaystyle \Delta \Phi } , of the MRI signal is manipulated by bipolar gradients (varying magnetic fields) that are preset to a maximum expected flow velocity. (wikipedia.org)
  • By applying additional magnetic fields (gradients) that vary linearly over space, specific slices to be imaged can be selected, and an image is obtained by taking the 2-D Fourier transform of the spatial frequencies of the signal (a.k.a., k-space). (wikipedia.org)
  • MRI scanners use strong magnetic fields, electric field gradients, and radio waves to generate images of the organs in the body. (wikipedia.org)
  • Pulses of radio waves excite the nuclear spin energy transition, and magnetic field gradients localize the signal in space. (wikipedia.org)
  • evaluate
  • CT angiography should not be used to evaluate for pulmonary embolism when other tests indicate that there is a low probability of a person having this condition. (wikipedia.org)
  • commonly
  • In the static magnetic fields commonly used in MRI, the energy difference between the nuclear spin states corresponds to a radio-frequency photon. (wikipedia.org)
  • main
  • The radio signal may be made to encode position information by varying the main magnetic field using gradient coils. (wikipedia.org)
  • The major components of an MRI scanner are: the main magnet, which polarizes the sample, the shim coils for correcting shifts in the homogeneity of the main magnetic field, the gradient system which is used to localize the MR signal and the RF system, which excites the sample and detects the resulting NMR signal. (wikipedia.org)
  • voltage
  • These changes in magnetization alignment cause a changing magnetic flux, which yields a changing voltage in receiver coils to give the signal. (wikipedia.org)