Mediastinal inflammatory pseudotumor is a rare benign disease with its capability for local invasion and rapid growth. We present a case of middle-mediastinal inflammatory pseudotumor and report its contrast-enhanced chest computed tomography, 18F-fluorodeoxyglucose positron emission tomography/computed tomography and pathologic findings.
Adult ; Diagnosis, Differential ; Fluorodeoxyglucose F18/*diagnostic use ; Granuloma, Plasma Cell/*diagnosis ; Humans ; Male ; Mediastinal Diseases/*diagnosis ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/*diagnostic use ; Tomography, X-Ray Computed/*methods

No abstract available.
Amyloidosis/*radionuclide imaging ; Female ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Liver Diseases/*radionuclide imaging ; Multiple Myeloma/*complications ; *Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/*diagnostic use

The 18F 2-fluoro-2-deoxyglucose (FDG) PET/CT scan is an imaging modality used in the management of patients with various types of malignancies. 18F-FDG PET/CT has demonstrated significant efficacy in the staging and detection of metastatic disease in malignancies of the gastrointestinal tract. The assessment of the metabolic response to chemotherapy and improvements of overall survivals in malignancies of esophagus and stomach has been demonstrated in several studies. This review focuses on the role of 18F-FDG PET/CT scan in staging, metastasis, predict of recurrence and assessment of metabolic response in malignancies of the upper gastrointestinal tract.
Esophageal Neoplasms/pathology/*radionuclide imaging ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Lymphatic Metastasis ; Neoplasm Metastasis ; Neoplasm Staging ; Positron-Emission Tomography ; Radiopharmaceuticals/diagnostic use ; Recurrence ; Stomach Neoplasms/pathology/*radionuclide imaging

Accurate prediction of cancer prognosis before the start of treatment is important since these predictions often affect the choice of treatment. Prognosis is usually based on anatomical staging and other clinical factors. However, the conventional system is not sufficient to accurately and reliably determine prognosis. Metabolic parameters measured by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) have the potential to provide valuable information regarding prognosis and treatment response evaluation in cancer patients. Among these parameters, volume-based PET parameters such as metabolic tumor volume and total lesion glycolysis are especially promising. However, the measurement of these parameters is significantly affected by the imaging methodology and specific image characteristics, and a standard method for these parameters has not been established. This review introduces volume-based PET parameters as potential prognostic indicators, and highlights methodological considerations for measurement, potential implications, and prospects for further studies.
Fluorodeoxyglucose F18/diagnostic use ; Glycolysis ; Humans ; Neoplasm Staging ; Neoplasms/pathology/*radionuclide imaging ; *Positron-Emission Tomography ; Predictive Value of Tests ; Prognosis ; Radiopharmaceuticals/diagnostic use ; Tumor Burden

18F-FDG PET scan is an useful functional whole body imaging modality that images various types of malignancies with relative high sensitivity and specificity in a reasonably rapid time. It depicts a lesion based on abnormal glucose metabolism whereas CT detects malignant process mostly based on altered anatomy. In patients with gastric cancers, PET scan detects only less than 50% of early cancers and 62-98% of advanced cancers. For initial T staging, anatomical imaging with a high spatial resolution is essential. There are a few studies on the prognostic significance of FDG uptake with inconsistent results. In spite of low sensitivity for lymph node staging, the specificity of CT and PET scan are very high, and the specificity of PET scan tends to be higher than that of CT. Detection of distant metastases on PET scan is dependent on tumor histology, degree of FDG uptake in primary tumors, sites of distant metastases, etc. There are only a few data available for the evaluation of recurrence detection and treatment responses using FDG PET scan. FDG PET scan has been used in the preoperative staging of colorectal cancer with some promising results. It seems to be the most useful in restaging recurrent tumors and selecting those patients who would benefit from surgery. PET scan has a potential value in assessing treatment responses after various combination of treatments in patients with colorectal cancer.
Fluorodeoxyglucose F18/*diagnostic use ; Gastrointestinal Neoplasms/pathology/radiography/*radionuclide imaging ; Humans ; Neoplasm Staging ; *Positron-Emission Tomography ; Radiopharmaceuticals/*diagnostic use ; Tomography, X-Ray Computed

