18F-脱氧葡萄糖正电子发射计算机断层显像CT检查在前列腺癌诊断和分期中的应用价值

目的 评价18F-脱氧葡萄糖(18F-FDG)正电子发射计算机断层显像CT检查(PET/CT)在前列腺癌诊断和分期中的应用价值.方法 经手术或穿刺活检病理证实为前列腺癌患者40例,年龄52 ～ 78岁,平均67岁.其中T24例,T316例,T420例.行18F-FDG PET/CT及99Tcm-MDPECT骨显像检查,统计PET/CT显像对前列腺癌原发灶、淋巴结转移及骨转移诊断的敏感性,对比分析PET/CT显像及99Tcm-MDPECT骨显像对骨转移的诊断效果.结果 40例患者中,18F-FDG PET/CT检查显示前列腺局部结节状放射性浓聚17例,对原发灶诊断敏感性为43％.17例淋巴结转移患者中CT检查发现8例,18F-FDG PET/CT检查发现15例,诊断敏感性为88％,其中5例患者因PET/CT检查改变了临床分期以及治疗方案.18F-FDG PET/CT对骨转移诊断的敏感性与99Tcm-MDP骨显像相近,但特异性(95％)和准确率(96％)均明显高于99Tcm-MDP骨显像,其中6例患者因PET/CT检查改变了临床分期,2例改变了治疗方案.结论 18F-FDG PET/CT对前列腺癌淋巴结转移和骨转移有较高诊断价值,对前列腺的分期具有特殊优势,可为临床医生制定治疗方案提供可靠依据.     

~(18)F-FDG PET/CT和PET/MRI在前列腺癌诊断及分期中的效能研究

目的对比前列腺癌2-氟-2脱氧-D-葡萄糖(~(18)F-FDG)正电子发射断层扫描/计算机断层成像(PET/CT)和正电子发射断层扫描/核磁共振成像(PET/MRI)影像学特征,探讨两种方法在前列腺癌筛查、诊断及分期中的价值。方法回顾性分析20例组织学证实为前列腺癌患者的~(18)F-FDG PET/CT和PET/MRI图像资料,比较两种方法影像学结果,并采用配对t检验和卡方检验进行统计学分析。结果 ~(18)F-FDG PET/CT和PET/MRI对病灶定量的最大标准摄取值(SUVmax)(2.9±0.25 vs.3.2±0.26)有统计学差异(P0.05),PET/CT和PET/MRI探查原发性前列腺癌阳性结果(11例vs.18例)有统计学差异(P0.05),探查周围组织(1例vs.4例)、盆腔淋巴结(4例vs.4例)及骨盆(6例vs.5例)的转移效能无统计学差异(P0.05)。结论 ~(18)F-FDG PET/MRI诊断原发性前列腺具有优势,在探查周围侵犯、盆腔淋巴或骨盆转移时和PET/CT无明显差异。临床工作中合理选择或联合应用有助于前列腺癌筛查、诊断及分期的全面评估。     

~(18)F-FDG PET/CT显像在泌尿系肿瘤中的临床应用

18F-脱氧葡萄糖正电子发射断层显像/CT技术(18F-FDG PET/CT)显像在多种恶性肿瘤的诊断、鉴别诊断、分期、随访监测、疗效与预后评估中起重要作用,但是其在泌尿系肿瘤中却因为18F-FDG由泌尿系统排泄而影响观察,肾细胞癌与前列腺癌原发肿瘤病灶则表现为少摄取或不摄取18 F-FDG而呈现假阴性表现。本文旨在探讨18F-FDG PET/CT显像在泌尿系统肿瘤中的潜在临床应用价值。     

