双时相PET显像在肺良恶性病变鉴别诊断中的应用

目的　评价双时相显像在肺部结节良恶性鉴别诊断中的应用价值。方法　对 3 2例肺癌患者和 15例肺良性病变患者进行1 8F 脱氧葡萄糖 (FDG)PET双时相显像 ,早期显像于注射FDG后40～ 65min ,延迟显像于注射后 1.5～ 2 .5h进行 ,测定两次显像病灶的标准摄取值 (SUV) ,并计算两次显像SUV变化率 (ΔSUV)。结果　肺癌组早期显像SUV为 4.3 2± 2 .5 9,延迟显像为 6.71± 4.2 6,ΔSUV为 ( 5 4.5 9± 2 8.96) %。而肺部良性病变早期显像SUV为 2 .83± 1.3 6,延迟显像为 3 .3 1± 1.95 ,ΔSUV为 ( 18.11± 2 5 .3 9) %。结论　双时相显像方法简便 ,在临床上具有一定的实用价值。肺恶性病变延迟显像SUV升高的幅度高于良性病变 ,但结核及炎性肉芽肿延迟显像SUV可增高     

Dual time point 18F-FDG PET imaging for differentiating malignant from inflammatory processes.

The aim of this study was to investigate the difference in the rates of FDG uptake between malignant and inflammatory cells and processes. METHODS: In vitro studies: (18)F-FDG uptake by different tumor cell lines (human mesothelioma [REN]; rat mesothelioma [II45]; mice melanoma [B18F10]; mice mesothelioma [AB12]; human myeloma [GM1500]; and human ovarian cancer [SKOV3]) and peripheral blood mononuclear cells isolated from 8 healthy human volunteers was measured 20 and 60 min after FDG was added into growth medium. Animal studies: II45 cells were implanted into the left flank of rats (n = 5) and a focal inflammatory reaction (mechanical irritation) was generated in the right flank. PET images at 45 and 90 min after injection of FDG were obtained and standardized uptake values (SUVs) were determined. Patient studies: Seventy-six patients who had dual time FDG PET scans were retrospectively analyzed. All results were expressed as the percentage change in SUV of the later time image from that of the earlier time (mean +/- SD). RESULTS: In vitro studies: Except for the SKOV3 cell line, which had only minimally increased FDG uptake (+10% +/- 26%; P > 0.3), all other tumor cell lines tested showed significantly increased FDG uptake over time (GM1500, +59% +/- 19%; B18F10, +81% +/- 15%; AB12, 93% +/- 21%; II45, +161% +/- 21%; REN, +198% +/- 48%; P < 0.01 for all). By contrast, FDG uptake in mononuclear cells was decreased in 7 of 8 donors. Animal studies: SUVs of tumors from 90-min images were significantly higher than those from 45-min images (+18% +/- 8%; P < 0.01), whereas the SUVs of inflammatory lesions decreased over time (-17% +/- 13% of the early images; P < 0.05). Clinical studies: The SUVs of delayed images from the known malignant lesions compared with those of earlier scans increased over time (+19.18% +/- 9.58%; n = 31; P < 0.001; 95% confidence interval, 15.8%-22.6%). By contrast, the SUVs of benign lung nodules decreased slightly over time (-6.3% +/- 8.1%; n = 12; P < 0.05; 95% confidence interval, -10.9% to -1.7%). The SUV of inflammatory lesions caused by radiation therapy (+1.16% +/- 7.23%; n = 8; P > 0.05; 95% confidence interval, -3.9%-6.2%) and the lesions of painful lower limb prostheses (+4.03% +/- 11.32%; n = 25; P > 0.05; 95% confidence interval, -0.4%-8.5%) remained stable over time. CONCLUSION: These preliminary data show that dual time imaging appears to be useful in distinguishing malignant from benign lesions. Further research is necessary to confirm these results.     

