胃肠道间质瘤的CT表现

目的探讨CT对胃肠道间质瘤（GIST）的诊断价值。方法回顾性分析41例经手术及病理和免疫组化证实的GIST的CT表现。41例GIST中,35例行平扫加增强扫描,6例行直接增强扫描,6例行延迟扫描。结果41例GIST中,胃间质瘤25例,小肠间质瘤8例,回肓部间质瘤2例,直肠间质瘤3例,横结肠系膜及小肠网膜间质瘤3例,其中2例合并胃腺癌,1例合并腹膜后淋巴瘤。肿块最小约2cm×1．5cm×1cm,最大约13cm×15cm×19cm。病变向腔内生长者16例（占39％）,腔外生长者25例（占61％）,较小肿块平扫密度较均匀,增强后呈均匀强化,较大病灶密度不均匀,增强后边缘强化较明显,中心强化不明显。结论GIST的CT表现有一定的特征性。与消化道有关的肿块,较小时密度均匀,边界清晰,强化明显且均匀,较大时中心伴囊变、坏死且增强后呈均匀或不均匀强化,应考虑GIST。     

胃肠道间质瘤的CT诊断

胃肠道间质瘤(gastrointestinal stromal tumor,GIST)是消化道常见的间叶源性肿瘤,长期以来一直被认为是消化道平滑肌(肉)瘤或(恶性)神经鞘膜瘤。1983年,Mazur和Clark运用电镜和免疫组化重新评估胃间叶源性肿瘤的发生,提出了GIST的概念[1]。近年来研究表明,GIST是胃肠道最常见的间叶源性肿瘤,其免疫组化和超微结构不同于平滑肌瘤及神经鞘瘤。本文回顾性分析了33例经手术病理证实多层螺旋CT平扫及双期增强扫描资料完整的GIST,旨在提高对本病的认识。1材料与方法1.1临床资料本组病例共33例,均为经手术病理证实的GIST患者,其中男19例…     

胃肠道间质瘤的多层螺旋CT诊断

目的探讨胃肠道间质瘤(GIST)的影像学表现特点。方法回顾性分析经手术病理证实的37例GIST的16层螺旋CT表现,全部病例均行CT平扫和增强扫描。结果 37例GIST中发生于胃23例,小肠8例,结肠3例,肠系膜3例。位于消化道的34例中,瘤体位于消化道腔外27例,腔内、外混合生长7例。CT表现:肿块密度均匀5例,不均匀32例,增强后均匀强化4例,不均匀强化33例,动脉期肿块实性部分轻中度强化,静脉期强化较动脉期更明显,呈中度或明显强化。结论胃肠道间质瘤CT主要表现为胃肠道腔外生长为主的软组织肿块,易囊变坏死,增强后动脉期肿块实性部分强化,静脉期强化较动脉期更明显,以肝脏和系膜转移较为常见,淋巴结转移、腹腔积液及肠梗阻较为少见。     

I-131 metaiodobenzylguanidine uptake in a parathyroid adenoma

We describe a patient with multicentric small bowel carcinoids, severe hypertension, primary hyperparathyroidism, and multiple parathyroid adenomas. Intense uptake of I-131 metaiodobenzylguanidine (MIBG) occurred in a parathyroid adenoma. There was no biochemical evidence of catecholamine secretion by the tumor but elevated serum levels of parathyroid hormone were demonstrated. We suspect that occasional parathyroid adenomas, like other APUDomas, may give false positive results when MIBG imaging is used to search for pheochromocytomas. This observation supports the inclusion of the parathyroid chief cells in the amine precursor uptake and decarboxylation (APUD) cell system.     

PET-CT在胃肠道间质瘤中的应用

胃肠道间质瘤是一种主要生长在胃肠道的具有恶性潜能的间叶源性肿瘤,由于缺乏特异性的体征,影像学检查是诊断胃肠道间质瘤的重要辅助方法.PET-CT在胃肠道间质瘤的分期、疗效评价及随访方面与常规影像学检杏相比,均表现出独特的优越性,该文综述了 PET-CT及相关影像学技术在胃肠道间质瘤方面的应用价值.     

PET-CT在胃肠道间质瘤中的应用

胃肠道间质瘤是一种主要生长在胃肠道的具有恶性潜能的间叶源性肿瘤,由于缺乏特异性的体征,影像学检查是诊断胃肠道间质瘤的重要辅助方法.PET-CT在胃肠道间质瘤的分期、疗效评价及随访方面与常规影像学检杏相比,均表现出独特的优越性,该文综述了 PET-CT及相关影像学技术在胃肠道间质瘤方面的应用价值.     