核磁共振、正电子发射扫描在感染性脊柱炎诊断中的应用价值研究

目的 探讨核磁共振(MRI)、18氟-氟代脱氧葡萄糖(18F-FDG)正电子发射断层扫描成像/计算机断层扫描成像(PET/CT)在感染性脊柱炎诊断中的应用价值.方法 回顾2001年1月～2019年12月期间在河北北方学院附属第一医院进行感染性脊柱炎筛查的100例患者的临床资料.所有受试者经组织病理学和细菌学检查,有明确的诊断结果,并接受MRI及18 F-FDG PET/CT检查.分析MRI、18 F-FDG PET/CT检查在感染性脊柱炎诊断中的意义.结果 MRI、18 F-FDG PET/CT检查均为感染性脊柱炎诊断结果的独立影响因素.ROC曲线分析结果显示,MRI、18 F-FDG PET/CT及联合预测因子在诊断感染性脊柱炎中的曲线下面积(AUC)分别为0.896、0.958、0.973,均有统计学意义(P<0.01).MRI与18F-FDG PET/CT联合检测在感染性脊柱炎诊断中的诊断效能最理想,准确度、敏感度、特异度分别为99.00％、100.00％、97.50％.结论 将MRI与18 F-FDG PET/CT联合检测感染性脊柱炎,能够明显提升诊断的准确率.     

18F-FDG PET/CT显像在肾癌中的临床应用价值

目的:评价18F-脱氧葡萄糖(18F-fluorodeoxyglucose,18F-FDG)正电子发射计算机断层扫描(PET)/CT显像对肾癌诊断和治疗方案选择的临床应用价值.方法:回顾性分析56例临床诊断为肾癌患者的全身18F-FDG PET/CT和CT平扫加增强扫描的影像学资料.比较两者对肾癌的诊断价值.结果:56例患者中,经手术病理检查实为肾癌者47例.其余9例因18F-FDG PET/CT显像发现有转移病灶者放弃手术.18F-FDG;PET/CT 榆古敏感度为80.4%;CT平扫加增强扫描的敏感度为92.9%.9例转移病例中,3例为腹膜后淋巴结转移,3例两肺多发转移,2例骨转移并肝转移,1例伴有下腔静脉和肾静脉癌栓形成,而CT平扫加增强扫描仅发现1例肾静脉和下腔静脉痛栓形成.结论:18F-FDG PET/CT显像对诊断原发性肾癌的敏感性不如CT,但对淋巴结转移及远处转移的诊断优于CT,对肾癌的分期、治疗方案的选择及预后的判断有重要意义.     

上尿路尿路上皮癌的18F-FDG PET/CT诊断及评价

目的探讨18F-FDG PET/CT在上尿路尿路上皮癌诊断中的应用价值。方法回顾性分析我中心自2000年4月至2010年12月间29例可疑上尿路尿路上皮癌患者的资料,29例患者在介入、手术及其他治疗前均行静脉尿路造影(IVU)、螺旋CT及18F-FDG PET/CT检查。分析3种影像学检查方法的诊断准确性。结果 29例中,18F-FDG PET/CT检查诊断上尿路尿路上皮癌26例(89.7%),26例均经手术病理证实为上尿路尿路上皮癌。对照手术病理结果,IVU的敏感性和特异性分别为64.0%和75.0%;螺旋CT的敏感性和特异性分别为75.0%和80.0%;而18F-FDGPET/CT的敏感性和特异性分别为92.9%和100%。18F-FDG PET/CT的敏感性高于IVU和螺旋CT(P=0.041vsCT,P=0.036vs IVU),同时特异性也高于IVU和螺旋CT(P=0.041vs CT,P=0.036vs IVU)。结论 18F-FDG PET/CT在上尿路尿路上皮癌的诊断中其敏感性和特异性均高于IVU和螺旋CT,为一种有用的临床诊断方法。上尿路尿路上皮癌的最后诊断需经手术病理证实。     

疑似前列腺癌患者行68Ga-PSMA-11 PET/CT检查的护理

对6例怀疑前列腺癌患者采用新型肿瘤显像剂~(68)Ga-PSMA-11行PET/CT检查,以~(18)F-FDG护理方法为参考,依据~(68)Ga-PSMA-11药理作用特点调整护理方法,均顺利完成检查并获得满意的诊断图像。提示~(68)Ga-PSMA-11用于PET/CT检查可部分参考~(18)F-FDG护理方法,但具有自己的特色,不需要禁食禁饮、不需要测空腹血糖、显像剂可与呋噻米同时静脉注射等。     

