MR imaging of hepatocellular carcinomas with biliary tumor thrombi

We retrospectively evaluate the MR imaging findings of hepatocellular carcinomas (HCC) with biliary tumor thrombi. MR imaging was performed on six patients presenting with obstructive jaundice and/or biliary hemorrhage. T1-weighted images, T2-weighted images, MR cholangiopancreatography (MRCP), and dynamic MR images were obtained. Duodenal endoscopy was performed on all cases and hepatic resection on two cases. HCCs were 1.8–10 cm in diameter (mean 5.8 cm). Biliary tumor thrombi were detected in all patients on MR imaging. Tumor thrombi showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and contrast enhancement on the early phase of dynamic MR images. MRCP showed intrahepatic bile duct dilatation in all cases. Biliary hemorrhage was clearly depicted by MR images in five cases and showed hyperintensity on T1-weighted images and hyperintensity or hypointensity on T2-weighted images. Biliary hemorrhage was confirmed by endoscopy in two cases. Portal vein thrombi were also associated in five of six patients. Pathologically, tumor thrombi of HCCs were demonstrated in two patients who underwent hepatic resection. In conclusion, MR imaging is useful for the diagnosis of biliary tumor thrombi from HCC and for evaluating the extension of thrombi and biliary hemorrhage.     

MR imaging of the pancreas

MR imaging is a valuable tool in the assessment of the full spectrum of pancreatic diseases. MR imaging techniques are sensitive for the evaluation of pancreatic disorders in the following settings: (1) TI-weighted fat-suppressed and dynamic gadolinium-enhanced SGE imaging for the detection of chronic pancreatitis, ductal adeno-carcinoma, and islet-cell tumors; (2) T2-weighted fat-suppressed imaging and T2-weighted breath-hold imaging for the detection of islet-cell tumors;and (3) precontrast breath-hold SGE imaging for the detection of acute pancreatitis. Relatively specific morphologic and signal intensity features permit characterization of acute pancreatitis,chronic pancreatitis, ductal adenocarcinoma, insulinoma, gastrinoma, glucagonoma, microcystic cystadenoma, macrocystic cystadenoma, and solid and papillary epithelial neoplasm. MR imaging is effective as a problem-solving modality because it distinguishes chronic pancreatitis from normal pancreas and chronic pancreatitis with focal enlargement from pancreatic cancer in the majority of cases.MR imaging studies should be considered in the following settings: (1) in patients with elevated serum creatinine, allergy to iodine contrast, or other contraindications for iodine contrast administration; (2) in patients with prior CT imaging who have focal enlargement of the pancreas with no definable mass; (3) in patients in whom clinical history is worrisome for malignancy and in whom findings on CT imaging are equivocal or difficult to interpret; and (4) in situations requiring distinction between chronic pancreatitis with focal enlargement and pancreatic cancer. Patients with biochemical evidence of islet-cell tumors should be examined by MR imaging as the first-line imaging modality because of the high sensitivity of MR imaging for detecting the presence of islet-cell tumors and determining the presence of metastatic disease.     

Collateral branches IPMTs: secretin-enhanced MRCP

Recently, the fantastic evolution of imaging modalities (especially MR, MDCT, EUS) has raised many issues regarding the correct classification of smaller and smaller lesions, their preoperative evaluations, and indications of most appropriate treatment. However, it is still debated which technique should be employed for the diagnosis and the follow-up of intraductal papillary mucinous tumours (IPMTs). Despite the superb spatial resolution of MDCT, nowadays most of the authors agree on considering MR with magnetic resonance cholangiopancreatography (MRCP) the imaging modality of choice in studying IPMTs. In particular, MRCP is rapid, non-invasive, and accurate in detecting, localizing, and correctly classifying IPMT. The diagnostic performance of MRCP is even improved after the introduction of secretin stimulation. In fact, dynamic MRCP studies after secretin administration, besides facilitating the depiction of the structural characteristics of the lesions, make easier the detection of the communicating duct of branch duct IPMTs with the main pancreatic duct, especially if the newest high resolution 3D heavily T2-weighted sequences are utilized. Secretin stimulation is also useful in the demonstration of early changes of associated chronic pancreatitis. Consequently, we believe that secretin-enhanced MRCP is the most suitable imaging modality in the diagnosis and follow-up of IPMTs of the collateral branches.     

