TURP手术对前列腺癌组织和非肿瘤组织血供影响的MRI评价

目的　应用动态增强MRI两室药物代谢动力学模型评价TURP手术对前列腺癌、前列腺良性增生和正常前列腺周围带血液供应的影响。方法　对 78例经病理组织学证实的前列腺癌 ,其中TURP手术组 2 4例 ,对照组 5 4例 ,使用GE 1.5T超导磁共振成像仪 ,采用FSPGR序列针对前列腺 ( 4层或 5层 )进行动态增强扫描 ,层厚 7mm ,层间间隔 2mm ,连续扫描采样 35次。应用两室药物代谢动力学模型进行分析 ,分别计算出前列腺癌、前列腺良性增生和正常前列腺周围带的最大增强指数、对造影剂的吸收幅度、造影剂的交换率和造影剂分布指数。结果　TURP组和对照组之间年龄、病理学分级、PSA和肿瘤的分期、大小均未见明显差异 (Ρ >0 .0 5 )。在TURP组中肿瘤区最大增强指数、造影剂分布指数和正常前列腺周围带的最大增强指数明显高于对照组 ,之间存在显著统计学差异 (Ρ <0 .0 5 )。结论　MRI药物代谢动力学模型 ,特别是最大增强指数和造影剂分布指数能够更准确地反映TURP手术对前列腺癌组织和非肿瘤组织的血液供应变化     

前列腺增生结节的MR动态增强研究

目的　研究正常前列腺和前列腺增生结节的MR动态增强特征。方法　 5例健康志愿者和 63例疑前列腺病变患者MR平扫,动态增强和延迟扫描,病变组 19例证实为结节样前列腺增生。对比正常前列腺中央叶和外围叶与前列腺增生结节的时间 -信号曲线。结果　正常对照组增强后至最大信号的时间:中央叶(2. 80± 0. 45)min, 外围叶 (2. 2±0. 45)min。最大强化率:中央叶 147%±16%,外围叶 110%±5%。前列腺增生结节组:于T2WI显示前列腺增生结节 42个,T1WI发现 1个。增强后,前列腺增生结节达最高信号的时间: (5. 23±1. 94)min(与中央叶相比,P=0.009;与外围叶相比,P=0.002),最大强化率 127% ±16% (与中央叶相比,P=0.011;与外围叶相比,P=0. 031)。结论　前列腺增生结节的强化时间较正常前列腺延迟,强化程度较中央叶低,较外围叶高。     

High-resolution MRI of excised human prostate specimens acquired with 9.4T in detection and identification of cancers: validation of a technique

Purpose:

To evaluate feasibility of high‐resolution, high‐field ex vivo prostate magnetic resonance imaging (MRI) as an aid to guide pathologists' examination and develop in vivo MRI methods.

Materials and Methods:

Unfixed excised prostatectomy specimens (n = 9) were obtained and imaged immediately after radical prostatectomy under an Institutional Review Board‐approved protocol. High‐resolution T2‐weighted (T2W) MRI of specimens were acquired with a Bruker 9.4 T scanner to correlate with whole‐mount histology. Additionally, T2 and apparent diffusion coefficient (ADC) maps were generated.

Results:

By visual inspection of the nine prostate specimens imaged, high‐resolution T2W MRI showed improved anatomical detail compared to published low‐resolution images acquired at 4 T as published by other investigators. Benign prostatic hyperplasia, adenocarcinomas, curvilinear duct architecture distortion due to adenocarcinomas, and normal radial duct distribution were readily identified. T2 was ≈10 msec longer (P < 0.03) and the ADC was ≈1.4 times larger (P < 0.002) in the normal peripheral zone compared to the peripheral zone with prostate cancer.

Conclusion:

Differences in T2 and ADC between benign and malignant tissue are consistent with in vivo data. High‐resolution, high‐field MRI has the potential to improve the detection and identification of prostate structures. The protocols and techniques developed in this study could augment routine pathological analysis of surgical specimens and guide treatment of prostate cancer patients. J. Magn. Reson. Imaging 2011. © 2011 Wiley‐Liss, Inc.     

Combined diffusion-weighted and dynamic contrast-enhanced MRI for prostate cancer diagnosis--correlation with biopsy and histopathology

PURPOSE: To determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI provides higher diagnostic sensitivity for prostate cancer than each technique alone. MATERIALS AND METHODS: Fourteen patients with a clinical suspicion of prostate cancer underwent endorectal MRI on a 1.5T scanner prior to transrectal ultrasound (TRUS)-guided biopsies. The average values of the apparent diffusion coefficient (ADC, calculated from b-values of 0 and 600), K(trans), v(e), maximum gadolinium (Gd) concentration, onset time, mean gradient, and maximum enhancement were determined. Correlation with histology was based on biopsy (six patients) and prostatectomy specimen (eight patients) results. The Tukey-Kramer test was used for statistical analysis. RESULTS: The average values of all MRI parameters, except v(e) and maximum Gd concentration, showed significant differences between tumor and normal prostate. The sensitivity and specificity values were respectively 54% (35-72%) and 100% (95-100%) for the ADC data, and 59% (39-77%) and 74% (63-83%) for the DCE data. When both ADC and DCE results were combined, the sensitivity increased to 87% (68-95%) and specificity decreased to 74% (62-83%). CONCLUSION: All but two DW- and DCE-MRI parameters showed significant differences between tumor and normal prostate. Combining both techniques provides better sensitivity, with a small decrease in specificity.     

前列腺癌内分泌治疗后复发的MRI研究

目的探讨前列腺癌内分泌治疗后复发的MR I征象。方法10例经临床诊断证实的前列腺癌内分泌治疗后复发的病人,在内分泌治疗过程中肿瘤复发前后都进行了MR I检查。对2次MR I图像中前列腺T2信号、体积变化、对周围组织侵犯、扫描范围内的骨转移和淋巴结转移等情况进行对比分析。结果与复发前对比,前列腺体积增大的有7例,体积未见明显变化的有3例。复发后新出现的周围组织侵犯包括精囊腺(3例)、膀胱(2例)、直肠(1例)、盆底肌(1例)。复发后扫描范围内(骨盆至髂血管分叉水平)原有骨转移病灶进展的有3例,新出现转移灶的有4例。新出现髂血管旁肿大淋巴结的有4例,腹股沟肿大淋巴结的有2例。结论MR I检查能提供有助于诊断内分泌治疗后肿瘤复发的多方面影像信息。     

MRI评价氩氦刀冷冻治疗前列腺癌16例疗效

目的：探讨MRI在氩氦刀冷冻治疗前列腺癌术后疗效评价中的价值。方法系统回顾2012年3月—2014年10月16例超声引导下氩氦刀冷冻治疗前列腺癌的临床及影像资料,分析术前术后实验室指标的变化,对比术前术后 MRI 资料,观察消融效果,包括有无术后残留、转移等。结果术后1个月MRI 提示所有患者冷冻消融范围满意,均表现为长T2信号,DWI及DCE-MRI未见明显异常复发,前列腺特异性抗原（PSA）轻度下降。术后6个月MRI提示前列腺明显缩小,PSA明显下降,未见明显复发征象。术后无尿道坏死、尿道狭窄、尿道直肠瘘发生。1例患者随访6个月时因其他原因死亡。结论 MRI在评价氩氦刀低温冷冻治疗前列腺癌消融范围、术后复发或转移等疗效方面具有较好的临床应用价值。