Exophytic adenocarcinoma of the stomach: computed tomography and ultrasonography features with emphasis on differentiation from a malignant gastrointestinal stromal tumor

The purpose of this study was to assess the computed tomography (CT) and ultrasonography (US) findings from cases of exophytic adenocarcinoma of the stomach (EAS) and to determine their value in distinguishing between an EAS and a malignant gastrointestinal stromal tumor (MST). US and CT findings of EAS and MST were assessed retrospectively. Antral location, thickening of the gastric wall adjacent to an exogastric mass, lymph node enlargement, and discordant images between US and CT are typical of EAS cases and allow distinction between cases of EAS and MST.     

螺旋CT对胃肠道间质瘤的诊断价值

目的探讨胃肠道间质瘤(G ISTs)的螺旋CT征象与诊断价值。方法收集经手术病理证实的27例胃肠道间质瘤,回顾性分析其在CT扫描中的特征。术前均行平扫、增强双期扫描。结果肿瘤均为单发,位于胃14例,小肠5例,十二指肠3例,直肠2例,食管、肠系膜、腹膜后各1例。肿块多呈类圆形或浅分叶状,良性5例,直径在3~5 cm,增强强化均匀;交界性5例,直径在4~7 cm,呈均匀或不均匀强化;恶性17例,肿块直径均>5 cm,增强明显不均匀强化,其内见不规则坏死、囊变区域。螺旋CT对该组病灶的定位准确度为93%,定性为78%。结论螺旋CT对胃肠道间质瘤的定位、良恶性判定具有较高的应用价值,对临床治疗方案及预后评估起到重要的作用。     

FDG PET imaging of metastatic gastrointestinal stromal tumor

A 75-year-old woman presented with an 8-month history of progressive abdominal distension and associated weight loss. Computed tomography (CT) showed a very large, partially enhancing, cystic/solid mass within the abdomen that extended from below the left diaphragm to the pelvis. A large (10 cm), partially enhancing lesion was also seen in segments 6 and 7 of the right lobe of the liver, consistent with metastatic disease. The patient underwent laparotomy and resection of a 5.7-kg abdominal tumor measuring 30 x 27 x 20 cm. Histology confirmed a gastrointestinal stromal tumor (GIST) of stomach origin. A whole-body F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scan performed 2 months postoperatively demonstrated multiple glucose-avid lesions in the liver as well as residual disease within the abdomen and pelvis. The patient was referred to medical oncology. The authors give a brief overview of this rare mesenchymal tumor of the gastrointestinal tract and the potential role of PET.     

高场MRI对胃肠间质瘤的诊断

目的 分析高场MRI对胃肠间质瘤(GIST)影像表现,探讨其对该肿瘤的诊断价值.方法 对经病理证实的45例GIST的高场磁共振影像学资料进行回顾分析.结果 45例GIST中,发生于骶前2例,会阴部5例,小肠5例,直肠10例,胃内23例.其中有11例为术后复发,余34例为新发.高场MRI表现为不均匀的肿块信号影,体积小者信号均匀,体积大者信号不均匀,可出现囊变、坏死、出血等;增强后肿块实性部分异常强化信号影,坏死、囊变区无明显强化信号影.肿瘤边界清晰或不清晰,邻近组织受压,易发生转移或腹腔内种植.病理结果显示: 肿瘤大体,切面呈灰白、灰红色,可见包膜.镜下主要由形态多样、数量不等的梭形细胞构成.免疫组化CD34(+)为43例;CD117(+)为40例;Desmin(+)为18例;Vimentin(+)为15例.结论 高场MRI对GIST可以准确定位,对其诊断及鉴别诊断具有重要价值.     

Conjugate view gamma camera method for estimating tumor uptake of iodine-131 metaiodobenzylguanidine

Therapy with [131I]MIBG has produced partial remissions of malignant pheochromocytomas but not all patients respond. Responses correlate with the quantity of radiation delivered. We developed the conjugate-view method of imaging using 131I reference sources of known radioactivity placed on the surface of the patient and standard nuclear medicine equipment (gamma camera and computer), to estimate tumor uptake of [131I]MIBG. Such an estimate is a first step toward calculating radiation absorbed dose. Three different methods of background subtraction were evaluated with an anthropomorphic phantom and in five patients. In phantom results, measured tumor activity decreased exponentially with a half-life in agreement with that of 131I to within 3%. However, in the phantom studies, in which non-tumor activity is zero, no single method of background subtraction is superior. In patients, two background subtraction methods, which take their estimate from regions immediately surrounding or adjacent to the tumor and reference source, are less sensitive to reference source position and appear more accurate than a third method which uses a background region of interest displaced from the tumor. The agreement of the calculated activity concentration (nCi/g) with that measured by counting portions of the excised tumors gives validation to the method.     

