Different sodium concentrations of noncancerous and cancerous prostate tissue seen on MRI using an external coil

Josephine L Tan; Vibhuti Kalia; Stephen E Pautler; Glenn Bauman; Lena V Gast; Max Müller; Armin M Nagel; Jonathan D Thiessen; Timothy J Scholl; Alireza Akbari

doi:10.1093/radadv/umae023

Different sodium concentrations of noncancerous and cancerous prostate tissue seen on MRI using an external coil

Radiol Adv. 2024 Sep 30;1(3):umae023. doi: 10.1093/radadv/umae023. eCollection 2024 Sep.

Authors

Josephine L Tan¹, Vibhuti Kalia^{2

3}, Stephen E Pautler^{4

5}, Glenn Bauman^{1

5}, Lena V Gast⁶, Max Müller⁶, Armin M Nagel^{6

7}, Jonathan D Thiessen^{1

2

8}, Timothy J Scholl^{1

9

10}, Alireza Akbari^{1

8

9}

Affiliations

¹ Medical Biophysics, Western University, London, N6A 3K7, Canada.
² Medical Imaging, Western University, London, N6A 3K7, Canada.
³ Medical Imaging, St Joseph's Health Care, London, N6A 4V2, Canada.
⁴ Surgery, Western University, London, N6A 3K7, Canada.
⁵ Oncology, Western University, London, N6A 3K7, Canada.
⁶ Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, 91054, Germany.
⁷ Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.
⁸ Lawson Imaging, Lawson Health Research Institute, London, N6A 5W9, Canada.
⁹ Robarts Research Institute, London, N6A 3K7, Canada.
¹⁰ Ontario Institute for Cancer Research, Toronto, M5G 0A3, Canada.

Abstract

Background: Sodium (²³Na) MRI of prostate cancer (PCa) is a novel but underdocumented technique conventionally acquired using an endorectal coil. These endorectal coils are associated with challenges (e.g., a nonuniform sensitivity profile, limited prostate coverage, patient discomfort) that could be mitigated with an external ²³Na MRI coil.

Purpose: To quantify tissue sodium concentration (TSC) differences within the prostate of participants with PCa and healthy volunteers using an external ²³Na MRI radiofrequency coil at 3 T.

Materials and methods: A prospective study was conducted from January 2022 to June 2024 in healthy volunteers and participants with biopsy-proven PCa. Prostate ²³Na MRI was acquired on a 3-T PET/MRI scanner using a custom-built 2-loop (diameter, 18 cm) butterfly surface coil tuned for the ²³Na frequency (32.6 MHz). The percent difference in TSC (ΔTSC) between prostate cancer lesions and surrounding noncancerous prostate tissue of the peripheral zone (PZ) and transition zone (TZ) was evaluated using a 1-sample t-test. TSC was compared to apparent diffusion coefficient (ADC) measurements as a clinical reference.

Results: Six healthy volunteers (mean age, 54.5 years ± 12.7) and 20 participants with PCa (mean age, 70.7 years ± 8.3) were evaluated. A total of 31 lesions were detected (21 PZ, 10 TZ) across PCa participants. Compared to noncancerous prostate tissue, prostate cancer lesions had significantly lower TSC (ΔTSC, -14.1% ± 18.2, P = .0002) and ADC (ΔADC, -26.6% ± 18.7, P < .0001).

Conclusion: We used an external ²³Na MRI coil for whole-gland comparison of TSC in PCa and noncancerous prostate tissue at 3 T. PCa lesions presented with lower TSC compared to surrounding noncancerous PZ and TZ tissue. These findings demonstrate the feasibility of an external ²³Na MRI coil to quantify TSC in the prostate and offer a promising, noninvasive approach to PCa diagnosis and management.

Keywords: 3 Tesla; apparent diffusion coefficient; human prostate cancer; sodium (23Na) MRI; tissue sodium concentration.