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。     

基于PET/CT的孤立性肺结节多模式影像对比研究

目的比较18F-FDG PET/CT融合图像、胸部薄层CT及18F-FDG PET/CT融合图像联合胸部薄层CT检查在诊断孤立性肺结节临床应用价值。方法回顾性总结2012年7月~2014年7月的40例孤立性肺结节(SPN)病例(男20例,女20例,年龄37~84岁,平均(59.2±12.4)岁。所有病例行18F-FDG PET/CT检查及胸部薄层CT扫描,37例患者最后由手术病理或穿刺病理确诊,3例经抗炎、抗结核治疗后复查,随访12个月以上。结果 40例SPN患者18FFDG PET/CT融合图像诊断灵敏度、特异性、PPV、NPV、准确性分别为75.9%、72.7%、88.0%、53.3%、75.0%;胸部薄层CT诊断SPN灵敏度、特异性、PPV、NPV、准确性分别为75.9%、63.6%、84.6%、50.0%、86.1%。18 F-FDG PET/CT融合图像联合胸部薄层CT诊断SPN灵敏度、特异性、PPV、NPV、准确性分别为93.1%、72.7%、90.0%、80.0%、87.5%。18F-FDG PET/CT融合图像及胸部薄层CT与18F-FDG PET/CT融合图像联合胸部薄层CT比较差距有统计学意义。结论 18F-FDG PET/CT联合应用胸部薄层CT对SPN诊断及鉴别诊断具有较高价值。     

~(18)F-FDG PET-CT和双源CT的LungCare软件在评估孤立性肺结节中的比较研究

目的 探讨18-氟-脱氧葡萄糖(~(18)F-FDG)PET/CT显像及Siemens双源CT的LungCare软件对孤立性肺结节(SPN)的辅助诊断能力及适用范围.方法 回顾分析经病理证实的24例SPN患者的PET-CT图像资料,并与利用双源CT的LungCare软件分析SPN进行比较研究.用χ~2检验对2种检查方法的评价结果进行统计学分析,以P<0.05作为差异有显著意义.结果 在24例SPN中,恶性结节15例,良性结节9例.LungCare软件评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为83.3%、80.0%、88.8%、92.3%、72.7%,PET-CT评估其良恶性的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为87.5%、93.3%、77.7%,87.5%、87.5%.LungCare软件和PET/CT定性SPN的准确性相当,两者之间并不存在明显的差异(P>0.05).PET/CT的敏感性、阴性预测值明显高于LungCare软件,但其特异性、阳性预测值明显低于LungCare软件(P<0.05).结论 ~(18)F-FDG PET-CT对肺结节的诊断有一定辅助作用,适用于对孤立性肺结节的良恶性鉴别诊断.PET/CT密切结合LungCare软件,可进一步提高诊断正确率.     

FDG-PET/MRI对局灶性癫病人致区检测的准确性高于FDG-PET/CT

正摘要目的通过比较 PET/MRI 和 PET/CT 检测致区(EZ)的准确性,进而检验 FDG-PET/MRI 在癫病人中的实用性。方法本前瞻性研究包括 31 例接受 EZ 手术切除的病     

~(18)F-FDG PET/CT在偶发性孤立性肺结节诊断中的应用价值

目的探讨偶发性孤立性肺结节(SPN)的临床及~(18)F-FDG PET/CT影像学特征。方法回顾性分析2009年7月~2016年7月间的CT扫描偶然发现的106例SPN病例,汇总其性别、年龄、实验室检查及影像学检查等资料。结果在106例患者中,71例确诊为肺癌,35例为良性病变,男44例,女62例,平均年龄(57.5±17.1)岁,结节最大标准化摄取值(3.62±3.50)(SUVmax值),均经病理学诊断或者随访3年以上;~(18)F-FDG PET/CT检查的灵敏度、特异性、准确性分别为91.6%、62.9%、82.1%,肺癌结节中,年龄≥55岁较年龄55岁的明显多,SPN是否具有分叶征、毛刺征、空泡征、胸膜牵拉征在良恶性结节诊断中数据差异有统计学意义,FDG糖代谢SUVmax值良恶性数据无差异。结论~(18)F-FDG PET/CT对偶发性SPN良恶性鉴别有重要价值,影像学特征结合临床资料能够明显提高诊断效能,并能够初步评估肺腺癌的分化程度,可为无法通过穿刺获得病理结果患者提供无创性的诊断手段,同时PET/CT能够修正SPN的诊疗策略。     

