MRI动态增强扫描在肝转移瘤诊断及血供分析中的应用(附60例病例报告)

目的:探讨MRI动态增强扫描尤其是动脉期扫描在检测肝转移瘤中的临床意义.方法:回顾性分析60例肝转移瘤560个病灶在MRI动态增强各期的图像表现,计算平扫及动态增强各序列显示的病灶数目,分析其血供类型及强化方式.结果:肝转移瘤在动脉期、门脉期及静脉期的检出率分别为95%、87%、86%;56个富血供转移瘤仅在动脉期显示.52%的乏血供转移瘤和89%富血供转移瘤在动脉期强化更明显.周边环形强化是肝转移瘤在动脉期的主要强化方式.结论:MRI多期增强扫描,尤其动脉期扫描能够较好的检测出肝转移瘤并分析其血供类型,从而为临床治疗方案的选择及预后评价提供参考依据.     

肺转移瘤的血供情况与动脉灌注栓塞疗效的关系

背景与目的：介入治疗已广泛应用于原发性肺癌,而在肺转移瘤中应用尚较少,其主要原因为对肺转移瘤血供的研究较少,且分歧较大。本研究旨在探讨肺转移瘤的支气管动脉供血情况与动脉灌注栓塞疗效的关系．以提高肺转移瘤的治疗效果。方法：对33例肺转移瘤患者,行选择性支气管动脉造影,了解肿瘤的分布、血液供应情况．对少血供转移瘤给予支气管动脉灌注化疗,对富血供转移瘤给予碘油乳剂栓塞治疗。结果：33例共89个肺转移瘤在肺内分布情况：内中带63个（70．8％）,外带26个（29．2％）。56个转移瘤富血供,33个转移瘤少血供。转移灶的支气管动脉供血类型与肿瘤的分布位置有关,内中带病灶以富血供为多．外带病灶以少血供或无支气管动脉供血的为多（P〈0.01）;肿瘤病灶的大小与支气管动脉供血的类型无明显相关性（P〉O．05）;肿瘤介入灌注栓塞的疗效与支气管动脉供血的类型有关,富血供栓塞组的有效率（71．4％）明显高于少血供灌注组（42．4％）（P〈0.01）,肝癌肺转移灶多数血供丰富,碘油沉积较好,随访中见病灶缩小明显,且病灶较稳定。结论：肺转移瘤仍主要由支气管动脉供血．支气管动脉供血丰富的转移瘤可采用支气管动脉灌注栓塞治疗。     

大肠癌肝转移瘤DSA表现和介入治疗

目的 探讨大肠癌不同类型肝转移瘤DSA表现和介入治疗效果评价。方法 回顾分析106例大肠癌肝转移瘤DSA表现，介入治疗方案选择和效果评价。结果 106例中，单结节和少结节转移灶(病灶≤3个)30例，占28．3％；DSA造影表现以富血供为主，多发转移瘤76例，占71．7％；DSA造影表现以乏血供为主单发富血供转移瘤行化疗栓塞，余经动脉药盒(PCS)行规律化疗灌注，前者生存期较后者明显延长。结论 大肠癌肝转移瘤以多发、乏血供的转移为主，介入治疗为肠癌肝转移瘤提供了一条较好的治疗途径。     

MR和CT动态扫描对小肝癌强化特征的比较研究

目的 前瞻性比较研究小肝癌（SHCC）在动态MR和螺旋CT多期扫描中的强化特征,探讨MR优于螺旋CT的原因。方法 53例SHCC患者,均行螺旋CT和MR动态增强扫描。螺旋CT全肝平扫后分别行动脉期、门脉期和延迟期的增强扫描。MR和SE序列和FMPSPGR序列动态增强多期扫描。结果 53例患者共发现病灶76个,MR和CT动脉期扫描分别有69个病灶和49个病 灶有明显强化。SHCC在MR和CT动脉期－门脉期－延迟期扫描中的典型表现为高－低－低信号（密度）和高－等－低信号（密度）;不典型的表现为高－高－高信号（密度）、高－等－等信号（密度）和低－低－低信号（密度）。结论 动态MR和螺旋CT多期扫描均可显示SHCC的强化特征。MR动脉期扫描更能充分反映SHCC富血供的特点;在定性诊断方面,结合SE序列上的一些信号特征,MR更优于螺旋CT。     

