表观弥散系数值的离散系数在胰腺癌及肿块型胰腺炎鉴别诊断中的应用

目的：探讨表观弥散系数（ADC）值的离散系数对于胰腺癌及肿块型胰腺炎鉴别诊断的应用价值.方法：收集胰腺癌患者28例,肿块型胰腺炎患者7例,行磁共振弥散加权成像（DWI）检查,分别测量每一病灶ADC值的均值（x）及标准差（s）,并计算每一个病灶ADC值的离散系数（CV,CV=s/x）.采用Student＇st检验对两组患者病灶ADC值均值及CV进行比较.结果：胰腺癌组ADC值均值为1.46±0.29,肿块型胰腺炎组ADC值均值为1.58±0.28,经Student＇s t检验显示两组间无显著差异（t=1.02,P=0.32）;胰腺癌组ADC值CV为0.16±0.06,肿块型胰腺炎组CV为0.10 ±0.04,两组CV之间具有显著差异（t=2.44,P=0.02）.结论：胰腺DWI检查中,ADC值CV较ADC值均值对于胰腺癌与肿块型胰腺炎的鉴别诊断具有更高价值.     

磁共振成像对胰腺癌与肿块型胰腺炎的诊断中的应用

目的探讨磁共振成像(MRI)对胰腺癌、肿块型胰腺炎的诊断价值。方法回顾性分析经病理证实的胰腺癌32例、肿块型胰腺炎30例患者、胰腺正常受检者30例的MRI资料,所有受检者均行常规MRI系列、DWI扫描及动态增强扫描,比较三组患者MRI影像学表现、DWI值及时间信号强度曲线(TIC)。结果 1胰腺癌T1WI病灶多呈低信号,部分病灶为等信号或混杂信号,T2WI多呈稍高信号;肿块型胰腺炎T1WI上多呈等、低信号,T2WI多呈不均匀稍高信号或等信号;2DWI序列胰腺癌组28例呈高信号,肿块型胰腺炎均呈稍高信号;胰腺癌ADC值显著高于肿块型胰腺炎,低于正常胰腺,差异有统计学意义(P0.05),肿块型胰腺炎ADC值显著低于正常胰腺,差异有统计学意义(P0.05);3胰腺癌组TIC曲线以缓升平台型为主,占84.36%,肿块型胰腺炎以缓升缓降型为主,占73.33%,正常胰腺组以速升速降型为主,占100%,三组TIC曲线比较差异有统计学意义(P0.05)。结论 MRI DWI序列及动态增强扫描对胰腺癌与肿块型胰腺炎的鉴别诊断具有显著价值。     

2种弥散加权成像对胰腺癌和肿块型胰腺炎的鉴别

目的:分析比较呼吸门控脂肪抑制弥散加权成像(diffusion weighted imaging,DWI)与憋气DWI在胰腺癌和肿块型胰腺炎中的鉴别诊断价值。方法:回顾分析经手术病理确诊的30例胰腺癌与17例肿块型胰腺炎患者术前行3.0T磁共振DWI检查的资料。DWI基于自旋回波-回波平面成像(SE-EPI)序列,包括憋气DWI和呼吸门控脂肪抑制DWI序列,b值为600 s/mm2。分析比较胰腺癌及肿块型胰腺炎的表观弥散系数(apparent diffusion coefficient,ADC)。采用受试者工作特征(receiver operating characteristic,ROC)曲线分析比较2种DWI序列鉴别诊断胰腺癌及肿块型胰腺炎的效能。结果:在憋气DWI序列上,胰腺癌与肿块型胰腺炎ADC值差异无统计学意义(P0.05);在呼吸门控脂肪抑制DWI序列上,胰腺癌与肿块型胰腺炎的ADC值差异有统计学意义(P0.01)。在呼吸门控脂肪抑制DWI序列中,以ADC≥1.33×10-3 mm2/s为诊断阀值从肿块型胰腺炎中鉴别诊断胰腺癌,灵敏度和特异度分别为86.7%和88.9%,阳性预测值和阴性预测值分别为96.3%和66.7%。在憋气DWI序列中,以ADC值≥1.45×10-3 mm2/s为诊断阀值从肿块型胰腺炎中鉴别诊断胰腺癌,灵敏度和特异度分别为73.3%和88.9%,阳性预测值和阴性预测值分别为95.7%和50.0%。结论:与憋气DWI比较,呼吸门控脂肪抑制DWI序列对胰腺癌和肿块型胰腺炎的鉴别诊断价值更高。     

