MR imaging and MR cholangiopancreatography of multifocal intraductal papillary mucinous neoplasms of the side branches: MR pattern and its evolution

PURPOSE: This paper describes the magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) pattern of multifocal intraductal papillary mucinous tumours (IPMT) of the pancreatic side branches and its evolution during followup. MATERIALS AND METHODS: Twenty-six patients with multifocal IPMT of the side branches were included in this retrospective study. Inclusion criteria were > or =2 ectasic side branches, presence of communication with the main pancreatic duct, and > or =2 MRI/MRCP examinations after > or = 6-12 months. Exclusion criteria were IPMT involving both the main pancreatic duct and its branch ducts, previous surgery and lack of follow-up MRI examinations. Median follow-up was 27 (range 6-59) months. Images were assessed qualitatively and quantitatively. Qualitative assessment considered: the number of cystic lesions of the branch ducts, morphology of the communication between the cystic lesion and the main duct (direct or neck), presence of intraluminal filling defects within the cystic lesions, presence of mural nodules and mural enhancement of the cystic lesion. quantitative assessment considered mean maximal diameter of the cystic lesions and mean length of the communication neck. RESULTS: At diagnosis, the mean number of cystic lesions of the side branches was 7.5. a communication neck was detected in 16/26 patients (60%). Intraluminal filling defects in the side branches were present in 6/26 patients (23%). Mural nodules were seen in 1/26 patients (4%). The mean diameter of the cystic lesions was 18.8 mm. The mean length of the communication neck was 6.9 mm. At follow-up, the mean number of cystic lesions of the side branches was 8.4. A communication neck was detected in 20/26 patients (77%). Intraluminal filling defects in the side branches were detected in 7/26 patients (27%); mural nodules were seen in 2/26 patients (8%). Mural enhancement of the branch duct was detected in 2/26 patients (8%). The mean diameter of the cystic lesions increased to 22.3 mm (p < 0.05), and the mean length of the communication neck was 8.6 mm. CONCLUSIONS: MultifocaL IPMT of the side branches shows a constant but very slow progression over time. In our series, only 2/26 patients showed mural nodules.     

Pancreatic and extrapancreatic lesions in patients with intraductal papillary mucinous neoplasms of the pancreas: a single-centre experience

Purpose

This study was performed to describe the possible presence of extrapancreatic neoplasms in patients with intraductal papillary mucinous neoplasm (IPMN) and to evaluate whether the extrapancreatic tumours were synchronous or metachronous to IPMNs.

Materials and methods

One hundred and forty-two patients (56 men and 86 women; mean age 69.5 years, range 37–98) with IPMN diagnosed using the Sendai criteria were enrolled. Six patients (4.2%) had type I, 103 (72.5%) type II and 33 (23.2%) type III IPMN. All patients were studied using the following imaging techniques: ultrasonography (US), multidetector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP).

Results

Pancreatic IPMN was localised in the head in 43 patients (30.3%), in the body in 13 (9.2%), in the tail in ten (7.0%), in the head-body in 17 (12.0%), in the body-tail in 15 (10.6%) diffuse throughout the gland in 44 (31.0%). The mean size of the cystic lesions was [(mean±standard deviation (SD)] 1.9±1.9 cm (range 0.5–8.0 cm). Twenty patients (14.1%) had associated pancreatic or extrapancreatic diseases. In evaluating the distribution of pancreatic or extrapancreatic diseases according to IPMN type, we found that this was not significantly different among types I, II and III (p=0.776).

Conclusions

The majority of pancreatic and extrapancreatic cancers occur before the diagnosis of IPMNs is made and is not related to the type of IPMN.     

Correlation between CT patterns and pathological classification of intraductal papillary mucinous neoplasm

Objective

To examine CT patterns of intraductal papillary mucinous neoplasm (IPMN), analyze their correlation with pathologic classification, and discuss the value of CT in the diagnosis and differential diagnosis of IPMN.