肝脏转移瘤的血管造影影像表现──附120例分析

为进一步加深对肝转移瘤动脉造影影像的认识，回顾性分析了120例肝转移瘤动脉造影表现，以血供多、中、少分析转移灶类型。多血供及中血供类型转移瘤，肿瘤有明显供血动脉，肿瘤染色明显，呈结节状或囊状，少血供类则少而细动脉供血，肿瘤呈斑片状或蜂窝状轻度染色，部分无肿瘤染色，结论：肝转移瘤多中止供类型多见；转移灶血供类型与病灶大小多呈正相关与转移途径关系相对较小；动脉血管造影是诊断肝转移瘤有效手段之一。     

大肠癌肝转移瘤DSA表现和介入治疗

目的　探讨大肠癌不同类型肝转移瘤DSA表现和介入治疗效果评价。方法　回顾分析 10 6例大肠癌肝转移瘤DSA表现 ,介入治疗方案选择和效果评价。结果　 10 6例中 ,单结节和少结节转移灶 (病灶≤ 3个 ) 3 0例 ,占 2 8.3 % ;DSA造影表现以富血供为主 ,多发转移瘤 76例 ,占 71.7% ;DSA造影表现以乏血供为主单发富血供转移瘤行化疗栓塞 ,余经动脉药盒 (PCS)行规律化疗灌注 ,前者生存期较后者明显延长。结论　大肠癌肝转移瘤以多发、乏血供的转移为主 ,介入治疗为肠癌肝转移瘤提供了一条较好的治疗途径。     

肝脏转移瘤的轿管造影影像表现

为进一步加深对肝转移瘤动脉造影影像的认识，回顾性分析了１２０例肝转移瘤动脉造影表现，以血从多、中、少分析转移研。多血供及中血供类型转移瘤，肿瘤有明显供血动脉，肿瘤染色明显，呈结节状或囊状、少血在则少而细动脉供血，肿呈斑片太或蜂窝状轻度染色，部分无肿瘤染色，结论：肝转移瘤多中血供类型多见，转移灶血供类型与病灶大小多呈正相关转移途径关系相对较小；动血管造影是诊断肝转移瘤有效手段之一。     

超声造影对增强计算机层析成像肝脏低密度病灶的诊断价值

目的探讨超声造影（CEUS）对增强计算机层析成像（CECT）肝脏低密度病灶的诊断价值。方法回顾性分析47例CECT提示肝脏低密度病灶的CEUS检查结果。结果47例病灶的病理结果为20例转移癌,9例炎性假瘤,6例血管瘤,4例原发性肝癌,2例囊肿,2例脓肿,2例结核,1例肝脏局灶性结节性增生（FNH）,1例肝脏局部脂肪组织浸润。45例CEUS诊断结果与病理或临床诊断相符合。囊肿和炎性假瘤在整个CEUS时相无增强,但炎性假瘤内可有穿行的血管。肝脏局部脂肪组织浸润与肝脏同步增强。乏血供转移癌中80％（12／15）的表现为周边快速、轻度增强,内部轻微均匀增强;富血供转移癌中80％（4／5）表现为整体明显快速增强。脓肿和结核在CEUS中的强化程度与坏死程度有关,表现为快速不均匀增强。血管瘤周边向中心缓慢增强,其持续增强时间较转移癌长,差异有统计学意义。FNH的CEUS表现由中心向外快进快出的典型增强方式。原发性肝细胞肝癌CEUS表现为整体快进快出的增强方式。结论CEUS对CECT肝脏低密度病灶有一定的诊断价值,有助于此类病灶的鉴别诊断。     

肝动脉化疗及栓塞治疗肝脏转移性肿瘤

作者对５４例肝脏转移性肿瘤进行了肝动脉化疗及栓塞，其中单纯化疗的２２例，化疗栓塞的３２例，经治疗后６个月、１２个月、１８个月的生存率各为７２，２２％、４２．５９％和２９．６３％，总缓解率达３５．５６％。还对单纯化疗及化疗栓塞两种方法的疗效进行了比较，认为化疗栓塞疗效更佳，即使是少血供型转移瘤也应尽可能采用栓塞法。同时就肝转移瘤的类型，血供情况及原发病灶与疗效的关系作了探讨。     