3.0T磁共振自由呼吸背景抑制弥散加权成像对胰腺肿块的诊断价值

目的:评价3.0T磁共振自由呼吸背景抑制弥散加权成像在胰腺肿块性病变中的鉴别诊断价值。方法:采用3.0T磁共振对58例胰腺肿块患者(胰腺癌患者30例、肿块型胰腺炎患者9例、实性假乳头状瘤患者9例及神经内分泌肿瘤患者10例)以及15例健康志愿者(对照组)行常规T1WI、频率饱和脂肪抑制T2WI、MRCP、DWI及三维LAVA平扫,并对所有患者进行增强扫描,自由呼吸背景抑制DWI基于SE-EPI序列及b值分别为0s/mm2和600s/mm2。比较不同组织的表观弥散系数(apparent diffusion coefficient,ADC)值,应用受试者工作特征(receiver operating characteristic,ROC)曲线分析其诊断效能。结果:组织的ADC值由高到低依次为正常胰腺、神经内分泌肿瘤、胰腺癌、肿块型胰腺炎和实性假乳头状瘤。单因素方差分析显示,不同组织的ADC值的差异有统计学意义(F=22.573,P<0.001);LSD两两检验显示,肿块型胰腺炎、胰腺癌及正常胰腺的ADC值之间差异有统计学意义(P均<0.001)。以ADC≥0.00133mm2/s为标准,从肿块型胰腺炎中鉴别诊断胰腺癌,灵敏度和特异度分别为86.7%和88.9%,阳性预测值96.3%,阴性预测值66.7%;以ADC≤0.00125mm2/s为标准,从神经内分泌肿瘤中鉴别实性假乳头状瘤,灵敏度和特异度分别为77.8%和100%,阳性预测值100%,阴性预测值83.3%。结论:行3.0T磁共振,自由呼吸背景抑制DWI序列的ADC值能够较好地反映正常胰腺及胰腺肿块的组织病理生理特征,有助于胰腺肿块的诊断与鉴别诊断。     

不同b值磁共振扩散加权成像鉴别诊断胰腺癌与慢性肿块型胰腺炎

目的 分析不同b值下胰腺癌、慢性肿块型胰腺炎与正常胰腺组织ADC值及其差值(DADC值)变化情况,探讨用于鉴别胰腺癌、慢性肿块型胰腺炎的最适b值.方法 对15例胰腺癌(Ⅰ组)、4例慢性肿块型胰腺炎患者(Ⅱ组)及15名胰腺正常的志愿者(Ⅲ组)行磁共振扩散加权成像(DWI),b值分别为333、667、1000 s/mm2.测量各b值下癌区、慢性炎症区和正常胰腺区的ADC值,并对不同b值时三种组织ADC值及不同组织间DADC值的变化进行分析.结果 相同b值时胰腺癌区ADC值低于慢性炎症肿块区和正常胰头区.不同b值时各组内ADC值差异均有统计学意义(P<0.05),随b值增大,三组的ADC值均有下降,其中胰腺癌区平均下降率最低(15.66%和5.19%).b=333和667 s/mm2时,胰腺癌区与慢性炎症肿块区、胰腺癌区与正常胰头区的ADC值差异均有统计学意义(P<0.05).不同b值时,胰腺癌区与慢性炎症肿块区、胰腺癌区与正常胰头区两配对组组内的DADC值差异均有统计学意义(P<0.05),且b=333 s/mm2时各配对组组内的DADC值最大.结论 在一定范围内小b值有助于胰腺癌与慢性肿块型胰腺炎的鉴别诊断.     

MRI DWI在急性水肿型胰腺炎诊断中的价值

目的探讨弥散加权成像(diffusion-weighted imaging,DWI)在急性水肿型胰腺炎诊断中的价值。方法采用Philips公司生产的Intra Achieva 1.5T磁共振成像系统获得MRI图像和b0=0s/mm2,b1=800s/mm2的DWI图像,测量21例急性水肿型胰腺炎及21例正常胰腺的大小径线,T1W、T2W胰头、胰体的信号强度,计算胰腺的表面弥散系数(apparent diffusion coefficient,ADC)值。采用SPSS 11.5软件进行统计学处理。结果 21例中T1W 16例低信号,5例等信号,T2W 12例为高信号,9例等信号,DWI均表现为高信号,6例胰腺周围见少量渗出和液体信号,均无明显坏死改变。与对照组比较,胰腺炎组DWI信号明显增高,ADC值低于对照组(P0.01),肝脏及脾脏的ADC值二组无明显差异(P0.05)。胰腺炎组胰头及胰体的径线大于对照组,胰体增大更显著(P0.01)。结论胰腺DWI上信号增高对于诊断急性水肿型胰腺炎有一定价值,ADC值的减低是急性水肿型胰腺炎的量化指标。     

