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 and contrast-enhanced CT findings of pulmonary cryptococcosis

PurposePulmonary cryptococcosis is an uncommon cause of pulmonary nodules in non-AIDS patients. This study reports the ¹⁸F-fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG PET/CT) and contrast-enhanced CT (CE-CT) findings of 42 patients with pulmonary cryptococcosis.Materials and methodsA retrospective review of the ¹⁸F-FDG PET/CT and CE-CT findings of 42 patients with histologically proven pulmonary cryptococcosis was conducted. All patients underwent PET/CT and CE-CT in the same session. The CT diagnosis was based on the location, morphological features, and enhancement of lesions. The PET/CT findings were recorded, and clinical data and surgical and histopathological findings were collected.ResultsThe results of the PET scans revealed that 37 (88%) of 42 patients showed higher FDG uptake, and 5 (12%) patients demonstrated lower FDG uptake than the mediastinal blood pool. The maximum standardized uptake value (SUV) of pulmonary cryptococcosis ranged from 1.4 to 13.0 (average: 5.7 ± 3.3, median 4.9). A single nodular pattern was the most prevalent pattern observed and was found in 29 (69%) patients. This pattern was followed by scattered nodular (n = 4, 10%), clustered nodular (n = 3, 7%), mass-like (n = 3, 7%), and bronchopneumonic (n = 3, 7%) patterns. The most frequent pattern of immunocompetent patients was the single nodular pattern (29 of 33, 88%). Immunocompromised patients most frequently pattern exhibited mass-like (3 of 9, 33%) and bronchopneumonic (3 of 9, 33%) patterns.ConclusionPulmonary cryptococcosis most commonly appears as single nodules in immunocompetent patients. Mass-like and bronchopneumonic patterns were common in immunocompromised patients. In 88% of patients, lung lesions showed high FDG uptake, thus mimicking a possible malignant condition.     

Evaluation of 18F-FDG uptake and arterial wall calcifications using 18F-FDG PET/CT.

Glucose metabolic activity expressed as (18)F-FDG uptake may be increased in active atherosclerotic plaque. Calcium depositions are often increased in mature atherosclerotic plaque. The purpose of the present study was to assess the patterns of vascular-wall (18)F-FDG uptake and CT calcifications using combined PET/CT. METHODS: One hundred twenty-two consecutive patients over the age of 50 (47 women and 75 men; mean age, 66 +/- 9 y) undergoing whole-body (18)F-FDG PET/CT for tumor assessment were retrospectively evaluated. PET, CT, and PET/CT slices were generated for review. Abnormal vascular findings in major arteries in the chest and abdomen were categorized as PET positive (PET+), PET negative (PET-), CT positive (CT+), or CT negative (CT-). The topographic relationship between increased vascular-wall (18)F-FDG uptake on PET and the presence of calcifications on CT was assessed on PET/CT fused images, with abnormal sites further classified as PET+/CT+, PET+/CT-, or PET-/CT+. The presence of CT calcifications and increased vascular-wall (18)F-FDG uptake was correlated with age, sex, presence of cardiovascular risk factors, and cardiovascular disease. RESULTS: Abnormal findings were identified at 349 sites. CT calcifications (CT+) were observed at 320 sites (92%) of 100 patients (82%), more commonly in men (P < 0.03), in older patients (P < 0.0001), in patients with hypertension (P < 0.003) or hyperlipidemia (P < 0.04), and in smokers (P < 0.008). Increased vascular-wall (18)F-FDG uptake (PET+) was observed at 52 sites (15%) of 38 patients (31%), more commonly in men (P < 0.02), in older patients (P < 0.0001), and in patients with hypertension (P < 0.02), and was borderline in patients with cardiovascular disease (P = 0.057). PET+ and CT+ findings correlated in 12 patients, a PET+/CT- pattern was found in 18 patients, and 8 patients had increased vascular-wall (18)F-FDG uptake in sites with and without calcifications (PET+/CT+, CT-). Twenty-two patients (18%) had a PET-/CT- pattern. CONCLUSION: Hybrid PET/CT can be used to identify and to correctly localize vascular-wall (18)F-FDG activity. Increased vascular-wall (18)F-FDG activity was found in 15% of sites and CT calcifications were noted in 92% of sites, with congruent findings in 7%. The clinical significance of the relationship between vascular-wall (18)F-FDG uptake and CT calcifications needs to be assessed by further prospective studies with long-term follow up.     

