3T-MR装置を用いた根治的前立腺全摘除術における手術支援用3D画像作成のための適切なMR撮像シーケンスと撮像条件の検討

摘要

The objective of our study was to optimize magnetic resonance image (MRI) sequences and parameters using operative assisted images (three-dimensional images) for radical prostatectomy at 3 tesla (T) MRI. Five healthy volunteers underwent MRI on the 3.0 T scanner. Various sequences and parameters [Cube (TE/TR=18, 50， 90 ms/2000 ms)， FIESTA (TE/TR/FA=2.4 ms/5 ms/40°， 90°)， fSPGR (TE/TR/FA=2.3 ms/11.2 ms/20°), slice thickness=1.2 mm, matrix=192×l60] were respectively compared. Several structures of the pelvis (the central zones and transition zones of the prostate, the peripheral zones of the prostate, seminal vesicles, rectum wall, bladder, muscle and fat) were determined. The signal intensities of these structures were measured on reformatted axial images and compared against several structures of the pelvis. Correlation with various sequences and parameters was based on the signal-to-noise ratio (SNR), the contrast ratio (CR) and the presence of artifacts. Student's （t-test was used for statistical analysis. With Cube (TE/TR=50 ms/2000 ms), the average value of visual evaluation with artifacts was high, and SNR and CR were higher than for other sequence and parameters. Optimized MRI sequences and parameters were Cube (TE/TR=50 ms/2000 ms) which provides improved SNR and CR and the presence of artifacts with operative assisted images for radical prostatectomy. These operative assisted images obtained from Cube (TE/TR=50 ms/2000 ms) are likely to be useful for surgery.%前立腺癌に対するmagnetic resonance image(MRI)検査は腫瘍の存在診断と病期診断に対し最良の画像診断法である.MRIによる前立腺癌の診断にはT_1,T_2強調のほか，diffusion weighted image (DWI), dynamic study, magnetic resonance spectroscopy (MRS)などの撮像法が用いられ，さまざまな情報を得ることができ.