肾良恶性占位超声造影定量参数分析的初步研究

目的 探讨肾良恶性占位超声造影定量参数特点及临床应用价值.方法 对60例经病理证实的肾占位行超声造影检查,用Sonoliver定量分析软件行脱机分析,获得最大峰值强度(maximum intcnsity,IMAX)、上升时间(rise time,RT)、达峰值时间(time to peak,TTP)、平均渡越时间(mean transit time,mTT)及曲线下面积(area under the curve,AUC)等参数,并进行统计学分析.结果 肾良恶性占位超声造影定量参数RT、mTT、AUC差异有统计学意义(P＜0.05),IMAX差异有显著统计学意义(P＜0.01),恶性肿瘤的RT及mTT均小于良性病灶,IMAX与AUC均大于良性病灶.结论 超声造影定量参数分析对肾占位性病变的诊断提供了更多的信息.     

小肾癌的MR表现

目的研究小肾癌(直径<3 cm)的MR表现.方法 19例手术病理证实的小肾癌患者,肿瘤直径均<3 cm,术前1个月内行MR检查,将手术病理结果与MR表现进行对照研究.结果 19例患者均被MR检出,14例边界清楚,5例部分边界不清.MR假包膜显示率为85.71%(12/14).平扫信号无特征性.6例MR增强扫描中,2例不均匀强化,其增强程度低于肾实质;2例未见明显强化;2例为囊性,增强后囊壁及分隔有强化.MR分期诊断准确率为78.94%(15/19).结论 MR可显示小肾癌的边界和信号特点,有助于小肾癌的检出和分期诊断.     

肾透明细胞癌的MRI分析

目的：分析、探讨肾透明细胞癌的MRI表现及特点。材料及方法：经手术病理证实的肾透明细胞癌212例（222灶）,男159例（168灶）,女53例（54灶）;年龄28~79岁（中位年龄55.6岁）。结合病理改变回顾性分析其MRI表现。结果：MRI平扫90.5%的病例信号不均匀,T1WI肿瘤以中低信号及低信号为主（73.4%）,T2WI及T2WI/SPIR肿瘤以混杂信号为主（70.3%）,部分呈高信号（23.4%）。增强扫描91.4%的肿瘤强化不均匀,以中、重度强化为主（88.6%）。病理上透明细胞癌质地不均匀,常见出血（27.5%）、坏死（47.3%）及囊性改变（24.3%）。出现假包膜、肾周组织（肾周脂肪囊及其以外的组织）侵犯、静脉瘤栓、淋巴结转移及远处转移的病例分别达68.5％、11.7％、8.6％、5.8％及3.2%。结论：肾透明细胞癌的MRI表现有一定特点,对肾细胞癌亚型的诊断与鉴别诊断较有价值。     

Quantitative analysis of cardiovascular MR images

The diagnosis of cardiovascular disease requires the precise assessment of both morphology and function. Nearly all aspects of cardiovascular function and flow can be quantified nowadays with fast magnetic resonance (MR) imaging techniques. Conventional and breath-hold cine MR imaging allow the precise and highly reproducible assessment of global and regional left ventricular function. During the same examination, velocity encoded cine (VEC) MR imaging provides measurements of blood flow in the heart and great vessels. Quantitative image analysis often still relies on manual tracing of contours in the images. Reliable automated or semi-automated image analysis software would be very helpful to overcome the limitations associated with the manual and tedious processing of the images. Recent progress in MR imaging of the coronary arteries and myocardial perfusion imaging with contrast media, along with the further development of faster imaging sequences, suggest that MR imaging could evolve into a single technique (‘one stop shop’) for the evaluation of many aspects of heart disease. As a result, it is very likely that the need for automated image segmentation and analysis software algorithms will further increase. In this paper the developments directed towards the automated image analysis and semi-automated contour detection for cardiovascular MR imaging are presented.     

