Metabolic network as an objective biomarker in monitoring deep brain stimulation for Parkinson's disease: a longitudinal study.

BACKGROUND: With the advance of subthalamic nucleus (STN) deep brain stimulation (DBS) in the treatment of Parkinson's disease (PD), it is desired to identify objective criteria for the monitoring of the therapy outcome. This paper explores the feasibility of metabolic network derived from positron emission tomography (PET) with 18F-fluorodeoxyglucose in monitoring the STN DBS treatment for PD. METHODS: Age-matched 33 PD patients, 33 healthy controls (HCs), 9 PD patients with bilateral DBS surgery and 9 controls underwent 18F-FDG PET scans. The DBS patients were followed longitudinally to investigate the alternations of the PD-related metabolic covariance pattern (PDRP) expressions. RESULTS: The PDRP expression was abnormally elevated in PD patients compared with HCs (P < 0.001). For DBS patients, a significant decrease in the Unified Parkinson's Disease Rating Scale (UPDRS, P = 0.001) and PDRP expression (P = 0.004) was observed 3 months after STN DBS treatment, while a rollback was observed in both UPDRS and PDRP expressions (both P < 0.01) 12 months after treatment. The changes in PDRP expression mediated by STN DBS were generally in line with UPDRS improvement. The graphical network analysis shows increased connections at 3 months and a return at 12 months confirmed by small-worldness coefficient. CONCLUSIONS: The preliminary results demonstrate the potential of metabolic network expression as complimentary objective biomarker for the assessment and monitoring of STN DBS treatment in PD patients. Clinical Trial Registration ChiCTR-DOC-16008645.  http://www.chictr.org.cn/showproj.aspx?proj=13865 .

18F-FDG imaging of a rare cutaneous infection by Mycobacterium avium complex.

A 17-year-old male patient was admitted into our hospital with granulomatous eruption (primarily on the lower extremities), diarrhea, fever, and weight loss for 6 months. F-FDG PET/CT scan was performed to rule out the possibility of malignant metastasis or paraneoplastic syndromes. F-FDG PET/CT scan showed multiple bone and skin lesions with significantly intense FDG uptakes and lymph nodes with moderate FDG uptake. A biopsy of the skin lesions was performed, and the tissue was sent for a broad-range polymerase chain reaction amplification, which showed that the pathogenic organism was Mycobacterium avium complex.

Differences in the metabolic status of healthy adults with and without active brown adipose tissue.

BACKGROUND: Previous studies have proven the existence of active brown adipose tissue (BAT) in adults; however, its effect on systematic metabolism remains unclear. AIM: The current study was designed to investigate the differences in the metabolic profiles of healthy adults with and without active BAT using positron emission tomography-computed tomography (PET-CT) scans in the un-stimulated state. METHODS: A cross-sectional analysis was performed to assess the health of adults using PET-CT whole-body scans at Huashan Hospital Medical Centre between November 2009 and May 2010. A total of 62 healthy adults with active BAT were enrolled in the BAT-positive group. For each positive subject, a same-gender individual who underwent PET-CT the same day and who had no detectable BAT was chosen as the negative control. Body composition was measured, and blood samples were collected for assays of metabolic profiles and other biomarkers. RESULTS: In both the male and female groups, BAT-positive individuals were younger and had lower body mass indexes, fasting insulin, insulin resistance, and leptin, but a greater level of high-density lipoprotein cholesterol compared with the negative controls. In the male group, body fat content and levels of tumor necrosis factor-α were significantly lower in the BAT-positive than in the negative control group. CONCLUSIONS: The healthy adults with active BAT in an un-stimulated state had favorable metabolic profiles suggesting that active BAT may be a potential target for preventing and treating obesity and other metabolic disorders.

[Influence of visual and auditory masking on the brain glucose metabolism in an idiopathic tinnitus patient].

OBJECTIVE: To study the influence of the audio-visual block (AB) on the brain glucose metabolism of idiopathic tinnitus patients. METHODS: The brain positron emission tomography (PET) test was performed on one chronic idiopathic tinnitus patient under audio-visual block and non-block (NB) conditions respectively. The visual analysis and statistical parameter mapping (SPM) analysis were both used to detect the brain glucose metabolism difference under AB and NB conditions. RESULTS: Under NB conditions, significant hyperactivity was detected at auditory and visual cortex on both sides of the brain. However, this phenomenon was not shown under AB conditions. Instead, a hyperactivity of brain was presented in the left Wernicke's area. CONCLUSIONS: The generation of chronic idiopathic tinnitus probably has no relationship with the auditory cortex abnormity. Wernicke's area might be involved in the central perception of tinnitus.

Efficacy of conventional whole-body ¹8F-FDG PET/CT in the incidental findings of parotid masses.

