^18F-FDG PET／CT显像全身骨髓代谢弥漫增高原因分析

目的分析^18F—FDG PET／CT所示全身骨髓代谢弥漫性增高临床原因。方法收集2005年8月至2009年11月期间在该院行^18F-FDG PET／CT检查,发现全身骨髓代谢弥漫性增高且已确诊的病例66例,分析影像学表现,并进行临床病程随访和病理结果分析。选择79名健康人作为对照组;分别测量骨髓代谢增高组和对照组的骨髓SUVmax和SUVmean以及纵隔SUVmax和SUVmean,并计算最大值比（SUVmax／纵隔SUVmax）及平均值比（骨髓SUVmean／纵隔SUVmean）,采用单因素方差分析对结果进行分析。结果（1）全身骨髓代谢弥漫l生增高原因有：近期升白细胞药物注射史27例,血液病21例,发热18例。（2）将上述3组及对照组SUVmean比（3．076±1．955,3．633±2．405,2．546±0．791,1．026±0．190）进行方差分析,F=34．465,P〈0．001,差异有统计学意义。健康对照组与3组骨髓代谢增高组进行多重比较,P均〈0．001,提示对照组与骨髓代谢增高组的SUVmean比差异均有统计学意义。（3）根据SUVmean比将骨髓代谢增高的程度分为2级：轻度（SUVmean比2．0—3．0）和重度（SUVmean大于3．0）。（4）3组骨髓代谢弥漫增高组中部分患者会伴有肝脾肿大及代谢增高,较常见的为血液病和发热。结论^18F-FDG PET／CT显像可以较敏感和准确地观察全身骨髓代谢的改变情况,良性和恶性病变均可引起骨髓代谢不同程度增高。     

多发性骨髓瘤的18F-FDGPET/CT诊断

目的:多发性骨髓瘤是一种浆细胞恶性增殖性疾病,大约有80％的患者存在骨骼侵犯.本文探讨多发性骨髓瘤的18F-fluorodexoxyglucose(18F-FDG)PET/CT表现特点,提高对多发性骨髓瘤的认识.方法:26例按2001年WHO诊断标准确诊为多发性骨髓瘤的患者,均在治疗前行18F-FDG PET/CT显像.所有患者均依赖骨髓穿刺或活检取得明确病理学诊断.结果:26名患者均出现不同程度的骨质疏松.25例患者出现多发性骨质破坏,占总数的96.2％;其中11例患者出现颅骨破坏,占42.3％;25例出现脊柱骨质破坏,占96.2％;15例出现胸骨骨质破坏,占57.7％;21例出现肋骨骨质破坏,占80.8％;21例出现骨盆骨质破坏,占80.8％.部分骨破坏病灶呈18F-FDG高代谢灶.结论:多发性骨髓瘤的18F-FDG PET/CT表现具有一定特征,结合临床、影像、实验室和病理学检查能提高本病的诊断率.     

Detection of Richter's transformation of chronic lymphocytic leukemia by PET/CT.

Our objective was to evaluate the accuracy of PET/CT for the diagnosis of Richter's transformation of chronic lymphocytic leukemia (CLL) to diffuse large cell lymphoma. METHODS: A retrospective study was performed of 37 patients with CLL who underwent 18F-FDG PET/CT at our institution between March 2003 and July 2005. All PET/CT scans were reviewed in consensus by 2 diagnostic radiologists. Sites of abnormal 18F-FDG uptake with a maximum standardized uptake value (SUVmax) of greater than 5 were considered highly suggestive of Richter's transformation. The PET/CT findings were correlated with histologic findings from bone marrow or lymph node biopsy performed within 6 wk of PET/CT and with clinical follow-up. RESULTS: The 37 patients (26 men and 11 women; mean age, 61 y, range, 40-82 y) underwent 57 PET/CT scans. In 10 (91%) of 11 patients with Richter's transformation, PET/CT detected sites of abnormal 18F-FDG uptake having an SUVmax of greater than 5. Richter's transformation was missed in 1 patient who had only low-grade 18F-FDG uptake (SUVmax < 5). Nine patients had false-positive PET/CT findings; in 3 of these patients, alternative malignancies were diagnosed (Hodgkin's disease; metastatic neuroendocrine carcinoma; non-small cell lung cancer). In all remaining patients, PET/CT correctly excluded Richter's transformation. For the specific diagnosis of Richter's transformation of CLL to diffuse large B-cell lymphoma, PET/CT had overall sensitivity, specificity, and positive and negative predictive values of 91%, 80%, and 53% and 97%, respectively. CONCLUSION: PET/CT can detect Richter's transformation of CLL to diffuse large B-cell lymphoma with a high sensitivity and a high negative predictive value.     

