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.     

18F-FDG PET显像在肝癌中的应用

18F-FDG PET在肝脏的原发肿瘤和转移性肿瘤的诊断中有重要价值,特别是在肝肿瘤的诊断、分期和治疗方案的选择方面.结合CT、MRI和超声可以提高诊断的准确性,同时,在对肝肿瘤疗效监测以及评价手术效果方面也有重要作用.     

18F-FDG PET显像在头颈部肿瘤中的应用

目的 探讨^18F-脱氧葡萄糖（FDG）PET显像在头颈部肿瘤中的应用.方法 39例头颈部肿瘤患者,共行56次^18F-FDG PET检查.图像分析采用视觉和半定量（标准摄取值,SUV）方法.结果 ①5例治疗前患者,PET显像使3例改变了分期;34例治疗后患者中,PET显像发现6例头颈部有残存或复发灶,11例淋巴结转移,4例肺部转移,3例骨转移.②22例PET显像阳性患者中,20例经手术病理检查或随访证实,2例假阳性;17例PET显像为阴性的患者均得到随访证实.PET显像用于头颈部肿瘤病情监测的灵敏度为100%,特异性为89.5%,准确性为94.9%.③21例患者有近期CT或MRI检查结果,其中6例PET显像发现了CT或MRI未发现的局部复发病灶和转移淋巴结.6例患者CT或MRI提示有肿瘤复发或转移,但PET显像结果阴性,并经随访证实.④9例患者多次进行PET检查随访,其中5例病灶消失,3例病情进展,1例无变化.结论 ^18F-FDG PET显像可较准确地发现头颈部肿瘤的残存、转移和复发病灶,并为肿瘤分期提供重要依据,但应与炎症鉴别.     

Intravenous furosemide injection during 18F-FDG PET acquisition

Urinary-system elimination of (18)F-FDG can be mistaken for pathologic uptake. Furosemide helps eliminate this artifact. Unnecessary administration should be avoided. Our approach obviates furosemide administration and other invasive procedures in many cases. METHODS: Thirty-seven cancer patients referred for PET to evaluate treatment response or suspected recurrence were prospectively studied using whole-body scanning, with (18)F-FDG injected via dorsal hand catheter beforehand. The catheter was left in place to enable injection of furosemide while the patient was inside the scanner. After abdominopelvic scanning, physicians evaluated the need to inject furosemide. Thirty minutes after furosemide injection, another abdominopelvic scan was obtained to detect postinjection urinary tract changes. RESULTS: Postfurosemide images showed effects due to physiologic elimination in 24 patients (64.9%), of whom 11 patients (45.8%) had more than one inconclusive prefurosemide finding. In 13 patients (35.1%), delayed images confirmed persistent lymph node uptake, including 3 patients (23.1%) with 1 lesion. CONCLUSION: Furosemide injection during scanning reduces artifacts, shortens examinations, and helps avoid invasive procedures.     

Substitution of oral (18)F-FDG for intravenous (18)F-FDG in PET scanning

The aim of this study was to see whether oral administration of (18)F-FDG could be substituted-without significant loss of information-for intravenous injection of (18)F-FDG in patients with difficult intravenous access of any cause, such as that often seen in cancer patients after many cycles of chemotherapy. METHODS: PET after both oral and intravenous administration of (18)F-FDG was performed on 2 healthy volunteers and 7 patients. An interval of 48 h was maintained between the oral administration and the intravenous administration. All scans were visually analyzed. Semiquantitative analysis of specific areas was done by calculating standardized uptake values (SUVs). Scanning was performed 60 min after intravenous tracer administration and 90 min after oral tracer administration. RESULTS: All lesions seen after intravenous administration were visualized on the oral study as well. SUVs were lower on the oral study than on the intravenous study. CONCLUSION: Oral (18)F-FDG can successfully be substituted for intravenous (18)F-FDG in patients with difficult intravenous access. However, because of the large amount of (18)F-FDG retained in the gut, careful interpretation will be required when disease of the gastrointestinal tract is being evaluated.     

FDG PET在肝脏恶性肿瘤诊断中的应用

目的　评价PET诊断恶性肝肿瘤的价值及其局限性。方法　肝内良性占位病变患者10例 ,其中肝囊肿 6例 ,肝血管瘤 4例 ;肝内恶性病变患者 2 8例 ,其中肝细胞肝癌 (HCC) 13例 ,胆管细胞癌 (CCC) 1例 ,转移性肝癌 14例。按体重注入 5 .5 5MBq/kg18F 脱氧葡萄糖 (FDG) ,使用SiemensE CATEXACTHR+ PET仪采集和重建图像。根据FDG摄取将病灶分为 3种类型 ,A型 :病变部位摄取高于周围正常组织 ;B型 :与周围组织相近 ;C型 :低于周围组织或无摄取。结果　 9例HCC和 1例CCC为A型 ,标准摄取值 (SUV)为 3 0 2± 1 33。 3例HCC为B型 ,1例为C型。 14例转移性肝癌PET共发现转移灶 19个。结论　FDGPET可对肝内病灶进行定位、定性及转移的早期诊断 ,但应警惕HCC显像的特殊性 ,以免误诊或漏诊。     

