Gd-EOB-DTPA-enhanced magnetic resonance imaging for bile duct intraductal papillary mucinous neoplasms

AIM: To investigate gadolinium-ethoxybenzyldiethylenetriamine-pentaacetic acid(Gd-EOB-DTPA)-enhanced magnetic resonance imaging(MRI) of intraductal papillary mucinous neoplasms of the bile duct(IPMN-B). METHODS: The imaging findings of five cases of IPMN-B which were pathologically confirmed at our hospital between March 2012 and May 2013 were retrospectively analyzed. Three of these cases were diagnosed by duodenal endoscopy and biopsy pathology, and two cases were diagnosed by surgical pathology. All five patients underwent enhanced and non-enhanced computed tomography(CT), magnetic resonance cholangiopancreatography, and Gd-EOB-DTPA-enhanced MRI; one case underwent both Gd-EOB-DTPA-enhanced MRI and positron emission tomography-CT. The clinical data and imaging results for these cases were compared and are presented.RESULTS: Conventional imaging showed diffusedilatation of bile ducts and multiple intraductal polypoid and papillary neoplasms or serrated changes along the bile ducts. In two cases, Gd-EOB-DTPA-enhanced MRI revealed dilated biliary ducts and intraductal tumors, as well as filling defects caused by mucin in the dilated bile ducts in the hepatobiliary phase. GdEOB-DTPA-enhanced MRI in one case clearly showed a low-signal tumor in the hepatobiliary phase, similar to what was seen by positron emission tomographyCT. In two patients, routine inspection was unable to discern whether the lesions were inflammation or tumors. However, Gd-EOB-DTPA-enhanced MRI revealed a pattern of gradual enhancement during the hepatobiliary phase, and the signal intensity of the lesions was lower than the surrounding liver parenchyma, suggesting tissue inflammation in both cases, which were confirmed by surgical pathology. CONCLUSION: Gd-EOB-DTPA-enhanced MRI reveals the intraductal mucin component of IPMN-B in some cases and the extent of tumor infiltration beyond the bile ducts in invasive cases.

Common bile duct diameter in an asymptomatic population:A magnetic resonance imaging study

AIM: To measure the common bile duct(CBD) diameter by magnetic resonance cholangiopancreatography(MRCP) in a large asymptomatic population and analyze its some affecting factors.METHODS: This study included 862 asymptomatic subjects who underwent MRCP. The CBD diameter was measured at its widest visible portion on regular endexpiration MRCP for all subjects. Among these 862 subjects, 221 volunteers also underwent end-inspiration MRCP to study the effect of respiration on the CBD diameter. The age, sex, respiration, body length, body weight, body mass index(BMI), portal vein diameter(PVD), length of the extrahepatic duct and CBD, cystic junction radial orientation and location were recorded. The subjects were divided into 7 groups according to age. All of the above factors were compared with the CBD diameter on end-expiration MRCP.RESULTS: Among the 862 subjects, the CBD diameter was 4.13 ± 1.11 mm(range, 1.76-9.45 mm) and was correlated with age(r = 0.484; P < 0.05), with a dilation of 0.033 mm per year. The upper limit of the 95% reference range was 5.95 mm, resulting in a reasonable upper limit of 6 mm for the asymptomatic population. Respiration and other factors, including sex, body length, body weight, BMI, PVD, length of the extrahepatic duct and CBD, cystic junction radia orientation and location, were not related to the CBD diameter.CONCLUSION: We established a reference range for the CBD diameter on MRCP for an asymptomatic population. The CBD diameter is correlated with age. Respiration did not affect the non-dilated CBD diameter.

Multiparameter magnetic resonance imaging of liver fibrosis in a bile duct ligation mouse model

