饮水排尿再充盈延迟显像在膀胱病灶PET／CT检查中的价值

目的探讨提高SUVmax显示阈值结合大量饮水排尿后充盈膀胱延迟显像在^18F—FDGPET／CT诊断膀胱病灶中的价值。方法回顾性分析2007年7月至2012年10月因可疑膀胱占位和膀胱肿瘤治疗后（保留膀胱）行^18F—FDGPET／CT显像的患者63例[男55例,女8例,平均年龄69．1岁],常规显像后患者饮水1500～2000ml,觉憋尿时排尿,重复3次后再次充盈膀胱行盆腔延迟显像。对常规显像图进行2次阅片分析,第2次是对提高SUVmax显示阈值（从6—8至8～20）后的显像图再分析。所有患者经病理活组织检查或随访（〉6个月）确诊。观察常规显像与延迟显像尿液SUVmax及膀胱病灶^18F—FDG代谢的变化。采用配对样本t检验分析数据。结果常规显像和延迟显像尿液的SUVmax分别为15．11±11．11和4．73±2．00,差异有统计学意义（t=4．15,P〈0．01）。经病理及临床随访,63例患者中,发现膀胱病变18例（恶性15例,良性3例）,均为PET／CT检出,3例PET／CT假阳性中,2例无^18F—FDG代谢增高（良性）,1例为炎性反应。余45例PET／CT显像膀胱未见明显异常的患者经临床影像学随访6个月以上均未发现病变。16个病灶（16例患者）表现为^18F—FDG代谢增高,其中15例为膀胱癌原发或复发病灶,1例为炎性反应。16例PET显像高代谢病灶中,常规显像SUVmax显示阈值范围下分析,有18．8％（3／16）为阳性;提高SUVmax显示阈值范围后43．8％（7／16）为阳性。结论提高SUVmax显示阈值结合大量饮水排尿后再次充盈膀胱行延迟显像用于可疑膀胱肿瘤及膀胱肿瘤治疗后的^18F—FDGPET／CT显像,可有效提高膀胱病灶的检出率和诊断准确性。     

^18F-FDGPET／CT在滤泡性淋巴瘤分期及疗效评价中的临床价值

目的探讨^18F—FDGPET／CT在滤泡性淋巴瘤（FL）的分期、疗效评价、复发监测及预后判断方面的临床价值。方法回顾性分析2005年12月至2013年1月行PET／CT检查的经病理确诊为FL的28例患者[男12例,女16例,平均年龄57（36～82）岁]资料。对患者均进行AnnArbor临床分期,统计行PET／CT检查后临床分期改变情况。比较不同临床分期组间、病理高级别（3a＋3b级）组和低级别（1＋2级）组间SUVmax差异。28例中有17例行化疗后PET／CT检查和电话随访（10-88个月）监测疗效,比较疗效佳（CR＋PR）和不佳（SD＋PD）者生存差异。统计分析采用Mann—Whitneyu秩和检验、Wilcoxon符号秩检验和Kaplan—Meier生存分析。结果（1）28例治疗前行^18F—FDGPET／CT的患者中,10．7％（3／28）分期上调,3．6％（1／28）分期下调。Ⅰ＋Ⅱ期组SUVmax为10．1±3．2,Ⅲ＋Ⅳ期组SUVmax为11．5±4．9,差异无统计学意义（z=-0．619,P〉0．05）。病理低级别组（15例）和高级别组（13例）SUVmax分别为6．9±3．6和12．4±5．6（Z=-3．706,P〈0．01）。（2）17例治疗前后均行^18F-FDGPET／CT检查的患者中,疗效佳组（11例）治疗前SUV～10．8±5．1,治疗后SUVmax3．4±2．3（Z=-2．312,P〈0．05）;疗效不佳组（6例）治疗前SUVmax11．2±6．9,治疗后SUVmax7．8±3．3,差异无统计学意义（Z=-1．153,P〉0．05）。疗效佳与疗效不佳组的中位无进展生存期（PFS）分别为48和26个月（x^2=4．207,P〈0．05）。结论^18F-FDGPET／CT有助于明确FL分期、评价疗效、监测复发及提示预后。     