胰腺癌磁共振弥散成像中b值的选择

目的：探讨胰腺癌磁共振弥散加权成像（DWI）中b值的最佳选择范围。方法：对73例检查者（胰腺癌41例,正常胰腺32例）进行MRI平扫及不同b值组合[（0,50）、（0,400）、（0,700）、（0,1000）s/mm2]的DWI扫描,对胰腺癌的表观弥散系数（Apparent diffusion coefficient,ADC）图进行评分,并分别测量胰腺癌肿、癌周胰腺及正常胰腺组织ADC值。结果：b值组合为（0,400）s/mm2时病变图像质量评分最高。不同b值组合,胰腺癌的ADC值与正常胰腺及癌周胰腺组织间具有统计学差异。结论：b值组合为（0,400）s/mm2时ADC图中病变显示清楚、伪影较少,有利于胰腺癌的诊断。     

磁共振扩散加权成像对胰腺癌的诊断价值

目的：探讨磁共振扩散加权成像（DWI）对胰腺癌的诊断价值。方法：收集31例胰腺癌（15例合并肝脏转移瘤、21例合并淋巴结转移）、25例正常对照组行磁共振常规扫描和DWI（b值取0、600 s/mm2）,分析比较胰腺癌病灶、剩余胰腺实质区与对照组胰腺DWI信号特点,并测定各组表观扩散系数（ADC）。定量分析比较各组间ADC值有无统计学差异。结果：31例胰腺癌中,27例呈高信号,15例合并肝脏转移瘤及21例合并淋巴结转移均呈高信号,胰腺癌组、剩余胰腺实质区、对照组ADC值分别为（1.57±0.26）×10-3 mm2/s、（1.93±0.49）×10-3 mm2/s、（1.77±0.19）×10-3 mm2/s,胰腺癌组ADC值低于剩余胰腺实质区（t=3.61,P＜0.001）、低于对照组（t=3.21,P＜0.01）,剩余胰腺实质区与对照组比较无统计学差异（t=1.54,P＞0.05）。结论：DWI可清晰显示胰腺癌病灶及肝脏转移、淋巴结转移灶,对胰腺癌诊断及分期具有重要价值。     

胰腺癌与胰腺炎性肿块的MRI影像特征分析

目的 分析胰腺癌与胰腺炎性肿块的磁共振成像(MRI)影像特征。方法 回顾分析2018年1月至2022年6月我院收治的45例检出胰腺炎性肿块、胰腺癌患者资料,所有患者均接受MRI平扫、弥散加权成像(DWI)、动态增强扫描,所有胰腺癌患者最终经病理学检查证实,将MRI检查结果与病理学结果做一致性分析,探究其对胰腺癌和胰腺炎性肿块的鉴别诊断效能;比较各类胰腺炎与胰腺癌患者的表观扩散系数(ADC)值及MRI影像特征,对差异有意义的单因素进行logistic分析。结果 MRI鉴别诊断胰腺癌与胰腺炎性肿块的敏感度为93.33%、特异度为95.56%、准确率为95.00%;胰腺癌MRI平扫T_(1)WⅠ多数呈低信号,T_(2)WⅠ呈高信号,部分混杂信号,增强扫描肿块呈延迟强化,多数呈均匀强化;肿块型胰腺炎MRI平扫T_(1)WⅠ多数呈等信号、低信号,T_(2)WⅠ呈等信号,部分混杂信号,增强扫描动脉期呈相对低密度,后期明显延迟强化,肿块强化程度高于周围正常组织;自身免疫性胰腺炎MRI平扫T_(1)WⅠ多数呈低信号,T_(2)WⅠ呈高信号,增强扫描呈均匀延迟强化;胰腺癌、胰腺炎性肿块的ADC值、T_(1)WⅠ、T_(2)WⅠ、门静脉期强化比较,差异均有统计学意义(P<0.05);多因素logistic分析显示:ADC值、T_(1)WⅠ信号是胰腺肿块诊断为胰腺癌的独立保护因素,T_(2)WⅠ信号、门静脉期强化为独立危险因素(P<0.05)。结论 MRI具有较好的胰腺癌与胰腺炎性肿块鉴别诊断效能。     