BACKGROUND Bile duct ligation(BDL)in animals is a classical method for mimicking cholestatic fibrosis.Although different surgical techniques have been described in rats and rabbits,mouse models can be more cost-effective and reproducible for investigating cholestatic fibrosis.Magnetic resonance imaging(MRI)has made great advances for noninvasive assessment of liver fibrosis.More comprehensive liver fibrotic features of BDL on MRI are important.However,the utility of multiparameter MRI to detect liver fibrosis in a BDL mouse model has not been assessed.AIM To evaluate the correlation between the pathological changes and multiparameter MRI characteristics of liver fibrosis in a BDL mouse model.METHODS Twenty-eight healthy adult male balb/c mice were randomly divided into four groups:sham,week 2 BDL,week 4 BDL,and week 6 BDL.Multiparameter MRI sequences,included magnetic resonance cholangiopancreatography,T1-weighted,T2-weighted,T2 mapping,and pre-and post-enhanced T1 mapping,were performed after sham and BDL surgery.Peripheral blood and liver tissue were collected after MRI.For statistical analysis,Student’s t-test and Pearson’s correlation coefficient were used.RESULTS Four mice died after BDL surgery;seven,six,five and six mice were included separately from the four groups.Signal intensities of liver parenchyma showed no difference on TI-and T2-weighted images.Bile duct volume,ΔT1 value,T2 value,and the rate of liver fibrosis increased steadily in week 2 BDL,week 4 BDL and week 6 BDL groups compared with those in the sham group(P<0.01).Alanine aminotransferase and aspartate transaminase levels initially surged after surgery,followed by a gradual decline over time.Strong correlations were found between bile duct volume(r=0.84),T2 value(r=0.78),ΔT1 value(r=0.62),and hepatic fibrosis rate(all P<0.01)in the BDL groups.CONCLUSION The BDL mouse model induces changes that can be observed on MRI.The MRI parameters correlate with the hepatic fibrosis rate and allow for detection of cholestatic fibrosis.

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT

Despite advances in patient and graft management,biliary complications(BC)still represent a challenge both in the early and delayed period after orthotopic liver transplantation(OLT).Because of unspecific clinical presentation,imaging is often mandatory in order to diagnose BC.Among imaging modalities,magnetic resonance cholangiography(MRC)has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively,using both the conventional technique(based on heavily T2-weighted sequences)and contrast-enhanced MRC(based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents).On this basis,MRC is generally indicated to:(1)avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications;and(2)provide a road map for interventional procedures or surgery.As illustrated in the review,MRC is accurate in the diagnosis of different types of biliarycomplications,including anastomotic strictures,nonanastomotic strictures,leakage and stones.

Magnetic resonance cholangiopancreatography image enhancement for automatic disease detection

AIM:To sufficiently improve magnetic resonance cholangiopancreatography(MRCP) quality to enable reliable computer-aided diagnosis(CAD).METHODS:A set of image enhancement strategies that included filters(i.e.Gaussian,median,Wiener and Perona-Malik),wavelets(i.e.contourlet,ridgelet and a non-orthogonal noise compensation implementation),graph-cut approaches using lazy-snapping and Phase Unwrapping MAxflow,and binary thresholding using a fixed threshold and dynamic thresholding via histogram analysis were implemented to overcome the adverse characteristics of MRCP images such as acquisition noise,artifacts,partial volume effect and large inter-and intra-patient image intensity variations,all of which pose problems in application development.Subjective evaluation of several popular pre-processing techniques was undertaken to improve the quality of the 2D MRCP images and enhance the detection of the significant biliary structures within them,with the purpose of biliary disease detection.RESULTS:The results varied as expected since each algorithm capitalized on different characteristics of the images.For denoising,the Perona-Malik and contourlet approaches were found to be the most suitable.In terms of extraction of the significant biliary structures and removal of background,the thresholding approaches performed well.The interactive scheme performed the best,especially by using the strengths of the graphcut algorithm enhanced by user-friendly lazy-snapping for foreground and background marker selection.CONCLUSION:Tests show promising results for some techniques,but not others,as viable image enhancement modules for automatic CAD systems for biliary and liver diseases.

Neuroendocrine Tumor Arising from Common Bile Duct: A Case Report and Literature Review

Neuroendocrine tumor (NET) arising from common bile duct (CBD) is a rare disease entity, whose origin is currently in discussion with various theories. We present a case of well-defined solid, exophytic and arterial hypervascular mass arising from CBD with relatively mild dilated central intrahepatic bile ducts in 50-year-old man, which was surgically confirmed to be extrahepatic biliary NET, and reviewed radiologic features of extrahepatic biliary NET in previous literature.