18F-FDG PET/CT对不同大小孤立性肺结节的诊断价值

目的 评价18F-脱氧葡萄糖(FDG) PET/CT对不同大小范围孤立性肺结节(SPN)良恶性鉴别诊断的价值.方法 从全国拥有PET/CT的10家医院筛选出已经获得病理学检查结果的SPN病例,收集诊断CT、PET/CT和病理检查结果以及标准摄取值(SUV)、结节大小等资料.诊断CT、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;难以确定阳性和阴性者为不确定.采用SPSS 10.0软件对资料进行分析.结果 120个(120例)SPN中良性结节28个,恶性结节92个.直径或(长径+短径)/2≤1.0cm的结节17个,恶性病变9个;1.1～2.0cm 57个,恶性病变占75.44%;2.1～3.0cm 46个,恶性病变占86.96%.28个良性结节SUV最大值(SUVmax)的平均值为4.5±4.9, SUV平均值(SUVmean)的平均值为2.9±3.6;92个恶性结节SUVmax平均值为6.7±4.2, SUVmean平均值为4.9±3.6;良性结节的SUV显著低于恶性结节的SUV.无论良性还是恶性结节,随着结节的增大,SUV升高.诊断CT对结节良恶性鉴别的灵敏度为78.26%,特异性3/8,准确性72.22%; PET/CT灵敏度为94.51%,特异性64.00%,准确性87.93%.结论 18F-FDG PET/CT在SPN鉴别诊断中具有较高的灵敏度、特异性和准确性,优于诊断CT;结节大小是判断SPN良恶性的重要指标,直径或(长径+短径)/2＞2.0cm的结节,恶性可能性约为87%; SUV可以作为鉴别诊断的依据,但鉴于良性结节SUVmean的平均值为2.9±3.6,界值2.5仅供参考,尤其是对于≤1.0cm的结节.     

PET/CT显像在食管癌术前分期中的临床应用

目的:评价18F-脱氧葡萄糖(FDG) PET/CT显像在食管癌术前分期中的价值.方法:20例病理学证实的食管癌患者行全身18F-FDG PET/CT显像.男性12例,女性8例,年龄40~75岁之间.PET/CT显像结果与病理组织学及临床随访6个月以上结果相对照.结果:20例患者中17例行手术切除,共切除病灶138处;3例共6处病灶临床随访6个月以上,食管癌术前FDG-PET/CT显像的灵敏度为90%,特异性为98%.结论:全身18F-FDG PET/CT显像在食管癌术前分期中有较高的灵敏度及特异性.     

^18FDG—PET在诊断头颈部鳞状细胞癌复发中的价值

目的了解18FDG-PET在诊断头颈部鳞状细胞癌复发中的价值,确定标准吸收值(SUV)来鉴别放疗后的炎症与肿瘤复发.材料和方法头颈部鳞状细胞癌患者43例,在放疗后至少4个月(平均11个月)进行18FDG-PET检查.计算感兴趣区的SUV值.肿瘤复发诊断依赖组织病理学检查或6个月以上的临床随访.结果43例患者中,FDG-PET阳性23例,其中3例为假阳性;20例为阴性,其中假阴性2例.FDG-PET的诊断准确性是88%(38/43),而CT/MRI的诊断准确性则为66%(25/38).肿瘤复发病灶和炎症病灶的SUV有部分重叠,无统计学上差异(p=0.31).结论18FDG-PET检测头颈部鳞状细胞癌复发中肉眼分析更有价值;18FDG-PET较CT/MRI更为准确.     