磁共振DWI在高血压脑病及急性期脑梗死中的鉴别诊断价值

目的探讨3.0T磁共振（Magnetic Resonance Imaging,MRI）弥散加权成像DWI（Diffusion Weighted Imaging）对高血压脑病（Hypertensive Encephalopathy）及急性期脑梗死的鉴别诊断价值。方法回顾性分析高血压脑病（HE）及急性期脑梗死各15例患者的常规MRI平扫及DWI图像,分别测量HE患者病灶区和急性期脑梗死患者病灶区的ADC值及ADC值变化范围,并进行统计学分析。结果 （1）15例HE和15例急性脑梗死患者的MRI平扫图像均可见长T1长T2信号,其中15例HE病灶区DWI呈低或等信号,少部分不典型呈高信号,ADC呈高信号;15例急性期脑梗死病灶区DWI全部为高信号,ADC呈低信号。（2）HE病灶的ADC值为（1.418±0.17）×10^-3 mm^2/s,明显高于急性期脑梗死病灶的ADC值（0.448±0.11）×10^-3 mm^2/s,差异具有统计学意义（P〈0.05）。结论常规MRI扫描无法区分高血压脑病及急性期脑梗死,而磁共振弥散加权成像作为一种简便易行的诊断方法,其DWI图像及ADC值测量在两者的鉴别诊断中有一定临床价值。     

MR诊断慢性胰腺炎的研究进展

慢性胰腺炎是一种进展性的胰腺慢性炎症疾病,最终会导致胰腺形态和功能的不可逆损害。因此早诊断、早治疗十分重要。此外,肿块型慢性胰腺炎与胰腺癌的鉴别也是临床工作中的难题。MR作为一种无创、无辐射的检查手段,具有较高的软组织分辨率,是诊断慢性胰腺炎的重要影像学依据,且功能MRI辅助常规MRI有助于慢性胰腺炎与胰腺癌的鉴别诊断。本文就功能MRI技术在慢性胰腺炎诊断及鉴别方面的应用现状和研究进展进行综述。     

Diffusion-weighed MR imaging of pancreatic carcinoma

Purpose The aim of this study was to demonstrate the feasibility of body diffusion-weighted (DW) MR imaging in the evaluation of a pancreatic carcinoma. Material and methods In nine normal volunteers and in eight patients with pancreatic carcinoma, DW images were obtained on the axial plane scanning with a multisection spin-echo-type single-shot echo planar sequence with a body coil. Moreover, we measured the apparent diffusion coefficient (ADC) value in a circular region of interest (ROI) within the normal pancreas, pancreatic carcinoma, and tumor-associated chronic pancreatitis. Results On the DW images, all eight carcinomas were clearly shown as high signal intensity relative to the surrounding tissue. The ADC value (×10⁻³ mm²/s) in the carcinoma was 1.44 ± 0.20, which was significantly lower compared to that of normal pancreas (1.90 ± 0.06) and tumor-associated chronic pancreatitis (2.31 ± 0.18). Conclusion Diffusion-weighted (DW) images can be helpful in detecting the pancreatic carcinoma and accessing the extent of the tumor.     

联合应用CT、MRI增强扫描鉴别诊断胰腺癌与慢性胰腺炎

目的探讨联合应用MSCT和MRI增强扫描在胰腺癌与慢性胰腺炎鉴别诊断价值。方法选择经手术病理证实或临床随访证实的胰腺癌及慢性胰腺炎患者56例。所有患者在手术或随访前均同时行MSCT及MRI增强扫描。由高年资医生观察胰腺MSCT及MRI影像,对其影像学特征进行分析。总结胰腺癌及慢性胰腺炎的影像学特征,统计其在胰腺癌组与慢性胰腺炎组的统计学差异;统计MSCT、MRI及二者组合在胰腺癌和慢性胰腺炎的鉴别诊断上的统计学差异。结果胰腺体积增大、胰腺周围组织及大血管的侵犯、胰腺周围淋巴结肿大、动脉期强化不明显、胰胆管不规则扩张等多见于胰腺癌;病变内及病变周围囊肿、病变钙化、胰胆管平滑状扩张多见于慢性胰腺炎。以上征象在胰腺癌组与慢性胰腺炎组间均存在明显统计学差异（P〈0．05）。应用各种MSCT和MRI影像学方法综合鉴别诊断胰腺癌和慢性胰腺炎,其诊断准确度均优于任何以上单一影像学技术（P〈0．05）;而MSCT增强扫描和MRI增强扫描在胰腺癌和慢性胰腺炎的鉴别诊断上,诊断准确度未见明显差异（P〉0．05）。结论MSCT和MRI增强扫描联合应用在胰腺癌与慢性胰腺炎的鉴别诊断上,具有突出的临床应用价值。     