The value of SUV in 18F-FDG and 18F-FLT PET imaging for diagnosing pulmonary nodules

目的:探讨18F-氟氏脱氧葡萄糖(18F-FDG)和18F-氟氏胸腺嘧啶(18F-FLT)PET显像诊断肺结块的影响因素,以提高PET/CT对肺结块的诊断价值.方法:选择肺结块患者55例为研究对象,其中28例为肺内孤立结块,其余为2～3个结块,结块大小0.6～11.0 cm.所有患者均行肺部18F-FDG和18F-FLT PET/CT检查.检查结果按不同性别、年龄、结块大小及病理类型进行分组,以各组18F-FDG和18F-FLT显像标准摄取值(SUV)的均数为界定标准.分析SUV与肺结块患者的性别、年龄、结块大小及病理类型等相互关系.结果:55例肺结块患者,不同性别、年龄、结块大小患者的18F-FDG和18F-FLT显像SUV差异均无统计学意义(P>0.05),不同病理类型患者的18F-FDG显像SUV差异无统计学意义(P>0.05),而不同病理类型患者的18F-FLT显像SUV差异有统计学意义(P<0.05).结论:肺结块患者结块的病理类型是影响18F-FLT显像SUV的重要因素,18F-FLT PET/CT显像SUV鉴别诊断肺结块良恶性具有重要的价值和意义.     

~(18)F-FDG和~(18)F-FLT PET显像SUV在肺结块诊断中的价值

目的:探讨18F-氟氏脱氧葡萄糖(18F-FDG)和18F-氟氏胸腺嘧啶(18F-FLT)PET显像诊断肺结块的影响因素,以提高PET/CT对肺结块的诊断价值。方法:选择肺结块患者55例为研究对象,其中28例为肺内孤立结块,其余为2～3个结块,结块大小0.6～11.0cm。所有患者均行肺部18 F-FDG和18 F-FLT PET/CT检查,检查结果按不同性别、年龄、结块大小及病理类型进行分组,以各组18F-FDG和18F-FLT显像标准摄取值(SUV)的均数为界定标准,分析SUV与肺结块患者的性别、年龄、结块大小及病理类型等相互关系。结果:55例肺结块患者,不同性别、年龄、结块大小患者的18 F-FDG和18F-FLT显像SUV差异均无统计学意义(P>0.05),不同病理类型患者的18 F-FDG显像SUV差异无统计学意义(P>0.05),而不同病理类型患者的18F-FLT显像SUV差异有统计学意义(P<0.05)。结论:肺结块患者结块的病理类型是影响18F-FLT显像SUV的重要因素,18F-FLT PET/CT显像SUV鉴别诊断肺结块良恶性具有重要的价值和意义。     

18F-FDG和18F-FLT PET/CT不同诊断方法在肺部单发结节中的临床价值分析

目的：探讨18F-FDG和18F-胸腺嘧啶核苷（FLT）PET/CT不同的诊断方法对肺部单发结节的诊断价值。方法对40例发现肺部单发结节的患者行18F-FDG和18F-FLT PET/CT显像,所有病例均经病理或密切随访确诊,应用受试者工作特征（ROC）曲线比较18F-FDG SUVmax、18F-FLT SUVmax、18F-FLT SUVmax/同层面椎体SUVmax对肺部恶性肿瘤的诊断价值;18F-FDG和18F-FLT PET/CT两种显像结果均行视觉分析和半定量分析,比较不同诊断方法的诊断效能。结果18F-FDG SUVmax、18F-FLT SUVmax及18F-FLT SUVmax/同层面椎体SUVmaxROC曲线下面积分别为0.687、0.821和0.817。以18F-FDG SUVmax>2.5、18F-FLT SUVmax>2.0为恶性诊断标准、18F-FDG PET/CT视觉分析评分法、18F-FLT PET/CT视觉分析评分法4种方法诊断肺癌的灵敏度、特异度和准确率分别为88.2%、73.9%和80.0%;58.8%、82.6%和72.5%;94.1%、91.3%和92.5%;88.2%、65.2%和75.0%。结论18F-FLT SUVmax及18F-FLT SUVmax/同层面椎体SUVmax单独诊断肺部恶性肿瘤的价值较18F-FDG SUVmax高,且前两者可替换使用。18F-FDG PET/CT视觉评分法在肺部单发结节良恶性的诊断中效能最佳。     

18F-FDG PET of pulmonary embolism

OBJECTIVE: The purpose of this study was to describe the manifestations of pulmonary embolism on 18F-FDG PET scans in 13 patients. CONCLUSION: The activity of acute pulmonary embolism on FDG PET scans was significantly higher than the activity of vessels not containing thrombi. The shape of the abnormal FDG uptake may be focal or curvilinear.     