Methods

CT patterns of 39 IPMN patients, whose clinical data were complete and whose diagnosis was confirmed by surgery and pathology, were classified into three types: (1) simple main pancreatic duct (MPD) dilation type, (2) MPD dilation with pancreatic cystic lesion type, and (3) simple pancreatic cystic lesion type. Correlations between the three CT types and Takada pathologic classification (MPD type, furcation type and mixture type) were analyzed. The 39 IPMN cases were pathologically classified as the benign group and the malignant/borderline group. CT characteristics including the presence or absence of mural nodules, intrafocal partitions, focal size and the degree of MPD and common bile duct (CBD) dilation were analyzed statistically.

Results

A correlation was found between the CT simple MPD dilation type and the pathological MPD type, between the MPD dilation with pancreatic cystic lesion type and the furcation and mixture types, and between the simple cystic lesion type and the furcation type (p < 0.001). The benign rate was 92% in patients without intrafocal mural nodules, and 42% in patients with intrafocal mural nodules. The difference between the two groups was statistically significant (p = 0.003). The presence or absence of intrafocal partitions was not correlated with benignancy or malignancy (p = 0.793). The maximum diameter of malignant/borderline lesions was bigger than that of benign ones (p = 0.016). There was no significant difference in MPD and CBD diameters between the benign and malignant/borderline groups. Regardless of pathological classification, the MPD diameter was larger than the CBD diameter in all cases (p = 0.02).

Conclusion

The three CT types of IPMN well correlated with the pathologic classification, which is helpful for analyzing CT manifestations and improving the accuracy of diagnosis. MPD dilation is usually larger than CBD dilation in IPMN patients, which is also helpful in the diagnosis and differential diagnosis of IPMN in the context of other related findings.     

The usefulness of 18F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with 18F-FDG PET/CT

Purpose

This study aimed at demonstrating the feasibility of retrospectively fused ¹⁸F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image.

Methods

We analyzed retrospectively 119 patients: 96 cancers and 23 benign lesions. FDG-PET/MRI fusion images (PET/T1 WI or PET/T2WI) were made by dedicated software using 1.5 Tesla (T) MRI image and FDG-PET images. These images were interpreted by two well-trained radiologists without knowledge of clinical information and compared with FDG-PET/CT images. We compared the differential diagnostic capability between PET/CT and FDG-PET/MRI fusion image. In addition, we evaluated additional findings such as tumor structure and tumor invasion.

Results

FDG-PET/MRI fusion image significantly improved accuracy compared with that of PET/CT (96.6 vs. 86.6 %). As additional finding, dilatation of main pancreatic duct was noted in 65.9 % of solid types and in 22.6 % of cystic types, on PET/MRI-T2 fusion image. Similarly, encasement of adjacent vessels was noted in 43.1 % of solid types and in 6.5 % of cystic types. Particularly in cystic types, intra-tumor structures such as mural nodule (35.4 %) or intra-cystic septum (74.2 %) were detected additionally. Besides, PET/MRI-T2 fusion image could detect extra benign cystic lesions (9.1 % in solid type and 9.7 % in cystic type) that were not noted by PET/CT.

Conclusions

In diagnosing pancreatic lesions, FDG-PET/MRI fusion image was useful in differentiating pancreatic cancer from benign lesions. Furthermore, it was helpful in evaluating relationship between lesions and surrounding tissues as well as in detecting extra benign cysts.     