^18F-FDG PET／CT在胰腺癌诊断中的价值

目的评价^18F-脱氧葡萄糖（FDG）PET／CT鉴别诊断胰腺良恶性病变及检测淋巴结和（或）远处转移的价值。方法回顾性分析上海交通大学医学院附属仁济医院行^18F—FDGPET／CT检查的46例临床疑胰腺肿瘤患者的影像学检查资料和临床资料,其中胰腺癌患者26例,良性病变者20例,比较分析PET和CT的特征。结果当选择最大标准摄取值（SUVmax）=2．95为判断良恶性的界值时,对胰腺癌诊断的灵敏度是88．5％（23／26）,特异性是85．0％（17／20）。^18F—FDGPET／CT显像假阳性3例,假阴性3例。同时发现16例检查前未确定的肝、肺、骨及淋巴结转移患者。根据显像结果,11例患者治疗方案得以修正。结论根据现有资料分析,^18F—FDGPET／CT是鉴别诊断胰腺良恶性病变及检测胰腺癌患者淋巴结和（或）远处转移一种较好的方法。     

18F-FDG PET/CT结合高分辨率CT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结合高分辨率CT（HRCT）对孤立性肺结节（SPN）的鉴别诊断价值。方法25例经手术病理检查或治疗随访证实的SPN（共27个）患者，同期行^18F—FDGPET／CT显像和病灶部位HRCT检查。^18F—FDGPET／CT用目测法结合半定量法判断良恶性。HRCT则根据病灶形态学特征判断良恶性。所得^18F—FDGPET／CT结果和^18F—FDGPET／CT与HRCT相结合结果分别与病理检查结果对照比较。结果27个SPN中15个恶性，12个良性。PET／CT正确诊断14个恶性和9个良性SPN。3个良性SPNPET／CT显像为阳性，其中2个经PET／CT和HRCT联合诊断为良性。联合诊断灵敏度和单纯PET／CT相同（93．3％），但特异性、阳性预测值、阴性预测值、准确性分别高于PET／CT（91．7％、93．3％、91．7％和93．7％对75．0％、82．4％、90．0％和85．2％）。结论^18F—FDGPET／CT结合HRCT是有效的无创性鉴别SPN良恶性的方法。     

^18F-FDGPET／CT对不同分级和分期滤泡性淋巴瘤诊断及预后评估的价值

目的探讨^18F—FDGPET／CT对治疗前不同组织学分级及不同临床分期的滤泡性淋巴瘤（FL）的诊断价值,及其对一线治疗后的预后评估作用。方法回顾性分析2007年5月至2013年4月经病理学证实的24例（男11例,女13例,中位年龄55岁）治疗前行^18F—FDGPET／CT显像的FL患者。将患者按不同组织学分级和临床分期进行分组,计算对各组的诊断效能,并采用析因设计的方差分析比较不同组患者的病灶SUVmax。将同期一线治疗后行^18F—FDGPET／CT显像的16例[男9例,女7例,中位年龄50．5岁;其中7例为前述治疗前也行显像的患者]按照PET／CT结果分为阳性组和阴性组,对患者进行随访（6～49个月）并评价预后。结果（1）24例患者中惰性FL（组织学分级1＋2级）13例,侵袭性FL11例（组织学分级3级及2级伴DLBCL转化）。PET／CT显像诊断隋性FL和侵袭性FL患者的灵敏度分别为92．3％（12／13）和100％（11／11）;SUVmax分别为5．26±1．70和9．54±5．09（F=5．196,P〈0．05）;（2）PET／CT将AnnArbor分期为I-Ⅱ3例患者（12．5％,3／24）上调至Ⅲ～Ⅳ期,将2例患者（8．3％,2／24）的分期由Ⅲ～Ⅳ期下调至I-Ⅱ期。I～Ⅱ期和Ⅲ～Ⅳ期患者的SUV～分别为5．22＋2．92和8．04＋4．46（F=2．904,P〉0．05）;（3）16例一线治疗后行PET／CT显像的FL患者中,PET／CT阴性和阳性患者分别为13和3例,2组6个月、1年及3年总生存率分别为100％（13／13）、9／9、4／5和2／3、2／3和1／2;无进展生存率分别为92．3％（12／13）、8／9、3／5和2／3、0／3和0／2。结论^18F—FDGPET／CT对治疗前不同组织学分级及不同临床分期的FL有较高的诊断价值。FL患者一线治疗后行^18F—FDGPET／CT检查可提示预后。     

