面向B超图像分割的动态权重因子水平集方法

目的研究和改进水平集方法,实现B超图像中病灶区域的准确快速分割。方法分析已有水平集方法在B超图像处理中
的局限,基于区域水平集的优点,将信息论中的熵引入图像处理,定义动态权重因子,准确反映局部灰度阶梯变化状况,定量度
量轮廓线像素点分别受到趋向目标、背景区域的两种作用力的动态权重,将其融合到区域水平集中,迭代引导曲线形变和位
移。由于B超图像病灶分割属于指定区域的局部分割,所以将计算约束到局部范围,从而明显降低运算代价。结果动态权重
因子水平集方法能够较好分割B超图像中的病灶区域,与几种主流水平集方法相比,本文方法精度更高,时间复杂度更小。结
论动态权重因子方法能够更合理准确地判断病灶边界像素点,局部计算策略有效地提高了分割效率。
     

Automatic correction of intensity inhomogeneities improves unsupervised assessment of abdominal fat by MRI

PURPOSE: To demonstrate that unsupervised assessment of abdominal adipose tissue distribution by magnetic resonance imaging (MRI) can be improved by integrating automatic correction of signal inhomogeneities. MATERIALS AND METHODS: Twenty subjects (body mass index [BMI] 23.7-44.0 kg/m(2)) underwent abdominal (32 slices) MR imaging with a 1.9T Elscint Prestige scanner. Many images were affected by relevant intensity distortions. Unsupervised segmentation of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) was performed by a previously validated algorithm exploiting standard fuzzy clustering segmentation. Images were also processed by an improved version of the software, including automatic correction of intensity inhomogeneities. To assess the effectiveness of the two methods SAT and VAT volumes were compared with manual analysis performed by a trained operator. RESULTS: Coefficient of variation between manual and unsupervised analysis was significantly improved by inhomogeneities correction in SAT evaluation. Systematic underestimation of SAT was also corrected. A less important performance improvement was found in VAT measurement. CONCLUSION: The results of this study suggest that the compensation of signal inhomogeneities greatly improves the effectiveness of the unsupervised assessment of abdominal fat. Correction of intensity distortions is important in SAT evaluation and less significant in VAT measurement.     

局部晚期宫颈癌CT图像引导下192Ir三维腔内后装治疗剂量体积参数与疗效关系

目的探讨CT图像引导下192Ir三维腔内后装治疗剂量体积参数与局部晚期宫颈癌临床疗效的相关关系。方法选取我院2011年1月到2013年12月间50例局部晚期宫颈癌患者为研究对象,对其进行盆腔外照射40Gy和同期化疗后进行CT图像引导下192Ir三维腔内后装治疗,且每次均在治疗前进行CT扫描定位,探讨剂量体积参数与局部晚期宫颈癌临床疗效的相关关系。结果 90.0%GTV的BED与EQD分别为(101.3±6.6)Gy、(85.3±5.6)Gy(α/β=10);90.0%CTV的BED与EQD分别为(95.2±6.3)Gy、(79.3±5.4)Gy(α/β=10);90.0%处方剂量对GTV和CTV的V90分别为(91.4±4.5)%、(88.4±7.3)%。1-2级放射性肠炎患者乙状结肠D2cm3剂量明显的高于其他危及器官的D2cm3剂量(P<0.05),统计学有意义。三维治疗计划中D90和V90明显的高于二维治疗计划D90和V90,数据的比较差异有统计学意义(P<0.05)。二维治疗计划拟合CT图像上显示其直肠参考点剂量和D2cm3以及A点剂量无明显的差异(P>0.05),统计学无意义;三维治疗计划仅仅提高膀胱参考点的剂量。结论 CT图像引导下192Ir三维腔内后装治疗能够提高其处方剂量对肿瘤靶区的覆盖率,提高临床治疗效果。     

医学图像处理技术在乳腺弹性成像技术中的应用价值

目的 研究医学图像处理技术在乳腺弹性成像鉴别肿块良恶性中的价值.方法 收集122例乳腺结节患者,共124个病灶,均接受常规超声、声脉冲辐射力成像技术检查声触诊组织成像(vTI).对VTI图像进行图像处理分析,通过Image J软件测得图像平均光密度值.以病理为金标准,比较每种方法及联合后的诊断效能.结果 经病理证实,124例乳腺肿块中,恶性病灶50例,良性病灶74例.VTI的平均光密度值的截点值为210.200,AUC为0.873.恶性病灶平均光密度值＞210.200的患者为45例,＜210.200的患者为5例,良性病变平均光密度值＞210.200的患者为7例,＜210.200的患者为67例(P ＜0.005).两者联合方法在诊断乳腺肿瘤的敏感度为96.0％、特异度为83.8％、阳性预测值为80.0％、阴性预测值为96.9％、准确率为88.7％.结论 乳腺肿块VTI成像后,医学图像处理技术可以通过平均光密度这个量化的指标来评估组织的硬度,在预测乳腺病变良恶性方面有重要意义,其与常规超声联合判断,并且能明显提高诊断的准确性.     

胆囊切除术后肝外胆管残余结石的预防

目的 探讨胆囊切除术后肝外胆管残余结石的预防.方法 回顾分析7 921例胆石症患者的临床资料.将磁共振胰胆管成像(magnetic resonance cholangiopancreatography,MRCP)作为胆石症术前常规检查,术中疑有胆管结石者及时行经胆囊管造影或经胆囊管胆道镜探查,术中尽量避免医源性胆管结石残留.结果 本组7921例胆石症患者,经MRCP检查及术中造影、胆道镜探查发现B超漏诊胆管结石152例,仅发生3例胆管结石残余,明显低于国外同类报道.结论 MRCP可作为胆囊切除术前常规辅助检查,能有效提高胆总管下端结石的确诊率.术中采取经胆囊管造影、经胆囊管胆道镜探查以及提高术者操作技巧等措施,可明显地减少胆囊切除术后肝外胆管残余结石的发生率.     