单发脑转移瘤的18F-FDG PET/CT显像特点

目的探讨单发脑转移瘤的18F-FDG PET/CT显像特点,以提高其诊断准确率。方法回顾性分析62例单发脑转移瘤患者的头部18F-FDG PET/CT显像资料,根据最大径将病灶分为1.0cm和≥1.0cm 2组,采用χ2检验比较2组病灶的瘤周水肿及18F-FDG摄取情况。依据CT表现将病灶分为高密度结节、等密度结节及囊性密度结节3种形式,采用χ2检验分析不同CT表现形式病灶的18 F-FDG摄取情况。结果本组62例单发脑转移瘤,发生于幕上52例(52/62,83.87%),幕下10例(10/62,16.13%)。1.0cm和≥1.0cm两组病灶的瘤周水肿差异有统计学意义(χ2=7.414,P=0.006),而18F-FDG摄取差异无统计学意义(χ2=2.647,P=0.104)。不同CT表现形式18 F-FDG摄取情况差异有统计学意义(χ2=14.480,P=0.001);大部分(11/12,91.67%)高密度结节型的病例18 F-FDG摄取不超过2级;而等密度结节型18F-FDG摄取均不低于1级,并以3级居多(17/34,50.00%);56.25%(9/16)的囊性密度结节型表现为18 F-FDG无摄取。结论单发脑转移瘤的18 F-FDG PET/CT表现形式多种多样,掌握其18 F-FDG PET/CT显像特点,有助于提高诊断准确率。     

乳腺癌BALB/c小鼠生物发光活体成像和小动物~(18)F-FDG PET/CT成像的比较研究

目的比较生物发光和小动物PET/CT成像技术在BALB/c小鼠乳腺癌原位移植模型中的显像效果,寻找适合的评价乳腺癌肿瘤模型的分子影像学方法。方法将表达荧光素酶基因的乳腺癌细胞4T1接种于雌性BALB/c小鼠左侧第二对乳房垫下使其成瘤,活体荧光成像和小动物PET/CT成像观察肿瘤的生长情况。~(18)F-FDG PET/CT显像利用IRW软件对图像进行分析,采用感兴趣区技术(ROI)测量组织~(18)F-FDG摄取值。结果生物发光活体成像操作步骤相对较简单;活体荧光成像系统观察能够特异性地探测到肿瘤组织,小动物PET/CT影像观察发现小鼠体内多数器官组织都有~(18)F-FDG摄取,但肿瘤组织在所有组织、器官中~(18)F-FDG摄取值最高;~(18)F-FDG药物吸收时间30~60 min,有放射性,荧光素钾盐药物吸收时间3~5 min,无放射性;小动物PET/CT成像用时20 min,生物发光活体成像用时3 min;小动物PET/CT分辨率1 mm,生物发光活体成像分辨率1~10 mm;小动物PET/CT呈三维成像,生物发光活体成像呈二维成像。结论生物发光活体成像比~(18)F-FDG PET/CT特异性好,操作简单,图像采集时间短,价钱便宜,无放射性,可检测细胞存活状态,但小动物PET/CT分辨率较高,可精准定位,图像三维立体,可监测到细胞的代谢能力,为以后实验研究中正确选择活体影像学监测手段提供依据。     

脊椎骨挫伤的18F-FDG PET/CT诊断价值

目的探讨18F-FDG PET/CT对脊椎骨挫伤的诊断价值。方法回顾我院18例脊椎骨挫伤的PET/CT表现,SUV>2.5定为放射性摄取增高,并对比MRI图像,分析其对脊椎骨挫伤的诊断符合率。随访时间为6～24个月。结果有完整资料的18例脊椎骨挫伤患者,X线平片及CT未能检出异常,MRI诊断骨挫伤6例(33.3%),其余均诊断为转移瘤。18F-FDG PET/CT诊断脊椎骨挫伤18例,共计20个椎体,其中16例为单一椎体,2例患者表现为2个椎体,以胸腰段椎体为主。PET/CT和MRl检出病灶率相同,均为100%,定性诊断正确率分别为100%和40%,二者定性诊断比较有统计学意义(X2=17.14,P<0.05)。结论 PET/CT在诊断脊椎骨挫伤方面优于MRI,能为临床的诊治提供更准确的影像信息。     

18F-FDG PET/CT影像组学预测恶性肿瘤预后

¹⁸F-FDG PET/CT影像组学可通过自动、高通量方法自PET/CT图像中提取大量定量特征。应用人工智能和机器学习技术进一步推动了¹⁸F-FDG PET/CT影像组学在恶性肿瘤预后研究的进展,有望更好地指导临床管理恶性肿瘤患者。本文对¹⁸F-FDG PET/CT影像组学用于评估常见恶性肿瘤预后进展进行综述。     