Standardized uptake values for [F] FDG in normal organ tissues: Comparison of whole-body PET/CT and PET/MRI

Purpose

To compare maximum and mean standardized uptake values (SUVmax/mean) of normal organ tissues derived from [¹⁸F]-fluoro-desoxyglucose (FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) using MR attenuation correction (MRAC) (DIXON-based 4-segment μ-map) with [¹⁸F]-FDG positron emission tomography/computed tomography (PET/CT) using CT-based attenuation correction (CTAC).

Methods and materials

In 25 oncologic patients (15 men, 10 women; age 57 ± 13 years) after routine whole-body FDG-PET/CT (60 min after injection of 290 ± 40 MBq [¹⁸F]-FDG) a whole-body PET/MRI was performed (Magnetom Biograph mMR™, Siemens Healthcare, Erlangen, Germany). Volumes of interest of 1.0 cm³ were drawn in 7 physiological organ sites in MRAC-PET and the corresponding CTAC-PET images manually. Spearman correlation coefficients were calculated to compare MRAC- and CTAC based SUV values; Wilcoxon-Matched-Pairs signed ranks test was performed to test for potential differences.

Results

The mean delay between FDG-PET/CT and PET/MRI was 92 ± 18 min. Excellent correlations of SUV values were found for the heart muscle (SUVmax/mean: R = 0.97/0.97); reasonably good correlations were found for the liver (R = 0.65/0.72), bone marrow (R = 0.42/0.41) and the SUVmax of the psoas muscle (R = 0.41). For subcutaneous fat, the correlation coefficient was 0.66 for SUVmean (p < 0.05). Correlations between MRAC and CTAC were non-significant for SUVmean of the psoas muscle, SUVmax of subcutaneous fat, SUVmax and SUVmean of the lungs, SUVmax and SUVmean of the blood-pool. The median SUVmax and SUVmean in MRAC-PET were lower than the respective CTAC values in all organs (p < 0.05) but heart (SUVmax) and the bone marrow (SUVmean).

Conclusion

In conclusion, in oncologic patients examined with PET/CT and PET/MRI SUVmax and SUVmean values generally correlate well in normal organ tissues, except the lung, subcutaneous fat and the blood pool. SUVmax and SUVmean derived from PET/MRI can be used reliably in clinical routine.     

18F-FLTPET／CT显像在鼻咽癌诊断及分期中的应用

目的探讨18F—FLTPET／CT显像在鼻咽癌诊断、分期和预后中的临床价值。方法13例鼻咽癌患者行18F—FLTPET／CT显像,其中1例患者也行18F-FDGPET／CT显像。通过软件自动获得病灶ROI的SUVmax和SUVmean。分析18F—FLTPET／CT显像病灶SUV与病理类型、分期及预后的关系,并进行1例患者的18F—FLT和“F—FDGPET／CT显像对比。结果13例鼻咽癌患者鼻咽部位高摄取18F—FLt灶22处,SUVmax为6．04±3．61,SUVmean。为5．09±2．89;淋巴结转移灶26处,SUVmax。为5．56±3．11,SUVmean。为4．65±2．79。18F＋Fu显像中鼻咽癌原发灶及淋巴结转移灶均能清晰显影。行2种显像的1例患者所有病灶18F—FLT显像的SUV较18F—FDG显像低：1处原发灶SUVmax分别为8．32和4．38,2处淋巴结转移灶SUVmax为3．30±0．07和1．48±0．06。13例鼻咽癌患者的TNM分期在进行18F—FLTPET／CT显像后有3例发生了改变。结论”F—FLTPET／CT显像能清晰显示鼻咽癌原发病灶及转移病灶,对确定患者TNM分期有临床应用价值。     

PET／CT对多发性骨髓瘤的诊断价值

目的探讨多发性骨髓瘤的PET／CT影像学特点,评价其在多发性骨髓瘤诊断中的价值。方法15例按2001年WHO诊断标准确诊为多发性骨髓瘤患者,均在治疗前行PET／CT显像。15例患者经骨髓穿刺和（或）手术病理检查测浆细胞,实验室检查显示有9例患者血清IgG明显升高（〉35g／L）,有8例24h尿本周蛋白增高（〉1g）,15例患者均有溶骨性病变。结果CT所示骨质破坏区域及PET示代谢变化骨髓瘤病灶137个。多发性骨髓瘤病变部位以颅骨37．2％（51／137）、肋骨26．3％（36／137）、椎体12．4％（17／137）为多发,其次为髂骨7．3％（10／137）、骶骨5．8％（8／137）、四肢骨4．4％（6／137）、锁骨3．6％（5／137）、肩胛骨2．9％（4／137）。在137个病灶中,有71个病灶PET显示放射性摄取增高,阳性率为51．8％;有66个病灶表现为放射性摄取稀疏及缺损。而CT主要表现为多发性穿凿样或虫蚀样骨质破坏。结论PET／CT显像对多发性骨髓瘤的临床诊断有较高的价值。     