Differential diagnosis of benign or malignant intraductal papillary mucinous neoplasm of the pancreas by multidetector row helical computed tomography: evaluation of predictive factors by logistic regression analysis

OBJECTIVE: The purpose of this study is to evaluate predictive factors for discriminating benign from malignant intraductal mucin-producing neoplasm (IPMN) of the pancreas on multidetector row computed tomography (MDCT). MATERIALS AND METHODS: Fifty-three patients with IPMN underwent MDCT, and the imaging and pathological findings were evaluated. In patients with branch duct-type tumors, sex and age of the patient, location, shape, size and multiplicity of the cystic lesion, presence of mural nodule, and maximum diameter of main pancreatic duct (MPD) dilatation were evaluated by logistic regression analysis. RESULTS: Tumors were classified as main duct-type (n = 7) and branch duct-type (n = 46). Among main duct-type tumors, all 7 lesions were diagnosed as malignant. Among 46 lesions of branch-type IPMN, 8 lesions were malignant, and 38 lesions were benign. On adjusted logistic regression analysis, combination factor of main duct dilatation and mural nodule or large cystic size had statistical significance for the risk of malignancy in branch duct-type IPMN. CONCLUSIONS: Main duct-type IPMN is highly suggestive for malignancy. Combination factors of main ductal dilation and mural nodule, and main ductal dilation, and large cystic tumor size are thought to be predictive factors for malignant branch-type IPMN.     

MRI in cystic pancreatic lesions,is it of value?

Introduction

Cystic pancreatic lesions are currently discovered at higher rate, hence adequate characterization of these lesions by the radiologist is important in guiding management.

胰腺导管内乳头状黏液性肿瘤恶变的影像表现

目的探讨胰腺导管内乳头状黏液性肿瘤(IPMN)恶变的影像表现和诊断价值。方法回顾分析经手术或超声内镜下活检病理证实的60例IPMN,探讨IPMN恶变的CT及MRI影像表现和诊断价值,并进行统计学分析。结果60例患者共发现良性IPMN 34例,恶性26例。良性IPMNs的特征性表现为胰腺内囊性病灶,和主胰管相通,IPMNs恶变的特征有:增粗的胰管内出现明显强化的壁结节(17/26),结节直径>10 mm(13/26);主胰管直径>10 mm(10/26);或IPMN随访过程中出现胰腺明显肿块,胰管、胆管逐渐增粗、扩张加重。MRCP对IPMN与胰管相通的显示率高达91.7%(55/60),明显高于CT(76.7%,46/60)(χ^2=5.065,P<0.05)。恶性IPMN中胆总管扩张有14例,而良性IPMN胆总管扩张仅2例。根据MRCP胆总管扩张情况诊断IPMN恶变的诊断敏感性及特异性分别为53.8%及94.1%,阳性预测值为87.5%。恶性IPMN DWI受限达21例(80.8%),良性IPMN DWI轻度受限5例(14.7%)。恶性IPMN的ADC值[(2.04±0.38)×10^-3mm^2/s]显著低于良性IPMN[(2.83±0.29)×10^-3mm^2/s],统计学有差异(P<0.05)。ROC曲线下面积为0.9383,以2.34×10^-3mm^2/s为阈值,敏感性和特异性分别达到80.8%和94.1%,95%可信区间值80.32%~99.28%。对IPMN恶变的诊断敏感性MRI及CT分别为88.5%(23/26)、80.8%(21/26),诊断特异性分别为88.2%(30/34)、79.4%(27/34),统计学无差异(P>0.05)。结论胰腺导管内乳头状黏液性肿瘤恶变的影像表现具有一定特征性,在IPMN随访过程中应注意并提早判断,有助于改善临床治疗方案及提高患者预后及生存。     

2型糖尿病患者中胰腺导管内乳头状黏液性肿瘤影像学分析

目的分析2型糖尿病患者中胰腺导管内乳头状黏液性肿瘤(IPMN)的影像学良恶性表现,提高影像学诊断水平。方法选取我院经手术病理证实的2型糖尿病患者伴胰腺IPMN患者20例。记录肿瘤分型、部位、大小、囊壁结节、胰管扩张等影像学表现。结果 20例IPMN中,头颈部9例,体尾部11例;混合型8例,多表现为主胰管不同程度扩张并周围分支胰管扩张,分支型6例,表现为单发单囊或多房囊性病灶;肿瘤平均直径约25.2 mm,主胰管型6例,表现为全程主胰管不同程度扩张,平均直径约15.9 mm;良性17例,恶性3例(2例为主胰管型均伴壁结节,1例混合型)。结论糖尿病患者的胰腺IPMN具有较为特征的影像学良性及恶性表现,临床上应严格把握手术和随访指征,结合患者的其他临床资料评估决定。     

Role of multislice computed tomography in the diagnosis of gene-mutation-associated pancreatitis (GMAP)

Purpose

The aim of this study was to review the computed tomography (CT) features of the pancreatic parenchyma and ducts in patients with gene-mutation-associated pancreatitis (GMAP).