18F-FDG PET/CT评价非霍奇金淋巴瘤骨髓浸润

目的探讨^18F-FDG PET／CT评价非霍奇金淋巴瘤（NHL）骨髓浸润的临床应用价值,并与骨髓活检（BMB）及流式细胞分析（FCM）进行比较。方法回顾性分析89例经病理证实且未经治疗的NHL患者^18F-FDG PET／CT资料,其中侵袭性NHL76例,惰性NHL13例。所有患者均在^18F-FDG PET／CT检查2周内接受BMB及FCM,对^18F-FDG PET／CT显示骨髓局灶性^18F—FDG摄取增高而BMB及FCM阴性患者,根据PET／CT所示骨髓异常部位再次行BMB确定骨髓是否受累。结果89例NHL患者中,根据BMB、FCM及PET／CT引导下再次BMB结果,共检出骨髓浸润26例,检出率为29．21％（26／89）,PET／CT检出率为21．35％（19／89）。PET／CT诊断骨髓浸润的灵敏度为73．08％（19／26）,特异度为96．83％（61／63）,准确率为89．89％（80／89）,阳性预测值为90．48％（19／21）,阴性预测值为89．71％（61／68）。BMB及FCM检出率均为19．10％（17／89）,PET／CT较BMB、FCM骨髓浸润检出率稍高,但差异无统计学意义（P〉0．05）。将PET／CT、FCM及BMB三种方法联合诊断骨髓浸润,其检出率高于其中任意一种方法（P〈0．05）。PET／CT对侵袭性NHL骨髓浸润的检出率22．37％（17／76）高于对惰性NHL骨髓浸润的检出率15．38％（2／13,P〈0．06）。结论^18F-FDG PET／CT在诊断NHL骨髓浸润中有较高的应用价值。对局灶性骨髓浸润患者,PET／CT有助于引导BMB部位,提高骨髓浸润的检出率。PET／CT未检出骨髓浸润的惰性NHL患者,应进一步行BMB及FCM检查。推荐PET／CT、FCM及BMB三种方法联合应用判断NHL骨髓浸润,从而更准确地进行分期、治疗及判断预后。     

18F-FDGPET/CT在非小细胞肺癌早期化疗疗效评价中的应用

18F-FDG PET/CT是一种从细胞分子水平反映肿瘤组织生化和代谢变化的功能显像方法,其监测肿瘤治疗疗效的原理是基于肿瘤细胞在化疗后对葡萄糖代谢的变化。近年来,越来越多的研究致力于18 F-FDG PET/CT在评价非小细胞肺癌化疗疗效方面的作用。本文就18F-FDG PET/CT在非小细胞肺癌早期化疗疗效评价中的应用价值进行综述。     

Clinical value of 18FDG PET/MRI in muscle-invasive,locally advanced,and metastatic bladder cancer

ObjectiveMetastatic bladder cancer is an aggressive disease that can often be difficult to diagnose and stage with conventional cross-sectional imaging. The primary objective of this study was to determine the clinical value of fluorine-18 2-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) PET/MRI for surveillance and restaging of patients with muscle-invasive, locally advanced, and metastatic bladder cancer compared to conventional imaging methods.Materials and MethodsThis retrospective study enrolled patients with muscle-invasive, locally advanced and metastatic bladder cancer in a single institute evaluated with ¹⁸F-FDG PET/MRI. All patients also underwent conventional imaging with CT. Additional imaging may also have included ¹⁸F-FDG PET/CT (¹⁸F-FDG PET), or sodium fluoride (NaF) PET/CT in some patients. Images were reviewed by a diagnostic radiologist/nuclear medicine physician. Number of lesions and sites of disease were captured and compared between ¹⁸F-FDG PET/MRI and conventional imaging. Lesions were confirmed by sequential imaging or lesion biopsy. All patients were followed for survival.ResultsFifteen patients (4 for surveillance; 11 for restaging) underwent 34 ¹⁸F-FDG PET/MRI scans. Each patient received a corresponding conventional CT around the time of the ¹⁸F-FDG PET/MRI (median 6 days). The 15 patients (11 male; 4 female) had a median age of 61.5 years (range 37–73) and histologies of urothelial carcinoma (n = 13) and small-cell carcinoma of the bladder (n = 2) diagnosed as stage 4 (n = 13), stage 3 (n = 1), or stage 2 (n = 1). ¹⁸F-FDG PET/MRI detected 82 metastatic malignant lesions involving lymph nodes (n = 22), liver (n = 10), lung (n = 34), soft tissue (n = 12), adrenal glands (n = 1), prostate (n = 1), and bone (n = 2) with a resultant advantage of 36% for lesion visibility in comparison with CT. Serial imaging or biopsy confirmed these lesions as malignant.Conclusion¹⁸F-FDG PET/MRI can detect metastatic lesions which cannot be identified on conventional CT, and this can allow for better treatment planning and improved disease monitoring during therapy.     

