Spectral diffusion analysis to improve the detection and classification of clinical significant prostate cancer
Author Block: B. Valentin, T. Thiel, T. Ullrich, M. Boschheidgen, J. P. Radtke, P. Albers, G. Antoch, H-J. Wittsack, L. Schimmöller; Düsseldorf/DE
Purpose: In this study, we applied the model-free nonnegative least squares (NNLS) method. The aim of this study was to assess the number of distinguishable diffusion components (spectral diffusion analysis) within the prostate and to differentiate between healthy and pathological prostate tissue.
Methods or Background: NNLS imaging was performed at 3 Tesla (Magnetom PRISMA® Siemens, Erlangen, Germany) in 10 patients with prostate cancer (PC) (PI-RADS 5 and subsequent biopsy). The 16 b values used were 0, 50, 100, 150, 200, 300, 400, 500, 600, 700, 800, 1000, 1200, 1400, 1600, 1800 s/mm 2. Relative signal fractions and mean diffusivities of the diffusion components in the peripheral zone, central zone and PI-RADS 5 lesion were obtained using the regularized NNLS fitting of the intravoxel incoherent motion data.
Results or Findings: Three different diffusion components (10–4, 10–3, and 10–2 mm2/s) were detected in prostate tissue. In comparison, the three peaks were significantly different between healthy and diseased tissue. The fraction of the slow component was significant higher in PC (maximum amplitude of 0.2) compared with the unaffected prostate tissue (maximum amplitude of 0.05).
Conclusion: This pilot study demonstrated the feasibility of spectral diffusion weighted imaging for the differentiation of PC. The three distinguishable components may be related to slow tissue diffusion caused by higher tissue density of PC lesions, intermediate fluid flow caused by glandular tissue, and fast blood flow in prostatic vessels. A larger cohort study with a ISUP range is needed to further evaluate this technique.
Limitations: This study exclusively focused on PI-RADS 5 lesions. Consequently, we were unable to differentiate between lesion sizes and did not account for variations in high-, intermediate-, and low-risk prostate cancer cases.
Funding for this study: This study was funded by DFG.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The local ethics committee has positively reviewed this prospective study.