Use of integrated FDG-PET/CT in sarcoidosis

We studied five patients with mediastinal lymph node enlargement suggestive of malignant lymphoma, lung cancer, or sarcoidosis. Integrated [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) was performed on all patients. Sarcoidosis can be a pitfall in PET/CT imaging, which may lead to false-positive results of malignancy. Increased FDG uptake in mediastinal lymph nodes is often comparable with malignant lymphoma or lymph node metastases. Histological confirmation of the lesions should be mandatory, except for patients in whom sarcoidosis can be accurately confirmed by other diagnostic methods.     

F-18 FDG-PET/CT in evaluation of patients with fever of unknown origin

Objectives

This study was carried out to evaluate the diagnostic utility of FDG-PET/CT in patients with fever of unknown origin (FUO).

Methods

Medical records of 103 patients who underwent FDG-PET/CT and anatomic imaging as a part of FUO workup were analyzed. Final diagnosis of the cause of FUO was reached based on serologic assays, cultures, biopsy, surgery or 6 months of clinical follow-up.

Results

The definite cause of fever was established in 69/103 patients. Abnormal FDG uptake was found in 63/103 patients and contributed to the final diagnosis (TP) in 62 patients (98.48 %). Of the remaining 40 patients with negative PET/CT, the final definite cause of fever (FN) could be determined only in seven patients (17.5 %). PET/CT had a sensitivity, specificity, positive predictive value and negative predictive value of 90, 97, 98.4 and 82.5 % compared to 43.5, 67.6, 73.2 and 37.1 %, respectively, for anatomic imaging. FDG-PET/CT had a higher accuracy (92.2 vs. 51.5 %; p = 0.003) compared to anatomic imaging for suggesting a cause of FUO.

Conclusions

PET/CT showed high sensitivity and specificity in suggesting a definite diagnosis in the evaluation of FUO.     

FDG-PET/CT in re-staging of patients with lymphoma

The aim of this study was to evaluate the clinical significance of combined fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) in patients with lymphoma, and to compare the FDG-PET/CT staging results with those of FDG-PET and CT alone. Twenty-seven patients were studied. Each patient had clinical follow-up for >12 months and entered complete follow-up evaluation. Patient-based evaluation showed a sensitivity of 78% for CT alone, 86% for FDG-PET alone, 93% for CT and FDG-PET read side by side, and 93% for combined FDG-PET/CT imaging. Region-based evaluation showed a sensitivity for regional lymph node involvement of 61%, 78%, 91% and 96% respectively. FDG-PET/CT imaging is superior to CT alone (P=0.02) and has additional benefit over FDG-PET alone due to exact anatomical localisation. We conclude that FDG-PET/CT imaging is accurate in re-staging lymphoma and offers advantages over separate FDG-PET and CT imaging.     

胸部结节病的CT表现

目的 分析胸部结节病的CT表现，探讨其CT扫描和诊断价值。方法 13例胸部CT扫描患者，均在深吸气状态下摄片。在常规深吸气后屏气进行CT扫描，观察胸部淋巴结，肺部病变及胸膜病变。结果 13例均有胸部淋巴结增大，其中9例对称性两侧肺门淋巴结增大伴纵隔淋巴结增大，3例纵隔淋巴结增大伴单侧肺门淋巴结增大，1例仅有纵隔淋巴结增大而无肺门淋巴结增大。胸部病变有8例，占所有病例61．52％，表现为肺内多发结节，其中，3例伴肺内斑片状实变影，2例伴肺组织纤维化。胸膜病变仅1例，表现为胸膜多发小结节伴胸腔积液。结论 CT扫描是诊断结节病和鉴别诊断结节病的非常有效的方法，明显优于胸片。     

胸部结节病的CT诊断

目的:分析胸部结节病的CT表现,提高对本病的认识和诊断水平。方法:回顾性分析经活检病理证实或临床治疗观察符合诊断标准的26例胸部结节病的CT表现。结果:26例结节病中,肺门、纵隔淋巴结肿大23例(88.5%),其中肺门或/和纵隔淋巴结肿大8例(30.7%),肺门或/和纵隔淋巴结肿大伴有肺内病变15例(57.7%),仅见肺部浸润性改变而无淋巴结肿大1例(3.8%),肺纤维性改变2例(7.7%)。肺内主要表现为结节影15例,支气管血管束增粗7例,小叶间隔增厚4例,实变影1例,磨玻璃影1例。结论:双侧肺门对称性淋巴结肿大和/或纵隔淋巴结肿大以及沿支气管血管束分布的结节影是胸部结节病的特征性表现;不典型者需密切结合临床检查及治疗后随访。     

