Human prostate <scp>MRI</scp> at ultrahigh‐performance gradient: A feasibility study
Ante Zhu, Matthew Tarasek, Yihe Hua, Eric Fiveland, Stephan E. Maier, Yousef Mazaheri, Maggie Fung, Carl‐Fredrik Westin, Desmond Yeo, Filip Szczepankiewicz, Clare M. Tempany, Oğuz Akın, Thomas Foo
Abstract
Abstract Purpose To demonstrate the technical feasibility and the value of ultrahigh‐performance gradient in imaging the prostate in a 3T MRI system. Methods In this local institutional review board–approved study, prostate MRI was performed on 4 healthy men. Each subject was scanned in a prototype 3T MRI system with a 42‐cm inner‐diameter gradient coil that achieves a maximum gradient amplitude of 200 mT/m and slew rate of 500 T/m/s. PI‐RADS V2.1–compliant axial T 2 ‐weighted anatomical imaging and single‐shot echo planar DWI at standard gradient of 70 mT/m and 150 T/m/s were obtained, followed by DWI at maximum performance (i.e., 200 mT/m and 500 T/m/s). In comparison to state‐of‐the‐art clinical whole‐body MRI systems, the high slew rate improved echo spacing from 1020 to 596 μs and, together with a high gradient amplitude for diffusion encoding, TE was reduced from 55 to 36 ms. Results In all 4 subjects (waist circumference = 81–91 cm, age = 45–65 years), no peripheral nerve stimulation sensation was reported during DWI. Reduced image distortion in the posterior peripheral zone prostate gland and higher signal intensity, such as in the surrounding muscle of high‐gradient DWI, were noted. Conclusion Human prostate MRI at simultaneously high gradient amplitude of 200 mT/m and slew rate of 500 T/m/s is feasible, demonstrating that improved gradient performance can address image distortion and T 2 decay–induced SNR issues for in vivo prostate imaging.