Dual-Time <Superscript>18</Superscript>F-FDG PET/CT Imaging in Initial Locoregional Staging of Breast Carcinoma: Comparison with Conventional Imaging and Pathological Prognostic Factors

The aims of this retrospective study were to consider the diagnostic role of dual-time ¹⁸F-fluorodeoxyglucose positron emission tomography and computed tomography (¹⁸F-FDG PET/CT) in detection of breast carcinoma and axillary lymph node (ALN) status and to evaluate the primary tumor ¹⁸F-FDG uptake pattern. Preoperative staging was performed by ¹⁸F-FDG PET/CT in 78 female patients with breast carcinoma. Conventional imaging results were evaluated by breast magnetic resonance imaging (MRI) of 79 lesions in 78 patients, bilateral mammography (MMG) of 40 lesions in 40 patients, and breast ultrasonography (USG) of 47 lesions in 46 patients. The primary tumor detection rate using ¹⁸F-FDG PET/CT was higher than those using MRI, USG, and MMG. The sensitivity and specificity of ¹⁸F-FDG PET/CT scans for detecting multifocality were higher than those of MRI. The specificity of ALN metastasis detection with MRI was higher than that with ¹⁸F-FDG PET/CT, but ¹⁸F-FDG PET/CT had higher sensitivity. Higher ¹⁸F-FDG uptake levels were detected in patients with ALN metastasis, histologic grade 3, estrogen–progesterone-negative receptor status, lymphatic invasion, and moderate to poor prognostic groups. There was no statistical difference for the retention index in categorical pathological parameters except for progesterone-negative status. In conclusion, ¹⁸F-FDG PET/CT scans may be a valuable imaging technique for evaluating primary tumor and axillary status in staging breast carcinoma and ¹⁸F-FDG uptake may be a prognostic factor that indicates aggressive tumor biology and poor prognosis. Dual-time imaging in breast carcinoma staging may not be used for predicting pathological criteria and the aggressiveness of primary lesions.     

18F-FDG PET/CT在胆道系统恶性肿瘤中的应用

目的探讨~(18)F-FDG PET/CT诊断胆道系统恶性肿瘤的价值。方法回顾性分析34例临床疑似胆道恶性肿瘤患者的PET/CT影像资料,均获得术后病理结果,其中12例经手术切除淋巴结或淋巴结穿刺活检对18枚淋巴结获得病理诊断;与病理结果对照,计算PET/CT对胆道恶性病变原发灶、淋巴结转移的灵敏度、特异度、阳性预测值、阴性预测值及准确率。结果 34例中,31例为恶性病变,3例为良性病变。PET/CT诊断胆道恶性肿瘤原发灶的灵敏度100%(31/31),特异度66.67%(2/3),阳性预测值96.88%(31/32),阴性预测值100%(2/2),准确率97.06%(33/34)。胆道恶性病变原发灶最大标准摄取值(SUV_(max))为8.42±4.27;3例胆道良性疾病SUV_(max)分别为12.90、2.00及1.90。共18枚淋巴结获得病理结果,包括转移性淋巴结13枚,良性增生5枚。PET/CT诊断淋巴结转移的灵敏度76.92%(10/13),特异度60.00%(3/5),阳性预测值83.33%(10/12),阴性预测值50.00%(3/6),准确率72.22%(13/18)。结论 PET/CT对胆道系统恶性肿瘤的诊断具有重要价值。     

