Bittencourt Leonardo K, Attenberger Ulrike I, Lima Daniel, Strecker Ralph, de Oliveira Andre, Schoenberg Stefan O, Gasparetto Emerson L, Hausmann Daniel
Leonardo K Bittencourt, Daniel Lima, Emerson L Gasparetto, CDPI Ressonância Magnética, Avenida das Américas, 4666 Barra da Tijuca, RJ 22631-000, Brazil.
World J Radiol. 2014 Jun 28;6(6):374-80. doi: 10.4329/wjr.v6.i6.374.
To evaluate the impact of computed b = 1400 s/mm(2) (C-b1400) vs measured b = 1400 s/mm(2) (M-b1400) diffusion-weighted images (DWI) on lesion detection rate, image quality and quality of lesion demarcation using a modern 3T-MR system based on a small-field-of-view sequence (sFOV).
Thirty patients (PSA: 9.5 ± 8.7 ng/mL; 68 ± 12 years) referred for magnetic resonance imaging (MRI) of the prostate were enrolled in this study. All measurements were performed on a 3T MR system. For DWI, a single-shot EPI diffusion sequence (b = 0, 100, 400, 800 s/mm²) was utilized. C-b1400 was calculated voxelwise from the ADC and diffusion images. Additionally, M-b1400 was acquired for evaluation and comparison. Lesion detection rate and maximum lesion diameters were obtained and compared. Image quality and quality of lesion demarcation were rated according to a 5-point Likert-type scale. Ratios of lesion-to-bladder as well as prostate-to-bladder signal intensity (SI) were calculated to estimate the signal-to-noise-ratio (SNR).
Twenty-four lesions were detected on M-b1400 images and compared to C-b1400 images. C-b1400 detected three additional cancer suspicious lesions. Overall image quality was rated significantly better and SI ratios were significantly higher on C-b1400 (2.3 ± 0.8 vs 3.1 ± 1.0, P < 0.001; 5.6 ± 1.8 vs 2.8 ± 0.9, P < 0.001). Comparison of lesion size showed no significant differences between C- and M-b1400 (P = 0.22).
Combination of a high b-value extrapolation and sFOV may contribute to increase diagnostic accuracy of DWI without an increase of acquisition time, which may be useful to guide targeted prostate biopsies and to improve quality of multiparametric MRI (mMRI) especially under economical aspects in a private practice setting.
使用基于小视野序列（sFOV）的现代3T磁共振系统，评估计算得出的b = 1400 s/mm²（C-b1400）与测量得到的b = 1400 s/mm²（M-b1400）扩散加权成像（DWI）对病变检出率、图像质量及病变边界清晰度的影响。
本研究纳入30例因前列腺磁共振成像（MRI）前来就诊的患者（前列腺特异抗原：9.5±8.7 ng/mL；年龄68±12岁）。所有测量均在3T磁共振系统上进行。对于DWI，采用单次激发EPI扩散序列（b = 0、100、400、800 s/mm²）。C-b1400通过体素逐一从表观扩散系数（ADC）和扩散图像计算得出。此外，采集M-b1400用于评估和比较。获取并比较病变检出率和最大病变直径。图像质量及病变边界清晰度根据5分李克特量表进行评分。计算病变与膀胱以及前列腺与膀胱的信号强度（SI）比值以评估信噪比（SNR）。
在M-b1400图像上检测到24个病变，并与C-b1400图像进行比较。C-b1400又额外检测到3个可疑癌性病变。C-b1400的整体图像质量评分显著更高，SI比值也显著更高（2.3±0.8对3.1±1.0，P < 0.001；5.6±1.8对2.8±0.9，P < 0.001）。病变大小比较显示C-b1400与M-b1400之间无显著差异（P = 0.22）。
高b值外推与sFOV相结合可能有助于提高DWI的诊断准确性，且不增加采集时间，这对于指导靶向前列腺活检以及提高多参数MRI（mMRI）质量可能有用，尤其从私人诊所的经济角度来看。