Materials and methods

Twenty-five patients with GMAP were included in this retrospective study. Patients were divided into two groups according to the time interval between the onset of symptoms and the first CT examination (group A ≤24 months and group B >25 months).

Results

On qualitative image assessment, in group A patients, pancreatic duct stones were detected in 2/13 with GMAP. All stones were calcified and homogenous. Enhancement of the pancreatic parenchyma was hypovascular in 7/13 patients. In group B patients, pancreatic duct stones were detected in 12/12 with GMAP. Stones were calcified in 10/12 cases and noncalcified (protein plugs) in 2/12; in 5/10 cases, the calcified stones were heterogeneous with noncalcified central core (bull’s-eye appearance). Enhancement of the pancreatic parenchyma was hypovascular in 12/12 patients. On quantitative image assessment, in group A patients, the mean diameter of duct stones was 0.6 mm (range 0–5 mm). Mean diameter of the main duct in the pancreatic head and body/tail was 4.8 mm and 4.9 mm, respectively. In group B patients, the mean diameter of duct stones was 21.9 mm (range 2–50 mm). Mean diameter of the main duct in the pancreatic head and body/tail was 18.8 mm and 13.9 mm, respectively.

Conclusions|

In patients with GMAP and time interval between symptom onset and first CT scan ≤24 months (group A), CT identified normal or slightly increased parenchymal thickness and a main pancreatic duct of normal calibre and without duct stones. In contrast, in patients with GMAP and time interval between symptom onset and first CT scan >25 months (group B), it identified large-calibre duct stones with bull’s-eye appearance.     

F18-FDG-PET/CT for evaluation of intraductal papillary mucinous neoplasms (IPMN): a review of the literature

Intraductal papillary mucinous neoplasms (IPMN) are intraductal mucin-producing neoplasms with tall columnar, mucin-containing epithelium, with or without papillary projections, involving the main pancreatic duct and/or major side branches. They account for approximately 25 % of all cystic neoplasms and can be subdivided into benign lesions, borderline lesions, and carcinoma. In this clinical scenario accurate preoperative diagnosis can eliminate unnecessary surgery, which is risky and potentially harmful, yet enable effective selection of patients who are candidates for surgery. In this review we try to provide a complete evaluation of the use of F18-FDG-PET/CT for diagnosis of this neoplasm on the basis of published papers. F18-FDG-PET/CT seems to be an useful technique for preoperative work-up of patients with suspected IPMN and is an improvement over conventional imaging in distinguishing benign from malignant lesions, especially for selecting patients for surgical treatment or for long-term follow-up.     

Imagerie en coupes des tumeurs kystiques du pancréas

Cystic tumors of the pancreas were considered to be rare. Their radiologic diagnosis has been dominated by their distinction from postnecrotic and retention pseudocysts. Widespread use of cross-sectional imaging with high resolution CT and MRI has revealed their real prevalence. Their identification has become a common daily problem. These new imaging procedures have also enabled a better understanding of their potential for degeneration, a determining factor for treatment. According to recent clinical research studies, 30% of common ductal pancreatic adenocarcinomas would issue from the degeneration of previous benign intraductural papillary mucinous neoplasms (IPMN) lesions (which have now become the most frequently encountered cystic pancreatic tumor). IPMN involving the main pancreatic duct have a very high malignant potential; at five years, the estimated risk of degeneration is 50%. Theoretically treatment involves as complete as possible resection, with the main goal of avoiding total pancreatectomy and the subsequent serious nutritional and functional sequelae. This surgical treatment must be discussed with a multidisciplinary staff, considering each individual patient's life expectancy and surgical risk. The five-year risk of degeneration for IPMN limited to the secondary pancreatic ducts ranges from 5 to 10%. A five-year follow-up is thus indicated for these patients; surgical resection can be proposed if mural nodules develop. Unlike mucinous and, to a lesser extent, serous adenoma, lymphoepithelial cysts of the pancreas are mainly encountered in the mid-aged male population.     