神经淋巴瘤病的^18F—FDG PET／CT影像特征分析

目的分析神经淋巴瘤病^18F—FDGPET／CT影像特征,并探讨其在评估神经淋巴瘤病中的应用价值。方法回顾性分析经病理检查证实的8例神经淋巴瘤病患者（男3例,女5例,年龄35～82岁）^18F—FDGPET／CT影像学资料,比较神经淋巴瘤病受累周围神经与健侧周围神经PET／CT表现的异同,并利用SPSS12．0软件对两者SUVmax行配对t检验。结果8例神经淋巴瘤病患者PET／CT共发现病灶11个,PET示病灶均沿神经丛、神经束或椎问孔走行,表现为束条形、根块状或结节状FDG代谢异常增高,SUVmax为6．54±3．23;病灶CT表现为沿神经束或神经根管走行的束条形、根块状或结节状软组织密度影,与周围软组织及邻近脂肪间隙分界不清。健侧对应部位周围神经在^18F-FDG PET／CT上未见明确显影,其SUVmax为1．15±0．48。神经淋巴瘤病受累神经与健侧周围神经SUVmax比较,差异有统计学意义（t=9．357,P〈0．001）。结论神经淋巴瘤病^18F—FDG PET／CT主要表现为沿神经丛、神经束或椎间孔走行的束条状、根块状或结节状FDG异常摄取灶,PET／CT可以准确反映肿瘤细胞对周围神经的浸润,显示病灶的大小、形态、分布及肿瘤活性。     

^18F—FDG PET／CT对局部进展性乳腺癌病人新辅助化疗早期反应的评价作用

我们评估^18F—FDG PET／CT对于乳腺癌病人新辅助化疗（NACT）2个周期后反应的评价作用。23例女性局部进展性乳腺癌病人纳入本研究。NACT2个周期后,根据临床检查、CT和^18F—FDG PET／CT评价早期反应。以NACT6个周期后手术病理结果作为参照。治疗前PET／CT显示23例病人共有26个病灶。原发性肿瘤大小为1．90～11．60cm,FDG最大标准摄取值（SUVmax）为3．6～38．6（平均11．7）。NACT2个周期后行PET／CT检查,原发性肿瘤大小为0．0—7．6cm,     

^18F-FDGPET／CT多次显像在监测和预测非小细胞肺癌术后复发和转移中的价值

目的探讨^18F-FDGPET／CT多次显像在监测和预测NSCLC术后复发和转移中的价值。方法NSCLC患者85例（男64例,女21例;平均年龄58．0岁）,分别于术前1周内和术后3个月接受多次全身^18F—FDGPET／CT显像。肿瘤复发和转移的诊断经病理学确诊或经多种影像学综合诊断并经临床随访证实。计算^18F—FDGPET／CT显像的诊断效能,统计学分析采用疋。检验和两独立样本t检验。结果85例患者中,肿瘤复发和转移43例,无复发和转移42例。PET／CT在半年内检出率为9.3％（4／43）,1年内为30．2％（13／43）,2年内为76．7％（33／43）,2年以上为97．7％（42／43）,未检出2。3％（1／43）。18F-FDGPET／CT对NSCLC复发和转移的诊断灵敏度、特异性、准确性分别为97．7％（42／43）、95．2％（40／42）和96．5％（82／85）。术前肿瘤分期、原发灶大小和原发灶SUVmax是2年内肿瘤复发和转移的影响因素似。12．360,t=3．281和2．465,均P〈0．05）,而性别、年龄和病理类型对其则均无明显影响。0．639、0．012和3．800,均P〉0．05）。结论^18F—FDGPET／CT多次显像有助于监测NSCLC术后复发和转移;术前肿瘤分期、原发灶大小及原发灶SUV。为2年内发生肿瘤复发和转移的影响因素。     