18F-DG PET/CT诊断孤立性肺结节数学模型的临床验证

目的 对前期建立的应用18F-DG PET/CT诊断肺孤立性结节(solitary pulmonary nodule,SPN)良、恶性的数学模型加以临床验证.方法 采用前瞻性试验方法,连续收集自2011年1月～2012年6月间于我中心行18F-DG PET/CT检查的SPN患者共109例(恶性67例,良性42例).根据前期模型所需,收集患者年龄、密度、瘤肺交界情况、分叶、血管集束征、胸膜牵拉征和FDG摄取程度作为诊断SPN的影响因子,输入数学模型,计算诊断效率,并与2名具有丰富PET/CT阅片经验的高年资医师诊断结果对比,比较其临床应用价值.结果 应用前期数学模型判断SPN良、恶性的诊断灵敏度为95.52％、特异度69.05％、阳性预测值83.12％、阴性预测值90.63％、准确率85.32％;医师的诊断灵敏度为97.01％、特异度52.38％、阳性预测值76.47％、阴性预测值91.67％、准确率79.82％；数学模型诊断SPN良、恶性的的ROC曲线下面积(AUC,area under curve)为0.887±0.034,明显高于医师的诊断结果(AUC 0.747士0.05).结论 利用二元Logistic回归建立的18F-DG PET/CT诊断SPN良、恶性的数学模型诊断准确率高,具有较高的临床应用价值.     

18F-氟脱氧葡萄糖正电子发射断层显像在妇科恶性肿瘤治疗后的随访价值

 目的 探讨18F-氟脱氧葡萄糖正电子发射断层显像(18F-FDG PET)在妇科恶性肿瘤治疗随访中的作用.方法 21例均经病理证实的妇科恶性肿瘤患者治疗后行18F-FDG PET检查.结果 21例中17例发现有残余或转移病灶,占80.9%,无假阳性病例;4例阴性显像患者中,3例提示未见明确复发和转移,1例为假阴性,为近期行化疗所致.FDG-PET对本组妇科肿瘤治疗后的复发或转移诊断的灵敏度、特异性和准确性分别为94.4%、100%和95.2%.结论 18F-FDG PET 对妇科恶性肿瘤治疗随访中有重要作用.     

Diagnostic performance of PET/CT in differentiation of malignant and benign non-solid solitary pulmonary nodules

OBJECTIVE: To evaluate whether [F-18] fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can distinguish benign from malignant solitary pulmonary nodules (SPNs) with non-solid components. METHODS: [F-18] FDG-PET/CT scans were performed on 53 consecutive patients (30 men, 23 women; mean age 65 years) who had SPNs with non-solid components identified by CT screening for lung cancer. All patients underwent surgical resection, and all lesions were pathologically proved. Visual score, maximal, and mean standardized uptake value (SUV), and maximal and mean lesion-to-normal tissue count density ratio (LNR) were calculated in all lesions. In addition, clinical characteristics, laboratory test results, and CT findings were assessed. RESULTS: Benign SPNs with non-solid components had a higher uptake on [F-18] FDG-PET/CT. Visual score, maximal and mean SUV, and maximal and mean LNR were significantly higher in the benign when compared with the malignant SPNs (P < 0.001). When the cutoff of 1.5 was assigned for maximal SUV, the diagnostic performance of [F-18] FDG-PET/CT in predicting benign SPN revealed 100.0% sensitivity, 96.4% specificity, and 100.0% accuracy. CONCLUSIONS: [F-18] FDG-PET/CT is useful for the differential diagnosis of SPNs with non-solid components.     

The value of FDG-PET/CT in assessing single pulmonary nodules in patients at high risk of lung cancer