High-intensity focused ultrasound (HIFU) in patients with solid malignancies: evaluation of feasibility, local tumour response and clinical results

Purpose

The purpose of this study was to evaluate the safety and efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) for ablation of solid tumours without damaging the surrounding structures.

Materials and methods

A specific written informed consent was obtained from every patient before treatment. From September 2008 to April 2009, 22 patients with 29 lesions were treated: nine patients with liver and/or soft-tissue metastases from colorectal carcinoma (CRC), six with pancreatic solid lesions, three with liver and/or bone metastases from breast cancer, one with osteosarcoma, one with muscle metastasis from lung cancer, one with iliac metastasis from multiple myeloma and one with abdominal liposarcoma. The mean diameter of tumours was 4.2 cm. All patients were evaluated 1 day, 1 month and 3 months after HIFU treatment by multidetector computed tomography (MDCT), positron-emission tomography (PET)-CT and clinical evaluation. The treatment time and adverse events were recorded.

Results

All patients had one treatment. Average treatment and sonication times were, respectively, 162.7 and 37.4 min. PET-CT or/and MDCT showed complete response in 11/13 liver metastases; all bone, soft-tissue and pancreatic lesions were palliated in symptoms, with complete response to PET-CT, MDCT or magnetic resonance imaging (MRI); the liposarcoma was almost completely ablated at MRI. Local oedema was observed in three patients. No other side effects were observed. All patients were discharged 1?C3 days after treatment.

Conclusions

According to our preliminary experience in a small number of patients, we conclude that HIFU ablation is a safe and feasible technique for locoregional treatment and is effective in pain control.     

多层螺旋CT对胰腺导管内乳头状黏液性肿瘤的诊断价值

目的探讨胰腺导管内乳头状黏液性肿瘤(IPMN)的多层螺旋CT诊断价值。方法分析12例经手术病理证实的IPMN的临床资料及CT图像表现,包括胰管扩张的程度、范围,病灶的大小、形态、密度、边缘和强化方式等。采用曲面重建技术显示扩张的主胰管和分支胰管。结果12例IPMN中,男性8例,女性4例,年龄48~85岁。肿瘤位于钩突部7例,胰腺体部3例,胰腺头部和尾部各1例。分支胰管宽度>5 mm者10例,主胰管宽度>5 mm者4例,其中2例表现为胰腺弥漫性肿胀和胰腺实质内肿块。分支胰管型8例,主胰管型3例,混合型1例。病理结果显示腺瘤4例,交界性肿瘤5例,腺癌3例。结论多层螺旋CT对IPMN的诊断、分型具有重要的临床应用价值。     

胰腺导管内乳头状黏液瘤影像特征及误诊病例分析

目的 分析胰腺导管内乳头状黏液瘤(IPMN)影像学表现和误诊原因,减少误诊率.方法 回顾性分析术前影像诊断或怀疑为IPMN和术前影像误诊为胰腺其他疾病但是术后被确诊为IPMN患者的资料,共计130例.由2名高年资影像诊断医生统计资料,总结IPMN影像学表现,分析误诊原因,找出对策.结果 130例患者经病理确诊为IPMN有105例(80.7%),确诊为胰腺其他病变25例(19.2%);IPMN与慢性胰腺炎(CP)和浆液性囊腺瘤(SCN)间相互误诊病例最多.将IPMN按照病理级别分为轻至中度组和重度、浸润癌组,2组在囊肿直径、有无壁结节、有无分隔、主胰管直径、是否伴有肝内外胆管扩张组间有统计学差异(P<0.05).误诊的主要原因为影像科医生诊断时未完整结合患者的临床资料;对少见类型影像学表现认识不足;对于病变与胰管关系判断错误.结论 在诊断IPMN时需要结合病变临床特征,明确肿块与胰管之间的关系,全面掌握影像学表现;对于反复发作胰腺炎患者需考虑IPMN存在的可能;长期IPMN可以存在CP.     

