Published in:
Open Access
01-08-2018 | Urogenital
Diagnostic evaluation of magnetization transfer and diffusion kurtosis imaging for prostate cancer detection in a re-biopsy population
Authors:
Tristan Barrett, Mary McLean, Andrew N. Priest, Edward M. Lawrence, Andrew J. Patterson, Brendan C. Koo, Ilse Patterson, Anne Y. Warren, Andrew Doble, Vincent J. Gnanapragasam, Christof Kastner, Ferdia A. Gallagher
Published in:
European Radiology
|
Issue 8/2018
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Abstract
Objective
To evaluate diffusion kurtosis imaging (DKI) and magnetisation transfer imaging (MTI) compared to standard MRI for prostate cancer assessment in a re-biopsy population.
Methods
Thirty-patients were imaged at 3 T including DKI (Kapp and Dapp) with b-values 150/450/800/1150/1500 s/mm2 and MTI performed with and without MT saturation. Patients underwent transperineal biopsy based on prospectively defined MRI targets. Receiver-operating characteristic (ROC) analyses assessed the parameters and Wilcoxon-signed ranked test assessed relationships between metrics.
Results
Twenty patients had ≥ 1 core positive for cancer in a total of 26 MRI targets (Gleason 3+3 in 8, 3+4 in 12, ≥ 4+3 in 6): 13 peripheral (PZ) and 13 transition zone (TZ). The apparent diffusion coefficient (ADC) and Dapp were significantly lower and the Kapp and MT ratio (MTR) significantly higher in tumour versus benign tissue (all p ≤ 0.005); ROC values 0.767-1.000. Normal TZ had: lower ADC and Dapp and higher Kapp and MTR compared to normal PZ. MTR showed a moderate correlation to Kapp (r = 0.570) and Dapp (r = -0.537) in normal tissue but a poor correlation in tumours. No parameter separated low-grade (Gleason 3+3) from high-grade (≥ 3+4) disease for either PZ (p = 0.414-0.825) or TZ (p = 0.148-0.825).
Conclusion
ADC, Dapp, Kapp and MTR all distinguished benign tissue from tumour, but none reliably differentiated low- from high-grade disease.
Key Points
• MTR was significantly higher in PZ and TZ tumours versus normal tissue
• K
app
was significantly lower and D
app
higher for PZ and TZ tumours
• There was no incremental value for DKI/MTI over mono-exponential ADC parameters
• No parameter could consistently differentiate low-grade (Gleason 3+3) from high-grade (≥ 3+4) disease
• Divergent MTR/DKI values in TZ tumours suggests they offer different functional information