18F-FDGPET／CT对继发性周围神经恶性病变的诊断价值

目的 总结继发性周围神经恶性病变18F-脱氧葡萄糖（FDG）PET／CT影像特征,探讨18F—FDGPET／CT在继发性周围神经恶性病变中的应用价值。方法回顾性分析经病理检查或长期随访证实的8例周围神经恶性病变患者18F-FDGPET／CT影像学资料,比较继发性周围神经恶性病变与健侧周围神经PET／CT表现的异同,利用SPSS10．0软件对受累的周围神经及健侧对应部位周围神经的最大标准摄取值（SUVmax）行配对t检验。结果8例继发性周围神经恶性病变患者共发现病灶12个,PET示病灶均沿神经束或椎间孔走行,且表现为束条形、根块状或结节状FDG代谢异常增高,SUVmax为6．86±3．87,同机CT病灶表现为沿神经束或神经根管走行之束条形、根块状或结节状软组织密度影,病灶均与周围软组织及邻近脂肪间隙分界不清;健侧对应部位周围神经在18F—FDGPET及同机CT上均未见明确显影,其SUVmax为1．10±0．46;继发性周围神经恶性病变与健侧周围神经SUVmax比较,差异有统计学意义（t=9．231,P〈0．001）。结论18F—FDGPET／CT可以准确反映肿瘤对周围神经的侵犯及转移,显示病灶的大小、形态、分布及肿瘤活性,对继发性周围神经恶性病变的诊断具有重要价值。     

18F-FDGPET／CT诊断腹膜转移瘤的临床价值

目的评价18F-脱氧葡萄糖（FDG）PET／CT在腹膜转移瘤诊断中的临床价值。方法回顾性分析22例有原发恶性肿瘤手术史或不明原因腹腔积液而临床高度怀疑腹膜转移的患者资料。所有病例均行18F—FDGPET／CT检查,经病理检查或临床随访证实。结果22例中,有18例18F-FDGPET／CT诊断阳性,其中16例确诊腹膜转移,2例确诊为腹腔结核;4例PET／CT诊断阴性,其中3例确诊为腹膜炎性病变,1例确诊为腹膜转移瘤。18F—FDGPET／CT诊断腹膜转移瘤的灵敏度为94．1％（16／17）,特异性为3／5,阳性预测值为88．9％（16／18）,阴性预测值为3／4,准确性为86．4％（18／22）。结论在诊断腹膜转移瘤方面,18F—FDGPET／CT是一种可靠的、准确性较高的无创性检查,有重要的临床应用价值。     

原发性肾上腺淋巴瘤合并肝细胞癌全身18F-FDG PET/CT显像1例

笔者报道了1例原发性肾上腺淋巴瘤（PAL）合并肝细胞癌患者全身18F-氟脱氧葡萄糖（FDG） PET/CT 显像,PAL在临床上相对少见,特别是遇到合并其他恶性肿瘤的患者时容易误诊为恶性肿瘤转移。笔者主要分析了PAL合并肝细胞癌全身18F-FDG PET/CT 显像的特点并进行文献复习,为其诊断提供更多参考。     

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.     

