Superscan-like Hypermetabolic Lesions on Delayed FDG PET/CT Imaging in a Patient With Lung Cancer

ABSTRACT: A 69-year-old man with a lung mass underwent multiple-time-point FDG PET/CT imaging for diagnostic evaluation. The initial PET imaging (performed at 1 hour after tracer injection) revealed equivocal bone marrow uptake in the right iliac bone and proximal femurs in addition to lung and mediastinal lesions. The 3-hour delayed PET imaging, however, demonstrated widespread bone marrow metastases. Biopsies of the right lung mass and right iliac bone marrow were later performed and revealed a poorly differentiated squamous cell carcinoma in both sites. This case indicates the value of delayed FDG PET in detecting superscan-like hypermetabolic bone marrow lesions in patients with lung cancer.     

PET/MRI and PET/CT in follow-up of head and neck cancer patients

Purpose

Positron emission tomography (PET)/MRI combines the functional ability of PET and the high soft tissue contrast of MRI. The aim of this study was to assess contrast-enhanced (ce)PET/MRI compared to cePET/CT in patients with suspected recurrence of head and neck cancer (HNC).

Methods

Eighty-seven patients underwent sequential cePET/CT and cePET/MRI using a trimodality PET/CT-MRI set-up. Diagnostic accuracy for the detection of recurrent HNC was evaluated using cePET/CT and cePET/MRI. Furthermore, image quality, presence of unclear ¹⁸F-fluorodeoxy-D-glucose (FDG) findings of uncertain significance and the diagnostic advantages of use of gadolinium contrast enhancement were analysed.

Results

cePET/MRI showed no statistically significant difference in diagnostic accuracy compared to cePET/CT (91.5 vs 90.6 %). Artefacts’ grade was similar in both methods, but their location was different. cePET/CT artefacts were primarily located in the suprahyoid area, while on cePET/MRI, artefacts were more equally distributed among the supra and infrahyoid neck regions. cePET/MRI and cePET/CT showed 34 unclear FDG findings; of those 11 could be solved by cePET/MRI and 5 by cePET/CT. The use of gadolinium in PET/MRI did not yield higher diagnostic accuracy, but helped to better define tumour margins in 6.9 % of patients.

Conclusion

Our data suggest that cePET/MRI may be superior compared to cePET/CT to specify unclear FDG uptake related to possible tumour recurrence in follow-up of patients after HNC. It seems to be the modality of choice for the evaluation of the oropharynx and the oral cavity because of a higher incidence of artefacts in cePET/CT in this area mainly due to dental implants. However, overall there is no statistically significant difference.     

舌病变的CT、MRI影像分析

目的 分析舌病变的CT及MRI表现,评价影像检查在舌病变诊断中的应用价值.方法 回顾性分析经手术、病理证实的28例舌病变患者资料,其中舌鳞癌20例,良性病变8例,比较分析其影像表现,并行统计学检验.结果 (1)20例舌鳞癌患者,在CT、MRI上表现为溃疡、浸润或疣型肿块影,增强扫描明显强化,与周围组织分界清;8例良性病变,除溃疡性嗜酸性肉芽肿和淋巴管瘤外,均未见肿块占位效应(x2=13.621,P=0.000).(2)MRI检查并有完整手术记录的7例舌鳞癌患者中,肿块最大径≥2 cm者6例,淋巴结转移5例,转移率为83.3％(5/6);肿块最大径＜2 cm者1例,未发现淋巴转移.结论 CT、MRI对舌良、恶性病变的鉴别诊断具有价值.     