血糖水平对18F-FDG PET/CT图像质量的影响

目的 研究血糖水平对18F-脱氧葡萄糖(FDG) PET/CT图像质量的影响.方法 80例行体格检查或评价肿瘤性质的受检者,按空腹血糖水平分为9组(组间距为1mmol/L),第1组为血糖正常组,即血糖＜6.0mmol/L(10例);第2～9组血糖水平高于正常,分别为6.0～6.9mmol/L(11例),7.0～7.9mmol/L(13例),8.0～8.9mmol/L(11例),9.0～9.9mmol/L(11例),10.0～10.9mmol/L(8例),11.0～11.9mmol/L(6例),12.0～12.9mmol/L(5例),≥13.0mmol/L(5例).受检者做完PET/CT检查后,图像质量由2位有经验的医师独立判断.同时根据肝不同层面的标准摄取值(SUV)最大值(SUVmax)及SUV平均值(SUVavg)分别计算肝图像噪声.采用SPSS 12.0软件进行统计学处理.结果 (1)9组之间图像质量评分、肝噪声差异有统计学意义(P均＜0.05).将第2～9组图像质量评分、肝噪声分别与第1组进行比较,第2～7组与第1组差异无统计学意义(P均＞0.05);第8,9组与第1组比较差异有统计学意义(P均＜0.05),且评分低于第1组.(2)血糖水平与图像质量评分呈负相关(r=-0.52,P＜0.05);血糖水平与肝噪声呈正相关(SUVmax、SUVavgr值分别为0.33和0.60,P均＜0.05);SUVavg所算噪声与血糖水平的相关性优于SUVmax.结论 图像质量随血糖水平的升高而下降,血糖＜12.0mmol/L时与血糖正常者PET/CT图像质量差异无统计学意义,但当血糖水平≥12.0mmol/L时图像质量将显著下降.     

18F-FDG PET/CT和同机CT增强扫描对肺硬化性血管瘤的诊断价值

目的 探讨肺硬化性血管瘤(PSH)的18F-FDG PET/CT显像和CT增强扫描特征及2种方法对该病的诊断价值.方法 回顾性分析2007年6月至2011年6月间,经病理证实为PSH、有同机18 F-FDG PET/CT双时相(早期、延迟)显像、病灶层面高分辨率(HR) CT扫描及多期增强CT扫描资料的5例患者,其中女4例,男1例,发病年龄39 ～66(平均51.6)岁.对PET/CT早期、延迟显像图及滞留指数,CT扫描的增强净增值、峰值下降时间及“边缘血管征”等进行综合分析.结果 PSH在双时相18 F-FDG PET/CT显像上表现为斑片样FDG代谢增高,早期显像SUVmax为3.3±1.1,延迟显像SUVmax增高或降低,平均为3.4±1.4,平均滞留指数为(2.1±20.8)％;HRCT可表现为边界清晰的圆形或类圆形结节或肿块,部分可见“空气新月征”,少数病灶内可见钙化点;多期CT增强扫描显示病灶呈中～高度强化(增强净增值为35 ～ 59 HU),增强后峰值下降(峰值下降时间为140～260 s),5例病例均可见1～4条数量不等的“边缘血管征”.结论 PSH 18F-FDG PET/CT显像的肿块或结节的斑片样高代谢表现提示其可能为良性病灶;结合病灶层面的诊断性CT扫描(包括增强)表现,可进一步明确PSH的诊断.     