Treatment monitoring by 18F-FDG PET/CT in patients with sarcomas: interobserver variability of quantitative parameters in treatment-induced changes in histopathologically responding and nonresponding tumors

Measurements of tumor glucose use by (18)F-FDG PET need to be standardized within and across institutions. Various parameters are used for measuring changes in tumor glucose metabolic activity with (18)F-FDG PET in response to cancer treatments. However, it is unknown which of these provide the lowest variability between observers. Knowledge of the interobserver variability of quantitative parameters is important in sarcomas as these tumors are frequently large and demonstrate heterogeneous (18)F-FDG uptake. METHODS: A total of 33 patients (16 men, 17 women; mean age, 47 +/- 18 y) with high-grade sarcomas underwent (18)F-FDG PET/CT scans before and after neoadjuvant chemotherapy. Two independent investigators measured the following parameters on the pretreatment and posttreatment scans: maximum standardized uptake value (SUVmax), peak SUV (SUVpeak), mean SUV (SUVmean), SUVmean in an automatically defined volume (SUVauto), and tumor-to-background ratio (TBR). The variability of the different parameters was compared by concordance correlation coefficient (CCC), variability effect coefficient, and Bland-Altman plots. RESULTS: Baseline SUVmax, SUVpeak, SUVmean, SUVauto, and TBR averaged 10.36, 7.78, 4.13, and 6.22 g/mL and 14.67, respectively. They decreased to 5.36, 3.80, 1.79, and 3.25 g/mL and 6.62, respectively, after treatment. SUVmax, SUVpeak, and SUVauto measurements and their changes were reproducible (CCC > or = 0.98). However, SUVauto poorly differentiated between responding and nonresponding tumors. The high intratumoral heterogeneity of (18)F-FDG resulted in frequent failure of the thresholding algorithm, which necessitated manual corrections that in turn resulted in a higher interobserver variability of SUVmean (CCCs for follow-up and change were 0.96 and 0.91, respectively; P < 0.005). TBRs also showed a significantly higher variability than did SUVpeak (CCCs for follow-up and change were 0.94 and 0.86, respectively; P < 0.005). CONCLUSION: SUVmax and SUVpeak provided the most robust measurements of tumor glucose metabolism in sarcomas. Delineation of the whole-tumor volume by semiautomatic thresholding did not decrease the variability of SUV measurements. TBRs were significantly more observer-dependent than were absolute SUVs. These findings should be considered for standardization of clinical (18)F-FDG PET/CT trials.     

肺癌MR扩散加权成像ADC与18F-FDG PET/CT代谢成像SUV的相关性研究

目的研究肺癌MR扩散加权成像(DWI)表观扩散系数(ADC)与PET/CT代谢成像标准摄取值(SUV)的相关性。方法搜集本院行胸部MR DWI和PET/CT代谢成像的26例肺癌患者的影像资料,分别测量MRDWI和PET/CT代谢成像对应层面病变实质部分的ADC最小值(ADCmin)、ADC平均值(ADCmean)和SUV最大值(SUVmax)、SUV平均值(SUVmean),计算相对ADC(rADC)(ADCmin/ADCmean)和相对SUV(rSUV)(SUVmax/SUVmean),分析ADCmin与SUVmax,ADCmean与SUVmean以及rADC与rSUV之间的相关性。结果 26例肺癌MR DWI的ADCmin为(0.891±0.167)×10-3mm2/s,ADCmean为(1.244±0.351)×10-3mm2/s,rADC为0.74±0.14;PET/CT代谢成像SUVmax为10.5±4.6,SUVmean为5.6±1.8,rSUV为1.80±0.28。ADCmin与SUVmax没有相关性(P=0.207>0.05),ADCmean与SUVmean没有相关性(P=0.331>0.05),rADC与rSUV呈负相关性(P=0.021<0.05),相关系数为-0.451。结论肺癌的MR DWI rADC与PET/CT代谢成像rSUV存在一定的负相关性,ADC与SUV在肺癌的临床应用中可以互为补充。     

