Redefining ultrasound as a minimally invasive diagnostic evaluation for kidney transplant: Practical guidance on...

Kidney transplants (KTx) require regular monitoring to prevent complications and graft loss. KTx fibrosis is a significant factor contributing to graft failure, and is a pathological state arising from transplant-associated injury, making its identification crucial for graft viability. Traditional biopsy methods, the gold standard for diagnosing fibrosis, are invasive and carry risks. This paper explores the potential use of Ultrasound Shear Wave Elastography (SWE) as a non-invasive supplementary assessment tool in managing KTx allografts.

The principles of SWE technology, and its ability to assess tissue stiffness for detecting fibrosis in KTx allografts were discussed. A review of existing English-language literature from Pubmed, EMBASE, and Cochrane Library, using keywords such as "kidney transplant fibrosis" and "ultrasound", revealed that most studies report moderate correlations between SWE metrics and histology. Diagnostic performance varies by vendor, protocol, and population, with no established generalised thresholds. This paper provides practical recommendations for implementing SWE in clinical settings, addressing common pitfalls and suggesting techniques to optimise SWE accuracy. With appropriate technique, SWE can effectively identify early graft fibrosis, facilitating timely interventions and improving patient outcomes.

This review highlights the significant role of SWE as an adjunctive tool in the evaluation of KTx allografts fibrosis. The integration of SWE can enhance monitoring strategies, minimising patient discomfort and risks.

The use of SWE as an adjunct to traditional ultrasound (greyscale, Doppler and Contrast-enhanced ultrasound) to prioritise patients for biopsy, especially to rule out conditions such as rejection, infection, and inflammation when needed, rather than to replace biopsy; thresholds remain investigational pending renal-specific consensus. Moreover, further standardised prospective studies are required to establish reliable thresholds and protocols for its use.