Purpose  To evaluate whether PET/low-dose CT (ldCT) using ¹⁸F-fluorodeoxyglucose (FDG) improves characterization of indeterminate single pulmonary nodules (SPNs) in patients at high risk of lung cancer. Methods  Retrospective analysis of 307 patients who underwent FDG-PET/CT for indeterminate SPNs identified 93 (70 men, age range 46–90 years) at high risk of lung cancer (age >40 years, minimum 10 pack-year smokers). SPNs were evaluated for the presence and intensity of FDG avidity and ldCT patterns. The performance of visual and semiquantitative FDG-PET/ldCT algorithms for characterization of SPNs was compared to that of ldCT. Incongruent FDG-PET and ldCT patterns were analyzed for significance in further patient management. Results  Malignancy was diagnosed in 38% patients. FDG avidity defined 33 SPNs as true-positive (TP) and 2 as false-negative (FN) (malignant), and 41 as true-negative (TN) and 17 as false-positive (FP) (benign). For SUVmax of 2.2 (by ROC analysis) there were 27 TP, 8 FN, 48 TN and 10 FP SPNs. LdCT defined 34 TP, 1 FN, 28 TN and 30 FP lesions. Of the FP lesions on ldCT, 60% were FDG-negative. Visual PET/ldCT analysis had a sensitivity of 94%, a specificity of 70%, an accuracy of 80%, a positive predictive value (PPV) of 66%, and a negative predictive value (NPV) of 95% as compared to 77%, 83%, 81%, 73%, 86% for semiquantitative PET/ldCT and 97%, 48%, 66%, 53%, 96% for ldCT, respectively. Both PET/ldCT algorithms had statistically significantly higher specificity and accuracy than ldCT. Semiquantitative analysis showed significantly higher PPV and lower sensitivity and NPV than found with ldCT. Conclusion  A single screening procedure encompassing FDG-PET and ldCT may improve screening for lung cancer in high-risk patients. The significantly improved specificity may potentially reduce FP ldCT results and further unnecessary invasive procedures.     

Cost-effectiveness of FDG-PET for the management of solitary pulmonary nodules: a decision analysis based on cost reimbursement in Germany

Management of solitary pulmonary nodules (SPNs) of up to 3 cm was modelled on decision analysis comparing "wait and watch", transthoracic needle biopsy (TNB), exploratory surgery and full-ring dedicated positron emission tomography (PET) using fluorine-18 2-fluorodeoxyglucose (FDG). The incremental cost-effectiveness ratios (ICERs) were calculated for the main risk group, a cohort of 62-year-old men, using first "wait and watch" and second exploratory surgery as the baseline strategy. Based on published data, the sensitivity and specificity of FDG-PET were estimated at 0.95 and 0.80 for detecting malignancy in SPNs and at 0.74 and 0.96 for detecting metastasis in normal-sized mediastinal lymph nodes. The costs quoted correspond to reimbursement in 1999 by the public health provider in Germany. Decision analysis modelling indicates the potential cost-effectiveness of the FDG-PET strategy for management of SPNs. Taking watchful waiting as the low-cost baseline strategy, the ICER of PET [3218 euros (EUR) per life year saved] was more favourable than that of exploratory surgery (4210 EUR/year) or that of TNB (6120 EUR/year). Changing the baseline strategy to exploratory surgery, the use of PET led to cost savings and additional life expectancy. This constellation was described by a negative ICER of -6912 EUR/year. The PET algorithm was cost-effective for risk and non-risk patients. However, the ICER of PET as the preferred strategy was sensitive to a hypothetical deterioration of any PET parameters by more than 0.07. To transfer the diagnostic efficacy from controlled studies to the routine user and to maintain the cost-effectiveness of this technology, obligatory protocols for data acquisitions would need to be defined. If the prevalence of SPNs is estimated at the USA level (52 per 100,000 individuals) and assuming that multiple strategies without PET are the norm, the overall costs of a newly implemented PET algorithm would be limited to far less than one EUR per member of the public health provider in Germany.     