肝内胆管囊腺瘤和囊腺癌的MRI鉴别诊断

目的分析肝内胆管囊腺瘤和囊腺癌之间的MRI表现差异,以提高对两种疾病的诊断准确率。方法分析经病理证实的24例囊腺瘤及10例囊腺癌患者的MRI表现,包括肿瘤部位、大小、瘤周胆管扩张,囊壁结节和强化方式等征象,并进行数据分析。结果24例囊腺瘤中单囊型5例,多囊型19例,多囊型病灶内有分隔,分隔菲薄且均匀;囊壁平均厚度(1.7±0.5)mm,伴瘤周胆管轻度扩张8例;增强后囊壁及囊隔中度强化5例,轻度强化19例。10例囊腺癌中单囊型6例,多囊型4例;10例均见囊壁不同程度增厚,平均厚度(2.2±0.7)mm;9例病灶囊壁见菜花状结节,伴瘤周胆管扩张8例;增强后囊壁中度强化8例,轻度强化2例。结论囊腺瘤和囊腺癌的分房、大小,瘤周胆管扩张,囊壁厚度,囊壁结节和强化方式的差异有统计学意义,MRI扫描及结合MRCP有助于诊断与鉴别诊断。

肝胆管囊腺瘤和囊腺癌的CT、MRI表现及其与病理对照分析

目的 探讨肝胆管囊腺瘤和囊腺癌的CT及MRI表现,并与病理对照分析,以提高对该病的术前影像诊断准确性及鉴别诊断水平。方法 回顾性分析经手术病理证实的11例肝胆管囊腺瘤及囊腺癌患者的影像学征象及病理学特点,其中9例均行CT平扫及三期增强扫描,5例同时行MRI平扫及动态增强扫描。结果 在11例患者中,囊腺瘤8例,囊腺癌3例:11例均为单发,肝左叶7例,右叶3例,肝多叶受累1例;1例囊腺瘤为单囊性病灶,囊壁光整,CT见囊内主要表现为水样密度;1例囊腺癌以实性成为主,其余9例囊腺瘤及囊腺癌呈多发囊状,5例囊腺瘤囊壁光整,厚薄一致,部分分隔均匀增厚,增强扫描无强化或轻度强化;2例囊腺瘤有囊壁钙化;2例囊腺癌囊壁及其内分隔厚薄不一,增强扫描可见实性结节强化,门静脉期强化减退,呈“结节”状或“菜花状”,部分断面锯齿状改变。结论 肝胆管囊腺瘤及囊腺癌的CT、MRI表现,充分反映其病理学特点,注意病变的一些影像学特征性表现,如分隔不均匀增厚,囊壁“结节”或“菜花样”突起及伴有粗大钙化,在囊腺瘤及囊腺癌的鉴别诊断上具有重要意义。

CT联合MR多序列成像对胆总管小微结石的诊断价值

目的探讨CT联合磁共振(magnetic resonance,MR)多序列成像对胆总管小微结石的诊断价值。方法回顾性收集上海市静安区市北医院放射科2019年3月—2021年7月所有行上腹部CT平扫和磁共振胰胆管水成像(magnetic resonance cholangiopancreatography,MRCP)检查并经内镜逆行胰胆管造影(endoscopic retrograde cholangiopancreatography,ERCP)证实的胆总管小微结石病例的影像及临床资料,共计55例。对比分析CT、磁共振各序列及两者联合诊断胆总管小微结石的阳性率。结果对于55例胆总管小微结石,CT薄层扫描检出阳性率为56.4%,MR多序列扫描阳性率为80.6%,MR多序列扫描对胆总管小微结石诊断优于CT扫描(χ2=7.08,P<0.05)。CT联合MR多序列阳性率为98.2%,CT联合MR多序列扫描诊断胆总管小微结石优于两种单独检查方法(χ2的值分别为27.38,P<0.01;9.35,P<0.05)。对于22例胆总管微结石,CT薄层扫描阳性率为40.9%,MR多序列扫描阳性率为68.2%,两者比较差异无统计学意义(χ2=3.30,P>0.05),CT联合MR多序列扫描阳性率为95.5%,CT联合MR多序列扫描诊断胆总管微结石也优于两种单独检查方法(χ2的值分别为15.09,P<0.01;5.50,P<0.05)。结论CT联合MR多序列成像有利于提高胆总管小微结石诊断的检出率,对胆总管小微结石的诊疗具有重要价值。

