Arjen Lindenholz

51 The Use and Pitfalls of Intracranial Vessel Wall Imaging 3 Table 1. 3T vessel wall MRI protocol used at our institution Scan parameter DWI 3D TOF-MRA 2D T 2 FLAIR 3D T 1 VIRTA +C 3D T 1 TFE +C FOV (mm 3 ) 230 x 230 x 140 200 x 200 x 70 230 x 183 x 140 200 × 167 × 45 230 x 230 x 160 Acquisition orientation Transverse Transverse Transverse Transverse oblique Transverse Acquisition spatial resolution (mm 3 ) 0.96 x 1.22 x 4.0 0.4 x 0.7 x 1.0 0.65 x 0.85 x 4.0 0.5 × 0.5 × 1.0 1.0 x 1.0 x 1.0 Reconstructed spatial resolution (mm 3 ) 0.45 x 0.45 x 4.0 0.36 x 0.36 x 0.5 0.41 x 0.41 x 4.0 0.5 × 0.5 × 0.5 0.96 x 0.96 x 1.0 TR / TE / TI (ms) 4056 / 68 / - 22 / 3.5 / - 10000 / 120 / 2800 1500 / 32 / - 8.5 / 3.9 / 1016 Flip-angle (degrees) 90 18 120 90 8 Echo spacing (ms) - - 9.6 4.5 - TSE factor - - 24 56 + 4 - Oversampling factor - - - 1.8 1.4 Readout bandwidth (Hz) 15.1 522.7 218.1 643.4 189.8 No. of signals acquired (NSA) 2 1 1 1 1 SENSE factor 3 (AP) 2 (RL) 2 (RL) 1.5 (RL) 3 (RL) Acquisition time (min:s) 1:25 5:12 5:00 8:03 2:29 AP, anteroposterior direction; +C, with contrast agent; FOV, field of view; NSA, number of signal averages; RL, right-left direction; SENSE, SENSitivity Encoding; TE, echo time; TI, inversion time; TR, repetition time; TSE, turbo spin echo; VIRTA, Volumetric Isotropically Reconstructed Turbo Spin Echo Acquisition. 43