Cost-effectiveness of FDG-PET for the management of solitary pulmonary nodules: a decision analysis based on cost reimbursement in Germany

Management of solitary pulmonary nodules (SPNs) of up to 3 cm was modelled on decision analysis comparing "wait and watch", transthoracic needle biopsy (TNB), exploratory surgery and full-ring dedicated positron emission tomography (PET) using fluorine-18 2-fluorodeoxyglucose (FDG). The incremental cost-effectiveness ratios (ICERs) were calculated for the main risk group, a cohort of 62-year-old men, using first "wait and watch" and second exploratory surgery as the baseline strategy. Based on published data, the sensitivity and specificity of FDG-PET were estimated at 0.95 and 0.80 for detecting malignancy in SPNs and at 0.74 and 0.96 for detecting metastasis in normal-sized mediastinal lymph nodes. The costs quoted correspond to reimbursement in 1999 by the public health provider in Germany. Decision analysis modelling indicates the potential cost-effectiveness of the FDG-PET strategy for management of SPNs. Taking watchful waiting as the low-cost baseline strategy, the ICER of PET [3218 euros (EUR) per life year saved] was more favourable than that of exploratory surgery (4210 EUR/year) or that of TNB (6120 EUR/year). Changing the baseline strategy to exploratory surgery, the use of PET led to cost savings and additional life expectancy. This constellation was described by a negative ICER of -6912 EUR/year. The PET algorithm was cost-effective for risk and non-risk patients. However, the ICER of PET as the preferred strategy was sensitive to a hypothetical deterioration of any PET parameters by more than 0.07. To transfer the diagnostic efficacy from controlled studies to the routine user and to maintain the cost-effectiveness of this technology, obligatory protocols for data acquisitions would need to be defined. If the prevalence of SPNs is estimated at the USA level (52 per 100,000 individuals) and assuming that multiple strategies without PET are the norm, the overall costs of a newly implemented PET algorithm would be limited to far less than one EUR per member of the public health provider in Germany.     

Image analysis methods for solitary pulmonary nodule characterization by computed tomography.

Computer software was designed for classifying solitary pulmonary nodules (SPNs) into benign and malignant from their CT images, using image analysis methods. The system made use of three features, computed from the CT density matrix of the SPN, and a class-discriminating algorithm. System evaluation was performed on 51 histologically confirmed SPNs of indeterminate CT diagnosis. Overall classification accuracy in distinguishing benign and malignant SPNs was 90.2%, while 83.3% of the benign and 93.9% of the malignant SPNs were correctly classified. The proposed system may be of value to the radiologist in assessing the probability of malignancy in patients with a solitary pulmonary nodule.     

Solitary pulmonary nodules: accuracy and cost-effectiveness of sodium iodide FDG-PET using Australian data

This study uses Australian data to confirm the accuracy of dedicated sodium iodide (NaI) fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in evaluating indeterminate solitary pulmonary nodules (SPNs) and to determine the conditions under which PET could play a cost-effective role in this evaluation. Ninety-two patients from two Australian hospitals in different states underwent FDG-PET for evaluation of an SPN. Observed values for prior probability of malignancy and diagnostic accuracy of PET were applied to previously published decision tree models using published Australian health care costs. The accuracy of FDG-PET was 93% with a sensitivity of 92% and a specificity of 95%. The prior probability of malignancy (0.54), PET sensitivity and PET specificity indicated cost savings per patient of up to EUR 455 (Adollars 774) based on a PET cost of EUR 706 (Adollars 1,200). PET would remain cost-effective for levels of prior probability up to 0.8-0.9 and a PET cost of EUR 736-1,161 (Adollars 1,252-Adollars 1,974). It is concluded that NaI PET is accurate, cost saving and cost-effective for the characterisation of indeterminate pulmonary nodules in Australia. Comparison with previous reports from the United States confirms that FDG-PET can remain cost-effective despite population differences in medical costs, disease prevalence and PET diagnostic performance.     

Differential diagnosis of solitary pulmonary nodules based on 99mTc-EDDA/HYNIC-TOC scintigraphy: the effect of tumour size on the optimal method of image assessment