肝纤维化磁共振扩散加权成像及与血液生化学的相关性分析

目的：评价MR扩散加权成像（DWI）对肝纤维化的诊断效能,探讨表观扩散系数（ADC）与肝纤维化血清学指标之间的相关性。方法：CCl4皮下注射建立大鼠肝纤维化模型（38只）和对照组（10只）进行MR常规和DWI扫描,按肝纤维化病理分期进行分组,b取333、666和1000s/mm2时,比较各组DWI图像的信号强度（SI）和ADC值的变化。检测肝纤维化大鼠血清HA、PC Ⅲ、C-Ⅳ和LN变化,与肝纤维化分期和ADC值进行相关性分析。结果：肝纤维化病理分级：S0（n=3）、S1（n=5）、S2（n=9）、S3（n=13）、S4（n=8）。b取333、666和1000s/mm2时,随肝纤维化程度加重,SI依次升高,ADC值依次降低,差异有显著统计学意义（P<0.01）。ADC值与肝纤维化分期之间有很好的相关性,以b=1000s/mm2时相关关系最密切。b=333和666s/mm2时,根据SI值和ADC值可以将S0~S2期与S4期进行区分,S0期与S3、S4期进行区分。b=1000s/mm2时,可将S0~S2期与S4期进行区分。血清HA、PC Ⅲ、C-Ⅳ和LN随肝纤维化分期进展依次升高,ADC值与肝纤维化血清学指标之间存在不同程度的负相关（P<0.05）。结论：DWI可检测S3、S4期肝纤维化,但对判定S0～S2期轻度纤维化有局限性。ADC值与肝纤维化血液生化学各指标间存在很好的相关性,共同反映肝纤维化细胞外基质（ECM）异常增生和沉积的特征性病理改变。     

MR imaging in the characterization of small renal masses

Objective

The aim of our study was to evaluate the effectiveness of MR imaging for the characterization of small (<2 cm) renal lesions described as indeterminate on prior US or CT

Materials and methods

Sixty-three small renal masses in 51 patients considered indeterminate on prior ultrasound or CT scans were included in the study. A retrospective evaluation of the examinations was performed independently by two body magnetic resonance imaging (MRI) radiologists who were unaware of the final diagnosis. A 3-point confidence scale (1: benign, 2: indeterminate, and 3: malignant) was established to determine the level of suspicion for malignancy. Interobserver agreement was determined with a weighted kappa statistic. The diagnosis was verified by imaging follow-up of at least 24 months (mean 60 months) in 53 lesions and by pathology in 10 lesions.

Results

MRI detected all eight malignancies in the series. There were eight malignant lesions and two benign lesions among those with pathologic follow-up. No interval growth or evidence of malignancy in the remaining 53 lesions was found for a minimum of 24 months by repeat imaging. The sensitivity, specificity, positive predictive value, and negative predictive value of MRI for differentiating benign from malignant small renal lesions were 100% (62.9–100%, 95% CI), 94.5% (84.9–98.8%, 95% CI), 72.7% (39.1–93.6%, 95% CI), and 100% (93.1–100%, 95% CI), respectively. The kappa value for interobserver agreement was 0.77 (95% CI 0.59–0.96, p-value <0.001).

Conclusion

MR imaging is an effective method for characterizing small (<2 cm) renal masses found to be indeterminate by US or CT.     