腹部CT与磁共振胰胆管成像在肝外胆管结石诊断中的应用价值

目的:分析腹部CT与磁共振胰胆管成像在肝外胆管结石诊断中的应用价值。方法:回顾性分析2020年1月—2022年5月郑州市第三人民医院接受诊治的70例疑似肝外胆管结石患者临床资料,对所有患者均进行腹部CT与磁共振胰胆管成像扫描诊断,以手术病理结果为金标准,统计两种诊断方式的诊断效能,统计两种诊断方式对直径<8 mm结石的检出率,记录检查所耗用的时间。结果:以手术病理结果为金标准,70例疑似患者中阳性和阴性分别为67例和3例,腹部CT与磁共振胰胆管成像诊断的符合率分别为53例(75.71%)和65例(92.86%),在诊断效能方面,两种诊断方式的特异度比较,差异无统计学意义(χ^(2)=0,P>0.05);磁共振胰胆管成像诊断的敏感度、准确率均较腹部CT高,差异有统计学意义(χ^(2)=8.873、8.776,P<0.05);磁共振胰胆管成像对直径<8 mm结石检出率较腹部CT高,但是所用的检查时间稍长,差异有统计学意义(χ^(2)=18.746;t=2.613,P<0.05)。结论:临床上对肝外胆管结石患者实施诊断时,应用腹部CT与磁共振胰胆管成像诊断均可,但是相比较而言,磁共振胰胆管成像诊断准确率更高,可为临床治疗提供可靠的指导依据。

磁共振胰胆管成像对胆道梗阻性疾病定位与定性诊断的价值

目的 探讨磁共振胰胆管成像 (MRCP)对胆道梗阻性疾患定位和定性诊断的价值。方法 对 85例梗阻性黄疸病人的MRCP进行分析 ,并与CT、US、直接胆道造影和临床手术病理结果对照。结果 全部病例MRCP检查均一次成功 ,其中 48例行直接胆道造影 ,与MRCP对照 ,二者所获图像极其相似。且对ERCP或PTC显示不完全的病例MRCP可补充有价值的诊断信息。MRCP对梗阻定位诊断准确率为 10 0 %。对梗阻定性诊断准确率为 89.4% ,结合MRI可提高至95 .3 %。结论 MRCP对梗阻性黄疸定位诊断与定性诊断准确率均高于CT及US。MRCP图像与直接胆道造影图像基本一致 ,方便易行无损伤 ,应列为胆道梗阻性疾病的术前常规检查方法。

多排螺旋CT与3.0T磁共振成像对肝外胆管结石的诊断效果分析

背景多排螺旋CT(MDCT)与磁共振成像(MRI)均为目前临床辅助诊断肝外胆管结石的常用影像学检查方法,但这两种检查各有其优势与劣势。目的对比分析MDCT和3.0T MRI对肝外胆管结石的诊断价值,探讨临床医生如何为可疑胆管结石患者选择更合理的影像学检查方法。方法对2009-06-18至2014-10-21河北医科大学第二医院收治的56例可疑肝外胆管结石患者于经内镜逆行性胰胆管造影术(ERCP)前2周内行MDCT、3.0T MRI检查,以ERCP为金标准,计算并比较两种方法的灵敏度、假阴性率(漏诊率)、特异度、假阳性率(误诊率)等指标。结果 MDCT诊断肝外胆管结石的灵敏度、漏诊率、特异度、误诊率、阳性预测值及阴性预测值分别为25.6%、74.4%、100.0%、0、100.0%、28.9%,3.0T MRI诊断肝外胆管结石的灵敏度、漏诊率、特异度、误诊率、阳性预测值、阴性预测值分别为69.8%、30.2%、100.0%、0、100.0%、50.0%。3.0T MRI诊断肝外胆管结石的灵敏度高于MDCT,漏诊率低于MDCT(P<0.001)。两种方法诊断肝外胆管结石的特异度和误诊率相同。结论临床怀疑肝外胆管结石的患者,若条件允许,建议首选MRI检查。