MR imaging of the gallbladder

T2-weighted imaging and MRCP, which have high sensitivity to edema and fluid, are paramount in the evaluation of certain gallbladder diseases, such as cholelithiasis, cholecystitis, adenomyomatosis, and cystic duct abnormalities. Dynamic gadolinium-enhanced MR imaging has the potential to differentiate among the many nonspecific-appearing lesions involving the gallbladder. MR imaging may not yet replace ultrasound as the workhorse of acute gallbladder imaging. Currently, MRCP is an ideal complementary study to inconclusive sonographic studies and can help plan surgical intervention in the setting of acute cholecystitis. Further investigation of hepatobiliary contrast agents, however, may reveal that MR imaging may be considered as first-line imaging in the acute setting.     

磁共振胰胆管成像对梗阻性黄疸的定性研究

目的:探讨磁共振胰胆管成像(MRCP)对胆道梗阻性疾病的诊断价值。方法:使用1.5T磁共振扫描仪,对489例可疑胆管梗阻性疾病及正常人行MRCP检查,原始图像作三维重建,然后分析其影像表现及诊断结果。结果:MRCP能清晰显示胰胆管的解剖结构,对胆道梗阻程度和梗阻部位判断的确诊率达100%。恶性梗阻的胆管扩张程度较良性梗阻重。结合MRCP原始图像和常规MRI能明确显示肿瘤大小及范围。MRCP鉴别良恶性梗阻的敏感性为92%,特异性为97%,准确性为95%。结论:MRCP检查的成功率高,胰胆管解剖结构显示清晰,适用于各种胰胆管疾病的诊断,可为恶性胰胆肿瘤术前可切除性提供评价,可作为该系统疾病诊断的首选方法。     

MR imaging of hepatocellular carcinoma

MR imaging is useful in the diagnosis and early detection of HCC. Characteristic findings for overt HCC, a pseudocapsule and an intratumoral mosaic pattern, are better demonstrated on MR imaging than by other imaging modalities such as ultrasound and CT scanning. Signal intensity on T2-weighted images is useful in evaluating the grade of malignancy of hepatocytic nodular lesions. Hyperintensity on T1-weighted MR imaging is almost always seen in precancerous hepatocellular lesions and in about one third of overt HCC tumors, whereas other hepatic tumors show hypointensity on T1-weighted MR imaging. In evaluating tumor vascularity, gadolinium-enhanced dynamic MR imaging is an essential and powerful tool.     

MRI在胰腺局灶性脂肪浸润的诊断价值

目的探讨胰腺局灶性脂肪浸润的MRI典型表现。方法回顾性分析MRI诊断胰腺局灶性脂肪浸润病人12例,除常规序列外,加扫化学位移成像序列,观察同、反相位图像组织信号变化情况,以确定有无脂肪浸润改变。所有病例MRI检查前均经CT平扫和/或增强扫描,因CT表现缺少特异性,不能明确低密度病灶性质而建议进一步检查,所有病例经随访5～36个月(平均16个月)无明显变化。结果12例胰腺局灶性脂肪浸润主要累及胰头和钩突前部,5例合并不同程度胰腺颈、体、尾部脂肪浸润,但仍以胰头和钩突前部脂肪浸润最明显。胰腺局灶性脂肪浸润区域在常规压脂T1WI、T2WI上9例未见明显异常信号,3例与周围正常胰腺对比呈稍低信号;在化学位移成像序列中,局灶性脂肪浸润区域在同相位上与周围正常胰腺对比呈等或稍高信号,而在反相位上局灶性脂肪浸润区域则较同相位上出现中度到明显不均匀信号下降,从而确立胰腺局灶性脂肪浸润诊断。结论胰腺局灶性脂肪浸润主要累及胰头和钩突前部或以此区域更明显,MRI化学位移成像具有典型表现,对胰腺局灶性脂肪浸润诊断具有重要价值。     