18F-FDG PET/CT在孤立性肺结节和肿块中误诊原因分析

目的多中心回顾性分析18^F-FDG PET／CT对孤立性肺结节和肿块误诊的原因，以提高诊断准确性。方法从全国拥有PET／CT的10家医院筛选出已经获得病理检查结果的孤立性肺结节和肿块病例，收集18^F-FDG PET／CT检查结果、病理检查结果、SUV等资料。18^F-FDG PET／CT结果为肺癌、肺癌可能性大、肺癌可能者为阳性；结果为良性病变、良性可能性大、良性可能者为阴性。采用SPSS10．0软件对资料进行分析。结果共收集到经病理检查证实的孤立性肺结节和肿块患者资料226例，其中18^F-FDG PET／CT误诊27例（11．95％）。27例中误诊为恶性病变18例（66．67％），误诊为良性病变9例（33．33％）。误诊为恶性病变的18例中，病理检查证实炎症8例，结核5例，炎性假瘤4例，纵隔良性肿瘤1例，炎症、结核、炎性假瘤共17例；误诊为良性病变的9例中，病理检查证实中高分化腺癌6例（包括1例细支气管肺泡癌），中高分化鳞癌1例，低分化鳞癌和肺黏膜相关淋巴瘤各1例。11例病理检查为良性病变的SUVmean〉2．5，4例病理检查为恶性病变的SUVmean。〈2．5，良恶性病变的SUV有交叉。良性病变的平均SUVmax为7．2±5．5，平均SUVmean。为5．0±4．5；恶性病变的平均SUVmax为5．3±3．5，平均SUVmean为3．9±2．9，良、恶性病变的SUV差异无统计学意义。27例误诊患者中，年龄〈60岁者11例，其中10例误诊为恶性病变，仅1例误诊为良性病变。27例误诊中的2例，因为对CT形态学缺乏必要的认识而误诊为恶性病变。结论18^F-FDG PET／CT对孤立性肺结节和肿块误诊的原因主要是：（1）炎症、结核、炎性假瘤易误诊为恶性病变，中高分化的腺癌、鳞癌易误诊为良性病变；（2）良性病变和恶性病变的SUV有交叉，且差异无统计学意义；（3）18^F-FDG PET／CT对孤立性肺结节和肿块进行鉴别诊断时，年龄是重要的参考指标；（4）部分PET／CT专业医师对CT的形态学表现缺乏足够的认识。     

Dual time point 18F-FDG PET imaging detects breast cancer with high sensitivity and correlates well with histologic subtypes.

This prospective study was designed to assess the utility of the dual time point imaging technique by (18)F-FDG PET in detecting primary breast cancer and to determine whether there is a relationship between (18)F-FDG uptake and its change over time and the histopathologic subtypes. METHODS: One hundred fifty-two patients with newly diagnosed breast cancer underwent 2 sequential PET scans (dual time point imaging) for preoperative staging. The maximum standardized uptake value (SUVmax) of (18)F-FDG was measured from both time points. The percent change in SUVmax (Delta%SUVmax) between time points 1 (SUVmax1) and 2 (SUVmax2) was calculated. Patients were divided into 2 groups according to histopathology as invasive and noninvasive. Invasive tumors were also divided into 2 groups (>10 mm and 4-10 mm). The tumor-to-contralateral normal breast (background) ratios of SUVmax at both time points for groups were measured and the Delta%SUVmax values were calculated. RESULTS: The mean +/- SD of the SUVmax1, the SUVmax2, and the Delta%SUVmax were 3.9 +/- 3.7, 4.3 +/- 4.0, and 8.3% +/- 11.5% for invasive; 2.0 +/- 0.6, 2.1 +/- 0.6, and 3.4% +/- 13.0% for noninvasive; and were 1.2 +/- 0.3, 1.1 +/- 0.2, and -10.0% +/- 10.8% for the contralateral normal breast groups, respectively. In the comparison of SUVmax1, Delta%SUVmax, and the tumor-to-background ratios among groups, all results were significant (P < 0.001). Visual assessment revealed that the sensitivity of dual time point imaging was 90.1% for invasive cancer >10 mm, 82.7% for invasive breast cancers 4-10 mm, and 76.9% for noninvasive breast cancers. CONCLUSION: Dual time point imaging is a simple and noninvasive method that may improve the sensitivity and accuracy of (18)F-FDG PET in assessing patients with primary breast cancer. The changes that are noted in SUVs in dual time point imaging vary depending on the histopathologic type of primary breast cancer.     