桥本甲状腺炎合并甲状腺良恶性肿瘤的超声与病理分析

目的 总结桥本甲状腺炎(HT)合并甲状腺结节样病变超声与病理学特征.方法 对89例超声显示HT合并甲状腺结节样病变患者的超声声像图表现与病理特征进行总结分析.结果 89例HT合并甲状腺结节术前超声诊断良性结节78例(87.6％,78/89),恶性结节11例(12.4％,11/89).其中78例良性结节最大径6.4 cm×4.6 cm,最小径0.4 cm×0.3 cm,超声表现:(1)甲状腺对称性弥漫性肿大,峡部肿大明显,腺体回声减低,可见细线状强回声交织呈网格状. (2) HT合并甲状腺结节形态多较规则(71.8％,56/78),边界清晰(73.1％,57/78),部分呈高回声(21.8％,17/78),多数结节(74.4％,58/78)内未见钙化,结节周围腺体分布不均匀(75.6％,59/78);少数结节(19.2％,15/78)内见环状或团状粗大钙化灶,结节周围腺体分布均匀(24.4％,19/78).(3)彩色多普勒血流成像示结节内血流信号较丰富(30.8％,24/78),部分结节(25.6％,20/78)边缘血流绕行.11例恶性结节最大径3.8 cm×2.6 cm,最小径0.5 cm×0.4 cm,超声表现:(1)甲状腺回声增粗不均或无明显改变.(2)恶性结节多呈不规则形(54.5％,6/11),边界不清(81.8％,9/11),低回声为主(90.9％,10/11),内部见粗大钙化(36.4％,4/11)或微小钙化(45.5％,5/11);多数结节(72.7％,8/11)周围腺体分布不均匀,少数结节(27.3％,3/11)周围腺体分布均匀.(3)彩色多普勒血流成像示结节边缘血流信号不丰富(9.1％,1/11),4例(36.4％,4/11)见粗大穿支血流信号.89例HT合并甲状腺结节术前超声与病理相关特征:(1)局灶性HT无合并结节22例,病理镜下示甲状腺内局灶性淋巴细胞浸润无明显纤维间隔形成;(2)HT合并结节性甲状腺肿49例,合并甲状腺腺瘤7例,合并甲状腺癌11例,病理镜下示结节周围淋巴细胞浸润,甲状腺滤泡重度萎缩,周边见粗大纤维间隔,与不均匀或网格样结构的声像图表现相吻合;病理镜下显示甲状腺滤泡轻度萎缩,结节周围未见粗大纤维分隔,与声像图表现的腺体回声均匀的图像表现相吻合.与手术病理诊断对照显示:术前超声诊断甲状腺良性结节及恶性结节与病理诊断符合率分别为91.0％ (71/78)及54.5％ (6/11).结论 HT合并甲状腺结节样病变因病理表现不同超声表现各异.腺体萎缩退化伴低回声结节内微小钙化或粗大钙化可能为HT合并甲状腺癌的特征性声像表现;腺体回声不均或出现网格状结构提示HT腺体严重萎缩,可能为HT合并甲状腺良性病变的特征性声像表现.     

肝脏炎性病灶超声造影定量分析

目的探讨超声造影定量分析对肝脏炎性病灶的诊断价值.方法对22例经手术或穿刺活检病理证实为肝脏炎性病灶的患者共22个病灶进行常规超声及超声造影检查.其中16个病灶为肝脏炎性假瘤,6个为肝脓肿.采用5级评分法对常规超声及超声造影诊断结果进行评分.利用Sonoliver软件进行数据分析,获得肝脏炎性病灶与病灶周围肝实质超声造影上升时间(RT)、达峰值时间(TTP)、平均渡越时间(mTT)、峰值强度(Imax)等参数以及动态血管模型(DVP)参数图并进行比较.结果以评分为1~2分定为诊断准确,本组22个肝脏炎性病灶常规超声检查诊断准确率为13.6%(3/22),超声造影诊断准确率为63.6%(14/22),超声造影诊断准确率高于常规超声检查,且差异有统计学意义(χ2=11.6,P<0.01).22个肝脏炎性病灶RT为(25.1±9.7)s,TTP为(29.0±13.9)s,均早于病灶周围肝实质的(32.4±8.8) s、(39.3±11.2) s,且差异均有统计学意义(t值均为-2.6, P均<0.05);22个肝脏炎性病灶mTT及Imax与病灶周围肝实质比较差异无统计学意义.16个肝脏炎性假瘤病灶与6个肝脓肿病灶RT、TTP、mTT、Imax差异均无统计学意义.22个肝脏炎性病灶DVP曲线Ⅰ型高增强未消退型占18.2%(4/22),Ⅱ型高增强消退型占36.4%(8/22),Ⅲ型低增强型占45.4%(10/22).16个肝脏炎性假瘤病灶与6个肝脓肿病灶仅动脉期强化方式及实质期坏死区形态差异有统计学意义(χ2值分别为9.9、8.32,P均<0.05),而动脉期峰值时增强形态、峰值时病灶边界差异以及实质期廓清速度、病灶边界差异无统计学意义.结论超声造影可提高肝脏炎性病灶的诊断准确率,超声造影定量分析可更客观地显示肝脏炎性病灶与肝脏的血流灌注特征,具有较好的临床应用价值.     