中场MRCP临床应用价值的初步探讨

目的 初步探讨中场ＭＲＣＰ对诊断胆胰疾病的临床指导价值。方法 采用０．５Ｔ中场磁共振机,对２８例胆胰疾病患临床治疗前行ＭＲＩ及ＭＲＣＰ检查。其中９例为胆系术后且Ｂ超或ＣＴ检查可疑胆胰疾病患,把ＭＲＣＰ检查结果与临床治疗后结果进行对比分析。结果 中场ＭＲＣＰ可清晰显示胆道梗阻性疾病的胆管胰管扩张程度和范围,对胆总管结石、胆管肿瘤、先天性胆总管囊肿、原发性硬一胆管炎及胰腺癌、转移淋巴结等胆管外压性疾病具有较高的诊断与鉴别诊断价值;但亦有假阳性与假阴性存在,如１例胆总管死蛔虫及１例肝左叶胆管癌均误诊为结石、２例胆总管较小结石漏诊等,２例急性胰腺炎ＭＲＣＰ周边均可见散与腹膜后积液“雪花”征存在,ＭＲＩ可弥补ＭＢＣＰ不能显示胆管外信息资料的不足。结论 结合ＭＲＩ的ＭＲＣＰ对胆管疾病临床诊断与治疗有着重要指导价值。尤其     

慢性胰腺炎的CT诊断分型及其对鉴别诊断的意义

目的探讨慢性胰腺炎CT表现特征,试图就其不同CT表现进行分型并探讨分型的意义。方法59例慢性胰腺炎,男43例,女16例,平均年龄40岁。36例有急性胰腺炎病史。常规上腹部CT平扫加增强,重点观察胰腺及病灶的大小、形态、密度等。结果27例(46%)表现为全胰腺萎缩型,均伴有不同程度胰实质钙化;13例(22%)表现为单发囊肿型伴囊壁不定型钙化;7例为多发囊肿型(12%)表现为胰腺及其周围多发假性囊肿;7例(12%)表现为单纯胰管扩张型;5例(8%)为肿块型,表现为局限性胰腺软组织样肿块,边缘清楚。结论慢性胰腺炎的CT表现可分为萎缩型、单发囊肿型、多发囊肿型、胰管扩张型和肿块型5型,CT诊断的分型对鉴别诊断及其病因的分析有一定的意义。     

胰腺导管内乳头状黏液性肿瘤的影像学诊断进展

胰腺导管内乳头状黏液性肿瘤是一种位于扩张的主胰管和(或)分支胰管内、伴大量黏液分泌的肿瘤,易与慢性胰腺炎或胰腺囊腺瘤混淆而延误诊断.本文就国内外近年来关于胰腺导管内乳头状黏液性肿瘤的临床病理学及影像学研究进展进行综述,评价不同影像技术(US、CT、MRCP、ERCP)在胰腺导管内乳头状黏液性肿瘤诊断中的作用.     

MRCP诊断总胆管结石及其影像学对比研究

目的     

Hilar cholangiocarcinoma: MRI/MRCP in staging and treatment planning

The role of MR imaging in hilar cholangiocarcinoma is to confirm/reach a diagnosis and to assess resectability. Hilar cholangiocarcinoma shows the same signal intensity pattern of peripheral tumors both on T1- and T2-weighted images. On magnetic resonance cholangiopancreatography (MRCP) images, hilar cholangiocarcinoma appears as a moderately irregular thickening of the bile duct wall (5 mm) with symmetric upstream dilation of the intrahepatic bile ducts. The aim of preoperative investigation in Klatskin tumors typically requires the evaluation of the level of biliary obstruction, the intrahepatic tumor spread, and the vascular involvement; it also needs to show any atrophy-hypertrophy complex. Because of its intrinsic high tissue contrast and multiplanar capability, MR imaging and MRCP are able to detect and preoperatively assess patients with cholangiocarcinoma, investigating all involved structures such as bile ducts, vessels and hepatic parenchyma. The main reason for surgical/imaging discrepancy is represented by the microscopic diffusion along the mucosa and in the perineural space.     