结节病18F-FDG PET显像分析

目的　探讨结节病1 8F 脱氧葡萄糖 (FDG)PET显像特征。方法　 2 4例结节病患者 ,其中有临床症状并经病理检查证实者 5例 ,无临床症状、结节病抗原 (Kveim)试验阳性者 19例。均有胸部CT检查结果。行1 8F FDGPET显像 ,经计算机重建获得冠状、横断、矢状断面图像 ,采用目视法观察病灶的部位和形态 ,计算标准摄取值 (SUV)。结果　目视法见 2 4例患者病灶均分布于双侧肺门和纵隔 ,呈结节形串珠状连接 ,其中 1例有症状患者还伴有左侧腋窝1 8F FDG摄取增高灶。 5例有症状患者 ,结节大小为 ( 2 .16± 0 .67)cm ,SUV为 2 .68± 0 .5 8;19例无症状患者 ,结节大小为 ( 1.5 5± 0 .2 1)cm ,SUV为 1.46± 0 .2 4,前者结节大小明显大于后者 (t =3 .5 4,P <0 .0 1) ,SUV明显高于后者 (t =7 3 8,P <0 .0 1)。 2 4例中CT检查仅发现 1例肺门及纵隔病变而提示为结节病。结论　病灶分布于双侧肺门和纵隔 ,呈结节形串珠状连接为结节病1 8F FDGPET显像特征。有临床症状者 ,结节病灶大小大于无临床症状者 ,1 8F FDG摄取亦高于无临床症状者     

18F-FDG PET显像诊断肾上腺肿瘤

目的　评价1 8F 脱氧葡萄糖 (FDG)PET显像对肾上腺肿瘤的诊断价值。方法　对 2 1例肾上腺肿瘤患者共 2 2个肾上腺病灶行1 8F FDGPET显像 ,对显像结果进行定性和半定量分析 ,并与CT和 (或 )MRI、针刺活组织检查、术后病理检查结果进行对比研究。结果　 9例肾上腺病灶处无明显FDG浓集 ,PET显像诊断为良性病变 ;12例病灶处FDG明显浓集 ,诊断为恶性病变。与病理检查结果比较 ,PET显像定性准确性为 10 0 % ,CT和 (或 )MRI为 6 4 %。良性病变与周围正常组织 (T N)放射性比值为 0 3～ 1 3,平均为 0 7,标准摄取值 (SUV)为 0 98～ 3 89,平均为 1 89;恶性病变T N比值为 3 1～15 1,平均为 6 9,SUV为 3 10～ 15 5 2 ,平均为 6 4 1,两组间差异均有显著性 (P均 <0 0 0 1)。病变性质与肿块大小无相关性。其中 4例PET显像发现了CT和 (或 )MRI未发现的局部淋巴结和远处转移灶12处。结论　1 8F FDGPET显像对肾上腺肿瘤定性诊断的准确性明显高于CT和 (或 )MRI。     

18F-FET与18F-FDG PET显像对照研究

目的探讨O（2-[^18F]氟代乙基）-L-酪氨酸（^18F—FET）对肿瘤的探测能力。方法2例脑瘤患者，用于了解^18F—FETPET显像的全身分布情况。经病理检查或手术证实的其他部位肿瘤患者12例（肺癌6例，胰腺癌、神经内分泌肿瘤各2例，肾上腺皮质癌、鼻咽癌各1例），均有近期CT检查，少数行MRI或全身骨显像检查，1周内分别行^18F—FET与^18F-脱氧萄萄糖（FDG）PET显像。结果①^18F—FET主要经泌尿及胆道系统排泄，骨骼、软组织及心、肝等仅轻度摄取，标准摄取值（SUV）0．38—1．64，肠道、胰腺基本不显影。②12例肿瘤患者^18F—FDGPET显像共检出110个病灶，^18F—FET仅检出15个，病灶的SUV也明显低于^18F—FDG。^18F—FET不仅对一些^18F—FDG代谢活性高的孤立病灶显示不清，对小病灶的检出率也明显低于^18F—FDG。结论^18F—FETPET显像对肺癌、胰腺癌、肾上腺皮质癌等的探测能力明显低于^18F—FDG。     