三期螺旋CT扫描技术对肝内肿瘤的诊断价值

目的：研究螺旋CT三期扫描对肝脏肿瘤的检出率及诊断价值。方法：选择经B超，MR，CT联合检查及病理证实（手术及穿刺)的病例156例，病灶340个，采用CT用非离子型造影剂，每人造影剂用量100－120mL，注射速率（2．5－3．5）mL/s，动脉期延迟20－30s，门静脉期延迟60－90s，延迟期（平衡期）延迟230－360s。结果：动脉期显示265（77．94％）个病灶，门静脉期显示204（60％）个病灶，延迟期显示239（70．29％）个病灶，三期综合显示323（95％）个病灶，总正确诊断率95．48％。结论：CT三期扫描在肝脏肿瘤性病变的检出率及正确诊断明显高于单期相扫描和双期扫描。     

Peribiliary liver metastases MR findings

We described magnetic resonance (MR) features of peribiliary metastasis and of periductal infiltrative cholangiocarcinoma. We assessed 35 patients, with peribiliary lesions, using MR 4-point confidence scale. T1-weighted (T1-W), T2-weighted (T2-W) and diffusion-weighted images (DWI) signal intensity, enhancement pattern during arterial, portal, equilibrium and hepatobiliary phase were assessed. We identified 24 patients with periductal-infiltrating cholangiocellular carcinoma. The lesions in 34 patients appeared as a single tissue, while in a single patient, the lesions appeared as multiple individual lesions. According to the confidence scale, the median value was 4 for T2-W, 4 for DWI, 3.6 for T1-W in phase, 3.6 for T1-W out phase, 3 for MRI arterial phase, 3.2 for MRI portal phase, 3.2 for MRI equilibrium phase and 3.6 for MRI hepatobiliary phase. According to Bismuth classification, all lesions were type IV. In total, 19 (54.3%) lesions were periductal, 15 (42.9%) lesions were intraperiductal, and 1 (2.8%) lesion was periductal intrahepatic. All lesions showed hypointense signal in T1-W and in ADC maps and hyperintense signal in T2-W and DWI. All lesions showed a progressive contrast enhancement. There was no significant difference in signal intensity and contrast enhancement among all metastases and among all metastases with respect to CCCs, for all imaging acquisitions (p value >0.05). MRI is the method of choice for biliary tract tumors thanks to the possibility to obtain morphological and functional evaluations. T2-W and DW sequences have highest diagnostic performance. MRI does not allow a correct differential diagnosis among different histological types of metastasis and between metastases and CCC.     

MRI、DSA和碘油CT联合应用对肝硬化结节癌变的诊断价值

背景与目的:肝硬化结节癌变是肝硬化转变成为肝癌的必经阶段,早期发现和早期干预对提高患者的生存率具有重要意义。本研究探讨联合应用MRI、DSA和碘油CT对肝硬化结节癌变诊断价值,旨在早期发现肝硬化结节癌变。方法:收集经病理证实的肝硬化癌变病例18例,所有患者均行MRI、DSA和和碘油CT检查,分析MRI、DSA和碘油CT对肝硬化结节恶变的诊断价值。结果:18例患者中共有31个病灶,其中MRI发现病灶29个,肿瘤病灶T1WI呈低信号12个,高信号9个,等信号8个;T2WI呈稍高信号20个,等信号9个;DWI呈高信号23个;三期动态增强扫描呈"快进快出"共18个,"快进慢出"3个,持续强化3个;另有5个病灶因T1WI呈高信号,强化表现观察不满意。DSA发现27个病灶,表现为肿瘤血管生成、血管扭曲、血供增多、肿瘤染色;2周后复查碘油CT,31个病灶均有碘油沉积。结论:MRI、DSA和碘油CT联合应用能提高肝硬化结节癌变的诊断准确性,从而早期发现肝硬化结节癌变。     

Solid Focal Liver Lesions: Dynamic and Late Enhancement Patterns with the Dual Phase Contrast Agent Gadobenate Dimeglumine

Introduction

The purpose of this paper is to illustrate contrast enhancement patterns of solid focal liver lesions on dynamic and late phase imaging with gadobenate dimeglumine (Gd-BOPTA).

Imaging Findings

Unenhanced T2- and T1-weighted, dynamic T1-weighted (arterial, portal-venous, and equilibrium) and late phase (1-3 h) Gd-BOPTA-enhanced MR imaging of different focal liver lesions (nodular regenerative hyperplasia, hepatic adenoma, liver adenomatosis, hepatocellular carcinoma, peripheral cholangiocarcinoma, hypervascular metastases, and hypovascular metastases) are shown. Dynamic imaging was performed using GRE T1-w sequences after the bolus injection of 0.1 mmol/kg Gd-BOPTA; late-phase imaging was obtained at 1-3 h after contrast injection.