原发性骨骼淋巴瘤的影像学诊断

目的:分析13例骨骼淋巴瘤的影像学特征以探讨其影像学的诊断价值。材料和方法:13例经手术病理证实的骨骼淋巴瘤病例,术前均经平片检查,其中CT检查10例,MR检查9例。结果:4例何杰金淋巴瘤和9例非何杰金淋巴瘤分别累及脊柱6例,长管状骨5例,骨盆2例,病变主要累及脊柱的椎体和长管状骨的骨干,骨质改变为溶骨型9例(69%)和混合型4例(31%),骨质破坏以浸润性虫噬状骨质破坏为主;骨皮质破坏11例,但皮质破坏的程度总是很轻微;骨膜成骨3例(23%),软组织肿块形成7例(54%)。软组织肿块CT表现为低密度或等密度,境界清楚;骨骼MRI T1WI低信号9例,T2WI显示为略低信号2例,等信号2例,高信号5例;软组织肿块的MR信号变化少,T1WI略低于肌肉,T2WI总是略高于肌肉,MR动态增强扫描为轻~中等程度强化。结论:骨骼淋巴瘤影像学特征:①明显的浸润性虫噬状骨质破坏,而骨皮质破坏轻微,骨膜反应少见;②软组织肿块T2WI信号略高,且信号相对均匀。平片、CT和MRI等影像学检查可以作出诊断。     

MRI T2WI及MRCP在腹腔镜胆囊切除术前诊断胆管结石的预期价值

目的探讨MRIT2WI及MRCP在腹腔镜胆囊切除术前诊断胆管结石的预期价值。方法回顾性分析97例经MRIT2WI及MRCP检查后行外科手术的胆石症病人资料。结果97例中MRCP真阴性66例,假阴性1例,真阳性24例,假阳性6例,敏感性为96.8%,特异性为92%,阴性预期价值为98.5%,阳性预期价值为80%,总的正确率为92.8%。横轴位T2WI真阴性71例,假阴性4例,真阳性21例,假阳性1例,敏感性为84.6%,特异性为98.6%,阴性预期价值为94.7%,阳性预期价值为95%,总的正确率为94.8%;冠状位T2WI真阴性72例,假阴性1例,真阳性24例,假阳性0例,敏感性为96%,特异性为100%,阴性预期价值为98.6%,阳性预期价值为100%,总的正确率为99%;97例MRCP中胆管显示率100%,胰管显示率97%,胆囊管显示率68%。结论胆管结石以及结石大小的判断应以冠状位T2WI为主,MRCP可以提供胆、胰系的空间解剖关系及结石的相对位置,因此应综合分析MRIT2WI、MRCP图像,为腹腔镜胆囊切除术前制定手术方案提供依据。     

CT和MRI诊断胆囊腺肌瘤病的比较研究

目的比较CT和MRI诊断胆囊腺肌瘤病(GBA)的作用与限度。方法分析19例经组织学证实的GBA患者的CT和MRI资料,比较常规T1WI、T2WI、3mm薄层T2WI、MRCP、平扫CT、螺旋CT胆道造影(SCTC),以及CT和MRI动态增强扫描各时相图像显示罗-阿窦和胆囊病变的能力。观察结果与病理标本所见对照。结果19例GBA包括局限型11例,节段型5例,弥漫型3例。MRI显示罗-阿窦优于CT。胆汁显著浓缩时,SCTC可补充MRCP的不足。结论MRI诊断GBA的作用优于CT。     

磁共振胰胆管成像在胰胆管疾病诊断中的应用探讨

目的：探讨磁共振胰胆管成像（ＭＲＣＰ）在胰胆管疾病诊断中的临床应用价值。方法：５４例胰胆管疾病病人行ＭＲＣＰ检查，同时行磁共振常规扫描。６例病人在ＭＲＣＰ检查后一周内行ＥＲＣＰ检查。１４例经手术和病理证实。ＭＲＣＰ采用重度Ｔ２加权ＴＳＥ快速成像序列，加用脂肪压抑技术，图像经三维最大信号强度投影（ＭＩＰ）后处理。结果：冠状位ＭＲＣＰ图像与ＥＲＣＰ图像相似，空间分辨率略逊于ＥＲ－ＣＰ，能较好地显示胰胆管疾病的病变部位、梗阻程度及梗阻两端的情况。结论：ＭＲＣＰ作为一种安全非侵入性影像学诊断技术，能较好地显示胰胆管系统的解剖和病理变化，无放射性损伤，不用造影剂，对ＥＲＣＰ检查失败者或显示不完全的病例ＭＲＣＰ能获得较为满意的胰胆管图像。与ＥＲＣＰ相辅相成，可提高胰胆管疾病的诊断水平     

