Reduced FOV T2-weighted imaging, 2.5D T2-weighted imaging, and high b-value diffusion-weighted imaging of the prostate at 5 T: a comparative study with 3 T.

Abstract

Objectives: To evaluate the image quality of prostate T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) at 5 T.

Methods: In this prospective study, asymptomatic adult male volunteers underwent conventional T2WI and multiple b-value DWI at both 3 T and 5 T, along with 2.5D T2WI at 5 T using the 2.5D imaging method. 2.5D imaging method improved in-plane resolution by reducing slice thickness and increasing the number of signal averaged to maintain the signal-to-noise ratio (SNR). Three scanning protocols were compared: conventional T2WI at 5 T vs. 3 T, 2.5D T2WI at 5 T vs. conventional T2WI at 5 T, and DWI at 5 T vs. 3 T. Quantitative analysis encompassed SNR, contrast-to-noise ratio (CNR), prostate dimensions, prostate volume (PV), edge rise distance of the dorsal prostate capsule, and ADC values in benign lesions. Image quality was qualitatively rated using a five-point Likert scale (1 = non-diagnostic, 5 = excellent). Statistical significance was assessed using paired t-test and Wilcoxon signed-rank test, with a significance threshold of P < 0.05.

Results: Twenty participants were enrolled. Compared to 3 T, 5 T significantly increased SNR and CNR for T2WI (sagittal, coronal, and axial planes) and DWI (b-values of 1000, 1500, 2000 s/mm²) (P < 0.05). Image sharpness and clarity were significantly enhanced for T2WI and DWI at 5 T (P < 0.05). The 2.5D imaging method further improved T2WI resolution, overall image quality, and clarity of the prostate capsule. No significant differences were observed in artifact presence or PV between the T2WI groups (P > 0.05).

Conclusion: 5 T bi-parametric MRI (bp-MRI) of the prostate demonstrated superior image quality.