磁共振成像技术对胰腺导管内乳头状黏液瘤的诊断价值

目的探讨胰腺导管内乳头状黏液瘤的MRI影像学特点,以提高该病的诊断准确率。方法搜集12例经手术证实的胰腺导管内乳头状黏液瘤患者的临床及影像学资料,回顾性分析主胰管型和分支胰管型的MRI表现。结果研究证实,12例中有主胰管型3例和分支胰管型9例。主胰管型MRI表现为主胰管节段性或弥漫性扩张,可伴有胰腺实质的萎缩;分支胰管型MRI表现为单房或多房型囊性病变,并与主胰管相通。结论 MRI对胰腺导管内乳头状黏液瘤是一种无创、有效的诊断方法,有助于提高该病的诊断准确率。     

Incidental pancreatic cysts: natural history and diagnostic accuracy of a limited serial pancreatic cyst MRI protocol

Objectives

To examine the natural history of incidentally detected pancreatic cysts and whether a simplified MRI protocol without gadolinium is adequate for lesion follow-up.

Methods

Over a 10-year period, 301-patients with asymptomatic pancreatic cysts underwent follow-up (45 months?±?30). The magnetic resonance imaging (MRI) protocol included axial, coronal T2-weighted images, MR cholangiopancreatographic and fat suppressed T1-weighted sequences before and after gadolinium. Three radiologists independently reviewed the initial MRI, the follow-up studies using first only unenhanced images, then secondly gadolinium-enhanced-sequences. Lesion changes during follow-up were recorded and the added value of gadolinium-enhanced sequences was determined by classifying the lesions into risk categories.

Results

Three hundred and one patients (1,174 cysts) constituted the study population. Only 35/301 patients (12 %) showed significant lesion change on follow-up. Using multivariate analysis the only independent factor of lesion growth (OR?=?2.4; 95 % CI, 1.7–3.3; P?<?0.001) and mural nodule development (OR?=?1.9; 95 % CI, 1.1–3.4, P?=?0.03) during follow-up was initial lesion size. No patient with a lesion initial size less than 2 cm developed cancer during follow-up. Intra-observer agreement with and without gadolinium enhancement ranged from 0.86 to 0.97. After consensus review of discordant cases, gadolinium-enhanced sequences demonstrated no added value.

Conclusion

Most incidental pancreatic cystic lesions did not demonstrate change during follow-up. The addition of gadolinium-enhanced-sequences had no added-value for risk assignment on serial follow-up.

Key points

? Significant growth of pancreatic cysts occurred in a minority of patients only. ? No lesion <2 cm demonstrated any change during the first year of follow-up. ? Intra-observer agreement between MR pancreatic protocols with and without gadolinium was excellent. ? Gadolinium application had limited value for follow-up of asymptomatic pancreatic cystic lesions.     

胰腺导管内乳头状黏液性肿瘤CT与MRI表现及鉴别诊断

目的探讨胰腺导管内乳头状黏液性肿瘤的CT及MRI表现特点及鉴别诊断。资料与方法回顾性分析经手术病理证实的26例胰腺导管内乳头状黏液性肿瘤的CT及MRI表现。结果主胰管型4例,主要表现为主胰管扩张,其中1例伴胰管内多发结节影且均匀强化;分支胰管型20例,呈单房或多房样囊性病灶,部分有分隔;混合型2例,表现为胰头及钩突囊性肿块影呈多房样改变,轻度强化,并可见主胰管扩张。结论 CT及MRI在胰腺导管内乳头状黏液性肿瘤的诊断及鉴别诊断中具有重要意义。     