18F-FDG PET/CT在IgG4相关性疾病中的应用进展

免疫球蛋白G4（IgG4）相关性疾病是近几年新发现和确定的一种复合性免疫系统疾病,其特征为血清IgG4水平升高、受累组织IgG4阳性浆细胞浸润。该病累及范围广,包括泪腺、唾液腺、肺、胰腺、肝脏、胆管、肾脏、前列腺和后腹膜等,临床表现为同时或不同时间各脏器肿大、结节或肥厚。全面、准确地诊断有利于该病的早期治疗和预后改善。18F-FDG PET/CT显像在IgG4相关性疾病中的诊断、疗效评估与随访监测等方面具有重要作用。笔者将对18F-FDG PET/CT在IgG4相关性疾病中的应用及研究进展进行综述。     

18F-FDG PET/CT of thymic epithelial tumors: usefulness for distinguishing and staging tumor subgroups.

The purpose of our study was to assess the usefulness of integrated PET/CT using 18F-FDG for distinguishing thymic epithelial tumors according to the World Health Organization (WHO) classification. METHODS: Thirty-three patients (age range, 34-68 y; mean age, 54.6 y) with thymic epithelial tumors, who underwent both integrated PET/CT and enhanced CT, were included. The clinicopathologic stages, maximum standardized uptake values (SUVs), and uptake patterns of tumors on integrated PET/CT images, and various enhanced CT findings, are described according to the simplified (low-risk [types A, AB, and B1] and high-risk [types B2 and B3] thymomas and thymic carcinomas) subgroups of the WHO classification. Discriminant analysis was performed to determine the relative capabilities of integrated PET/CT and enhanced CT findings to differentiate tumor subgroups. RESULTS: Tumors included 8 low-risk thymomas, 9 high-risk thymomas, and 16 thymic carcinomas. The maximum SUVs of high-risk thymomas (P < 0.001) and low-risk thymomas (P < 0.001) were found to be significantly lower than those of thymic carcinomas. Homogeneous 18F-FDG uptake within tumors was more frequently seen in thymic carcinomas than in high-risk thymomas (P = 0.027) or low-risk thymomas (P = 0.001). The uptake pattern (homogeneous vs. heterogeneous) on integrated PET/CT images and the presence of mediastinal fat invasion on enhanced CT images were found to be useful for differentiating tumor subgroups. In addition, integrated PET/CT helped detect lymph node metastases, which were not identified on enhanced CT in 2 patients. CONCLUSION: Integrated PET/CT was found to be useful for differentiating subgroups of thymic epithelial tumors and for staging the extent of the disease.     

FDG肿瘤显像相关分子机制研究进展

18F-FDG(18F-氟代脱氧葡萄糖)PET显像是依靠不同组织对18F-FDG的吸收差异来完成的,18F-FDG在肿瘤中的摄取增高与肿瘤的代谢及增殖情况、病理分级、分化程度、细胞的增生活性、倍增时间等生物学特性密切相关。进一步研究FDG吸收机制,将有助于对肿瘤的生物学特性更深一步的了解。     

18F-FDG PET/CT delayed images after diuretic for restaging invasive bladder cancer.

PET with (18)F-FDG has been considered of limited value for detection of bladder cancer because of the urinary excretion of the tracer. The purpose of this study was to investigate the role of PET/CT in the detection and restaging of bladder cancer using furosemide and oral hydration to remove the excreted (18)F-FDG from the bladder. METHODS: Seventeen patients with bladder cancer (11 without cystectomy, 6 with total cystectomy and urinary diversion) underwent (18)F-FDG PET/CT from head to the upper thighs 60 min after the intravenous injection of 370 MBq of (18)F-FDG. Additional pelvic images were acquired 1 h after the intravenous injection of furosemide and oral hydration. PET/CT findings were confirmed by MRI, cystoscopy, or biopsy. RESULTS: PET/CT was able to detect bladder lesions in 6 of 11 patients who had not undergone cystectomy. These images changed the PET/CT final reading in 7 patients: Recurrent bladder lesions were detected in 6 patients, pelvic lymph node metastases in 2 patients, and prostate metastasis in 1. This technique overcame the difficulties posed by the urinary excretion of (18)F-FDG. Hypermetabolic lesions could be easily detected by PET and precisely localized in the bladder wall, pelvic lymph nodes, or prostate by CT. Seven of 17 patients (41%) were upstaged only after delayed pelvic images. CONCLUSION: Detection of locally recurrent or residual bladder tumors can be dramatically improved using (18)F-FDG PET/CT with delayed images after a diuretic and oral hydration.     

Evaluation of liver metastases after radiofrequency ablation: utility of 18F-FDG PET and PET/CT

OBJECTIVE: Our objective was to review the CT appearance of liver metastases after radiofrequency ablation and to describe the imaging findings of and utility of (18)F-FDG PET and PET/CT in assessing tumor recurrence after ablation. CONCLUSION: (18)F-FDG PET and PET/CT can provide added diagnostic information compared with conventional imaging in patients after radiofrequency ablation of liver metastases and can be useful in guiding repeat ablation procedures.     