Radioactive seed localization of breast lesions: an adequate localization method without seed migration

Preoperative localization is important to optimize the surgical treatment of breast lesions, especially in nonpalpable lesions. Radioactive seed localization (RSL) using iodine-125 is a relatively new approach. To provide accurate guidance to surgery, it is important that the seeds do not migrate after placement. The aim of this study was to assess short-term and long-term seed migration after RSL of breast lesions. In 45 patients, 48 RSL procedures were performed under ultrasound or stereotactic guidance. In the first 12 patients, the lesion was localized with two markers: an iodine-125 seed and a reference marker. In 33 patients, 36 RSL procedures were performed using a single iodine-125 seed. All patients received control mammograms after seed placement and prior to surgery. In the patients with two markers, migration was defined as the difference in the largest distance between the markers observed in the mammograms. For single-marked lesions, migration was assessed by comparing distances between anatomical landmarks in the mammograms. RSL was successful in all patients. Seeds were in-situ for 59.5 days on average (3-136 days). The detection rate during surgery was 100%. Overall, an average seed migration of 0.9 mm (standard deviation 1.0 mm) was observed. Neither differences in lesion type, nor days in situ, type of surgery or radiologic localization method were found to have impact on seed migration. RSL is an accurate preoperative localization method for breast lesions with negligible seed migration, independent of time in-situ.     

多模态医学影像数据融合三维构建肢体肿瘤及其周围解剖整体结构

目的利用多模态医学影像数据三维重建和配准融合的方法构建肢体肿瘤及瘤周解剖整体结构,明确肿瘤的局部特征和三维空间关系,为肿瘤外科治疗术前评估和计划提供客观的空间可视化信息。方法采集4例肢体肿瘤患者盆部和大腿上段CT、MRI和MRA影像数据,分别导入三维重建软件,基于CT和MRI对人体不同组织结构成像敏感度的差异,从各模态影像数据中分别提取肿瘤及其周围目标结构进行三维重建。依据体内解剖参照点对各个组织的三维结构进行配准融合,构建肢体肿瘤及瘤周解剖整体结构。结果通过CT、MRI和MRA影像数据构建出包括肿瘤及周围骨骼、肌肉、神经、血管、盆腔脏器等组织的三维整体结构,显示了肿瘤的大小、形状、部位等局部特征以及肿瘤与其周围结构的三维空间关系。结论以多模态影像数据通过三维重建和配准融合的方法可以构建肿瘤区域多种组织的三维整体结构,清楚而直观地显示肿瘤的局部特征以及与周围结构的空间解剖关系,具有个体化肿瘤术前评估和计划的应用价值。     

Thoracoscopy-assisted magnetic resonance guided microwave coagulation therapy for hepatic tumors

BACKGROUND: Microwave coagulation therapy (MCT) has become a safe and effective modality with which to treat hepatic tumors; MCT can be applied percutaneously, laparoscopically, thoracoscopically, and during laparotomy. When combined with magnetic resonance (MR) imaging, MCT can be used to treat hepatic tumors located in the subdiaphragmatic area that are difficult to approach by ultrasound, because of the overlaying lower lung field. METHODS: To determine the usefulness of thoracoscopy-assisted interventional MR-MCT (T-IVMR-MCT, n = 73), we compared patients with hepatic tumors that were treated with percutaneous IVMR-MCT (P-IVMR-MCT, n = 69) and with T-IVMR-MCT. RESULTS: None of patient background, complication and recurrence rate, or length of hospital stay significantly differed between the 2 groups. CONCLUSIONS: IVMR-MCT is a useful modality for treating hepatic tumors. Especially when tumors are located at the hepatic dome, T-IVMR-MCT was minimally invasive, while it appears to improve targeting of peridiagmatic hepatic lesions and has a complication profile similar to P-IVMR-MCT.     

体象障碍患者对美容手术的满意度调查

目的 观察体象障碍患者在整形手术中的一般情况及其对手术的满意程度.方法 采用自制问卷调查21名体象障碍组和对照组对手术的满意程度及体象障碍组对两次手术的满意程度.结果 体象障碍组和对照组在手术满意度上有显著差异,体象障碍组的第1次与第2次手术的满意度有显著差异.结论 体象障碍患者对手术的满意程度较低,反复的手术导致更低的满意程度.     

腰椎间盘MRI或T2相变化与冯氏临床分型（四步腰型）关系的研究

目的探讨腰椎间盘突出症患者MRI T2相信号、性别、年龄、病程、临床分型之间的关系,验证冯氏临床分型与腰椎间盘MRI T2相信号变化的相关性。方法本研究收集102例腰椎间盘突出症患者的临床资料,根据腰椎间盘MRI T2相信号分3型,根据临床分型分为A、B两组,对患者性别、年龄、病程、腰型、腰椎间盘T2相信号变化,用医学统计软件spss13.0进行秩和检验和非参数相关性检验。结果1、MRI T2相信号与性别、年龄不相关;2、MRI T2相信号变化与临床分型密切相关,结论椎间盘T2相信号变化与临床分型有很强的相关性,但要结合临床综合判断,我们要重新认识椎间盘T2相信号变化的临床意义。