Conclusions

Dynamic imaging with Gd-BOPTA provides the same information as with conventional gadolinium-based extracellular contrast agents, while late-phase imaging gives additional information for lesion identification and characterization.     

纤维板层型肝癌的影像学表现

目的 观察纤维板层型肝癌（ＦＬ－ＨＣＣ）的影像学表现。方法 １１例ＦＬ－ＨＣ互病理证实。做超声波（ＤＳ）检查１０例,ＣＴ扫描１１例,ＭＲＩ８傲因管造影９例。结果 ＵＳ显示肿瘤呈高回声４例,混杂回声６例,４例有大小不一的囊性区,ＤｏｐｐｌｅｒＵＳ提示肿瘤实性部分血供丰富。ＣＴ显示肿瘤单发９例,多个结节融合２例,平扫均为低密度,７例肿块中心区见放射状更低密度区,病理检查为致密胶原瘢痕,４例见点状钙化,     

An Overview of Hepatocellular Carcinoma with Atypical Enhancement Pattern: Spectrum of Magnetic Resonance Imaging Findings with Pathologic Correlation

BackgroundIn the setting of cirrhotic liver, the diagnosis of hepatocellular carcinoma (HCC) is straightforward when typical imaging findings consisting of arterial hypervascularity followed by portal-venous washout are present in nodules larger than 1 cm. However, due to the complexity of hepatocarcinogenesis, not all HCCs present with typical vascular behaviour. Atypical forms such as hypervascular HCC without washout, isovascular or even hypovascular HCC can pose diagnostic dilemmas. In such cases, it is important to consider also the appearance of the nodules on diffusion-weighted imaging and hepatobiliary phase. In this regard, diffusion restriction and hypointensity on hepatobiliary phase are suggestive of malignancy. If both findings are present in hypervascular lesion without washout, or even in iso- or hypovascular lesion in cirrhotic liver, HCC should be considered. Moreover, other ancillary imaging findings such as the presence of the capsule, fat content, signal intensity on T2-weighted image favour the diagnosis of HCC. Another form of atypical HCCs are lesions which show hyperintensity on hepatobiliary phase. Therefore, the aim of the present study was to provide an overview of HCCs with atypical enhancement pattern, and focus on their magnetic resonance imaging (MRI) features.ConclusionsIn order to correctly characterize atypical HCC lesions in cirrhotic liver it is important to consider not only vascular behaviour of the nodule, but also ancillary MRI features, such as diffusion restriction, hepatobiliary phase hypointensity, and T2-weighted hyperintensity. Fat content, corona enhancement, mosaic architecture are other MRI feautures which favour the diagnosis of HCC even in the absence of typical vascular profile.Key words: hepatocellular carcinoma, liver cirrhosis, magnetic resonance imaging, diffusion magnetic resonance imaging     

Magnetic resonance imaging of pelvic endometriosis

Endometriosis is a multifocal disease involving multiple pelvic sites. Although laparoscopy is the elective exam in the study of patients with clinically suspected endometriosis, MR imaging represents a valid noninvasive procedure for the study of areas unapproachable with laparoscopy. On MR imaging, areas of endometriosis over 1 cm in size appear homogeneously hyperintense in T1-weighted images and hypointense in T2-weighted images, while areas of endometriosis less than 1 cm in size appear hyperintense in T1-weighted images and with variable signal in T2-weighted images. Endometriosis may also appear as small cystic lesions, hyperintense in T1-weighted images. While MR imaging has some limitations in the visualization of small endometriotic implants and adhesions, it has the ability to characterize the lesions, to study extraperitoneal locations and the contents of pelvic masses. The reliability of MR imaging findings of endometriosis and the assessment of pelvic organ involvement is important for guiding subsequent laparoscopy.     

The value of F-18-fluorodeoxyglucose PET for the 3-D radiation treatment planning of malignant gliomas

Purpose: The aim of the study was to determine the impact of positron emission tomography using the glucose analogue fluorine-18-fluorodeoxyglucose (FDG-PET) on the delineation of the target volume in three-dimensional radiation treatment planning of primary brain tumors.

