High-resolution and highly accelerated MRI T2 mapping as a tool to characterise renal tumour subtypes and grades

Horvat-Menih, Ines; Li, Hao; Priest, Andrew N.; Li, Shaohang; Gill, Andrew B.; Mendichovszky, Iosif A.; Francis, Susan T.; Warren, Anne Y.; O’Carrigan, Brent; Welsh, Sarah J.; Jones, James O.; Riddick, Antony C. P.; Armitage, James N.; Mitchell, Thomas J.; Stewart, Grant D.; Gallagher, Ferdia A.

Abstract

Background: Clinical imaging tools to probe aggressiveness of renal masses are lacking, and T2-weighted imaging as an integral part of magnetic resonance imaging protocol only provides qualitative information. We developed high-resolution and accelerated T2 mapping methods based on echo merging and using k-t undersampling and reduced flip angles (TEMPURA) and tested their potential to quantify differences between renal tumour subtypes and grades. Methods: Twenty-four patients with treatment-naïve renal tumours were imaged: seven renal oncocytomas (RO); one eosinophilic/oncocytic renal cell carcinoma; two chromophobe RCCs (chRCC); three papillary RCCs (pRCC); and twelve clear cell RCCs (ccRCC). Median, kurtosis, and skewness of T2 were quantified in tumours and in the normal-adjacent kidney cortex and were compared across renal tumour subtypes and between ccRCC grades. Results: High-resolution TEMPURA depicted the tumour structure at improved resolution compared to conventional T2-weighted imaging. The lowest median T2 values were present in pRCC (high-resolution, 51 ms; accelerated, 45 ms), which was significantly lower than RO (high-resolution; accelerated, p = 0.012) and ccRCC (high-resolution, p = 0.019; accelerated, p = 0.008). ROs showed the lowest kurtosis (high-resolution, 3.4; accelerated, 4.0), suggestive of low intratumoural heterogeneity. Lower T2 values were observed in higher compared to lower grade ccRCCs (grades 2, 3 and 4 on high-resolution, 209 ms, 151 ms, and 106 ms; on accelerated, 172 ms, 160 ms, and 102 ms, respectively), with accelerated TEMPURA showing statistical significance in comparison (p = 0.037). Conclusions: Both high-resolution and accelerated TEMPURA showed marked potential to quantify differences across renal tumour subtypes and between ccRCC grades. Trial registration: ClinicalTrials.gov, NCT03741426. Registered on 13 November 2018. Relevance statement: The newly developed T2 mapping methods have improved resolution, shorter acquisition times, and promising quantifiable readouts to characterise incidental renal masses. Graphical Abstract:

Citation

Horvat-Menih, I., Li, H., Priest, A. N., Li, S., Gill, A. B., Mendichovszky, I. A., Francis, S. T., Warren, A. Y., O’Carrigan, B., Welsh, S. J., Jones, J. O., Riddick, A. C. P., Armitage, J. N., Mitchell, T. J., Stewart, G. D., & Gallagher, F. A. (2024). High-resolution and highly accelerated MRI T2 mapping as a tool to characterise renal tumour subtypes and grades. European Radiology Experimental, 8(1), Article 76. https://doi.org/10.1186/s41747-024-00476-8

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2024
• Online Publication Date: Jul 10, 2024
• Publication Date: Jul 10, 2024
• Deposit Date: Sep 10, 2024
• Publicly Available Date: Sep 13, 2024
• Journal: European Radiology Experimental
• Electronic ISSN: 2509-9280
• Publisher: SpringerOpen
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 1
• Article Number: 76
• DOI: https://doi.org/10.1186/s41747-024-00476-8
• Keywords: Kidney cortex, Carcinoma (renal cell), Kidney neoplasms, Magnetic resonance imaging, Oncocytoma (renal)
• Public URL: https://nottingham-repository.worktribe.com/output/37301286
• Publisher URL: https://eurradiolexp.springeropen.com/articles/10.1186/s41747-024-00476-8