Differential Diagnosis of Benign and Malignant Intraductal Papillary Mucinous Tumors of the Pancreas: MR Cholangiopancreatography and MR Angiography

Objective

To compare the usefulness of magnetic resonance cholangiopancreatography (MRCP) and MR angiography (MRA) in differentiating malignant from benign intraductal papillary mucinous tumors of the pancreas (IPMTs), and to determine the findings which suggest malignancy.

Materials and Methods

During a 6-year period, 46 patients with IPMT underwent MRCP. Morphologically, tumor type was classified as main duct, branch duct, or combined. The diameter of the main pancreatic duct (MPD), the extent of the dilated MPD, and the location and size of the cystic lesion, septum, and communicating channel were assessed. For all types of IPMTs, enhanced mural nodules and portal vein narrowing were evaluated at MRA.

Results

Combined-type IPMTs were more frequently malignant (78%) than benign (42%) (p < 0.05). Compared with benign lesions, malignant lesions were larger, and the caliber of the communicating channel was also larger (p < 0.05). Their dilated MPD was more extensive and of greater diameter (p < 0.05), and the presence of mural nodules was more frequent (p < 0.001).

Conclusion

Combined MRCP and MRA might be useful for the differential diagnosis of malignant and benign IPMTs of the pancreas.     

胰腺导管内乳头状黏液性肿瘤的MRI表现

目的 探讨胰腺导管内乳头状黏液性肿瘤(IPMN)的MRI特征.资料与方法 6例经病理或逆行性胆胰管造影(EBCP)证实的胰腺IPMN患者.MR扫描包括T_1WI、T_2WI、MRCP和动态增强.分析胰腺IPMN的MRI征象,并与临床及病理对照.结果 主胰管型、分支胰管型及混合型各2例,病灶主要位于胰头颈部,最大径(27.4±14.5)mm,呈分叶状,边缘清晰,T_1WI上呈低信号,T_2WI上呈高信号,增强后无强化或线状强化.2例病灶远端胰腺萎缩.2例分支胰管型主胰管最大径2.9 mm和2.2 mm,其余4例最大径(5.9 ±1.6)mm.结论 MRI对发现和正确诊断胰腺IPMN有较高价值.     

The MRI features of histologically proven ovarian cystadenofibromas��an assessment of the morphological and enhancement patterns

Objectives

To assess the morphological and enhancement features of histologically proven cystadenofibromas (CAFs) on magnetic resonance imaging (MRI).

Methods

Forty-seven histologically proven CAFs (42 benign, five borderline) were retrospectively reviewed. One benign CAF had a synchronous adenocarcinoma in the same ovary. The morphological, signal and enhancement characteristics on MRI were recorded.

Results

The mean long axis diameter of the CAFs was 80?mm. The contralateral ovary was abnormal in 45?% of cases. A solid component was seen in 85?%, which returned low T2-weighted signal in 75?% of CAFs. Septa were seen in 74?% and one CAF was purely cystic. The majority of solid components and septa demonstrated enhancement that was less than the myometrium. Wash-in rates (WIR) of the solid tissue were available for measurement in nine patients with an average WIR of 3.2?l/s.

Conclusion

This is the largest series describing MRI appearances of histologically proven CAFs. They are typically complex adnexal lesions containing septa, cystic components and solid tissue. The majority of solid components demonstrate low T2 signal and minimal enhancement. Almost half of the cases have an abnormal contralateral ovary.

Key Points

? Cystadenofibromas are complex adnexal lesions containing septa, cystic, and solid components. ? Some MRI features of cystadenofibromas overlap with those of malignant ovarian lesions. ? Almost 50?% of patients with a cystadenofibroma have an abnormal contralateral ovary. ? Most contralateral lesions are benign, but we found four borderline tumours.