喉癌18F-FDG PET/CT显像的临床应用价值

目的探讨18F-脱氧葡萄糖(FDG)PET/CT显像相对于单独的18F-FDG PET显像在喉癌诊断中的临床价值以及评价平均标准化摄取值(SUVmean)在喉癌和喉生理性显像鉴别中的作用。方法疑似喉癌患者23例。男19例,女4例,年龄30～70岁。空腹6H以上,静脉注射7.4MBq/kg 18F-FDG后40min后仰卧位行头颈部或全身扫描。分别评价18F-FDG PET和18F-FDG PET/CT显像对病灶诊断的灵敏度和特异性。19例病理为鳞癌的喉癌患者与15例喉生理性显像患者作为对照,测定显像部位的SUVmean,试用受试者工作曲线特征(Receivrer Operation Characteristic,ROC)及阳性似然比(positive likelihood ratio,+LR)确定SUVmean阈值。结果 23例喉癌患者,108处病灶。18 F-FDGPET显像和18F-FDG PET/CT显像对病灶诊断的灵敏度分别为85.1%(40/47)和89.4%(42/47),差异无统计学意义(P>0.05),特异性分别为和72.1%(44/61)和91.8%(56/61),差异有统计学意义(P<0.05)。19例病理为鳞癌的喉癌患者SUVmean均数为7.3±2.9,15例喉生理性显像SUVmean均数为4.9±1.1,差异有统计学意义(P<0.05)。SU-Vmean阈值选定为6.1,18 F-FDG PET/CT显像喉癌诊断的灵敏性为63.2%,特异性为86.7%。结论 18 F-FDG PET/CT显像明显改善18F-FDG PET显像的特异性。SUVmean阈值选定为6.1,有利于喉癌和喉生理性显像的鉴别。     

The Clinical Usefulness of 18F-FDG PET/CT in Patients with Systemic Autoimmune Disease

Purpose

Individuals with systemic autoimmune disease have an increased susceptibility to both inflammation and malignancy. The aim of this study was to evaluate the clinical usefulness of ¹⁸F-FDG PET/CT in patients with systemic autoimmune disease.

Methods

Forty patients diagnosed with systemic autoimmune disease were enrolled. Diagnostic accuracy of FDG PET/CT for detecting malignancy was assessed. FDG PET/CT findings, including maximum standardized uptake (SUVmax) of lymphadenopathy (LAP), liver, bone marrow, spleen, joint and muscles, were considered for the characterization of LAPs.

Results

FDG PET/CT could detect metabolically activated lesions in 36 out of 40 patients (90%) including inflammatory lesions in 28 out of 32 patients (88%). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG PET/CT for the detection of malignancy were 100, 67, 70, 25, and 100%, respectively. Multiple LAPs were found in 25 of 40 patients (63%), and comprised three malignancies, four cases of tuberculosis, and 18 reactive changes. A SUVmax ratio of bone marrow to liver below 0.78 could distinguish malignancy from tuberculosis + reactive change (AUC = 1.000, sensitivity: 100%, specificity: 100%). The SUVmax ratio of spleen to liver in the reactive group was also significantly higher than that in the malignancy group (P = 0.014). SUVmax of LAP in the TB group was significantly higher than that in the reactive group (P = 0.040).

Conclusions

PET/CT is useful in detecting and differentiating inflammation and malignancy in patients with systemic autoimmune disease. Frequent false-positive interpretations can be minimized by consideration of FDG uptake in bone marrow and spleen.     

Ordered subset expectation maximisation vs Bayesian penalised likelihood reconstruction algorithm in 18F-PSMA-1007 PET/CT

The aim of the study was to compare widely used ordered subset expectation maximisation (OSEM) algorithm with a new Bayesian penalised likelihood (BPL) Q.Clear algorithm in 18F-PSMA-1007 PET/CT. We retrospectively assessed 25 18F-PSMA-1007 PET/CT scans with both OSEM and Q.Clear reconstructions available. Each scan was independently reported by two physicians both in OSEM and Q.Clear. SUVmax, SUVmean and tumour-to-background ratio (TBR) of each lesion were measured. Reports were also compared for their final conclusions and the number and localisation of lesions. In both reconstructions the same 87 lesions were reported. Mean SUVmax, SUVmean and TBR were higher for Q.Clear than OSEM (7.01 vs 6.53 [p = 0.052], 4.16 vs 3.84 [p = 0.036] and 20.2 vs 16.8 [p < 0.00001], respectively). Small lesions (< 10 mm) had statistically significant higher SUVmax, SUVmean and TBR in Q.Clear than OSEM (5.37 vs 4.79 [p = 0.032], 3.08 vs 2.70 [p = 0.04] and 15.5 vs 12.5 [p = 0.00214], respectively). For lesions ≥ 10 mm, no significant differences were observed. Findings with higher tracer avidity (SUVmax ≥ 5) tended to have higher SUVmax, SUVmean and TBR values in Q.Clear (11.6 vs 10.3 [p = 0.00278], 7.0 vs 6.7 [p = 0.077] and 33.9 vs 26.7 [p < 0.00001, respectively). Mean background uptake did not differ significantly between Q.Clear and OSEM (0.42 vs 0.39, p = 0.07). In 18F-PSMA-1007 PET/CT, Q.Clear SUVs and TBR tend to be higher (regardless of lesion localisation), especially for small and highly avid lesions. Increase in SUVs is also higher for lesions with high tracer uptake. Still, Q.Clear does not affect 18F-PSMA-1007 PET/CT specificity and sensitivity.     