Nodular regenerative hyperplasia of the liver in Budd–Chiari syndrome: CT and MR features

We report the imaging findings of spiral computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography in a patient with nodular regenerative hyperplasia of the liver associated with Budd–Chiari syndrome. Spiral CT showed multiple enhancing nodules during the hepatic arterial and portal venous phases. MR images showed multiple hyperintense nodules on T1-weighted images and hypointense or isointense nodules on T2-weighted images. MR angiography showed thrombotic occlusion of three hepatic veins, suggesting Budd–Chiari syndrome. Received: 25 June 1999/Revision accepted: 22 September 1999     

Intraductal papillary mucinous neoplasms of the pancreas: correlation of helical CT and dynamic MR imaging features with pathologic findings

BACKGROUND: We assessed the imaging features of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas paying special attention to underlying pancreatic fibrosis on three-phase helical computed tomography (CT) and dynamic magnetic resonance (MR) imaging. METHODS: Sixteen patients with histopathologically proven IPMNs underwent three-phase helical CT and dynamic MR imaging. RESULTS: IPMNs were seen as a cluster of cyst-like structures in branch duct (n = 5) and combined types (n = 10), and as a fusiform appearance in the main duct type (n = 1). IPMN shape was most easily visualized at the portal venous dominant phase or delayed phase owing to rim-like enhancement of the dilated ducts. Pathologically mild to severe fibrosis was seen on this enhanced rim replacing the surrounding pancreatic parenchyma. Communication between the dilated branch ducts and main pancreatic duct was identified in 15 patients on helical CT and 14 patients on dynamic MR imaging. In patients with fibrosis of pancreatic parenchyma surrounding this, communication was most easily visualized at the later phase on CT and MR imaging. Adenocarcinomas were depicted as papillary projections in eight of nine patients on CT and MR imaging. Invasion of the pancreatic parenchyma was seen in five of six patients as a solid mass in the pancreatic parenchyma. These masses were most easily visualized at the arterial dominant phase on both CT and MR imaging. CONCLUSION: Three-phase helical CT and dynamic MR imaging were useful in the diagnosis of IPMN of the pancreas.     

磁共振胰胆管成像对正常胰管的评价

目的探讨正常胰管的磁共振胰胆管成像(MRCP)表现。方法300例无胰腺及相关病史者,用单次激发快速自旋回波序列,沿胰腺头、体、尾一系列多层多角度斜位厚层采集,观察各段胰管显示情况及走行。结果胰腺头、体、尾主胰管显示率99.3%、95.7%、87.3%;分支胰管、副胰管显示率4.67%、44.3%;胰腺分裂检出率7.7%;胰腺头、体、尾主胰管平均直径(2.36±0.60)mm、(2.05±0.72)mm、(1.67±0.86)mm;胰管走行:下降型(66.0%)、“S”型(16.0%)、垂直型(10.7%)和环型(9.3%)。结论MRCP能满意显示胰管正常解剖及变异。     

胰腺癌MRI各征象的诊断价值

目的观察磁共振成像(MRI)中胰腺癌各征象及其组合对胰腺癌诊断的价值。方法因胰腺及其周围疾病手术患者80例,胰腺癌及非胰腺癌各40例。均在术前1个月内进行全面的MR检查。以选定MRI征象或其组合为参考标准,诊断为胰腺癌。结果与手术及病理检查报告对比,进行统计分析,画出ROC曲线。结果应用动态对比增强诊断胰腺癌效果较好,40例胰腺癌发现36例,在40例其他疾病中有6例被错误地归类至胰腺癌。其敏感性、特异性和正确性分别为90%、85%和87.5%。应用磁共振胰胆管造影(MRCP)检查,以胰管非穿透性扩张为指标,特异性95%,敏感性52.5%。结论动态对比增强检查在应用MRI诊断胰腺癌时非常重要,在动态对比增强的MRI图像中发现病灶呈轻度或无强化是诊断胰腺癌的较好指标。MRCP对胰头癌诊断很有必要,如发现胰腺改变并有胰管非穿透性扩张,则诊断基本可以确立。