DWI-related texture analysis for prostate cancer: differences in correlation with histological aggressiveness and data repeatability between peripheral and transition zones

Abstract

Background: We investigated the correlation between texture features extracted from apparent diffusion coefficient (ADC) maps or diffusion-weighted images (DWIs), and grade group (GG) in the prostate peripheral zone (PZ) and transition zone (TZ), and assessed reliability in repeated examinations.

Methods: Patients underwent 3-T pelvic magnetic resonance imaging (MRI) before radical prostatectomy with repeated DWI using b-values of 0, 100, 1,000, and 1,500 s/mm². Region of interest (ROI) for cancer was assigned to the first and second DWI acquisition separately. Texture features of ROIs were extracted from comma-separated values (CSV) data of ADC maps generated from several sets of two b-value combinations and DWIs, and correlation with GG, discrimination ability between GG of 1-2 versus 3-5, and data repeatability were evaluated in PZ and TZ.

Results: Forty-four patients with 49 prostate cancers met the eligibility criteria. In PZ, ADC 10% and 25% based on ADC map of two b-value combinations of 100 and 1,500 s/mm² and 10% based on ADC map with b-value of 0 and 1,500 s/mm² showed significant correlation with GG, acceptable discrimination ability, and good repeatability. In TZ, higher-order texture feature of busyness extracted from ADC map of 100 and 1,500 s/mm², and high gray-level run emphasis, short-run high gray-level emphasis, and high gray-level zone emphasis from DWI with b-value of 100 s/mm² demonstrated significant correlation, excellent discrimination ability, but moderate repeatability.

Conclusions: Some DWI-related features showed significant correlation with GG, acceptable to excellent discrimination ability, and moderate to good data repeatability in prostate cancer, and differed between PZ and TZ.

Keywords: Diffusion magnetic resonance imaging; Image interpretation (computer-assisted); Neoplasm grading; Prostate neoplasms; Reproducibility of results.

Fig. 1

Flowchart of study showing inclusion and exclusion criteria, and patient and lesion numbers

Fig. 2

Multiparametric magnetic resonance imaging of the case (70 years, right peripheral zone cancer, GG of 3, PI-RADS of 4, T2aN0M0). a Axial T2-weighted image (repetition time of 4,000 ms and echo time of 80 ms). b First axial apparent diffusion coefficient (ADC) map (100, 1,000). c Second axial ADC map (100, 1,000). d Dynamic contrast-enhanced T1-weighted image. e First DWI 1,500. f Second DWI 1,500. Arrows indicate polygonal areas of the region of interests on e and f

Fig. 3

Multiparametric magnetic resonance imaging of the case (61 years, transition zone cancer, GG of 2, PI-RADS of 5, T2cN0M0). a Axial T2-weighted image (repetition time of 4,000 ms and echo time of 80 ms). b First axial apparent diffusion coefficient (ADC) map (100, 1,000). c Second axial ADC map (100, 1,000). d Dynamic contrast-enhanced T1-weighted image. e First DWI 1,500. f Second DWI 1,500. Arrows indicate polygonal areas of the region of interests on e and f

Fig. 4

Peripheral zone cancer. a Correlation between grade group and mean of the first and second apparent diffusion coefficient (ADC) 10% based on ADC (100, 1,500). b XY plot of the first and second ADC 10% based on ADC (100, 1,500). Open circle, closed square, and line indicate grade group (GG) of 1 and 2, GG of 3, 4, and 5, and Y = X line, respectively

Fig. 5

Transition zone cancer. a Correlation between grade group and mean of the first and second busyness of neighborhood gray-level difference matrix based on apparent diffusion coefficient (ADC) (100, 1,500). b XY plot of the first and second busyness of neighborhood gray-level difference matrix based on ADC (100, 1,500). Open circle, closed square, and line indicate grade group (GG) of 1 and 2, GG of 3, 4, and 5, and Y = X line, respectively

Fig. 6

Transition zone cancer. a Correlation between grade group and mean of the first and second high gray-level run emphasis of gray-level run-length matrix based on diffusion-weighted (DWI) 100. b XY plot of the first and second high gray-level run emphasis of gray-level run-length matrix based on DWI 100. Open circle, closed square, and line indicate grade group (GG) of 1 and 2, GG of 3, 4, and 5, and Y = X line, respectively