Dual-time-point 18F-FDG PET for the evaluation of gallbladder carcinoma.

Conventional imaging techniques such as ultrasonography, CT, and MRI are able to detect gallbladder abnormalities but are not always able to differentiate a malignancy from other disease processes such as cholecystitis. The purpose of the present study was to evaluate the efficacy of dual-time-point (18)F-FDG PET for differentiating malignant from benign gallbladder disease. METHODS: The study evaluated 32 patients who were suspected of having gallbladder tumors. (18)F-FDG PET (whole body) was performed at 62 +/- 8 min (early) after (18)F-FDG injection and was repeated 146 +/- 14 min (delayed) after injection only in the abdominal region. We evaluated the (18)F-FDG uptake both visually and semiquantitatively. Semiquantitative analysis using the standardized uptake value (SUV) was performed for both early and delayed images (SUV(early) and SUV(delayed), respectively). The retention index (RI) was calculated according to the equation (SUV(delayed) - SUV(early)) x 100/SUV(early). The tumor-to-liver ratio was also calculated. Results: The final diagnosis was gallbladder carcinoma in 23 patients and benign disease in 9 patients. For visual analysis of gallbladder carcinoma, delayed (18)F-FDG PET images improved the specificity of diagnosis in 2 patients. When an SUV(early) of 4.5, SUV(delayed) of 2.9, and RI of -8 were chosen as arbitrary cutoffs for differentiating between malignant and benign conditions, sensitivity increased from 82.6% to 95.7% and 100% for delayed imaging and combined early and delayed imaging (i.e., RI), respectively. With the same criteria, specificity decreased from 55.6% to 44.4% for delayed imaging and combined early and delayed imaging, respectively. The specificity of (18)F-FDG PET improved to 80% in the group with a normal level of C-reactive protein (CRP) and decreased to 0% in the group with an elevated CRP level. For gallbladder carcinoma, both SUV and tumor-to-liver ratios derived from delayed images were significantly higher than the ratios derived from early images (P < 0.0001). CONCLUSION: Delayed (18)F-FDG PET is more helpful than early (18)F-FDG PET for evaluating malignant lesions because of increased lesion uptake and increased lesion-to-background contrast. However, the diagnostic performance of (18)F-FDG PET depends on CRP levels.     

