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Keywords:

  • motion;
  • distal renal artery;
  • contrast-enhanced magnetic resonance angiography;
  • kidney;
  • breath-hold;
  • artifacts

Abstract

Purpose

To study the potential detrimental effects of renal motion on breath-hold three-dimensional contrast-enhanced (CE) magnetic resonance angiography (MRA).

Materials and Methods

A computer model simulating linear motion was applied to MRA pulse sequences. Subsequently, to study whether renal motion was present, 24 patients being evaluated for possible renovascular hypertension underwent a breath-hold nonenhanced single slice two-dimensional dynamic turbo field-echo magnetic resonance imaging (MRI) scan with a typical duration of 32 seconds. This sequence was followed by breath-hold three-dimensional CE renal MRA. CE-MRA images were evaluated by two independent observers.

Results

The computer model revealed linear renal motion to cause artifacts. The severity of these artifacts correlated with velocity. Significant (P < 0.001) near linear cranial motion of the kidneys and diaphragm during a sustained breath-hold was found for the right kidney, left kidney, right diaphragm, and left diaphragm (0.26 ± 0.21 mm/second, 0.25 ± 0.23 mm/second, 0.43 ± 0.43 mm/second, and 0.29 ± 0.33 mm/second [mean ± SD], respectively). CE-MRA images showed artifacts of the distal renal artery that corroborated the computer model findings.

Conclusion

The observed cranial motion of the kidneys during a breath-hold adversely affects distal renal artery image quality on three-dimensional CE-MRA and jeopardizes reliable clinical evaluation. Shortening scan time may be beneficial for decreasing image degradation caused by this phenomenon. J. Magn. Reson. Imaging 2002;16:685–696. Published 2002 Wiley-Liss, Inc.