CT findings in severe thoracic sarcoidosis

Severe thoracic sarcoidosis includes manifestations with significant clinical and functional impairment and a risk of mortality. Severe thoracic sarcoidosis can take on various clinical presentations and is associated with increased morbidity. The purpose of this article was to describe the CT findings in severe thoracic sarcoidosis and to explain some of their mechanisms. Subacute respiratory insufficiency is a rare and early complication due to a high profusion of pulmonary lesions. Chronic respiratory insufficiency due to pulmonary fibrosis is a frequent and late complication. Three main CT patterns are identified: bronchial distortion, honeycombing and linear opacities. CT can be helpful in diagnosing some mechanisms of central airway obstruction such as bronchial distortion due to pulmonary fibrosis or an extrinsic bronchial compression by enlarged lymph nodes. An intrinsic narrowing of the bronchial wall by endobronchial granulomatous lesions may be suggested by CT when it shows evidence of bronchial mural thickening. Pulmonary hypertension usually occurs in patients with end-stage pulmonary disease and is related to fibrotic destruction of the distal capillary bed and to the resultant chronic hypoxemia. Several other mechanisms may contribute to the development of pulmonary hypertension including extrinsic compression of major pulmonary arteries by enlarged lymph nodes and secondary pulmonary veno-occlusive disease. Aspergilloma colonization of a cavity is the main cause of hemoptysis in sarcoidosis. Other rare causes are bronchiesctasis, necrotizing bronchial aspergillosis, semi-invasive pulmonary aspergillosis, erosion of a pulmonary artery due to a necrotic sarcoidosis lesion, necrosis of parenchymal sarcoidosis lesions and specific endobronchial macroscopic lesions.     

胸部结节病的CT表现

目的:探讨CT诊断胸部结节病的影像学表现。方法:回顾性分析经临床和病理证实并在治疗前后均进行CT检查的20例胸部结节病的CT征象。结果:20例均可见胸部淋巴结增大,其中14例有广泛的纵隔和对称性肺门淋巴结肿大;4例纵隔和单侧淋巴结肿大;2例可见纵隔淋巴结肿大。13例出现肺部病(包括9例肺内多发结节,3例斑片状融合块影,1例肺纤维化);1例胸膜病变。结论:结节病的胸部平片及临床表现缺乏特异性,CT对胸部结节病的诊断及鉴别诊断有一定的价值。     

18F FDG-PET/CT findings in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is an indolent and primary disease of the larynx and the trachea and rarely extends to smaller airways. F-18 fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT) evaluation in this condition has not been reported earlier. We report FDG-PET/CT findings in a case of RRP that included a large papillomatous lung mass resembling cancer.     

胸部结节病的CT诊断

目的：探讨胸部结节病的CT表现。方法：回顾性分析经临床和病理证实并在治疗前后都进行CT扫描的23例胸部结节病的CT征象。结果：21例有广泛的纵隔和对称性肺门肿大的淋巴结，增大的淋巴结内部密度均匀，边缘相对清楚，无浸润性改变，增强扫描淋巴结均匀强化；9例见增大的淋巴结使周围支气管受压、移位。肺实质异常15例(其中13例伴有肺门纵隔淋巴结肿大)，主要表现为沿淋巴管分布的微小结节，多分布在肺门旁支气管血管束周围、胸膜下和小叶间隔；肺问质纤维化2例。结论：CT对胸内结节病的诊断有一定的价值。     

Clinical value of a high-fat and low-carbohydrate diet before FDG-PET/CT for evaluation of patients with suspected cardiac sarcoidosis

Background

We hypothesized that a high-fat and low-carbohydrate (HFLC) diet before FDG-PET/CT could identify patients with active cardiac sarcoidosis (CS).

Methods

Fifty-eight sarcoidosis patients with a suspicion of CS consumed a HFLC diet before FDG-PET/CT. Clinical, electrical, and other imaging investigations were compared to PET results.

Results

Using Japanese Ministry of Health and Welfare (JMHW) criteria as a gold standard, 21% (12/58) of patients had a CS. Sensitivity and specificity of PET (visual analysis) were 83% (10/12) and 78% (36/46), respectively, with a very good interobserver agreement (k = 0.86). 70% (7/10) of the patients with a positive PET and negative JMHW criteria exhibited abnormalities suggestive of CS either on MR (n = 3) or SPECT (n = 4). Comparison with the presence of delayed enhancement on magnetic resonance imaging helped to classify patients with active (PET positive) or non-active CS (PET negative). In addition, when MR and PET were both negative, none of the patients met the JMHW criteria. PET response under treatment was concordant with clinical evolution in 11/13 patients.