继发性噬血细胞性淋巴组织细胞增多症^18F-FDG PET/CT显像特点

目的 探讨继发性噬血细胞性淋巴组织细胞增多症（sHLH）的^18 F-FDG PET/CT显像特点.方法 回顾性分析南京医科大学第一附属医院2008年1月至2012年6月初诊的31例（男18例,女13例,平均年龄42岁）sHLH患者临床资料及^18F-FDG PET/CT显像资料,根据病因将患者分为肿瘤相关HLH（MAHLH）组（13例）、感染相关HLH（IAHLH）组（13例）及风湿病相关HLH（RAHLH）组（5例）,分别统计各组病灶FDG摄取情况和SUVmax.采用单因素方差分析及两样本t检验对各组SUV max进行比较.结果 23例患者脾肿大合并^18F-FDG摄取增高,RAHLH组、IAHLH组及MAHLH组对应例数分别为4、9和10例,对应脾脏SUVmax分别为3.16±0.61、5.67±3.37和6.04±3.06,差异无统计学意义（F=1.051,P＞0.05）.15例淋巴结增大合并^18F-FDG摄取增高：其中IAHLH组（8例）与MAHLH组（7例）肿大淋巴结SUVmax分别为5.35±1.69和10.14±5.24,差异有统计学意义（t=-2.456,P＜0.05）.17例骨髓^18F-FDG摄取增高：其中RAHLH组1例,SUVmax为4.6;IAHLH组（7例）与MAHLH组（9例）骨髓SUVmax分别为5.31±2.05和6.36±3.71（t =-0.670,P＞0.05）.10例肝脏体积增大的患者中,4例合并^18F-FDG摄取增高,SUVmax为4.9～10.2.MAHLH组、IAHLH组及RAHLH组SUVmaw分别为8.15±4.38、5.62±2.45和3.02±1.31,MAHLH最高（F=9.123,t=2.562、5.236、3.030,均P＜0.05）.结论 RAHLH多表现为脾脏肿大伴^18F-FDG摄取轻度增高,IAHLH和MAHLH多表现为脾脏肿大,侵犯淋巴结及骨髓;且MAHLH FDG摄取最高.上述^18F-FDG PET/CT显像特点有助于对该病的准确诊断.     

肝反应性淋巴样组织增生18F-FDG PET/CT双时相显像表现

目的 探讨肝反应性淋巴样组织增生（RLH）的18F-氟脱氧葡萄糖（FDG） PET/CT双时相显像表现。 方法 回顾性分析2016年9月至2021年7月于复旦大学附属中山医院行18F-FDG PET/CT双时相显像并经手术标本或穿刺组织病理学检查结果确诊为肝RLH的7例患者的临床资料和影像资料,其中男性2例、女性5例,年龄（60.4±3.7）岁。观察肝RLH的 18F-FDG PET/CT显像表现,分别测量及计算病灶长径、病灶与邻近肝脏的CT值、早期显像及延迟显像的最大标准化摄取值（SUVmax）、肝本底 SUVmax、滞留指数（RI）。符合正态分布的计量资料的比较采用两独立样本t检验。 结果 7例肝RLH患者中,71.4%（5/7）患者为单发病灶、28.6%（2/7）患者为多发病灶,共11个病灶,均位于肝包膜下,其形态呈类圆形或椭圆形,边界模糊,长径5.5~19.2（14.9±1.2） mm。CT平扫结果显示,11个病灶密度均匀,其中2个病灶呈等密度,9个病灶呈低密度,其CT值为（42.1±3.1） HU,低于邻近肝实质的CT值（55.9±1.5） HU,且二者的差异有统计学意义（t=−7.36,Ρ<0.001）。18F-FDG PET/CT显像结果显示,63.6%（7/11）病灶的18F-FDG摄取高于肝实质,其中85.7%（6/7）病灶延迟显像的SUVmax升高,14.3%（1/7）病灶延迟显像的SUVmax降低,早期、延迟显像病灶的SUVmax分别为6.2±0.4和6.8±0.7,RI为12.2%（8.9%,15.5%）;36.4%（4/11）病灶的18F-FDG 摄取低于或邻近肝实质,延迟显像病灶的SUVmax无明显变化,早期、延迟显像病灶的SUVmax分别为2.2±0.4和2.1±0.4。 结论 肝RLH病灶多位于肝包膜下,呈均匀稍低密度灶,边界模糊。18F-FDG PET/CT显像显示多数病灶18F-FDG高摄取,少数病灶呈等摄取或低摄取,延迟显像SUVmax多升高,多发病灶18F-FDG摄取相近或相差很大。     