Role of 18F-FDG PET/CT in staging and follow-up of lymphoma in pediatric and young adult patients

OBJECTIVE: To assess the role of 18F-Fluorodeoxyglucose (18F-FDG) PET/CT in pediatric patients with Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL). MATERIALS AND METHODS: 31 patients, mean age 12.9 +/- 5.1, HD (n = 24), and NHL (n = 7) underwent 18F-FDG PET/CT at diagnosis (n = 31 studies) and later in the course of the disease (n = 75 studies). The findings of PET/CT were correlated with diagnostic CT and clinical follow-up. RESULTS: PET/CT findings resulted in a change of disease staging in 10 patients (32.3%), upstaging in 7 (22.6%) and downstaging in 3 (9.6%). On a lesion analysis, 164 disease sites were detected by PET/CT of which 38 were overlooked by DCT.At mid-treatment, PET was negative in 28 out of 31 patients (90%) with negative predictive value of 96% as all latter patients except for 1, were disease free (mean 15.4 +/- 8.8 months). The positive predictive value of persistent increased 18F-FDG uptake was 100% as 3 patients with latter findings had active disease. On the CT part, 76 residual masses were identified in 22 patients. Increased 18F-FDG uptake was detected in 11 masses in 4 patients who had active disease. Remaining 65 PET negative masses were false positive findings. The positive predictive value of residual CT mass was 14%. CONCLUSIONS: PET/CT is associated with change in staging in approximately 1 out of 3 pediatric patients with HD and NHL. When used for monitoring response to treatment, a negative study is associated with disease-free period, even when residual mass is detected. A positive PET study indicates residual malignant disease.     

18F-FDG PET/CT in the evaluation of adrenal masses.

Our purpose was to evaluate the performance of (18)F-FDG PET/CT, using data from both the PET and the unenhanced CT portions of the study, in characterizing adrenal masses in oncology patients. METHODS: One hundred seventy-five adrenal masses in 150 patients referred for (18)F-FDG PET/CT were assessed. Final diagnosis was based on histology (n = 6), imaging follow-up (n = 118) of 6-29 mo (mean, 14 mo), or morphologic imaging criteria (n = 51). Each adrenal mass was characterized by its size; its attenuation on CT, expressed by Hounsfield units (HU); and the intensity of (18)F-FDG uptake, expressed as standardized uptake value (SUV). Receiver operating characteristic curves were drawn to determine the optimal cutoff values of HU and SUV that would best discriminate between benign and malignant masses. RESULTS: When malignant lesions were compared with adenomas, PET data alone using an SUV cutoff of 3.1 yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 98.5%, 92%, 89.3%, 98.9%, respectively. For combined PET/CT data, the sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98%, 97%, 100%, respectively. Specificity was significantly higher for PET/CT (P < 0.01). Fifty-one of the 175 masses were 1.5 cm or less in diameter. When a cutoff SUV of 3.1 was used for this group, (18)F-FDG PET/CT correctly classified all lesions. CONCLUSION: (18)F-FDG PET/CT improves the performance of (18)F-FDG PET alone in discriminating benign from malignant adrenal lesions in oncology patients.     

18F-FDG PET in evaluation of adrenal lesions in patients with lung cancer.

The purpose of this study was to assess the role of PET with (18)F-FDG in differentiating benign from metastatic adrenal masses detected on CT or MRI scans of patients with lung cancer. METHODS: This retrospective study analyzed (18)F-FDG PET scans of patients with lung cancer who were found to have an adrenal mass on CT or MRI scans. One hundred thirteen adrenal masses (75 unilateral and 19 bilateral; size range, 0.8-4.7 cm) were evaluated in 94 patients. PET findings were interpreted as positive if the (18)F-FDG uptake of the adrenal mass was greater than or equal to that of the liver. PET findings were interpreted as negative if the (18)F-FDG uptake of the adrenal mass was less than that of the liver. All studies were reviewed independently by 3 nuclear medicine physicians, and the results were then correlated with clinical follow-up or biopsy results when available. RESULTS: PET findings were positive in 71 adrenal masses. Sixty-seven of these were eventually considered to be metastatic adrenal disease. In the remaining 4, no changes in lesion size were noted on follow-up examinations. PET findings were negative in 42 adrenal masses, of which 37 eventually proved to be benign. Among the 5 adrenal masses that were false-negative, one was a large necrotic metastasis; 1 was a 2.4-cm lesion with central hemorrhaging, and the remaining 3 were lesions of less than 11 mm. The sensitivity, specificity, and accuracy for detecting metastatic disease were 93%, 90%, and 92%, respectively. CONCLUSION: (18)F-FDG PET is an accurate, noninvasive technique for differentiating benign from metastatic adrenal lesions detected on CT or MRI in patients with lung cancer. In addition, PET has the advantage of assessing the primary cancer sites and detecting other metastases.     