胃神经鞘瘤的CT表现与病理对照研究

目的：探讨胃神经鞘瘤的CT表现及病理学特点。方法：回顾性分析10例经手术和病理证实的胃神经鞘瘤CT资料,并与病理所见相对照。结果：肿瘤均为单发病灶,6例发生于胃体部,2例发生于胃窦,2例发生于胃底,肿块大小不一,但以<3 cm为主,其内密度均匀,呈等或稍低密度,1例密度略不均匀,均未见明确囊变、坏死区,2例可见溃疡面形成,增强扫描静脉期呈中度强化,4例行延迟期扫描,强化程度未见下降。结论：胃神经鞘瘤的CT表现具有一定的特点,CT检查有助于胃神经鞘瘤的定位、定性以及观察肿瘤与周围组织结构的关系,但具体诊断仍需结合病理表现。     

甲状腺结节的MR扩散加权成像与病理对照

目的 探讨甲状腺结节MR DWI表现,评价DWI鉴别甲状腺良、恶性结节的价值.方法 对111例甲状腺单发结节性病变进行MR DWI检查.其中,恶性结节23例,良性结节88例.观察和比较不同良、恶性结节的ADC值差异,确定最佳b值和ADC阈值,并与病理结果相对照.结果 随着b值增大,ADC值均降低.不同b值时甲状腺恶性结节的ADC值均低于良性结节(P均＜().05).甲状腺癌的ADC值明显低于腺瘤和结节性甲状腺肿(P＜0.01),而与甲状腺炎差异无统计学意义(P＞0.05).b=500 s/mm2时,选取ADC值1.70×10-3mm2/s为阈值,诊断甲状腺恶性结节的敏感度、特异度和准确率分别为92.32％、87.51％和86.93％.良、恶性结节的ADC值差异与其病理表现有关.结论 DWIADC值对鉴别甲状腺良、恶性结节有较高价值.     

磁共振小视野表面线圈在距骨软骨损伤成像中的应用

目的 比较靴形线圈的质子密度加权成像（2D-FSE-PD）、三维可变翻转角快速自旋回波序列（3D-SPACE）成像和小FOV表面线圈2D-FSE-PD序列成像对距骨软骨损伤成像的准确率。方法 对 43例患者（45个踝关节）采用靴形线圈行2D-FSE-PD和3D-SPACE序列扫描,然后更换为小FOV表面线圈行2D-FSE-PD成像。以关节镜检查结果为金标准,比较3种扫描方法显示距骨软骨损伤的符合率。结果 小FOV表面线圈2D-FSE-PD序列的符合率为86.67%（39/45）,靴形线圈2D-FSE-PD序列的符合率为60.00%（27/45）,靴形线圈3D-SPACE序列的符合率为68.89%（31/45）。小FOV表面线圈2D-FSE-PD序列的符合率高于靴形线圈3D-SPACE序列（χ²=4.114,P=0.002）和2D-FSE-PD序列（χ²=8.182,P<0.001）,而靴形线圈3D-SPACE序列的符合率与2D-FSE-PD序列的差异无统计学意义（χ²=0.776,P=0.125）。结论 与靴形线圈的2D-FSE-PD与3D-SPACE序列相比,小FOV表面线圈2D-FSE-PD成像能更好地显示距骨软骨损伤。     

胰腺导管内乳头状黏液癌：动态增强CT、MR表现及其病理基础

目的：探讨胰腺导管内乳头状黏液性癌（IPMC）的MSCT、MR表现及诊断价值。材料和方法：经手术病理证实的IPMC 9例,术前均经多排螺旋CT平扫和增强扫描,5例行MR平扫和增强扫描,复习扫描结果并和手术病理作回顾性对照分析。结果：9例患者中主胰管型5例,表现为主胰管明显扩张,多数见管壁结节,CT呈稍高密度,MRI为稍长T1长T2信号,不均匀,胰管内呈长T1长T2信号;分支胰管型3例,表现为分叶状单发囊性或多发囊性病变,腔内见分隔及结节样突起或肿块,CT呈稍高密度,MRI为稍长T1长T2信号,2例CT MPR图像及MRCP显示病灶与主胰管相通;混合型1例,表现为囊状病灶,内有附壁结节,合并主胰管扩张,囊内为长T1长T2信号。6例病灶主胰管不同程度扩张（4～45mm）,6例胰腺不同程度萎缩,3例显示十二指肠乳头膨大,2例见不规则点状钙化。增强扫描分隔强化较明显,附壁结节强化稍弱且不均匀。结论：MSCT薄层扫描及MRI对IPMC诊断价值较大,结合MPR、CPR、MRCP能够显示胰腺IPMC的病理特征,有利于显示较小结节及胰管改变,结合其临床特征,多数病例可与胰腺导管内良性乳头状黏液性肿瘤鉴别。     