18F-FLT PET/CT与18F-FDG PET/CT在鼻咽癌诊断和分期中的应用比较

目的 通过与18F-FDG PET/CT显像对比,探讨18 F-FLT PET/CT检测鼻咽癌原发灶和颈部淋巴结转移灶的可行性.方法 12例初治且经病理确诊的鼻咽癌患者(年龄22～62岁)自愿进入该前瞻性临床研究.每位患者先行18F-FDG PET/CT检查,次日行18F-FLF PET/CT检查.至少有2位核医学科和放射科医师阅片,比较18F-FDG PET/CT和18F-FLT PET/CT图像,采用ROI技术计算鼻咽肿瘤、颈部淋巴结转移灶、正常组织对18F-FDG、18F-FLT的SUVmax、SUVmean和MTV.采用非参数Wilcoxon秩和检验比较组间摄取和MTV差异.结果 12例鼻咽癌患者病灶均明显摄取18F-FLT.18F-FLT PET/CT和18F-FDG PET/CT均可准确诊断该组病例,二者对原发灶和淋巴结转移灶的检测结果无明显差别.鼻咽癌病灶的18F-FDG和18F-FLT SUVmax分别为10.7±5.8和6.0±2.4,SUVmean分别为5.8±3.0和3.6±1.5;SUVmax和SUVmean组间差异均有统计学意义(Z=-2.589和-2.353,P均＜0.05),而 MTV在18F-FDG和8F-FLT PET/CT 2种显像方法之问的差异无统计学意义(15.9±9.2和18.1±11.1;Z=-0.786,P＞0.05).6例有颈部淋巴结转移灶患者的SUVmax、SUVmean和MTV在2种显像方法间差异均无统计学意义(8.5±6.2比6.4±2.5、5.3±4.2比3.8±1.4、6.5 ±4.8比6.0±4.4;Z=-0.734、-0.734和-0.674,P均＞0.05).18F-FLT在颞叶摄取(SUVmax 0.7±0.3)明显低于18F-FDG(SUVmax 8.3±2.7;Z=-3.062,P＜0.01),其对于原发灶颅内浸润显示较18F-FDG更清晰.结论 18F-FLT PET/CT在鼻咽癌原发灶和淋巴结转移灶的诊断效能与18F-FDG PET/CT相当,对于显示原发灶的颅底附近侵犯更有利,其临床应用值得进一步研究.     

Usefulness of Respiratory-Gated <Superscript>18</Superscript>F-FDG PET/CT in Detecting Upper Abdominal Fever Focus

Respiratory-gated ¹⁸F-fluorodeoxygluocse (¹⁸F-FDG) PET/CT has been successfully used to better localize malignancies in the lung or upper abdominal organs. However, clinical usefulness of respiratory-gated ¹⁸F-FDG PET/CT in detection of fever focus has not been reported yet. A 68-year-old male patient with a history of living donor liver transplantation and biliary stenting was referred for ¹⁸F-FDG PET/CT due to fever of unknown origin (FUO). To find the accurate fever focus, respiratory-gated and non-gated ¹⁸F-FDG PET/CT was performed. Respiratory-gated PET/CT readily revealed prominent hypermetabolic lesion in the distal common bile duct (CBD) area where previous surgical graft was in situ. Maximum standardized uptake value (SUVmax) and SUV ratio (SUR) were greater in the gated PET/CT (SUVmax 5.4 and SUR 3.5) than in the non-gated PET/CT (SUVmax 4.6 and SUR 3.0). Fever dramatically subsided after removal of the graft in the CBD. This case report implies that respiratory-gated ¹⁸F-FDG PET/CT can visualize upper abdominal fever focus with better contrast than the conventional non-gated method.     

