Presented by: Bum Soo Kim MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Introduction

This study was conducted to validate the diagnostic accuracy of contrast enhanced ultrasonography (CEUS) for the assessment of small renal mass (SRM) (≤ 4 cm) compared with kidney dynamic computed tomography (KDCT) and magnetic resonance imaging (MRI).

Materials

A total of 62 patients with SRM who underwent renal biopsy or nephrectomy (partial or radical) between September 2020 and April 2023 were prospectively included. All patients underwent KDCT, MRI and CEUS prior to renal biopsy or nephrectomy. All images were interpreted by a single expert uro-radiologist. Imaging results were compared with histological data.

Results

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Mean tumor size and renal score was 20.5±10.1 mm and 7.0±1.8, respectively. Of 62 patients, 50 patients underwent partial nephrectomy, 1 patient underwent radical nephrectomy and 11 patients underwent renal biopsy. Renal cell carcinoma (RCC) was confirmed in 46 patients, while 16 patients showed benign tumor (angiomyolipoma: 8, oncocytoma: 2, other benign tumor: 6). There were no significant differences in clinicopathologic variables between RCC and benign group. Diagnostic accuracy for RCC of KDCT, MRI and CEUS was 72.6%, 69.4% and 72.6%, respectively (p>0.05). While the sensitivity was slightly higher in KDCT (93.5%) and MRI (91.3%) than in CEUS (82.6%), the specificity, positive and negative predictive values were higher in CEUS (43.8%, 80.9% and 46.7%) compared to those of KDCT (12.5%, 75.4% and 40.0%) and MRI (6.3%, 73.7% and 20.0%).

Conclusion

The present results demonstrated that CEUS could be useful in improving the assessment of SRM. In particular, CEUS showed the highest specificity, positive and negative predictive values. Therefore, CEUS can be a good option counseling patients who are planned to undergo nephrectomy or renal mass biopsy.

Funding

None

Co-Authors

Young Jun Moon, MD
Department of Urology, Kyungpook National University Hospital

Jae-Wook Chung, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Yun-Sok Ha, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Seock-Hwan Choi, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Jun Nyung Lee, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Hyun Tae Kim, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Tae-Hwan Kim, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Eun Sang Yoo, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University

Tae Gyun Kwon, MD, PhD
Department of Urology, School of Medicine, Kyungpook National University