Methods and Materials: In 18 patients with histologically proven (8× biopsy, 10× subtotal resection) primary brain tumors (8 astrocytomas °III, one mixed glioma °III, and 9 glioblastomas), magnetic resonance imaging (MRI) with gadolinium-DTPA and FDG-PET were performed in radiation treatment position within the same week. A computer program was developed for fusion of the PET and MR images. On corresponding axial slices, FDG uptake was compared to contrast enhancement in T1-weighted and to signal hyperintensity in T2-weighted MR images. Based on PET and MRI data, three-dimensional treatment planning was performed. All patients underwent linear accelerator (LINAC) radiotherapy.

Results: In MRI, all tumors and the surrounding edema were visible as hyperintense lesions in the T2-weighted images. 17/18 tumors showed contrast enhancement. In FDG-PET, 16 tumors showed hypermetabolism compared to normal white matter, whereas only 8/18 tumors showed hypermetabolism compared to normal gray matter. White matter edema was associated with decreased FDG uptake in all patients. The area of increased FDG uptake correlated closely with contrast enhancement, only in one case the volume of increased FDG uptake was larger than the area of contrast enhancement. Mean tumor volumes obtained by MRI T1 + Gd, T2, and PET were 30, 106, and 10 ml, respectively. Survival was comparable to data in the literature with a 1-year survival of 39% and a median survival of 310 days.

Conclusion: Only in a minority of patients did FDG-PET provide additional information for radiation treatment planning. This is mainly caused by the high intensity of FDG uptake in normal brain tissue. PET may be of greater value in the definition of regions that should obtain a radiation dose boost.     

MRI findings of large low-grade angiosarcoma of the breast with subsequent bone metastases: a case report

We describe the magnetic resonance imaging (MRI) findings of 13 cm-sized low-grade angiosarcoma of the breast that occurred in a 23-year-old woman. Magnetic resonance examination revealed an ill-defined mass with marked high-signal intensity on T2-weighted images and persistent heterogeneous enhancement. Thirty months later she developed bone metastases, incidentally found on an MRI performed to evaluate the pelvis. There were well-defined bone lesions with high-signal intensity on T2-weighted images and persistent contrast enhancement on delayed phases. The metastases were not detected on previous computed tomography and fluoro-deoxyglucose positron emission tomography scans because the lesions were subtle osteoblastic type with a low proliferative index.     

3T MRI in evaluation of asbestos-related thoracic diseases - preliminary results

Background

3T high-field magnetic resonance imaging (MRI) scanners have recently become available for the clinical use and are being increasingly applied in the field of whole-body imaging and chest imaging as well. The aim of this study was to evaluate the diagnostic potential of 3 T MRI as a complementary imaging modality to CT in detecting the pathological changes of asbestos-related thoracic diseases.

Patients and methods

Fifteen patients with the asbestos-related thoracic disease were scheduled for 3T MRI. Five had a benign form of the disease and 10 had malignant pleural mesothelioma (MPM). From the patients with a benign form of the disease their last CT examination in digital form was acquired and patients with MPM were scheduled for CT examination with contrast media. The protocol of MR imaging consists of T2-weighted cardiac-gated breath-hold turbo spin echo (TSE) sequences in coronal, sagittal and axial plane and T1-weighted cardiac-gated breath-hold TSE black blood in axial plane. In T2-weighted sequences in axial plane, fat saturation was also used. CT examinations were obtained with the administration of the contrast medium from lung apices to the lower end of the liver. Images of 5 mm (mediastinum window) and 3 mm (lung window) in axial plan were reconstructed. MRI signal intensity of lesions and adjacent muscles on Syngo MultiModality Work Place were measured.

Results

Compared to muscles pleural plaques appeared hypo-intense to iso-intense on T1 weighted images (in 100%) and also hypo-intense on T2 fs-weighted images (in 100%). MPM appeared inhomogeneous hypo-intense to iso-intense on T1-weighted and hyperintense on T2 fs-weighted images in all patients (100%).

Conclusions

These preliminary results pointed out that MRI was equal or even better compared with CT examination for detecting possible malignant potential of pleural changes in the asbestos-related pleural disease, using signal intensity measurements of T2 fs-weighted images. The 3T MRI enabled the accurate determination of chest pathology and it could be used for imaging of patients with the asbestos-related thoracic disease. MRI is particularly valuable because a patient is not exposed to the harmful radiation which is important if imaging methods are used repeatedly, like in screening programs or in monitoring of treatment results. This finding turned us to propose 3T MRI imaging technique as a non-ionizing imaging method for the follow-up of patients with the isolated pleural form of the asbestos-related disease.