OBJECTIVE: The objective of this study was to evaluate the incidence of incidental parotid masses with conventional whole-body ¹8F-deoxyglucose (FDG) PET/CT and assess the ability of PET/CT to characterize these unexpected parotid lesions. METHODS: Fifty eight incidental findings of parotid masses with routine FDG PET/CT whole-body scan were reviewed in this retrospective analysis, which were selected from the patients without any known or suspected parotid disease in our PET center, from June 2005 to May 2009. 51 cases were operated or underwent a biopsy after a short-term PET/CT study; the remaining 7 cases had a follow-up. Parotid mass that showed both noncontrast CT (irregular shape and blurry border) and PET malignant features (high FDG uptake, SUV(max) > 3.0) was considered as positive for malignancy. Correlation of FDG PET/CT with histology or follow-up outcome was performed. RESULTS: Fifty eight unexpected findings of parotid masses accounted for 0.3% of the total cases in 4 years, including 11 (19.0%) malignant tumors and 47 (81.0%) benign lesions. 13 lesions manifested single nodule with malignant CT features and intense FDG activity, of which 6 were proved to be malignant; thus, sensitivity and positive predictive values were 54.5% (6 of 11) and 46.2% (6 of 13), respectively. 45 lesions showed either single nodule with benign CT features, or a low FDG uptake (SUV(max) ≤ 3.0), of which 40 were true negatives; therefore, specificity and negative predictive values were 85.1% (40 of 47) and 88.9% (40 of 45), respectively. All parotid masses except 9 benign and 1 malignant showed a high FDG uptake. Compared with SUV only, combined interpretation of PET and CT results displayed a lower sensitivity (90.9-54.5%), but a higher specificity (19.1-85.1%) and a higher overall accuracy. CONCLUSIONS: Whole-body FDG-PET/CT at the time of surveying the entire body condition is helpful for detecting the asymptomatic parotid masses. Combined noncontrast CT is an essential evidence for improving the diagnostic accuracy of FDG-PET/CT for parotid masses.

Granulomatous slack skin: assessment of disease progression and treatment response using positron emission tomography/computed tomography.

Granulomatous slack skin (GSS) is an extremely rare subtype of cutaneous T-cell lymphoma. A 14-year-old boy had suffered from progressive infiltrative erythema and plaques that gradually evolved into lax masses and pendulous skin on his axilla, anterior wall of the abdomen, bilateral inguinal region, and thighs. Histopathologic examination of the skin lesion and inguinal lymph node demonstrated granulomatous infiltration with multinucleated giant cells. Positron emission tomography (PET)/computed tomography (CT) scan was performed after acute exacerbation and exhibited slightly high fluorodeoxyglucose (FDG) distribution of skin lesions, without any evidence of abnormality in the metabolism of FDG in lymph nodes or other extralymphatic organs. Concurrent use of corticosteroid and recombinant interferon-alpha successfully controlled the disease, and posttreatment PET/CT scan confirmed the response to the therapy with decreased levels of FDG uptake. PET/CT is suggested to be helpful in the assessment of disease progression and treatment response in the management of patients with GSS.

Non-Hodgkin's lymphoma of supraclavicular lymph nodes can mimic metastasis of breast cancer during chemotherapy on FDG PET/CT.

A 43-year-old woman who had a history of right mastectomy for breast cancer presented with fever and swelling in the right supraclavicular region during her second course of chemotherapy. An FDG PET/CT was performed to evaluate this patient, which revealed mildly increased FDG activity in the lymph node in the supraclavicular region. A metastatic lesion from the known breast cancer was considered. However, biopsy results demonstrated that the abnormal activity in the right supraclavicular region is due to T-cell lymphoma.

Misdiagnoses of 11C-choline combined with 18F-FDG PET imaging in brain tumours.

BACKGROUND AND OBJECTIVE: The widely applied F-FDG is known for its disadvantage in brain tumour PET imaging because of its high background uptake. C-choline can achieve high contrast of brain tumour imaging and was expected to have higher sensitivity and specificity. We analysed the misdiagnoses in C-choline PET imaging in brain tumours with the aim of improving the accuracy of diagnosis with C-choline PET imaging. PATIENTS AND METHODS: We selected 10 patients proven to have been misdiagnosed on the basis of histopathological correlation and clinical follow-up among 94 patients (110 studies) who underwent C-choline PET/CT for diagnosed or suspected brain tumour between 23 March 2005 and 8 February 2007. C-choline PET imaging were performed on a Biograph Sensation 16 PET/CT scanner (Siemens Medical Systems), F-FDG imaging was also performed as reference. RESULTS: Of all 10 misdiagnosed patients, five were false positive (one abscess, one tuberculosis, one benign gliocyte proliferation, one inflammatory granuloma and one demyelination), four were false negative (two metastases from lung cancer, one lymphoma, one grade II glioma) and one was misdiagnosed by wrong interpretation due to lack of experience. The rate of false positives was (5/110) 4.55%; the rate of false negatives was (4/110) 3.64%; the accuracy of C-choline alone was (93/110) 84.5%; by comparison, the accuracy of F-FDG alone was (78/110) 70.9%. CONCLUSIONS: C-choline imaging has a certain rate of false positivity and false negativity. With proper application, C-choline might have greater potential than F-FDG for brain tumour PET imaging.