18 F-FDG PET/CT in diagnostic and prognostic evaluation of patients with cardiac masses: a retrospective study

Correct diagnosis and prognostic assessment of cardiac masses are crucial before therapy. We evaluated the diagnostic and prognostic value of 18F-FDG PET/CT in patients with cardiac masses. 18F-FDG PET/CT images of 64 patients with 65 cardiac masses were retrospectively analysed (34 men, 30 women; average age, 51.2 ± 17.5 years). Comparisons of CT features and 18F-FDG metabolic indices between benign and malignant entities, as well as among primary and secondary malignancies and lymphoma, were performed. The diagnostic values of PET/CT for distinguishing benign versus malignant masses were calculated. PET/CT data were further assessed for the predictive value for overall survival (OS) using the Cox proportional hazards model to assess potential independent predictors. Kaplan-Meier curves were generated to assess the value of PET/CT for prognostication. Statistically significant differences in various morphological features and metabolic indices between benign and malignant masses were found. An SUVmax of 6.75 was the optimal cutoff value to differentiate between benign and malignant masses, and the diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 92.11%, 88.89%, 90.77%, 92.11%, and 88.89%, respectively. Taking CT features and SUVmax ≥ 6.75 as a criterion, the values were 76.32%, 100.00%, 86.15%, 100.00%, and 75.00%, respectively; taking ≥ 3 CT features or SUVmax ≥ 6.75 as a criterion, the values were 94.74%, 88.89%, 92.31%, 92.31%, and 92.31%, respectively, indicating optimal diagnostic performance when paired with the anatomic information provided by the CT component. A univariate analysis of OS determined that surrounding tissue infiltration, epicardial infiltration, necrosis, multiple chambers or vessel involvement, distant metastasis, SUVmax, SUVmean, metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were significant predictors of survival. In the multivariate analysis, only SUVmax ≥ 6.715 was significant (P < 0.01). Median OS was 1460 days for SUVmax < 6.715 and 342 days for SUVmax ≥ 6.715 (P < 0.01). 18F-FDG PET/CT is helpful in the diagnosis of cardiac masses before treatment and has value in detecting extracardiac primary or secondary tumours. 18F-FDG PET/CT could also be a promising tool to provide prognostic information for these patients, especially SUVmax displaying independent prognostic value.     

18F-FDG PET/CT in HIV-related central nervous system pathology

Purpose

To evaluate the utility of ¹⁸F-FDG PET/CT in suspected cerebral pathology in HIV-infected individuals.

Methods

¹⁸F-FDG PET/CT scans from 29 HIV-infected individuals (29 brain scans, 22 whole-body scans) who presented with neurological symptoms and signs were retrospectively reviewed and compared with subsequent clinical investigations.

Results

The majority of patients (n?=?25) were referred to differentiate infection from malignant causes of cerebral pathology. Ten of the 11 patients with an eventual diagnosis of toxoplasmosis infection were correctly diagnosed by ¹⁸F-FDG PET/CT showing lesional uptake less than that of normal brain cortex (mean SUVmax 3.5, range 1.9 – 5.8). All five patients with a final diagnosis of primary central nervous system lymphoma (PCNSL) were correctly diagnosed by ¹⁸F-FDG PET/CT showing lesional uptake greater than that of normal brain cortex (mean SUVmax 18.8, range 12.4 – 29.9). Four of the five patients with ¹⁸F-FDG PET/CT features suggesting a vasculitic process had vasculitis confirmed as the final diagnosis. Three patients showed variable uptake in multiple cerebral lesions (including final diagnoses of tuberculosis and metastases from lung cancer in two patients) and there were four other miscellaneous diagnoses. In 12 patients biopsies were performed at sites guided by PET abnormality (7 brain, 5 lymph nodes) confirming or excluding significant disease in 11.

Conclusion

¹⁸F-FDG PET/CT is particularly useful for differentiating between infection and PCNSL in HIV-infected patients with a cerebral lesion on MRI or CT. ¹⁸F-FDG PET/CT was also a helpful tool in the diagnostic work-up of patients with other HIV-related cerebral pathology. Additional advantages of ¹⁸F-FDG PET/CT are the abilities to assess abnormally increased glucose metabolism in the body and to identify potential sites for biopsy.     