自身免疫性胰腺炎患者胰腺内外CT和MRI表现

目的:分析自身免疫性胰腺炎(AIP)患者胰腺和胰外受累组织器官的CT和MRI影像表现。方法:回顾性分析24例AIP患者胰腺和胰外受累组织器官的CT和MRI扫描资料和临床表现。CT检查18例,MRI检查11例,CT和MRI联合检查10例。CT和MRI平扫后均行胰腺期、门脉期和延迟期三期动态增强扫描,扫描时间设定为静脉对比剂注射后35、70、180 s。结果:24例表现为胰腺弥漫性肿大,呈"腊肠样"外观6例(25.0%)、局灶性肿大9例(37.5%)、结合型6例(25.0%)、正常外形3例(12.5%)。CT平扫显示胰腺病灶区密度降低2例;增强后扫描显示受累胰实质区异常强化17例:动脉期低强化9例(50%)、延迟期延迟强化17例(94.4%)。MRI平扫显示胰腺实质信号异常9例:T1WI序列呈低信号变化7例、等信号4例,T2WI序列呈高信号变化7例、等信号2例、低信号2例;增强后扫描显示病变区异常强化11例:动脉期呈低强化9例(81.8%,9/11),延迟期延迟强化11例(100%,11/11)。胰腺周围表现为包膜样环9例(37.5%,9/24),其中CT显示6例,MRI显示7例。病灶区胰管显影消失24例(100%,24/24),病灶远侧胰管扩张8例,平均内径为(3.1±0.47)mm。胰腺段胆总管狭窄14例(58.3%,14/24)。其他:胰周静脉狭窄9例,动脉狭窄1例,胰周少量积液2例,假性囊肿3例,无一例胰实质钙化。胰外组织器官受累14例(58.3%,14/24),包括肝门部胆管狭窄5例、胆囊壁增厚5例、后腹膜纤维化2例、小肠系膜纤维化2例、肝圆韧带纤维化1例、肾受累3例、胰周和腹主动脉周围淋巴结肿大10例,以及溃疡性结肠炎3例。结论:AIP患者胰腺具有"腊肠样"外观、胰周包膜样环、延迟期延迟强化、胰管节段性狭窄而远侧段胰管扩张轻和胰外组织器官受累等一些CT和MRI的特征性征象,临床结合血清学检查和胰腺穿刺活检,常可做出正确诊断。

胆管扩张时线条样假性充盈缺损病变的磁共振胰胆管成像(MRCP)表现及意义

目的 探讨MRCP中胆管内线条样充盈缺损的表现及成因。方法 分析 3 0 0例胆总管扩张病人和 5 0例正常人的MRCP ,所见与轴位T2WI、T1WI、B超及ERCP检查和 (或 )手术相对照。结果 MRCP图像中胆总管内线条样充盈缺损见于中 重度扩张胆总管 ,但B超、ERCP检查和外科手术未能证实其存在。结论 MRCP图像中扩张胆总管中央的线条样低信号很可能是由胆汁流动形成的假性病变或伪影。

MRCP诊断梗阻性黄疸的价值评价

目的 :探讨磁共振胆胰管成像 (MRCP)在梗阻性黄疸定位、定性诊断中的应用价值。方法 :采用重T2 加权TSE序列采集、MIP法三维重建 ,并与US、CT、ERCP/PTC及手术和病理相对照。结果 :MRCP定位诊断准确率达 10 0 % ,优于US (P <0 .0 5 ) ,与CT、ERCP/PTC无显著差异 ;MRCP结合常规MRI定性诊断准确率达 89.7% ,优于US(P <0 .0 2 5 ) ,与CT、ERCP/PTC无显著差异。结论 :MRCP安全、简便、无创伤 ,在梗阻性黄疸的定位、定性诊断上具有很高的敏感性、准确性 。

肝门胆管癌的磁共振诊断

目的 :评价磁共振成像 (MRI)及磁共振胰胆管造影 (MRCP)在肝门胆管癌的分型和分期诊断中的作用。方法 :回顾性分析 2 3例肝门胆管癌的 MRI及 MRCP影像特点 ,并与手术及病理结果对照。 结果 :肿瘤按形态分型 :浸润型 11例、肿块型 12例 ;按侵犯肝门胆管范围 Bism uth分型 : 型 2例、 型 15例、 型 6例 ;肿瘤侵及血管 9例 ;无淋巴结、肝内或腹腔转移。结论 :MR对肝门胆管癌的大小、分型以及对胆道受累范围的估价是有效可靠的 ,对肿瘤侵犯血管范围的估价与病理结果接近 ,但尚有不足。