Purpose The aim of the study was to determine an optimal method for the evaluation of scintigrams obtained with ^99mTc-EDDA/HYNIC-TOC for the purpose of differential diagnosis of solitary pulmonary nodules (SPNs) and to assess the diagnostic value of the method. Methods Eighty-five patients (48 males and 37 females, mean age 57 years, range 34–78 years) were enrolled in the study. Patients underwent ^99mTc-EDDA/HYNIC-TOC scintigraphy for the purpose of differential diagnosis of SPNs (size between 1 and 4 cm). Images of all patients were evaluated visually in a prospective manner. Results Positive scintigraphic results were found in 37 out of 40 (93%) patients with malignant SPNs including 34 out of 35 (97%) patients with primary lung carcinoma. Two remaining false negative cases turned out to be metastatic lesions of malignant melanoma and leiomyosarcoma. Among 45 benign tumours, negative results were obtained in 31 cases (69%) and positive results in 14. The accuracy of the method was 80%. Analysis of the results of the visual assessment of scintigrams revealed a significantly higher frequency of false positive results among larger nodules (diameter at least 1.4 cm). Uptake of the tracer in those nodules was therefore assessed semi-quantitatively (using the tumour-to-background ratio), in expectation of an improvement in the low specificity of the visual method. The semi-quantitative assessment reduced the total number of false positive results in a subgroup of larger nodules from 13 to six, while preserving the high sensitivity of the method. Conclusion The combination of visual analysis (for lesions smaller than 1.4 cm in diameter) and semi-quantitative assessment (for larger lesions) provided a high sensitivity of the method and significantly improved its specificity (84%) and accuracy (88%) in comparison with visual analysis (p<0.05).     

Dynamic magnetic resonance imaging of solitary pulmonary nodules: utility of kinetic patterns in differential diagnosis

OBJECTIVE: The aim of this study was to evaluate the clinical feasibility of dynamic magnetic resonance (MR) imaging with a 3-dimensional (3D) gradient recalled echo (GRE) volumetric interpolated breath-hold examination (VIBE) sequence to differentiate between benign and malignant solitary pulmonary nodules (SPNs). METHODS: Dynamic 3D GRE VIBE was performed in 45 patients with SPNs. For each lesion, the morphologic parameters, including the edge configuration, presence of peripheral enhancement (PE), and an internal signal on T2-weighted images, and the kinetic enhancement parameters were evaluated. RESULTS: All 29 of the malignant SPNs had internal enhancement, whereas 13 (81%) of the benign SPNs did not exhibit internal enhancement. A washout pattern was only observed in the malignant SPNs. The presence of PE was found in 56% of the benign SPNs and in 50% of the malignant SPNs. The lesion size was significantly different between malignant SPNs with PE and those without PE (P <0.01). The positive predictive value for malignancy was 91% (29 of 32 malignant SPNs). The negative predictive value was 100% (13 of 13 benign SPNs). CONCLUSIONS: A combination of morphologic criteria and kinetic information is useful for differentiating between benign and malignant SPNs. In particular, internal enhancement with PE and positive visual washout is thought be a useful tool.     

Clinical application of pharmacokinetic analysis as a biomarker of solitary pulmonary nodules: Dynamic contrast-enhanced MR imaging

The purpose of this study is to evaluate perfusion indices and pharmacokinetic parameters in solitary pulmonary nodules (SPNs). Thirty patients of 34 enrolled with SPNs (15–30 mm) were evaluated in this study. T1 and T2‐weighted structural images and 2D turbo FLASH perfusion images were acquired with shallow free breathing. B‐spline nonrigid image registration and optimization by χ² test against pharmacokinetic model curve were performed on dynamic contrast‐enhanced MRI. This allowed voxel‐by‐voxel calculation of k_ep, the rate constant for tracer transport to and from plasma and the extravascular extracellular space. Mean transit time, time‐to‐peak, initial slope, and maximum enhancement (E_max) were calculated from time–intensity curves fitted to a gamma variate function. After blinded data analysis, correlation with tissue histology from surgical resection or biopsy samples was performed. Histologic evaluation revealed 25 malignant and five benign SPNs. All benign SPNs had k_ep < 1.0 min^?1. Nineteen of 25 (76%) malignant SPNs showed k_ep > 1.0 min^?1. Sensitivity to diagnose malignant SPNs at a cutoff of k_ep = 1.0 min^?1 was 76%, specificity was 100%, positive predictive value was 100%, negative predictive value was 45%, and accuracy was 80%. Of all indices studied, k_ep was the most significant in differentiating malignant from benign SPNs. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.