18F-FDG PET/CT的特点及其在肿瘤诊断中的应用

最近几年,具有高性能PET和CT的同机PET/CT已投入临床,其在肿瘤学中的应用呈迅速增长之势.加入高档CT的PET较之传统的PET在技术和临床方面具有明显优势.CT扫描一方面为PET提供了快速、准确的衰减校正数据,大大缩短采集时间,另一方面为PET图像提供了精确的解剖定位,使结果更加肯定,但引入CT的PET扫描也带来了一些技术上的新问题.PET/CT在头颈、腹盆肿瘤具有明显优势,即使在生理运动影响较大的胸部也取得了满意的效果.初步临床研究表明,PET/CT较之单独CT或PET在临床肿瘤学中具有明显优势,PET/CT融合显像对肿瘤患者和临床医生具有越来越重要的价值.     

兔肺VX2移植瘤放疗前后~（18）F-FDG PET及CT观察

目的：探讨兔肺VX2移植瘤模型用于评估肺部肿瘤放射治疗效果的可行性。方法：12只兔肺VX2移植瘤模型行短期大剂量放疗,放疗前及放疗后第7天行18F-FDGPET及CT检查,以常规病理作为金标准。结果：兔肺VX2移植瘤放疗前PET显像,常规SUVmax为2.95±1.04,延迟SUVmax为3.58±1.32;放疗后第7天PET显像,常规SUVmax为1.47±0.36,延迟SUVmax为1.88±0.44。放疗后PET常规显像较放疗前18F-FDG代谢变化百分率下降60.48±5.66,PET延迟显像18F-FDG代谢变化百分率下降57.18±6.79。兔肺VX2移植瘤放疗前后PET常规显像SUV改变与放疗前后PET延迟显像的SUV改变均以t检验分析,放疗前后SUV变化有统计学意义。病理检查见肿瘤组织内大片凝固坏死。结论：兔肺VX2移植瘤模型短期大剂量放疗后行18F-FDGPET显像,其SUV显著降低,可在兔肺VX2移植瘤出现CT形态学改变之前早期评估兔肺VX2移植瘤对放射治疗的反应。     

Beads phantom for evaluating heterogeneity of SUV on 18F-FDG PET images

Annals of Nuclear Medicine - This study aimed to develop a dedicated phantom using acrylic beads for texture analysis and to represent heterogeneous 18F-fluorodeoxyglucose (FDG) distributions in...     

18F-FDG PET显像监测肝癌TACE治疗疗效

目的 :评价18F FDGPET显像监测肝癌动脉插管化疗加栓塞 (TACE)疗效的作用。材料和方法 :3 3例肝癌患者 ,男 2 6例 ,女 7例 ,年龄 2 5～ 74岁 ,18F FDGPET共检查 40人次。其中有 7人 2次行PET显像检查。结果 :2 1例原发性肝癌(HCC)TACE后 ,11例病灶部位代谢降低呈放射性稀疏或缺损 ,SUV1.2～ 1.5 ,其中有 8例SUVratio≤ 0 .6;9例肝脏原发灶代谢增高 ,SUV3 .0～ 7.3 ;1例HCC伴腹水患者PET检查阴性 ,但CT发现肝内结节伴门静脉癌栓形成。 2例胆管细胞癌中 ,1例阴性 ,另 1例第 2次PET检查发现肝门部、腹腔淋巴结转移。 3例转移性肝癌病灶呈放射性缺损 ,SUV1.1～ 1.3 ;其余 7例患者肝内呈多灶性高代谢区 ,SUV3 .0～ 7.6。结论 :FDGPET显像是判断肝癌TACE后肿瘤坏死与存活的有效方法。     

18F-FDG PET显像观察强迫症患者内囊前肢毁损术后脑内环路的改变

目的　用1 8F 脱氧葡萄糖 (FDG)PET显像观察强迫症患者行内囊前肢毁损术后脑内环路的改变。方法　强迫症患者 8例 ,均于行内囊前肢毁损术前后分别行1 8F FDGPET显像 ,应用统计参数图 (SPM)对图像进行分析。结果　SPM分析显示内囊毁损术后左侧扣带回 (Brodmann 32区 )、边缘叶灰质、尾状核、丘脑背内侧核、扣带回 (Brodmann 2 4区 )、中额叶及下额叶白质及右侧壳核外白质、丘脑背内侧核、中额叶及下额叶白质葡萄糖代谢减低 (P <0 0 0 1)。结论　SPM分析可在活体上显示强迫症患者内囊前肢毁损术后扣带回、纹状体和丘脑的代谢明显减低 ,与手术使异常脑环路中断有关。