Achieva 3t tx

The mpMRI data were acquired on Philips Achieva 3T-TX scanner (Philips Healthcare, Netherlands) using a 6-channel cardiac phased array coil placed around the pelvis, combined with an endorectal coil (Medrad, Bayer Healthcare, USA). After T2W imaging and DWI, baseline T1 mapping was performed using a variable flip angle (VFA) sequence (TR/TE = 12/2.3 ms, field of view (FOV) = 385×250 mm, matrix size = 308×220, flip angle = 3°, 5°, 10°, 15°, 20°, 30°, slice thickness = 3.5 mm, number of slices = 24, SENSE factor = 1.67, half scan factor = 0.675). Subsequently, DCE data using 3D T1-FFE mDIXON sequence were acquired pre- and post-contrast media injection 0.1 mmol/kg of Multihance (TR/TE1/TE2 = 4.6/1.7/3.3 ms, FOV = 250×385 mm², matrix size = 200×308, flip angle = 10°, slice thickness = 3.5 mm, number of slices = 24, SENSE factor = 1.67, half scan factor = 0.675) for 60 dynamic scans with temporal resolution of 8.3 s/image.

Patients underwent sedation prior to MRI using a 5% chloral hydrate (50 mg/kg) enema administered by an anesthesiologist 30 minutes prior to the study and were monitored by the clinically responsible physician throughout the examination. All examinations were performed on a Philips 3.0 Tesla (3 T) MRI system with pencil beam (pencil beam is a kind of B₀ shimming method through a pencil beam volume shimming algorithm) and second-order shimming (Achieva 3T TX; Philips Healthcare Systems, Best, Netherlands), using a body coil for transmission and an eight-channel sensitivity-encoding (SENSE) receiver coil. Each examination was interpreted separately by two experienced radiologists.
The conventional brain MRI examination included T1WI, T2WI, and DWI sequences. A fast-field echo (FFE) sequence was performed for T1WI using the following parameters: TR of 200 ms; TE of 2.3 ms; FOV of 180 × 161 mm²; matrix of 224 × 162; slice thickness of 5 mm. Parameters for the turbo spin-echo (TSE) sequence used for T2WI were as follows: TR of 4.6 ms; TE of 200 ms; FOV of 180 × 155 mm²; matrix of 224 × 162; slice thickness of 5 mm. Parameters for the spin-echo (SE) sequence used for DWI were as follows: TR of 2500 ms; TE of shortest time; FOV of 200 × 200 mm²; matrix of 124 × 124; slice thickness of 5 mm.

The examinations were performed with a Philips Achieva 3T TX magnetic resonance scanner (Philips Healthcare; Best, The Netherlands) incorporating a 16-channel dedicated abdominal coil. MR protocol included the following sequences: T2W_TSE_Tra_HR; STIR_Tra_FB; VISTA_COR_Sense; mDixon_Tra;DWI_5b_Tra_navi; sMRCP_3D_HR_COR; e-THRIVE_COR_FB; mDixon_Tra C+.
The dynamic sequence of choice was 3-D thrive (Enhanced T1 High-Resolution Isotropic Volume Excitation). This sequence was optimized (regarding the field of view (FOV) and number of slices) for each patient to improve spatial and temporal resolution.
The time of examination was up to 40 min (depending on patient breathing frequency with breathing triggering option), including a dynamic sequence, which took 15 min on average. All children received intravenous infusion of at least 10 ml of normal saline per kg of body weight 1 h before the study.
The diuretic (Furosemidum Polpharma, Polpharma SA) at the dose of 0.25–0.5 mg/kg up to 15 mg was administered 15 min before contrast injection.
Children younger than 5 years old were examined under general anesthesia.

Subjects were scanned in supine position on a 3T MRI scanner (Achieva 3T-TX, Philips Healthcare, Best, Netherlands) equipped with a Quasar Dual gradient system (60 mT/m; 200 mT/m/ms) and dual-source parallel RF transmission (MultiTransmit) technology [7 (link)]. A 6-channel cardiac phased array receiver coil, 4-lead vectorcardiogram, respiratory belt and blood pressure monitoring were used. For each perfusion scan, an intravenous bolus of 0.075 mmol/kg gadobutrol (Gadovist, Bayer, Germany) was administered followed by a 20 ml saline flush (Spectris Solaris power injector, Pittsburgh, Pennsylvania, USA).