18F-FDG PET/CT在肺部占位性病变诊断中的价值

目的:探讨18F-FDG PET/CT在诊断肺部占位性病变中的价值.方法:对100例肺部占位性病变进行回顾性分析,比较PET/CT与PET及CT的诊断效度、不同大小肿瘤的SUV、不同病理类型肺癌的SUV.结果:①PET/CT的灵敏度、阴性预测值、准确率优于CT(P<0.01),PET/CT的特异度优于PET(P<0.05).②依据肿瘤大小分为<3cm、3～5cm、>5cm组,应用单向方差分析对比不同组间SUV,3组间SUV均有差异,P<0.01.各组间SUV两两比较,发现小于3cm组SUV<3～5cm组SUV<5cm以上组SUV.③鳞癌组与腺癌组SUV无显著差异(P=0.821,P>0.05).结论:18F-FDG PET/CT在诊断肺部占位性病变中将PET代谢学特征密切结合CT的形态学表现,可大大提高各项诊断效率,达到优势互补的目的.     

An update on the role of PET/CT and PET/MRI in ovarian cancer

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as ¹⁸F-fluorothymidine (FLT) or ¹¹C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer.     

CT双窗在胸部疾病鉴别诊断中的应用

作者在30例胸部CT检查有病变的病例中使用双窗技术,分别阅读肺窗、纵隔窗以及双窗位片,比较使用双窗前后的诊断结果。发现使用双窗前,有5例误诊,应用双窗后没有误诊。讨论了CT双窗技术的原理以及其优点与限度。     

Thoracic and Extrathoracic Malignancies in Lung Cancer Screening Patients With Histories of Malignancy

PurposeThe objective of this study was to assess whether a history of malignancy affects the incidence of extrathoracic malignancies and lung cancer in patients undergoing CT lung cancer screening (LCS).MethodsAll patients who underwent a LCS CT between June 2014 and August 2018 in a single health care system were included. History of prior nonskin malignancy was extracted from billing records. Subsequent diagnoses of malignancy were extracted from clinical pathology reports. Risk for subsequent malignancy was compared between patients with and those without prior malignancy and evaluated using multivariate logistic regression including age and history of malignancy.ResultsA total of 5,835 LCS CT studies were included, and 1,243 (21%) were performed on patients with diagnoses of malignancy before CT. For the 4,592 scans performed on patients without histories of malignancy, 87 patients (1.9%) were diagnosed with lung cancer and 68 (1.5%) were diagnosed with nonlung malignancies in the following year. Among patients with histories of malignancy, 17 (1.4%) were diagnosed with lung cancer, and 25 (2%) were diagnosed with nonlung malignancies. Logistic regression for subsequent diagnosis of malignancy (including lung cancer) demonstrated age to be predictive, with an odds ratio of 1.6 per decade (P < .0001); history of malignancy was not predictive of subsequent malignancy (P = .50).ConclusionsPatients with histories of malignancy referred for LCS have a similar risk for developing lung cancers and extrathoracic malignancies as patients without histories of malignancy. Patients with histories of malignancy who are believed by their referring providers to be at low risk for metastasis should not be excluded from LCS.     

胸腔入口区病变的螺旋CT评价

目的 探讨螺旋CT在胸腔入口区疾病的诊断价值。资料与方法回顾性分析118例经病理或DSA证实的胸腔人口区疾病的CT表现。结果 118例螺旋CT平扫中定位诊断正确者112例(约占95％)，定性诊断正确者98例(约占83％)。53例增强CT扫描中定位诊断正确者51例(约占96％)，定性诊断正确者48例(约占91％)。结论 螺旋CT对胸腔入口区疾病的诊断是一种有价值的检查方法，尤其增强扫描能清楚地显示病变与其周围结构的关系。     

Detection of recurrent rectal cancer with CT, MRI and PET/CT

Computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) all have the potential to directly visualize local and distant relapse of colorectal cancer (CRC). Nevertheless, the role of diagnostic imaging for routine follow-up of CRC patients remains controversial. Although MRI and PET have advantages over CT in the detection of local recurrence, until now only a few surveillance programs recommend the use of annual CT for routine follow-up. The objective of this review is to elucidate the current status of diagnostic imaging for the detection of recurrent rectal cancer based on the recent literature and our own experience. Furthermore, an insight into contemporary surveillance programs and an outlook concerning a novel technical approach to moving-table MRI at 1.5 Tesla for staging purposes are given.