Three-dimensional T1-weighted gradient echo is a suitable alternative to two-dimensional T1-weighted spin echo for imaging the canine brain

Volumetric imaging (VOL), a three-dimensional magnetic resonance imaging (MRI) technique, has been described in the literature for evaluation of the human brain. It offers several advantages over conventional two-dimensional (2D) spin echo (SE), allowing rapid, whole-brain, isotropic imaging with submillimeter voxels. This retrospective, observational study compares the use of 2D T1-weighted SE (T1W SE), with T1W VOL, for the evaluation of dogs with clinical signs of intracranial disease. Brain MRI images from 160 dogs who had T1W SE and T1W VOL sequences acquired pre- and postcontrast, were reviewed for presence and characteristics of intracranial lesions. Twenty-nine of 160 patients were found to have intracranial lesions, all visible on both sequences. Significantly better grey-white matter (GWM) differentiation was identified with T1W VOL (P < .001), with fair agreement between the two sequences (weighted kappa = 0.35). Excluding a mild reduction in lesion intensity in three dogs precontrast on the T1W VOL images compared to T1W SE, and meningeal enhancement noted on the T1W VOL images in one dog, not identified on T1W SE, there was otherwise complete agreement between the two sequences. The T1W VOL sequence provided equivalent lesion evaluation and significantly improved GWM differentiation. Images acquired were of comparable diagnostic quality to those produced using a conventional T1W SE technique, for assessment of lesion appearance, number, location, mass effect, and postcontrast enhancement. T1W VOL, therefore, provides a suitable alternative T1W sequence for canine brain evaluation and can facilitate a reduction in total image acquisition time.