F-18 FDG PET imaging in gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most frequent mesenchymal malignancy of the gastrointestinal tract. Liver and peritoneum are the most frequent metastatic sites. Surgery is the mainstay of treatment in patients with localized disease. Imatinib mesylate (Gleevec; Novartis Pharmaceuticals, East Hanover, NJ), an inhibitor of tyrosine kinase activity of KIT receptor, has been shown to be an effective treatment in metastatic or unresectable disease. Follow-up of patients treated with Gleevec is controversial. The authors present a case of GIST that showed near-total response with Gleevec on fluorodeoxyglucose positron emission tomography. They suggest positron emission tomography as a useful imaging modality for the monitoring of therapy response in GIST tumors treated with Gleevec.     

胃肠间质瘤的CT诊断及治疗评价

目的:探讨胃肠间质瘤(GIST)的CT表现及分子靶向药物甲磺酸伊马替尼(STI571)对胃肠间质瘤疗效的CT评价。方法:选择经手术及病理证实的胃肠间质瘤病例32例进行回顾性分析。对19例接受STI571治疗者进行定期CT检查随访,观察病灶大小、形态及密度变化,评价药物疗效。结果:32例GIST中,发生于胃部的18例,小肠11例,肠系膜1例,直肠2例。①CT特征:恶性度较高的胃肠间质瘤CT表现为:肿块相对较大,密度不均,肿瘤中央坏死及囊变多见;肿瘤边缘多不光整,可呈分叶状。增强扫描肿瘤呈不均匀强化;少数巨大肿瘤密度较低,极少数可见高密度出血及钙化灶。良性GIST体积较小,密度均匀,肿瘤坏死及囊变少见,病灶边缘光整,增强扫描多呈均匀强化;②19例接受STI571治疗者定期CT检查疗效评价为(肿瘤缩小):疗效达PR(部分缓解)者9例,占47.4%,疗效为SD(疾病稳定)者8例,占42.1%,病灶进展(PD)者2例,占10.5%。术后2年内复发及转移者19例。结论:①螺旋CT扫描是诊断胃肠间质瘤最常用和最有价值的影像检查手段,其定位诊断率达81%以上;②应用CT扫描观察测量病灶变化是评价药物(STI571)治疗胃肠间质瘤疗效最重要和最直接的方法之一;对指导临床治疗具有重要意义。     

C-kit-targeted imaging of gastrointestinal stromal tumor using radiolabeled anti-c-kit monoclonal antibody in a mouse tumor model

IntroductionGastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor arising from the gastrointestinal tract and highly expresses mutated c-kit. We aimed to develop a specific and sensitive method for detecting GISTs using radiolabeled anti-c-kit monoclonal antibody.MethodsA mutated c-kit-expressing cell clone was established by transfecting an expressing vector of mutated c-kit gene into HEK293 human embryonic kidney cells. The tumors were developed by inoculating c-kit-expressing cells into nude mice. ¹²⁵I- and ¹¹¹In-labeled anti-c-kit antibodies (12A8 and 41A11) were evaluated in vitro by cell binding, competitive inhibition and cellular internalization assays, and in vivo by biodistribution and imaging studies in tumor-bearing mice.ResultsBoth ¹²⁵I- and ¹¹¹In-labeled antibodies showed specific binding with c-kit-expressing cells with high affinity (dissociation constants = 2.2–7.1×10⁹ M^?1). Internalization assay showed that ¹²⁵I-labeled antibodies were rapidly internalized and dehalogenated, with the release of ¹²⁵I from the cells, resulting in reduction of cell-associated radioactivity with time. In contrast, ¹¹¹In-labeled antibody was internalized but did not result in the reduced radioactivity associated with tumor cells. Reflecting this phenomenon, the in vivo tumor uptake of ¹²⁵I-labeled antibody was low on Day 1, further decreasing with time, while tumor uptake of ¹¹¹In-labeled antibody was high on Day 1, further increasing with time. The xenografted tumor was clearly visualized by scintigraphy after injection of ¹¹¹In-labeled antibody.ConclusionThe anti-c-kit monoclonal antibody labeled with a metal radionuclide would be promising for c-kit-targeted imaging of GISTs.     

Quantitative study of radioiodinated metaiodobenzylguanidine uptake in children with neuroblastoma: correlation with tumor histopathology

Six children with neuroblastoma and one with ganglioneuroma received [125I] metaiodobenzylguanidine (MIBG) before major surgery. Uptake of [125I]MIBG in the excised tissues was measured by scintillation counting, and the material was submitted for histopathology. The ranges of uptake of [125I]MIBG, expressed as percent of the injected dose per gram of tissue, were as follows: for neuroblastoma 0.0013-0.071, for ganglioneuroma 0.0017-0.0028, and for non-neoplastic control tissues 0.0002-0.011. The quantitative uptake of [125I]MIBG by neuroblastoma varied between different patients and between different parts of individual tumors. The more undifferentiated tumors took up more [125I]MIBG and may be more likely to respond to targeted radiotherapy with MIBG.