Tumor-associated focal chronic pancreatitis from invasion of the pancreatic duct by common bile duct carcinoma: radiologic–pathologic correlation

We report a case of tumor-associated focal chronic pancreatitis of the uncinate process of the pancreas. The chronic pancreatitis was secondary to stenosis of the main pancreatic duct from invasion by a common bile duct carcinoma. A feature distinguishing the chronic pancreatitis from pancreatic carcinoma was the localized dilatation of pancreatic duct branches evident in the focal lesion of the uncinate process.     

Tumor-associated focal chronic pancreatitis from invasion of the pancreatic duct by common bile duct carcinoma: radiologic-pathologic correlation

We report a case of tumor-associated focal chronic pancreatitis of the uncinate process of the pancreas. The chronic pancreatitis was secondary to stenosis of the main pancreatic duct from invasion by a common bile duct carcinoma. A feature distinguishing the chronic pancreatitis from pancreatic carcinoma was the localized dilatation of pancreatic duct branches evident in the focal lesion of the uncinate process.     

多种MRI技术联合应用鉴别诊断胰腺癌与慢性胰腺炎

目的　评价联合应用多种MRI技术在鉴别诊断胰腺癌和慢性胰腺炎中的价值。方法　回顾分析 47例胰腺癌与 2 8例慢性胰腺炎的MRI表现。MRI技术包括 :平扫FSFLASHT1WI和TSET2 WI、MR胆胰管成像 (MRCP)及多时相动态增强扫描。测量肿块与正常胰腺信号值 ,计算对比噪声比 (CNR)。结果　平扫FSFLASHT1WI和TSET2 WI对胰头癌的敏感率为 5 9.4% ,对胰体癌为 86.7% ,对慢性胰腺炎为 78.6%。MRCP对胰头癌的敏感率为 90 .6% ,对胰体癌为 6.67% ,对慢性胰腺炎为 82 .1%。多时相动态增强扫描对胰头癌的敏感率为 78.1% ,对胰体癌为 93 .3 % ,对慢性胰腺炎为85 .7%。联合应用多种MRI技术对胰头癌的敏感率为 96.9% ,对胰体癌为 93 .3 % ,对慢性胰腺炎为 92 .9% (P <0 .0 1)。结论　多种MRI技术联合运用 ,是一项对胰腺癌和慢性胰腺炎进行鉴别诊断的准确有效的方法     

Non-invasive detection of infection in acute pancreatic and acute necrotic collections with diffusion-weighted magnetic resonance imaging: preliminary findings

Purpose

The purpose of this study was to evaluate the contribution of diffusion-weighted magnetic resonance imaging (DW-MRI) to the detection of infection in acute pancreatitis-related collections.

Methods

A total of 21 DW-MRI, and computed tomography (CT) were performed on 20 patients diagnosed as acute pancreatitis with acute peri-pancreatic fluid or necrotic collections. Collections were classified as infected or sterile according to the culture and follow-up results. Collections with gas bubbles on CT images were considered to be infected. Collections with peripheral bright signals on DW-MRI images were considered to be positive, whereas those without signals were considered to be negative. Apparent diffusion coefficient (ADC) values of the peripheral and central parts of the collections were measured. Student’s t test was used to compare the means of ADC values of independent groups.

Results

Apart from one false positive result, the presence of infection was detected by DW-MRI with 95.2% accuracy. The sensitivity and accuracy of DW-MRI were higher than CT for the detection of infection. The ADC values in the central parts of the collections were significantly different between the infected and sterile groups.

Conclusion

DW-MRI can be used as a non-invasive technique for the detection of infection in acute pancreatitis-associated collections.     

Current options for the diagnosis of chronic pancreatitis

The diagnostic options for chronic pancreatitis have evolved over recent years. The previous gold standard references for structural imaging and exocrine pancreatic function testing have both been supplanted and redesigned. Endoscopic retrograde pancreatography has now been overtaken by endoscopic ultrasound and magnetic resonance cholangiopancreatography, whilst the old technique for Dreiling tube pancreatic function testing has now been replaced by the endoscopic pancreatic function test. New advances in endoscopic ultrasound elastography have also extended the options for evaluating pancreatic masses to differentiate mass-forming chronic pancreatitis from malignancy. Genetic contribution to chronic pancreatitis is also now more widely recognized than ever before.