腺癌性孤立性肺结节的^18F—FDG PET／CT表现

目的探讨腺癌性孤立性肺结节（ASPN）的^18F—FDG PET／CT显像特点。方法回顾分析35例ASPN的^18F-FDG PET／CT显像形态学和代谢特点,计算SUVmax,以公式[（延迟显像SUVmax-早期显像SUVmax）／早期SUVmax×100％]计算△SUVmax。以SPSS11．5软件对数据分别行t检验、方差分析和Fisher确切概率法检验。结果（1）42．86％（15／35）ASPN呈典型的癌性肺结节表现（结节状FDG摄取增高）,另有57．14％（20／35）ASPN FDG摄取呈片状、云雾状、肉眼无法辨认;结节状、云雾状、片状、肉眼无法辨认ASPN的SUVmax大小顺序递减,不同FDG摄取形态的ASPN早期和晚期SUVmax差异均有统计学意义,F=30．696和24．758,P均〈0．001。（2）54．29％（19／35）ASPN SUVmax≥2．5,45．71％（16／35）ASPN SUVmax〈2．5。（3）68．57％（24／35）ASPN呈实性密度结节,31．43％（11／35）ASPN呈“磨玻璃”密度结节;早期SUVmax分别为4．54±2．69、1．30±0．87,t=-5．234,P〈0．001。（4）延迟显像ASPN的SUVmax为422±3．52,高于早期显像的3．49±2．72（t=-4021,P〈0．1301）;延迟显像SUVmax是否增高与早期显像SUVmax的高低相关：94．74％（18／19）SUVmax≥2．5ASPN的△SUVmax为正值,仅56．25％（9／16）SUVmax〈2．5ASPN的△SUVmax为正值,P=0．013。（5）高分化ASPN SUVmax为1．70±1．51,低于中低分化ASPN的4．91±2．69,t=-3．951,P〈0．001,且△SUVmax〉0的比例（10／17）也低于中低分化ASPN（13／14）,P=0．045。结论ASPNFDG摄取形态、代谢活性差异大,SUVmax〈2．5ASPN比例较高,△SUVmax对这类结节良恶性的鉴别有一定帮助。     

18F-FDG PET/CT双时相显像对孤立性肺结节的诊断价值

目的探讨^18F-脱氧葡萄糖（FDG）PET／CT双时相显像对孤立性肺结节（SPN）的诊断价值。方法31例SPN待查患者行^18F—FDGPET／CT双时相显像，计算标准摄取值（SUV），随访时间5～17个月。结果19例患者（61．3％）有病理学诊断结果，其余为临床诊断。肺癌患者结节的延迟相平均SUV明显高于早期相，早期相和延迟相最大SUV间无差异；单纯以平均SUV变化幅度[ASUV平均=（SUV延迟-SUV早期）／SUV早期×100％]≥15％为诊断肺癌的标准，灵敏度为81．8％，特异性为77．8％，准确性为80．6％；PET／CT综合的诊断灵敏度为95．5％，特异性为85．7％，准确性为87．1％。单纯以ASUV平均≥15％为标准，诊断肺癌的阳性预测值和阴性预测值分别为90．0％和63．6％；以ASUV平均≥15％伴结节放射性高于纵隔血池为标准，阳性预测值和阴性预测值分别为93．3％和85．7％。结论^18F—FDGPET／CT双时相显像鉴别诊断SPN的良恶性有一定的临床价值，其与临床表现结合诊断准确性较高。     

Dual time point 18F-FDOPA PET as a tool for characterizing brain tumors

(18)F-FDOPA is an amino acid analogue used to evaluate presynaptic dopaminergic activity, which has aroused great interest in neuro-oncology. We have evaluated five (18)F-FDOPA PET studies of patients referred for study of parkinsonian syndrome. Two subjects had previously treated high-grade brain tumors, one nonspecific brain injury, and 2 subjects presented unexpected tumoral lesions. For all lesions SUVmax, time to SUVmax and tumor-to-normal grey matter SUVmax rate (T/N) were calculated, and 90 minutes (18)F-FDOPA kinetics were analyzed. Tumor lesions corresponded to three malignant neurocytomas, one meningioma, one pineocytoma and one intrasinusal hemangioma. Both malignant and benign tumors exhibited high uptake of (18)F-FDOPA well above the normal cortex. However, the analysis of the curve uptake displayed characteristic patterns that facilitate the characterization of tumor lesions. A dual phase maximum uptake was observed, with an early 10 minutes uptake in malignant lesions, and a late 60 to 90 minutes uptake in benign or low grade lesions.     

