Assessment of Late Gadolinium Enhancement in Nonischemic Cardiomyopathy: Comparison of a Fast Phase-Sensitive Inversion Recovery Sequence (PSIR) and a Conventional Segmented 2D Gradient Echo Recall (GRE) Sequence-Preliminary Findings

Background: Reliable detection of myocardial scarring in nonischemic cardiomyopathy is time-consuming using techniques that require determination of optimal inversion time. Therefore we evaluated an inversion-time-insensitive approach using a fast phase-sensitive inversion recovery (PSIR) sequence to detect and quantify late gadolinium enhancement (LGE).

Patients and Methods: Twenty patients (mean age 40 years, 9 females) with nonischemic cardiomyopathy and evidence of LGE were evaluated. After administration of 0.2 mmol/kg gadolinium diethylene triamine pentaacetic acid, a segmented 2D inversion recovery turbo fast low-angle shot gradient echo recall (GRE) sequence [echo time (T_E) 4.3 milliseconds, repetition time (T_R) 750 milliseconds, α 30°, voxel size 1.7 × 1.3 × 8-10 mm] was obtained and served as the standard of reference. Second, a fast multislice single-shot 2D PSIR sequence (T_E 1.1 millisecond, T_R 700 milliseconds, α 40°, voxel size 2.5 × 1.7 × 8-10 mm) was acquired in the same slice positions. The PSIR_IR images were used to analyze LGE. Altogether 53 short-axis slices with LGE were evaluated. Contrast-to-noise ratio and area of LGE were calculated and compared by 2 experienced readers. Image quality and confidence level for identification of LGE were rated on 5-point scales. Interobserver variability was evaluated in 10 patients.

Results: All images were interpretable. Imaging time was reduced from 385 ± 127 seconds to 20 ± 3 seconds (P < 0.001). Contrast-to-noise ratio was 8.29 for PSIR_mag and 12.07 for the conventional GRE images (P < 0.001). The mean area of LGE was 1.01 ± 0.62 cm² for the GRE sequence and 1.10 ± 0.62 cm² for PSIR_IR (P = NS). The general linear model showed no interaction between the results and no significant difference of the mean (r = 0.09, mean difference 0.09 cm²). The overall interobserver variability of PSIR_IR and GRE was excellent, with Pearson's correlation coefficients of r = 0.96 for PSIR_IR and r = 0.98 for GRE. PSIR_IR and conventional GRE were comparable in terms of image quality and confidence level (image quality: 1.6 ± 0.67 vs. 1.5 ± 0.93, P = NS; confidence level: 1.4 ± 0.84 vs. 1.3 ± 0.5; P = NS).

Conclusions: Fast PSIR sequences enable accurate detection and quantification of LGE in nonischemic cardiomyopathies. The examination time can be significantly shortened using the single-shot approach of the PSIR technique.