1.5t system

CMR imaging and spectroscopy was performed on a 1.5 T system (Achieva, Philips Healthcare, Best, The Netherlands) using a 5-channel phased array coil. After scout and reference scans, anatomical and geometric data were acquired using balanced steady-state free precession (bSSFP) sequence in standard long-axis geometries (two-, three- and four-chamber view) as well as in short-axis view with full LV coverage from base to apex (repetition time (TR)/echo time (TE) = 3.3 / 1.6 ms, flip angle = 60°, spatial resolution = 1.5 × 1.5 × 8 mm³, 50 phases, 2 slices per breathhold).
In cases with an estimated glomerular filtration rate (eGFR) > 35 mL/min and informed consent of the subject, a gadolinium-based contrast agent (Gadovist, Bayer Healthcare, Berlin, Germany) was injected for LGE imaging to visualize fibrosis and scarring. Ethical approval constrains only allowed the administration of contrast agent in amyloidosis patients. All patients were eligible to receive gadolinium. After a period of 10 min, a 3-dimensional gradient spoiled turbo fast-field echo sequence with a non-selective 180° inversion pre-pulse was performed at end diastole (TR/TE = 3.3/1.6 ms, flip angle = 15°, spatial resolution = 1.6 × 1.6 × 5 mm³, adjusted inversion delay, one breath-hold for each anatomical location) in the same anatomical location as the bSSFP scans [17 (link)].

MRI scans were acquired using a 1.5 T system (Philips Medical Systems, Achieva). Brain dual-echo (DE) turbo spin-echo, 3D T1-transient field echo, and pulsed gradient SE single shot echo-planar sequences were obtained. All MRI post-processing was performed by a single experienced observer, blinded to subject’s identity. The following MRI variables were assessed: a) WMH severity and location using a visual scale (Wahlund scale) [35] (link), a semi-automatic threshold-based approach (WMH load), and lesion probability maps; b) the pattern of GM atrophy using voxel-based morphometry (VBM) in SPM8; and c) WM mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (radD), and axial diffusivity (axD) using tract-based spatial statistics (TBSS) in FSL. The Appendix S1 reports the complete MRI protocol and details on the MRI analysis.

Between March 2017 and June 2018, 12 patients with AL or ATTR CA (63 ± 11 years, 3 female), referred to the local outpatient clinic, and 10 healthy, age-matched controls (62 ± 11 years, 4 female) were prospectively enrolled. Exclusion criteria were cardiovascular disease other than CA, kidney failure with estimated glomerular filtration rate (eGFR) < 30 ml/min/1.76 m² and the standard exclusion criteria for CMR [20 (link)]. Height and weight of all study subjects were recorded to calculate the body surface area (BSA). All patients had histologically proven (positive Congo red staining of endomyocardium, abdominal fat, kidney, rectum or bone marrow biopsies) amyloidosis and echocardiographic or CMR findings typical for cardiac involvement. Imaging was performed on a clinical 1.5 T system (Achieva, Philips Healthcare, Best, The Netherlands) equipped with a 5-channel cardiac receiver array. Prior to imaging, written informed consent was obtained from all subjects. The study protocol was approved by the ethics committee of the canton of Zurich; it allowed the administration of GBCA only in the CA patient group.

All CMR examinations were performed on a 1.5 T system (Philips Healthcare, Best, The Netherlands). All subjects were placed in supine position and images were acquired at end‐expiratory breath hold with ECG gating. Scout images were acquired to locate the heart. For time‐resolved cine imaging of myocardial function, a multi‐slice multiphase steady state free precession (SSFP) sequence was applied approximately 5 min after intravenous administration of a gadolinium‐based extracellular contrast agent (0.2 mmol/kg). The contrast enhanced SSFP (CE‐SSFP) images (temporal resolution: 30 frames/cardiac cycle) were acquired in the short‐axis view (slice thickness: 8 mm; in‐plane resolution: typically 1.5 × 1.5 mm) covering the LV from base to apex and in 2‐, 3‐, and 4‐chamber views.
End‐diastolic short‐ and long‐axis late gadolinium enhancement (LGE) images in image planes corresponding to those for contrast enhanced SSFP were acquired at expiratory breath hold approximately 15 min after injection of contrast administration. The LGE‐images were acquired using an inversion‐recovery gradient‐recalled echo sequence (slice thickness: 8 mm, no slice gap; In‐plane resolution: typically 1.5 × 1.5 mm; inversion time adjusted to null viable myocardium).
¹¹ (link)