18F-FDG与18F-FLT PET/CT延迟显像对肺结节诊断效能的评价

目的 通过对多中心、前瞻性研究中接受了18F-脱氧葡萄糖(FDG)与18F-脱氧胸腺嘧啶核苷(FLT)延迟显像病例的分析,探讨18F-FDG与18F-FLT延迟显像对肺结节诊断的效能.方法 6个PET/CT中心,从2006年1月至2007年6月,按照统一标准,采用同机型、同一扫描条件,开展了肺结节样病变18F-FLT和18F-FDG PET/CT显像的多中心临床研究.在经确诊的55例病例中,25例患者进行了18F-FLT显像和延迟显像,34例患者进行了18F-FDG延迟显像.按常规计算延迟显像时病灶最大标准摄取值(SUVmax)及与早期显像时SUVmax相比的变化率(△SUVmax).对照临床确诊结果分析其诊断效能.采用SPSS11.0软件进行统计学处理.结果 18F-FDG延迟显像患者中,6例肺癌中5例、12例结核中9例、16例炎症或其他良性结节中9例的SUVmax较早期相升高.18F-FLT延迟显像组中,7例肺癌中3例、8例结核中3例和10例其他良性病灶中2例的SUVmax上升.经分组统计分析,不同疾病组间18F-FDG延迟显像SUVmax和△SUVmax差异无统计学意义;18F-FLT延迟显像SUVmax和△SUVmax组间差异也无统计学意义.无论18F-FDG还是18F-FLT,延迟显像的诊断效能均不如早期相.无论早期还是延迟显像,单独18F-FDG或18F-FLT显像的诊断效能均不如二者联合应用.结论 18F-FDG和18F-FLT延迟显像的SUVmax变化规律性不强,不宜单独应用于肺结节的鉴别诊断.     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的

 目的 探讨18F-FDG PET/CT显像结合高分辨率CT(high resolution CT,HRCT)对孤立性肺结节(solitary pulmonary nodule,SPN)的诊断价值。方法 回顾性分析124例SPN患者的18F-FDG PET/CT检查资料,其中76例加做HRCT扫描,所有病例经病理或临床随访证实。18F-FDG PET/CT通过目测法和半定量法判断病灶的代谢情况,结合CT或HRCT病灶的形态学特征判断良、恶性。结果 48例仅行18F-FDG PET/CT检查的SPN患者,正确诊断32例为恶性,8例为良性,假阳性与假阴性各4例。76例加做HRCT的患者,正确诊断62例恶性与8例良性,假阳性与假阴性分别为2例和4例。18F-FDG PET/CT 结合HRCT与单纯18F-FDG PET/CT诊断SPN的灵敏度、特异性及准确率分别为94%、80%、90%与89%、67%、83%。结论 18F-FDG PET/CT协同HRCT可提高对SPN性质判断的灵敏度、特异性及准确率。     

18F-FDG PET/CT联合肺动脉灌注成像指数在单发肺结节中的应用价值

目的探讨18F-FDG PET/CT联合320容积CT双入口灌注成像(DI-CTP)肺动脉灌注指数(PPI)对单发性肺结节的鉴别诊断价值。方法搜集经病理证实40例单发性肺结节患者的18F-FDG PET/CT及320排CT灌注成像影像资料(恶性结节24例、良性结节16例),PET/CT以结节18F-FDG摄取值SUV≥2.5为诊断恶性结节阈值,18F-FDG PET/CT联合PPI则在SUV≥2.5诊断阈值的基础上综合PPI<50%判定,并分析SUV与PP均值在良恶性结节间差异性及相关性。结果PET/CT联合PPI正确诊断38例,其中恶性结节22例、良性结节16例,误诊2例。18F-FDG PET/CT联合PPI诊断肺单发结节的敏感性91.6%,特异性100%,准确性95.0%;18F-PDG摄取值SUV在良、恶性结间差异无统计学意义(t=1.66,P>0.05),而PPI均值在良、恶性结节间差异有统计学意义(t=-3.14,P<0.01);SUV与PPI间相关性无统计学意义(r=0.20,P>0.05)。结论18F-FDG PET/CT联合PPI可以提高诊断肺单发肺结节敏感性、特异性和准确性,减少误诊率。     

18F-FDG PET reduces unnecessary hemithyroidectomies for thyroid nodules with inconclusive cytologic results.

