Abbreviations: 3-D = three-dimensional, AASDD = age-associated striatal dopaminergic denervation, ANCOVA = analysis of covariance, BMI = body mass index, DAT = dopamine transporter, ICD-9 = International Classification of Diseases-9th Revision, MMSE = Mini-Mental State Examination, MR = magnetic resonance, MRI = MR imaging, PD = Parkinson disease, PET = positron emission tomography, SD = standard deviation, SPGR
= spoiled gradient recall, UPDRS = Unified Parkinson's Disease Rating Scale, VA = Department of Veterans Affairs, VOI = volume of interest.
These sequences have advantages over standard GRE or SPGR sequences in signal-to-noise ratio (SNR) and vascular contrast.
The addition of fat saturation to the 3-dimensional SPGR sequence can help to improve background suppression and emphasize vascular signal, at a small cost in acquisition time.
ECG-gating, whether of SSFP or CE SPGR sequences, is often useful in reducing or eliminating artifact from cardiac motion.
Assessment of portal and hepatic veins is usually accomplished within a standard hepatic protocol that includes 3-phase dynamic CE 3-dimensional SPGR imaging (Figure 8).
6 90 62 256 x 192 Ax T2W FSE 4000 100 -- 15 256 x 256 Ax Dyn GRE 3D min min 15 31 256 x 160 Sag SPGR
22 min 30 12 256 x 160 Pulse sequence Slice Fat suppression NEX FOV Cor SSFSE 5 x 0 No 0.
5 Further characterization or staging of malignancy 3D TOF SPGR
Axial min/min 200 31 GRASS Axial 30/6 33.