Pancreatic pseudocyst observed on F-18 FDG PET imaging

A 72-year-old man with right lower lobe squamous cell carcinoma of the lung-status, post resection-and prostate carcinoma was referred for restaging with whole-body PET using F-18 FDG. PET images, in addition to the presence of moderate hypermetabolic activity seen in the left lower paratracheal and bilateral hilar regions, revealed a large hypometabolic space-occupying lesion in the abdomen. The appearance of this lesion was highly suggestive of a pancreatic pseudocyst. Further review of a CT scan performed 3 years ago confirmed the presence of a pancreatic pseudocyst. However, this information was not available to the nuclear medicine physician at the time of the PET examination.     

Iatrogenic artifacts on whole-body F-18 FDG PET imaging

PURPOSE: Whole-body F-18 FDG PET images frequently show artifacts related to medical and surgical interventions. We present some of the common artifact patterns in this atlas article. MATERIALS AND METHODS: We studied whole-body F-18 FDG PET images of 30 adult patients (17 males and 13 females). Of these, 9 patients had lymphoma, 7 had colon cancer, 6 had lung cancer, 3 had lung nodules, 2 each had breast and bladder cancer, and 1 patient had brain cancer. All patients had a history of some surgical or medical intervention for malignant or some other associated disease. RESULTS: PET images of 8 patients showed artifacts related to implanted prostheses and ports and 9 patients showed artifacts related to percutaneous insertion or opening of catheters, tubes, and stomas. Six patients had artifacts from previous surgery, 3 from previous radiation therapy, 3 from previous chemotherapy, and 1 from changes in glucose metabolism. CONCLUSIONS: Medical and surgical interventions can give rise to artifacts on whole-body F-18 FDG PET images. The possibilities and patterns of these artifacts should be kept in mind while reporting these studies.     

F-18 FDG PET imaging in gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most frequent mesenchymal malignancy of the gastrointestinal tract. Liver and peritoneum are the most frequent metastatic sites. Surgery is the mainstay of treatment in patients with localized disease. Imatinib mesylate (Gleevec; Novartis Pharmaceuticals, East Hanover, NJ), an inhibitor of tyrosine kinase activity of KIT receptor, has been shown to be an effective treatment in metastatic or unresectable disease. Follow-up of patients treated with Gleevec is controversial. The authors present a case of GIST that showed near-total response with Gleevec on fluorodeoxyglucose positron emission tomography. They suggest positron emission tomography as a useful imaging modality for the monitoring of therapy response in GIST tumors treated with Gleevec.     

Unusually elevated liver radioactivity on F-18 FDG PET in Hodgkin's disease: hepatic 'superscan'

Increased focal concentration of FDG in the background of relatively lower normal hepatocyte uptake is usually regarded as the hallmark of metastatic involvement of the liver from a known primary. The authors present the clinical, radiologic, and laboratory profile of a very unusual hepatic uptake pattern in a case of Hodgkin disease, in which the FDG PET showed intensely diffuse hepatic tracer uptake and was the earliest indicator of extensive hepatic involvement by the disease process. The diagnosis of hepatic involvement with lymphoma was inferred. As experience with FDG PET is growing, it is important to become familiar with the various physiological and pathologic FDG uptake patterns. The term "hepatic superscan", demonstrating intense diffuse hepatic tracer uptake coupled with surprisingly low brain and cardiac FDG uptake, owes its origin from its apparent similarity with the superscan seen in conventional skeletal scintigraphy and represents an entity hitherto undescribed.     

F-18 FDG PET brain imaging in symptomatic arthroprosthetic cobaltism

European Journal of Nuclear Medicine and Molecular Imaging - Imaging studies of cobalt toxicity from cobalt-chromium alloy arthroprosthetics have focused on the local intra-articular and...     

FDG PET在胰腺癌中的应用

胰腺癌的影像诊断手段较多 ,如CT、MRI、超声等 ,由于特异性及其敏感性的限制 ,难以早期作出诊断 ,延误患者早期的治疗。因此如何早期提高胰腺癌的诊断为早期治疗提供理论上的依据 ,仍是影像医学和临床医学的研究热点。正电子发射计算机断层(PET)是利用正电子放射性药物在体内的分布来反映人体组织的生理生化代谢功能 ,其中FDGPET利用肿瘤组织的葡萄糖代谢增加来鉴别恶性病变与良性病变。本文就PET的显像基本原理及其在胰腺癌诊断和分期中的应用价值作一简要介绍 ,可以看到FDGPET在胰腺肿块的良恶性鉴别的灵敏度和特异性均较高 ,对临床分析有很好的应用价值 ,在胰腺癌的分期 ,尤其是确定有否肝脏转移方面极具价值。并对FDGPET临床应用的优点和局限性做出分析。     

Myelofibrosis on F-18 FDG PET Imaging

A 60-year-old male was referred for a positron emission tomography (PET) scan using F-18 fluoro-2-deoxyglucose (F-18 FDG) for evaluation of a right lung opacity identified on a computed tomography (CT) scan. The patient also had a history of idiopathic myelofibrosis. The PET scan revealed markedly increased uptake throughout the spleen and liver, which were massively enlarged. There was also significantly increased uptake diffusely throughout the bone marrow. These findings are a reflection of the patient's myelofibrosis.     

Diagnosis of labia metastasis by F-18 FDG PET and CT fusion imaging in sarcoma follow-up

ABSTRACT A 32-year-old woman with a history of pelvic sarcoma underwent whole-body fluorine-18 fluorodeoxyglucose positron emission tomography (PET) and computed tomographic (CT) fusion imaging for restaging after primary surgery and adjuvant combined radiation and chemotherapy. Interpreting the PET images alone showed an area of focal tracer accumulation in the pelvic floor and was interpreted as being secondary to urine contamination. Image fusion with fully coregistered CT scans showed a localized site of increased uptake from a metastasis to the labia, which was confirmed by biopsy. The presented case illustrates the usefulness of combined PET/CT fusion imaging to overcome some pitfalls of PET imaging alone (eg, differentiating malignant tumor from pooling of tracer in the genitourinary tract or contamination).