Achieva quasar dual

Three days before CAS, magnetic resonance (MR) examinations, including 3D-T1 gradient echo (GRE) carotid plaque imaging, were performed on all patients after diagnostic angiography. No ischemic events, such as transient ischemic attack or stroke, occurred between pre-procedural MR examinations and CAS. MR imaging was performed using a 3.0-T MR imaging system (Achieva Quasar Dual, Philips Medical Systems, Best, The Netherlands).
3D-T1 GRE carotid plaque imaging was performed in the coronal plane with null blood conditions (effective inversion time, 600 ms; TR/TE, 5.0/2.3 ms) and the water excitation technique to suppress fat signals. Other scanning parameters were as follows: FOV, 260 mm; voxel size, 0.68×0.68×1.00 mm; flip angle, 13°; partitions, 56 partitions covering 70 mm around the carotid bifurcation; and data acquisition time, 4 min 2 s.
MR images were reviewed by a neurointerventionalist blinded to the clinical data. Regions of interest were drawn manually on a workstation around the carotid plaque and the adjacent sternocleidomastoid muscle (SCM) with coronal 3D-T1TFE images that detected the largest carotid plaque segment. The signal intensity ratio (SIR) was defined as the signal intensity of the carotid plaque divided by the signal intensity of SCM, being >1.8 for vulnerable plaques and ≤1.8 for stable plaques, as previously described [14] (link).

Scanning was conducted using a 3 T MRI scanner (Achieva Quasar Dual, Philips). Blood oxygenation level-dependent (BOLD) T2*-weighted MR signals were measured using a gradient echo-planar imaging sequence. Forty 3-mm-thick contiguous slices covering the entire brain were acquired (repetition time [TR] = 2,500 ms, echo time = 30 ms, flip angle = 85°, field of view = 192 mm², and scan matrix = 64 × 64). Excluding the first two “dummy” volumes to stabilize the T1-saturation effect, 388 volumes were acquired in each fMRI session.

All studies were performed on a clinical 3 T CMR scanner (Achieva Quasar Dual; Philips Healthcare, Best, The Netherlands) equipped with a dedicated cardiac software package and a 32-element cardiac phased-array coil (16 posterior elements, 16 anterior elements); a 4-lead vector electrocardiogram (ECG) was used for cardiac gating. In all patients, double-angulated scout images were obtained to plan cardiac axis views, and retrospective ECG gated cine imaging was performed using a segmented balanced steady state free precession (bSSFP) sequence in continuous short-axis views, spanning the entire left ventricle (LV) from base to apex. Ten minutes after the injection of 0.2 mmol/kg gadopentetate dimeglumine (Magnevist; Bayer Healthcare, Berline, Germany), we acquired three-dimensional (3D) IR sequences that spanned the LV from the base to the apex, selecting the myocardium null TI values from the TI scout images. The imaging parameters were: repetition time/echo time, 3.4/1.6 ms; TI, 300–400 ms; flip angle, 15°; field-of-view, 350 mm × 350 mm; pixel size, 1.6 mm × 2.3 mm; slice thickness, 10.0 mm; sensitivity encoding (SENSE) factor, 2.4.