磁共振扩散加权成像在胆管癌诊断中的价值研究

目的:探讨磁共振扩散加权成像(DWI)对胆管癌及肝良、恶性占位性病变的鉴别诊断价值。材料和方法:对50例健康志愿者、25例胆管癌患者及59例肝局灶性占位性病变患者行DWI检查,并测量表观扩散系数(ADC值)。本研究胆管癌组仅包括肝内胆管细胞癌及肝门部胆管癌,肝良、恶性占位组包括肝细胞癌10例,肝转移瘤11例,肝血管瘤20例及肝囊肿18例。所有患者同时作多期动态增强MRI,通过观察病灶各期强化特点,进一步为定性诊断提供依据。结果:正常肝组织ADC值(单位:mm2/1000s)为1.46±0.23,胆管癌、肝细胞癌及肝转移瘤的ADC值分别为1.31±0.09,1.24±0.16,1.26±0.22,三者之间差异无统计学意义(P>0.05);肝血管瘤、肝囊肿ADC值分别为1.83±0.33,3.34±0.59;以上恶性肿瘤ADC值均低于良性病变,即胆管癌的ADC值与肝良性病变之间有显著性差异(P<0.01)。在动态增强扫描中,35.2%肝癌、80%胆管癌与36%转移瘤病灶可见门静脉期及延迟期强化。结论:DWI分析及ADC值测量对胆管癌及肝局灶性良性病变的鉴别诊断有一定价值,可作为一种肝、胆脏器MRI的补充检查序列。

MRI3D-VIBE序列评价胆道梗阻性病变的价值

目的通过与磁共振胆胰管成像(MRCP)和MR梯度回波(GE)2DT1W序列增强扫描比较,探讨MRGE快速三维容积式插入法屏气检查(3D-VIBE)序列在诊断胆道梗阻性病变中的价值。方法132例疑有胆道梗阻性病变而接受包括3D-VIBE序列在内的全套MR检查患者,通过与手术、病理及临床随访结果对照,比较三种MR成像序列对胆道梗阻性病变的诊断价值。结果①病灶检测及定位:118例有明确梗阻部位,共计160个病灶中。MRCP检出149个(93.1%),优于3D-VIBE序列及2DGET1W序列(P<0.05);②定性诊断:132例患者中,三种方法准确率分别为3D-VIBE97.7%(129/132)、2DGET1W91.7%(121/132)、MRCP84.8%(112/132),3D-VIBE占优(P<0.05);③推断病灶组织学来源:三种方法准确率分别为3D-VIBE97.0%(128/132)、2DGET1W87.1%(115/132)、MRCP76.5%(101/132)。它们两两之间的差异均有统计学意义(P<0.05),3D-VIBE效果最佳。结论MR3D-VIBE序列对胆道梗阻性病变(特别是非结石性病因)显示出较佳的诊断价值。

多序列MRI和MSCT诊断胆道结石对照研究

目的对比探讨多序列磁共振成像(MRI)及多层螺旋CT(MSCT)诊断胆道系统结石的价值。方法抽取2011年7月～2012年7月共58例胆道结石病例,均行MSCT平扫和多序列MRI检查,MRI检查序列包括:轴位T2WI、轴位T2WI压脂、轴位T1WI、冠状位T2WI、厚层块MRCP和薄层MRCP。2种检查时间间隔不超过2天,所有病例均经手术和病理证实。按结石所在部位分成肝内胆管结石、上段胆总管结石、下段胆总管结石及胆囊结石进行统计。将MSCT和多序列MRI诊断结果进行对比,应用配对四格表行2检验统计分析。结果共102个部位存在结石,其中胆囊结石30个部位,上段胆总管结石9个部位,下段胆总管结石36个部位,肝内胆管结石27个部位。多序列MRI诊断100个部位存在结石,MSCT诊断66个部位存在结石,多序列MRI诊断正确率为98.03%(100/102),MSCT诊断正确率为64.7%(66/102),二者差异有统计学意义(χ2=40.0,P<0.01)。结论多序列MRI诊断胆道系统结石明显高于MSCT,为外科手术提供可靠的诊断依据。