^18F-FDG PET／CT 结合 HRCT 对肺微浸润性腺癌的诊断价值

目的：^18 F-FDG PET/CT结合 HRCT 对肺微浸润性腺癌（minimally invasive adenocarcinoma ,MIA）的诊断价值。方法搜集经手术病理证实28例肺 MIA 患者的^18 F-FDG PET/CT 及 HRCT 影像资料,患者均先行^18 F-FDG PET/CT显像,后行HRCT扫描检查,分析其形态学表现及放射性分布,同时测量其SUVmax值,分析PET/CT、HRCT、PET/CT结合 HRCT三者的准确率。结果28例患者中,18 F-FDG PET 显像有19例出现高于肺本底的局灶性异常放射性摄取增高影,以SUVmax＞2．5为标准,诊断MIA的灵敏度为32．1％（9/28）。HRCT 病灶显示磨玻璃密度结节27例（96．4％）,其中单纯磨玻璃密度结节10例,混杂磨玻璃密度结节17例,单纯实性密度结节1例;病灶出现边缘分叶征18例（64．3％）,毛刺征20例（71．4％）,空泡征或支气管充气征21例（75％）,胸膜凹陷征12例（42．9％）,血管集束征10例（35．7％）,圆形结节征13例（46．4％）。PET/CT、HRCT、PET/CT结合 HRCT 三者的准确率分别为71．4％、82.1％和96．4％。结论^18 F-FDG PET/CT诊断MIA易出现假阴性,PET/CT结合HRCT有利于提高诊断准确率。     

18F-FDG PET/CT伪影和不常见生理性摄取分析

目的 探讨^18F-脱氧葡萄糖（FDG）PET/CT显像各种伪影的影像学表现及其产生的原理.方法 回顾性分析^18F-FDG PET/CT检查患者的图像,根据伪影产生的原因进行分类,同时对临床不常见的生理性摄取进行分析.结果 伪影分为自身因素和设备技术因素伪影,自身因素所致伪影中以呼吸运动伪影和高密度物质伪影最为常见;设备因素伪影中以截断伪影、注射点外漏和放射性污染最为常见.不常见的生理性摄取包括：子宫内膜摄取、乳腺摄取和脂肪摄取.结论 PET显像伪影影像学表现可分为“热区”或“冷区”.不常见的生理性摄取主要表现为“热区”.伪影产生原因中以CT应用于PET显像后物理学因素多见.不常见的生理性摄取与检查技术有关.     

18F-FDG PET/CT superior to serum CEA in detection of colorectal cancer and its recurrence

The aim of this study was to examine whether positron emission tomography (PET)/computed tomography (CT) can detect more cases of colorectal cancer (CRC) than serum carcinoembryonic antigen (CEA), both at initial staging and during surveillance for recurrence. A retrospective review of 639 CRC patients imaged with PET/CT was performed. PET/CT was superior to serum CEA in detecting CRC, identifying 2.5 times as many CRC at initial staging compared to serum CEA and 1.5 times as many CRC recurrences. The current guideline recommendations of utilizing PET/CT only in the context of a rising serum CEA will miss more than one third of all CRC recurrences.     

Cosmetic-related changes on 18F-FDG PET/CT

We present 4 cases of cosmetic-related changes on 18F-FDG PET/CT. These cases represent post-treatment changes from facial juvederm injection, silicone injection in the chest wall and gluteal areas, paraffin injection in the gluteal region, and liposuction. Recognition of cosmetic-related changes and their appearance on PET and CT will help to avoid potential false-positive interpretations.     

18F-FDG PET/CT棕色脂肪摄取的影像学分析

目的:分析18F-FDG PET/CT检查中棕色脂肪组织(BAT)摄取的规律和特点,以避免不必要的误诊.方法:回顾性分析行PET/CT全身检查的2350例受检者的图像.结果:34例(1.44％)有不同程度BAT摄取,其中恶性肿瘤患者9例(甲状腺癌术后4例).BAT显影主要在寒冷季节出现,女性比例(2.57％)高于男性(0.76％);特征性表现为对称性分布于肩颈部、锁骨上区、脊柱两旁、纵隔、肾上腺及肾周区的高摄取灶,SUVmax为7.18±4.27.BAT显影部位的数目与摄取的SUVmax呈正相关(r=0.78,P＜o.05);5例检查者进行了延迟扫描,延迟后BAT分布、形态无明显变化,SUVmax显著升高(P＜0.05).4例甲状腺癌术后复查病例的BAT摄取不同程度影响了对区域淋巴结的观察.结论:BAT摄取的分布及影像表现具有一定的特征性,显影部位越多,SUVmax越大,延迟扫描后SUVmax显著升高,容易干扰对显影区域病灶的观察.     

Increased 18F-FDG uptake in degenerative disease of the spine: Characterization with 18F-FDG PET/CT.

