Ultrasound hepatorenal index for the diagnosis of steatosis in patients with type 2 diabetes: a prospective validation study.

OBJECTIVES

To evaluate the performance of the ultrasound hepatorenal index (US-HRI) for the diagnosis of hepatic steatosis in patients with type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD), using MRI proton density fat fraction (MRI-PDFF) as reference.

MATERIALS AND METHODS

This two-center prospective study included 129 and 263 patients in the training and validation cohorts, respectively, between 2019 and 2022. Hepatic steatosis was classified according to MRI-PDFF as S0 (≤ 6.5%), S1 (6.5-16.5%), S2 (16.5-22%), and S3 (> 22%). Obuchowski measurement (OB) was performed to assess the diagnostic performance of US-HRI in the whole cohort. Optimal cut-offs of US-HRI for diagnosing ≥ S1 and ≥ S2 were identified in the training cohort by maximizing the Youden index and were applied in the validation cohort.

RESULTS

Overall, 392 patients were included (mean age, 59 years ± 9.5; 235 men). The OB (four class problem S0 to S3) was 0.79 ± 0.01. Pairwise accuracy was good for S0 vs S1, S2 or S3 (0.78 to 0.89) but decreased for distinguishing among higher grades (0.54 to 0.62). Optimal US-HRI threshold for diagnosing ≥ S1 was 1.16, with a sensitivity of 82.7% (95% CI: 77.4-87.3), specificity of 80.0% (95% CI: 56.3-94.3), and AUC of 0.81 (95% CI: 0.76-0.86). The threshold for diagnosing ≥ S2 was 1.47, with a sensitivity of 49.0% (95% CI: 39.1-59.0), specificity of 73.0% (95% CI: 65.3-79.7), and AUC of 0.61 (95% CI: 0.55-0.67).

CONCLUSION

US-HRI was a reliable tool for diagnosing steatosis in type 2 diabetic patients with MASLD. However, its performance in assessing more severe grades of steatosis was inadequate.

KEY POINTS

Question Ultrasound hepatorenal index (US-HRI) performance for the diagnosis of steatosis in type 2 diabetic patients with metabolic dysfunction-associated steatotic liver disease (MASLD) is not well defined. Findings US-HRI demonstrated good diagnostic performance for steatosis (S0 vs S1-S3), but this decreased for diagnosing S2-S3. Clinical relevance US-HRI provides a quantitative approach for detecting hepatic steatosis in patients with MASLD and type 2 diabetes, but has shown limited effectiveness in grading higher grades.