Conclusions

FDG-PET/CT after HFLC diet is a sensitive tool for the diagnosis of active CS. Combined use of PET and MR is promising for the detection and characterization of CS lesions.     

胸部结节病的CT表现

目的:探讨胸部结节病的CT表现。方法:回顾性分析经临床治疗和病理证实的15例胸部结节病的CT征象。结果:15例均有胸部淋巴结增大,其中9例为纵隔和双侧肺门淋巴结增大,4例为纵隔和单侧肺门淋巴结增大,2例仅出现纵隔淋巴结增大。伴肺实质异常11例,主要表现为肺内微小结节(8例)及肺磨玻璃样改变(2例),肺间质纤维化1例。结论:CT是诊断胸内结节病的一种重要方法。     

Anatomo-metabolic characteristics of atelectasis in F-18 FDG-PET/CT imaging

PURPOSE: To evaluate the structural and metabolic characteristics of atelectasis in FDG-PET/CT. METHODS: Twenty one consecutive patients (13 males, 8 females, median age 67 years) with CT features of atelectasis, undergoing PET/CT imaging for preoperative staging of histologically proven malignancies (20 lung cancer and 1 ovarian cancer metastasis to lung), were included in the study. RESULTS: Hounsfield units of atelectasis (-383.58+/-189, range -631 to 82) were significantly higher than in normal lung (-756+/-67.46, range -839 to -555; P=0.0001), and lower than in malignant tissue (35+/-19, range 4-77; P=0.0001). The main patterns of FDG uptake observed in atelectasis were diffuse and homogenous. The standard uptake value (SUV) in atelectasis was low to moderate (SUV(avg): 1.13+/-0.50; SUV(max): 1.44+/-0.54), and generally lower than in tumor tissue (SUV(avg): 6.25+/-3.58, range 2.0-16.5), but always higher than in normal lung (0.56+/-0.18 and 0.70+/-0.23, respectively) (P=0.0001). There was a positive correlation between the density of atelectatic lesions and the degree of uptake, with no relationship to size. CONCLUSION: There is a positive relationship between the density of collapsed lung and the intensity of FDG uptake. FDG uptake in atelectasis is higher than in normal lung, and generally lower than in tumor tissue.     

不典型胸部结节病的CT表现

目的　认识不典型胸部结节病的发生情况和CT表现。方法　回顾性复习了 4 3例 (平均年龄 5 2 14岁 )符合诊断标准的胸部结节病的CT影像表现 ,凡无两侧肺门淋巴结肿大者为不典型胸部结节病。结果　 2 2例 (5 1 16 % )呈不典型表现 ,其中以仅有纵隔淋巴结肿大者最多 (9例 ,2 0 93% ) ,其次为伴纵隔淋巴结肿大的一侧肺门淋巴结肿大 (6例 ,13 95 % )和无纵隔淋巴结肿大的一侧肺门淋巴结肿大 (1例 ,2 33% ) ;6例仅有肺部异常表现 ,而无胸部淋巴结肿大 ,在初诊时均误诊。18例 (81 82 % )不典型者发生在 >5 0岁的病例中 ,仅 4例 (18 18% )发生在 <5 0岁的病例中。结论　半数胸部结节病病例的CT表现不典型 ,多发生在 >5 0岁的较年长者中 ,容易引起误诊     

The clinical utility of FDG-PET/CT in follow up and restaging of breast cancer patients

Background

Early diagnosis and accurate staging of loco-regional and distant recurrence after treatment of breast cancer is decisive for further therapeutic planning. Our aim was to evaluate the role of FDG-PET/CT in the follow up and restaging of breast cancer patients.

Methods

We retrospectively evaluated 34 female patients with a history of breast cancer. Patients were referred for a PET/CT scan because of suspected recurrence (n = 15), whole body staging in already confirmed cases of recurrence (n = 5), follow up and reassurance in asymptomatic patients (n = 7), follow up after local ablative therapy of liver metastases (n = 5), follow up after treatment of bone metastases (n = 2). PET-CT findings were compared with the findings obtained by other imaging modalities, histopathology, together with clinical and imaging follow up for at least 6 months.

Results

The PET/CT was considered pathological in 21/34 patients. Incorrect interpretations of PET/CT images occurred in 3 patients (8.8%). PET/CT showed an overall diagnostic accuracy of 91.2% with a sensitivity of 90.5% and a specificity of 92.3%. The PPV and NPV were 95% and 85.7%, respectively.

Conclusion

FDG-PET/CT may play a substantial role in the restaging and follow up of patients with breast cancer showing high sensitivity and specificity.