MR电影对正常小肠运动功能定量评估的应用价值

目的探讨MR电影技术定量评估正常小肠运动功能的可行性。材料与方法运用美国GE公司MR Discovery 750HD 3.0 T扫描仪,采用32通道Body线圈,对2012年10月至2014年3月间44名肠道志愿者进行MR口服造影扫描,在不憋气状态下进行时间为2 min的MR电影序列扫描。将采集的电影图像传送至ADW 4.5工作站,并对每帧图像中左上腹及右下腹两段肠管的肠腔管径进行测量。通过绘制时间-肠腔管径曲线进一步对每段肠管的最大肠腔管径,收缩频率、收缩周期以及间歇期进行测定。结果所有志愿者均完成了检查。一共对86段充盈良好的小肠肠管进行了定量分析。所有肠段均存在间歇期。左上腹及右下腹两段肠管间的最大肠腔管径、收缩频率、收缩周期和间歇期分别为（17.66±2.27）mm、（8.64±0.69）s、（3.03±0.61）min、（54.19±15.10）s和（17.42±1.87）mm、（8.75±0.77）s、（3.86±0.54）min、（47.47±15.82）s。两段肠管间的收缩频率以及间歇期存在统计学差异（P〈0.01）。结论 MR电影能够对正常小肠的蠕动功能状况进行定量评估。理论上在了解正常小肠运动特征的基础上,可以运用MR电影这项无创的检查方法对器质性以及功能性小肠疾病患者异常的小肠运动状况进行进一步的研究。     

腹膜假性黏液瘤的超声表现与手术病理对照分析

目的 通过比较腹膜假性黏液瘤(PMP)超声表现与手术探查所见,探讨超声在检查PMP中的诊断价值.方法 对22例手术和/或超声引导下穿刺活检病理证实为PMP患者的声像图表现和外科手术病理结果 进行回顾性分析及比较.结果 22 例中术前超声检查提示PMP 21例,漏诊1例,诊断准确率95.5%.超声分型表现:以腹水表现为主8例,以腹膜增厚表现为主伴腹水14例(7例以蜂窝状增厚为主,7例以肿块型增厚为主).14例以腹膜增厚表现为主的PMP,彩色多普勒血流成像显示稀疏血流信号7例,另7例未见血流信号.17例进行了手术治疗,术中见大网膜呈板状增厚6例,其中4例术前超声显示网膜普遍增厚;手术中见大网膜呈结节状5例,术前超声所见2例;手术见果冻样腹水11例,而术前超声检查15例呈黏液样腹水;术中发现病变原发于阑尾或回盲部6例,而术前超声诊断仅发现1例.结论 超声检查对PMP有较高诊断准确率,应作为首选影像诊断手段;PMP的超声表现为黏液样腹水和大网膜普遍或结节状增厚,具有较高特异性,而对原发病灶显示率较差.     