Prognostic value of PET using 18F-FDG in Hodgkin's disease for posttreatment evaluation.

Detection of relapse after completion of therapy in patients with Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHL) constitutes an important challenge in modern medical imaging. An accurate assessment of the presence of residual disease is essential to determine which patients would benefit from additional therapy. The objective of this study was to assess the diagnostic accuracy of (18)F-FDG PET in detecting residual disease or relapse during the posttherapy period in patients with HD in comparison with CT. We also established different predictive values for (18)F-FDG PET according to the time interval between the end of therapy and the PET study. METHODS: Forty-eight patients with HD underwent (18)F-FDG PET after the completion of chemotherapy (median, 58 d) between March 1999 and April 2002. Disease-free intervals and proportions were calculated using the Kaplan-Meier method. Standardized uptake values of the most active lesion in each patient with a positive study were also measured. PET and CT results were compared with clinical follow-up, with relapse being defined by a positive biopsy or the introduction of a second-line treatment. RESULTS: Thirty-four patients were still disease-free during a mean follow-up of 605 d. Fourteen patients relapsed during a mean follow-up of 197 d. The sensitivity and specificity of (18)F-FDG PET to predict relapse were 79% and 97%, respectively. The positive predictive value and the negative predictive value were both equal to 92%. The diagnostic accuracy of (18)F-FDG PET (92%) was significantly higher than the accuracy of CT (56%) (P < 0.0005). Patients with positive (18)F-FDG PET also had a far shorter median disease-free interval (79 d) than those with positive CT (disease-free proportion of 52% at 1,143 d) (P = 0.0046). The 3 cases of false-negative (18)F-FDG PET studies that we observed occurred in patients who underwent their PET study within the first 49 d after the end of chemotherapy. CONCLUSION: Positive (18)F-FDG PET after the end of therapy in HD patients is a strong predictor of relapse. A negative PET study is also an excellent predictor of good prognosis. The diagnostic accuracy of (18)F-FDG PET to assess the presence of residual disease after therapy is superior to that of CT.     

18F-FDG PET/CT in patients with suspected recurrent or metastatic well-differentiated thyroid cancer.

PET using 18F-FDG has been shown to effectively detect various types of cancer by their increased glucose metabolism. The aim of this study was to evaluate the use of coregistered PET and CT (PET/CT) in patients with suspected thyroid cancer recurrence. METHODS: After total thyroidectomy followed by radioiodine ablation, 61 consecutive patients with elevated thyroglobulin levels or a clinical suspicion of recurrent disease underwent 18F-FDG PET/CT. Of these, 59 patients had negative findings on radioiodine (131I) whole-body scintigraphy (WBS). Fifty-three of the 61 patients had both negative 131I WBS findings and elevated thyroglobulin levels. PET/CT images were acquired 60 min after intravenous injection of 400-610 MBq of 18F-FDG using a combined PET/CT scanner. Any increased 18F-FDG uptake was compared with the coregistered CT image to differentiate physiologic from pathologic tracer uptake. 18F-FDG PET/CT findings were correlated with the findings of histology, postradioiodine WBS, ultrasound, or clinical follow-up serving as a reference. The diagnostic accuracy of 18F-FDG PET/CT was evaluated for the entire patient group and for those patients with serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL. RESULTS: Thirty patients had positive findings on 18F-FDG PET/CT; 26 were true-positive and 4 were false-positive. In 2 patients, increased 18F-FDG uptake identified a second primary malignancy. 18F-FDG PET/CT results were true-negative in 19 patients and false-negative in 12 patients. The overall sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 68.4%, 82.4%, and 73.8%, respectively. The sensitivities of 18F-FDG PET/CT at serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL were 60%, 63%, and 72%, respectively. Clinical management changed for 27 (44%) of 61 patients, including surgery, radiation therapy, or chemotherapy. CONCLUSION: Coregistered 18F-FDG PET/CT can provide precise anatomic localization of recurrent or metastatic thyroid carcinoma, leading to improved diagnostic accuracy, and can guide therapeutic management. In addition, the findings of this study suggest that further assessment of 131I WBS-negative, thyroglobulin-positive patients by 18F-FDG PET/CT may aid in the clinical management of selected cases regardless of the thyroglobulin level.     

