European Radiology Experimental (Jul 2024)

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

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

DOI
https://doi.org/10.1186/s41747-024-00476-8
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 11

Abstract

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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

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