Texture Analysis of Native T1 Images as a Novel Method for Noninvasive Assessment of Uremic Cardiomyopathy

Background: Noncontrast cardiac T₁ times are increased in dialysis patients which might indicate fibrotic alterations in uremic cardiomyopathy.

Purpose: To explore the application of the texture analysis (TA) of T₁ images in the assessment of myocardial alterations in dialysis patients.

Study type: Case-control study.

Population: A total of 117 subjects, including 22 on hemodialysis, 44 on peritoneal dialysis, and 51 healthy controls.

Field strength: A 3 T, steady-state free precession (SSFP) sequence, modified Look-Locker imaging (MOLLI).

Assessment: Two independent, blinded researchers manually delineated endocardial and epicardial borders of the left ventricle (LV) on midventricular T₁ maps for TA.

Statistical tests: Texture feature selection was performed, incorporating reproducibility verification, machine learning, and collinearity analysis. Multivariate linear regressions were performed to examine the independent associations between the selected texture features and left ventricular function in dialysis patients. Texture features' performance in discrimination was evaluated by sensitivity and specificity. Reproducibility was estimated by the intraclass correlation coefficient (ICC).

Results: Dialysis patients had greater T₁ values than normal (P < 0.05). Five texture features were filtered out through feature selection, and four showed a statistically significant difference between dialysis patients and healthy controls. Among the four features, vertical run-length nonuniformity (VRLN) had the most remarkable difference among the control and dialysis groups (144 ± 40 vs. 257 ± 74, P < 0.05), which overlap was much smaller than Global T₁ times (1268 ± 38 vs. 1308 ± 46 msec, P < 0.05). The VRLN values were notably elevated (cutoff = 170) in dialysis patients, with a specificity of 97% and a sensitivity of 88%, compared with T₁ times (specificity = 76%, sensitivity = 60%). In dialysis patients, VRLN was significantly and independently associated with left ventricular ejection fraction (P < 0.05), global longitudinal strain (P < 0.05), radial strain (P < 0.05), and circumferential strain (P < 0.05); however, T₁ was not.

Data conclusion: The texture features obtained by TA of T₁ images and VRLN may be a better parameter for assessing myocardial alterations than T₁ times.

Level of evidence: 4 TECHNICAL EFFICACY: Stage 3.