Role of 18F-FDG PET/CT in the assessment of bone involvement in newly diagnosed multiple myeloma: preliminary results

Purpose Multiple myeloma (MM) is a malignant B cell and plasma cell disorder which involves the skeleton in more than 80% of patients at diagnosis. The aim of this study was to compare whole-body X-ray (WBXR), MRI and ¹⁸F-FDG PET/CT in patients with MM. Methods The study population comprised 28 newly diagnosed MM patients. Findings of ¹⁸F-FDG PET/CT were compared with those of WBXR and MRI with regard to the number and site of lesions detected. Results Comparing ¹⁸F-FDG PET/CT and WBXR, it was found that in 16/28 pts (57%) ¹⁸F-FDG PET/CT detected more lesions, all of which were located in the skeleton. Nine of these 16 patients had a completely negative WBXR survey. In 12/28 pts (43%) the two methods yielded equivalent findings. Comparing ¹⁸F-FDG PET/CT and MRI, it was found that in 7/28 pts (25%), ¹⁸F-FDG PET/CT detected more lytic bone lesions, all of which were located outside the field of view of MRI (bone lesions in six cases and a soft tissue lesion in one). In 14/28 pts (50%), ¹⁸F-FDG PET/CT and MRI detected the same number of lesions in the spine and pelvis, while in 7/28 pts (25%) MRI detected an infiltrative pattern in the spine whereas ¹⁸F-FDG PET/CT was negative. Conclusion ¹⁸F-FDG PET/CT appears to be more sensitive than WBXR for the detection of small lytic bone lesions, whereas it has the same sensitivity as MRI in detecting bone disease of the spine and pelvis. On the other hand, MRI may be superior to ¹⁸F-FDG PET/CT in diagnosing an infiltrative pattern in the spine. Therefore, careful evaluation of MM bone disease at diagnosis should include both MRI of the spine and ¹⁸F-FDG PET/CT.     

18F-FDG PET/CT显像在恶性胸膜间皮瘤诊断中的价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT显像在恶性胸膜间皮瘤(MPM)诊断中的临床价值及原发肿瘤病灶平均标准摄取值(SUVmax)对患者预后的判断价值.方法 回顾性总结17例2002-2008年临床疑诊MPM患者18F-FDG PET/CT显像资料,测量病灶的SUVmax.将病理检查及临床随访证实的MPM患者按照有无转移分为2组,测定每例患者原发肿瘤病灶的SUVmax,用受试者工作特征(ROC)曲线评价SUVmax对患者转移与否的诊断价值,判断预后.采用SPSS 11.0软件进行t检验.结果 经病理及随访结果证实MPM 12例,良性胸膜病变5例,二者的SUVmax分别为5.78±1.81和2.72±2.51,差异有统计学意义(t=2.8,P<0.05).全身18F-FDG PET/CT显像诊断MPM的灵敏度为100%(12/12),特异性为4/5,准确性为94%(16/17),18F-FDG PET/CT显像有7例MPM伴有骨和(或)淋巴结转移.SUVmaxROC曲线分析表明曲线下面积(AUC)为0.80.结论 全身18F-FDG PET/CT显像对于MPM的诊断有重要价值.原发肿瘤病灶SUVmax越高越易发生转移,预后越差.     

原发纵隔大B细胞淋巴瘤的^18F-FDGPET/CT显像表现

目的探讨原发纵隔大B细胞淋巴瘤(PMBL)的^18F-脱氧葡萄糖(FDG)PET/CT显像特征。方法回顾性分析2010年7月至2019年4月间南京医科大学第一附属医院经病理证实的27例PMBL患者[男10例,女17例,中位年龄31(19~57)岁]的^18F-FDG PET/CT显像资料,观察病灶的位置、形态、密度、坏死及钙化情况、周围及远处侵犯情况等。通过阈值自动分割法计算病灶的最大标准摄取值(SUVmax)、代谢体积(MTV)和糖酵解总量(TLG)。采用Spearman相关分析评价SUVmax、MTV、TLG与最大长径、Ann Arbor分期的相关性。结果27例患者病灶表现为前纵隔肿块,其中25例肿块在前纵隔内跨区生长;24例患者病灶边缘不光整,呈分叶状;^18例患者病灶内可见低密度坏死灶;15例患者病灶包绕大血管生长;12例气管受压变窄;3例肿瘤侵犯肺组织;1例肿瘤累及腹腔淋巴结和骨髓;所有患者脾脏均未见肿大。27例患者病灶最大长径、SUVmax、MTV、TLG分别为(11.6±3.7)cm、21.07(15.78,25.09)、190.43(130.14,350.75)cm3、2165.54(1465.86,4^185.21)g。SUVmax与病灶最大长径无相关性(rs=-0.305,P=0.122),MTV、TLG均与最大长径呈正相关(rs=0.741、0.532,均P<0.05)。最大长径、MTV、TLG均与分期呈正相关(rs=0.394、0.413、0.422,均P<0.05),而SUVmax与Ann Arbor分期无相关性(rs=0.031,P>0.05)。结论PMBL^18F-FDG PET/CT显像多表现为前纵隔大肿块,^18F-FDG摄取较高,病灶内坏死多见,腹腔淋巴结、脾脏及骨髓侵犯少见;病灶MTV、TLG与Ann Arbor分期呈正相关。