We determined the prevalence of abnormal spinal 18F-FDG uptake and assessed the relationship between the severity of findings on 18F-FDG PET and the severity of degenerative spinal disease (DSD) on CT. METHODS: PET/CT scans of 150 patients >18 y old, referred for whole-body 18F-FDG PET/CT for evaluation of known or suspected malignancy from June to July 2002, were analyzed retrospectively for the presence of increased 18F-FDG uptake in the spine and for anatomic correlates. Initially, PET images were examined and foci of 18F-FDG uptake in the spine were graded on a 0-4 scale based on intensity of 18F-FDG uptake (0 = definitely normal, 1 = probably normal, 2 = equivocal, 3 = probably abnormal, 4 = definitely abnormal). From PET alone, an impression as to whether lesions were most likely metastases or degenerative, as well the level of the spine involved, was also recorded. CT images of all 150 patients were reviewed independently by a musculoskeletal radiologist, who was unaware of patient identification, history, and findings of other imaging modalities, with the location recorded and severity graded on a 4-point-scale (0 = normal, 1 = mild, 2 = moderate, 3 = severe for both degenerative disk and facet disease). The relationship between PET and CT findings was then determined. RESULTS: Of the 150 patients, 63 (42.0%) had no abnormal findings in the spine on PET (grade 0), 27 (18.0%) had grade 1, 25 (16.7%) had grade 2, 17 (11.3%) had grade 3, and 16 patients (10.7%) had grade 4 18F-FDG uptake for DSD. Two additional patients had apparent spinal metastases with no degenerative changes. Five patients had metastases and DSD (included above). Of the patients who had abnormal spinal findings graded as probable or definite for DSD on CT (grades 3-4), 11 had abnormal findings in the cervical spine, 16 in the thoracic spine, and 23 patients in the lumbosacral spine. Seven patients (4.7%) had PET findings suggestive of spinal metastases. For patients with a maximum regional DSD score of 3, the mean 18F-FDG uptake for that spinal level was 1.4 +/- 1.5, whereas for patients with a maximum regional DSD score of 0, the mean PET grade was significantly lower at 0.4 +/- 0.9 (P = 0.0001). CONCLUSION: Incidental findings on PET suggestive of DSD are common (22% of patients), most common in the lumbosacral spine, and can be recognized on CT. The severity of PET findings correlates with the severity of degenerative disk and facet disease as graded by CT, likely due to the fact that the inflammatory process that accompanies DSD is evident on PET. Increased 18F-FDG uptake in DSD should not be confused with metastatic disease.     

18F-FDG PET/CT and COVID-19

European Journal of Nuclear Medicine and Molecular Imaging -     

18F-FDG PET and PET/CT for detection of pulmonary metastases from musculoskeletal sarcomas

OBJECTIVE: Sarcomas represent a significant therapeutic challenge and their potential for distant pulmonary metastases is well known. [(18)F]Fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) has a role in differentiating sarcomas from benign tumours and assessing the response to therapy in advanced sarcomas. However, PET appears to be less accurate in detection of pulmonary metastases. We were therefore prompted to review our experience with PET and PET/computed tomography (CT) in osseous and soft tissue sarcomas (OSTSs). METHODS: This is a retrospective study (January 1995 to December 2004) of 106 patients with histological diagnosis of OSTS, who had PET and PET/CT at our institution. The group included 52 men and 54 women, aged 12-92 years (average, 45+/-20 years). RESULTS: For all the patients in the analysis, the sensitivity and specificity were 68.3% (95% CI: 53-80.4) and 98.4% (95% CI: 91.8-99.7) for PET, with 95.1% sensitivity (95% CI: 83.8-98.6) and 92.3% specificity (95% CI: 83.2-96.7) for CT. Pulmonary metastases were seen in 40 patients. CT identified 17 lesions larger than 1.0 cm, while PET identified 13 of them (76.5%). CONCLUSIONS: Chest CT is more sensitive than PET in detecting pulmonary metastases from OSTS. A significant portion of known pulmonary metastases greater than 1.0 cm on CT, are PET negative. Sub-centimetre CT lesions should not be considered false positive if inactive on PET. A negative PET scan in the presence of suspicious CT findings in the chest cannot reliably exclude pulmonary metastases from OSTS.