18F-FDGPET/CT与传统影像检查寻找骨转移瘤原发灶的比较

[目的]比较18F-FDG PET/CT与传统影像检查(胸片、彩超、CT及MRI等)为骨转移瘤患者寻找原发灶的临床价值.[方法]回顾性分析37例于2008年5月～2010年6月间本中心收治的经病理证实的骨转移瘤患者的病例资料,并随访其后续的诊治情况.以病理结果或临床随访作为原发灶确认标准.并将PET/CT与传统影像检查对原发灶的检出情况进行比较.且对治疗方案的调整进行汇总.[结果]37例患者中,PET/CT提示原发灶28例,其中正确检出原发灶27例(73％),1例为假阳性;传统影像检查正确检出原发灶17例(46％),两者原发灶正确检出率的差异有显著性(x2=5.61,P=0.018).27例经PET/CT正确检出原发灶的病例中,17例(63％)采取了针对原发灶的治疗措施.此外9例PET/CT未提示原发灶的患者中,3例经病理证实为假阴性.[结论]与传统影像检查相比,18F-FDG PET/CT可更有效、更便捷的找出骨转移瘤患者原发灶,进而为制定更合理的治疗方案提供依据.     

La tomographie par émission de positons au 18F-FDG en pathologie rénale non oncologique : indications actuelles et perspectives

Positron emission tomography combined with computed tomography (PET/CT) is a nuclear imaging technique which provides anatomical and functional information. PET/CT is increasingly used in non-oncological nephrology since conventional radiological approaches after injection of contrast agents are relatively contra-indicated in patients with chronic kidney disease (CKD). PET/CT after i.v. injection of ¹⁸F-fluoro-deoxy-glucose (FDG) is not toxic and is characterized by a high sensitivity. The level of irradiation (∼5 mSv) is acceptable. CKD does not significantly influence tissue uptake of ¹⁸F-FDG. The purpose of the present review aims at detailing the non-oncological indications of ¹⁸F-FDG PET/CT in general nephrology and after kidney transplantation. Particularly, ¹⁸F-FDG PET/CT appears useful in the diagnosis of cyst infection in patients with autosomal dominant polycystic kidney disease, as well as in the characterization of retroperitoneal fibrosis. In kidney transplant recipients, ¹⁸F-FDG PET/CT may help in the diagnostic work-up of suspected acute rejection, thereby eventually avoiding unnecessary kidney transplant biopsy. Perspectives in ¹⁸F-FDG PET/CT imaging are discussed, including innovative approaches of image analysis.     

Characteristics of Primary Papillary Thyroid Carcinoma with False-Negative Findings on Initial 18F-FDG PET/CT

Background

We often observe that uptake of tracer is not detected in the primary cancer focus in patients with histologically proven papillary thyroid carcinoma (PTC) on preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT). Therefore, we analyzed the clinical and pathologic variables affecting false-negative findings in primary tumors on preoperative ¹⁸F-FDG PET/CT.

Methods

We retrospectively reviewed the medical records of 115 consecutive patients who underwent ¹⁸F-FDG PET/CT for initial evaluation and were diagnosed with PTC by postoperative permanent biopsy. The clinical and pathologic characteristics that influence the ¹⁸F-FDG PET/CT findings in these patients were analyzed with respect to the following variables: age, gender, tumor size, multifocality of the primary tumor, perithyroidal invasion, lymphovascular or capsular invasion, and central lymph node metastasis-based final pathology.

Results

Twenty-six (22.6%) patients had false-negative ¹⁸F-FDG PET/CT findings. In patients with negative ¹⁸F-FDG PET/CT findings, tumor size, and perithyroidal and lymphovascular invasion were significantly less than in patients with positive ¹⁸F-FDG PET/CT findings. Tumors >1 cm in size were correlated with ¹⁸F-FDG PET/CT positivity. On multivariate analysis, perithyroidal invasion (P = 0.026, odds ratio = 7.714) and lymphovascular invasion (P = 0.036, odds ratio = 3.500) were independent factors for ¹⁸F-FDG PET/CT positivity. However, there were no significant differences between ¹⁸F-FDG PET/CT positivity and age, gender, capsular invasion, and central lymph node metastasis based on final pathology.

Conclusions

Tumor size and perithyroidal and lymphovascular invasion of papillary carcinoma can influence ¹⁸F-FDG PET/CT findings. Absence of perithyroidal and lymphovascular invasion were independent variables for false-negative findings on initial ¹⁸F-FDG PET/CT in patients with PTC.