Neurolymphomatosis; a case report

We present a case of indolent neurolymphomatosis in a 55-year-old male patient with worsening pain and weakness in his right leg over the past few months. The patient has a past medical history of type II diabetes mellitus, four-year history of worsening left foot drop, left lower limb pain and weakness attributed to diabetic amyotrophy, and back pain. The new right-sided symptoms prompted further imaging which revealed a left sciatic nerve mass which was biopsied. Initial biopsy results were inconclusive. ¹⁸F-FDG PET/CT revealed the full extent of this patient's disease and helped plan for a more representative biopsy site, which finally established a diagnosis of diffuse large B-cell lymphoma involving the lumbosacral nerve roots. The patient underwent a course of chemotherapy. ¹⁸F-FDG PET/CT was ordered again at the end of treatment showing partial response to therapy. He underwent radiation therapy to the site of residual disease, with complete metabolic response of lesions on follow up PET CT.     

Prosthetic vascular graft infection: the role of 18F-FDG PET/CT.

Graft infection after prosthetic vascular reconstruction is an uncommon but severe complication. The clinical presentation is often subtle and nonspecific and may occur long after surgery. Although defining a prosthetic vascular graft infection can be difficult, early diagnosis and treatment are important because of the relatively high rates of amputation and death. The present study assessed the role of PET/CT using 18F-FDG for the diagnosis of vascular graft infections. METHODS: Thirty-nine patients (35 men and 4 women; age range, 44-82 y) with suspected vascular graft infection underwent 18F-FDG PET/CT. The performance of PET/CT for the diagnosis of an infectious process and its localization to the graft or soft tissues was assessed. The final diagnosis was based on histopathologic findings and microbiologic assays obtained at surgery or on clinical and imaging follow-up. RESULTS: PET/CT detected foci of increased 18F-FDG uptake suspected as infection in 27 patients and localized these findings to the graft in 16 patients. Vascular graft infection was confirmed in 14 of these patients (88%). PET/CT excluded graft involvement in 11 patients, and in 10 (91%) of these 11, long-term follow-up further confirmed that the infectious process was limited to surrounding soft tissues only. No abnormal 18F-FDG uptake was found in any of the 12 patients with no further evidence of infection. PET/CT had a sensitivity of 93%, specificity of 91%, positive predictive value of 88%, and negative predictive value of 96% for the diagnosis of vascular graft infection. CONCLUSION: 18F-FDG PET/CT is a reliable noninvasive imaging modality for the diagnosis of vascular graft-related infection. The precise anatomic localization of increased 18F-FDG uptake provided by PET/CT enables accurate differentiation between graft and soft-tissue infection.     

原发性肺弥漫大B细胞淋巴瘤18F-FDG PET/CT显像一例

笔者报道了一例原发性肺弥漫大B细胞淋巴瘤的18F-FDG PET/CT显像病例,从临床症状、实验室检查、18F-FDG PET/CT影像学等方面分析该病特点,并通过文献回顾了原发性肺弥漫大B细胞淋巴瘤鉴别诊断要点。研究结果显示,本例原发性肺弥漫大B细胞淋巴瘤18F-FDG PET/CT影像学表现为巨大软组织团块影、边缘光滑、内见多发点状钙化灶,18F-FDG代谢团块状增高,SUV_max为26.2。18F-FDG PET/CT显像能够为原发性肺弥漫大B细胞淋巴瘤的诊断提供参考依据。