肾脏占位性病变38例误诊原因分析

目的：探讨不典型肾脏占位性病变的误诊原因，以降低其误诊率。方法：总结分析38例不典型肾脏占位性病变误诊病例的影像学资料。结果与结论：38例的影像学表现均不典型，经手术及病理活组织检查（活检）证实肾癌误诊为肾错构瘤7例；肾脏良性占位性病变为误诊为肾癌31例，其中肾错构瘤合并出血14例，局灶型黄色肉芽肿性肾盂肾炎8例，多房性囊性肾瘤4例，肾平滑肌瘤2例，肾脓肿2例，肾纤维脂肪瘤1例。误诊原因与肾脏占位性病变的影像学表现不典型、临床医师对有关疾病的认识不足、询问病史不仔细、术前未做穿刺活组织检查（活检）等有关。提示临床医师应加深对不典型肾脏占位性病变的认识。对于不典型肾脏占位性病变，术前进行穿刺活检或术中冰冻切片送病理检查可避免误治。     

Multi-task recurrent convolutional network with correlation loss for surgical video analysis

Surgical tool presence detection and surgical phase recognition are two fundamental yet challenging tasks in surgical video analysis as well as very essential components in various applications in modern operating rooms. While these two analysis tasks are highly correlated in clinical practice as the surgical process is typically well-defined, most previous methods tackled them separately, without making full use of their relatedness. In this paper, we present a novel method by developing a multi-task recurrent convolutional network with correlation loss (MTRCNet-CL) to exploit their relatedness to simultaneously boost the performance of both tasks. Specifically, our proposed MTRCNet-CL model has an end-to-end architecture with two branches, which share earlier feature encoders to extract general visual features while holding respective higher layers targeting for specific tasks. Given that temporal information is crucial for phase recognition, long-short term memory (LSTM) is explored to model the sequential dependencies in the phase recognition branch. More importantly, a novel and effective correlation loss is designed to model the relatedness between tool presence and phase identification of each video frame, by minimizing the divergence of predictions from the two branches. Mutually leveraging both low-level feature sharing and high-level prediction correlating, our MTRCNet-CL method can encourage the interactions between the two tasks to a large extent, and hence can bring about benefits to each other. Extensive experiments on a large surgical video dataset (Cholec80) demonstrate outstanding performance of our proposed method, consistently exceeding the state-of-the-art methods by a large margin, e.g., 89.1% v.s. 81.0% for the mAP in tool presence detection and 87.4% v.s. 84.5% for F1 score in phase recognition.     

肝脏原发性神经内分泌肿瘤的MRI表现及其病理学基础分析

目的探讨不同级别的原发肝脏神经内分泌肿瘤(primary hepatic neuroendocrine tumors,PHNETs)MRI表现及其相应的病理学基础。材料与方法回顾性分析6例PHNETs的MRI及病理学资料,分析不同级别PHNETs的MRI表现及相关病理学基础。结果 G1级1例,MRI表现为单发结节,T1WI呈稍低信号、T2WI呈稍高信号,信号均匀,动脉期明显均匀强化,门脉期及延迟期强化程度有所减低,其病理表现为瘤细胞呈小梁状排列,周围血窦丰富。G2级3例,其中1例为多发,T1WI表现为不均匀稍低信号、T2WI表现为不均匀稍高信号,所有病灶内均可见类圆形T2WI高信号,3个病灶内可见出血信号,动脉期不均匀明显强化,门脉期及延迟期强化程度减低,但持续强化,且部分病灶强化范围有扩大趋势;镜下瘤细胞呈缎带样排列,瘤周血窦丰富,且周围伴随纤维化,3个病灶窦腔内见出血。G3级2例,均多发,MRI表现为T1WI、T2WI不均匀信号,肿块体积较大,动脉期不均匀轻度强化,门脉及延迟期呈持续强化,程度减低;肿瘤细胞呈片状浸润性生长,核大、异型性明显、间质血管相对丰富,肿瘤内见多灶性坏死。结论 MRI表现可反映不同级别PHNETs的病理学特征,有助于提高PHNETs术前诊断的准确度。     

Colon lesions: pathology specific to women

Lymphocytic colitis and collagenous colitis represent two conditions that fall under the category of microscopic abnormalities within the lamina propria of the colon. Patients are predominantly women in the sixth decade of life who present with non-bloody watery diarrhea. Few other symptoms exist. Diagnosis is based upon finding characteristic abnormalities in the colonic mucosa, more likely to be found on the right side of the colon than the left. Treatment is symptomatic, although some newer therapies suggest regression of the lesion. Other autoimmune associations have been described, including celiac disease, and appropriate work-up for this condition should be considered for the patient who has seemingly refractory colitis. The natural history is benign, and most patients experience resolution of their symptoms.