Fine-needle aspiration biopsy (FNAB) is inconclusive in up to 20% of patients with solitary thyroid nodules. In these cases, hemithyroidectomy is necessary, but only 20% of the nodules prove to be thyroid carcinoma. The aim of this study was to explore the potential of (18)F-FDG PET to reduce the number of unnecessary hemithyroidectomies in the preoperative assessment of thyroid nodules with inconclusive FNAB results. METHODS: Forty-four consecutive patients, scheduled for hemithyroidectomy because of inconclusive FNAB findings, participated in this prospective study. (18)F-FDG PET of the thyroid region was performed before hemithyroidectomy, and standardized uptake values were calculated. The final histopathologic diagnosis served as a standard of reference. RESULTS: Histopathologic examination of the surgical specimens revealed 7 well-differentiated thyroid carcinomas in 6 patients, all accumulating (18)F-FDG (negative predictive value, 100%). (18)F-FDG accumulated in 13 of 38 benign nodules. The pre-PET probability for cancer in this study population was 14% (6/44), and the post-PET probability increased to 32% (6/19). The percentage of unnecessary hemithyroidectomies in a hypothetical algorithm using (18)F-FDG PET was only 30% (13/44), compared with 86% (38/44) without (18)F-FDG PET. (18)F-FDG PET reduced the number of futile hemithyroidectomies by 66% (25/38) (95% confidence interval, 49%-80%; Fisher's exact test, P = 0.0038). Semiquantitative analysis using standardized uptake values did not help to further reduce this number. CONCLUSION: In addition to data in the literature demonstrating accurate detection of thyroid cancer by (18)F-FDG PET, this study showed that (18)F-FDG PET should play an important role in the management of patients with inconclusive cytologic diagnosis of a thyroid nodule. (18)F-FDG PET reduced the number of futile hemithyroidectomies by 66%. Although PET is a relatively costly procedure, this cost outweighs the costs and risks associated with unnecessary thyroid surgery.     

图像纹理特征在肺结节18F-FDG PET/CT显像诊断中的应用

目的 探讨18F-FDG PET/CT图像纹理特征参数对良恶性肺结节的鉴别能力,并与FDG SUVmax的诊断效能比较.方法 回顾性分析170例肺结节患者的18F-FDG PET/CT图像,其中男102例,女68例,年龄29 ～ 81(平均59)岁;恶性89例(PET图像230层),良性81例(PET图像193层).参照CT图像勾画ROI,获得病灶PET/CT图像的13项纹理特征参数值[包括均值、标准差、偏度、峰度、角二阶矩(ASM)、熵、对比性、相关性、粗糙度、对比度、频度、复杂度、强度]和SUVmax.采用logistic回归分析进行统计,提取有效的纹理参数,建立回归方程,并通过ROC曲线评估其判断肺结节良恶性的能力.利用Mann-Whitney u检验比较不同病理类型肺癌患者间纹理特征参数的差异.ROC曲线评价SUVmax对良恶性肺结节的检验效能,采用x2检验对纹理特征参数与SUVmax的诊断效能进行比较.结果 偏度、峰度、ASM和强度4项纹理特征参数与肺结节良恶性判断有关(β=1.7058、-1.0989、-4.4140和0.5626,均P＜0.05).纹理特征参数对应ROC AUC为0.775(95％ CI0.732～0.819;P＜0.001);灵敏度为89.6％ (206/230),特异性为50.8％ (98/193).89例肺癌患者中,鳞状细胞癌组(21例)和腺癌组(62例)的ASM和强度差异有统计学意义[ASM:0.0303 (95％CI0.0392～0.0724)和0.0594(95％ CI0.0721 ～0.0947);强度:2.4714(95％ CI 2.4632 ～4.1050)和1.5945(95％ CI1.9003 ～2.4652);u=3082.0和3115.0,均P＜0.01].ROC曲线示SUVmax诊断肺癌的AUC为0.757(95％ CI0.711 ～0.802;P＜0.001);SUVmax ≥2.5时灵敏度为80.9％ (186/230),特异性为50.3％ (97/193).纹理特征参数与SUVmax鉴别肺结节良恶性的灵敏度差异有统计学意义(x2=6.903,P＜0.01).结论 纹理特征参数可用于18F-FDG PET显像辅助诊断肺结节良恶性;不同病理类型肺癌的纹理特征参数不同,且纹理特征参数对肺结节性质鉴别灵敏度优于SUVmax.