OBJECTIVE: We developed a new computed tomography (CT)-based spatial normalization method and CT template to demonstrate its usefulness in spatial normalization of positron emission tomography (PET) images with [18F] fluorodeoxyglucose (FDG) PET studies in healthy controls. MATERIALS AND METHODS: Seventy healthy controls underwent brain CT scan (120 KeV, 180 mAs, and 3 mm of thickness) and [18F] FDG PET scans using a PET/CT scanner. T1-weighted magnetic resonance (MR) images were acquired for all subjects. By averaging skull-stripped and spatially-normalized MR and CT images, we created skull-stripped MR and CT templates for spatial normalization. The skull-stripped MR and CT images were spatially normalized to each structural template. PET images were spatially normalized by applying spatial transformation parameters to normalize skull-stripped MR and CT images. A conventional perfusion PET template was used for PET-based spatial normalization. Regional standardized uptake values (SUV) measured by overlaying the template volume of interest (VOI) were compared to those measured with FreeSurfer-generated VOI (FSVOI). RESULTS: All three spatial normalization methods underestimated regional SUV values by 0.3-20% compared to those measured with FSVOI. The CT-based method showed slightly greater underestimation bias. Regional SUV values derived from all three spatial normalization methods were correlated significantly (p < 0.0001) with those measured with FSVOI. CONCLUSION: CT-based spatial normalization may be an alternative method for structure-based spatial normalization of [18F] FDG PET when MR imaging is unavailable. Therefore, it is useful for PET/CT studies with various radiotracers whose uptake is expected to be limited to specific brain regions or highly variable within study population.
Adult ; Aged ; Brain/pathology/*radiography ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; *Positron-Emission Tomography ; Radiopharmaceuticals/*diagnostic use ; Tomography, X-Ray Computed

A 50-yr-old man presented with intermittent hemoptysis and was diagnosed small cell lung cancer. 18F-FDG PET/CT for staging demonstrated extensive hypermetabolic lesions throughout the skeleton and liver. Interestingly, skeletal muscles of limbs, mediastinum, bowel, and especially brain showed very low FDG uptake. Because of some characteristics in common with super scan on skeletal scintigraphy, this case could be considered as 'metabolic super scan'.
Carcinoma, Small Cell/complications/radionuclide imaging ; Fluorine Radioisotopes/diagnostic use ; Fluorodeoxyglucose F18/*diagnostic use ; Hemoptysis/complications/radionuclide imaging ; Humans ; Liver Neoplasms/diagnosis/secondary ; Lung Neoplasms/complications/radionuclide imaging ; Male ; Middle Aged ; *Positron-Emission Tomography ; Radiopharmaceuticals/*diagnostic use

OBJECTIVE: Angiomyolipoma is the most common benign kidney tumor. However, literature describing FDG PET findings on renal angiomyolipoma (AML) is limited. This study reports the FDG PET and PET/CT findings of 21 cases of renal AML. MATERIALS AND METHODS: The study reviews FDG PET and PET/CT images of 21 patients diagnosed with renal AML. The diagnosis is based on the classical appearance of an AML on CT scan with active surveillance for 6 months. The study is focused on the observation of clinical and radiographic features. RESULTS: Six men and 15 women were included in our study. The mean age of the patients was 57.14 +/- 9.67 years old. The mean diameter of 21 renal AML on CT scans was 1.76 +/- 1.00 cm (Min: 0.6 cm; Max: 4.4 cm). CT scans illustrated renal masses typical of AMLs, and the corresponding FDG PET scans showed minimal FDG activities in the area of the tumors. None of the 21 AMLs showed a maximum standardized uptake value (SUVmax) greater than 1.98. No statistically significant correlation was present between SUVmax and tumor size. CONCLUSION: Renal AMLs demonstrate very low to low uptake on FDG PET and PET/CT imaging in this study. When a fat-containing tumor in the kidney is found on a CT scan, it is critical to differentiate an AML from a malignant tumor including an RCC, liposarcoma, and Wilms tumor. This study suggests that FDG PET or PET/CT imaging is useful for differentiating a renal AML from a fat-containing malignant tumor.
Angiomyolipoma/*radionuclide imaging ; Contrast Media/diagnostic use ; Ehlers-Danlos Syndrome ; Female ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Kidney Neoplasms/*radionuclide imaging ; Male ; Middle Aged ; *Positron-Emission Tomography ; *Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/diagnostic use ; Retrospective Studies

18-Fluoredeoxyglucose position emission tomography and computed tomography (F-18FDG PET/CT) scanning has been useful in the evaluation of malignant disorders and has been extensively used in cancer screening.1 However, F-18FDG uptake was not found to be specific for cancer diagnosis. Here, we describe increased F-18FDG uptake on PET/CT caused by extensive tuberculous lymphadenitis in a 62-year-old woman with malignant melanoma.
Female ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Lymphatic Metastasis/*diagnosis ; Melanoma/*complications/*pathology/radiography ; Middle Aged ; Positron-Emission Tomography/*methods ; Tomography, X-Ray Computed/*methods

Schwannoma is a benign neoplasm of the Schwann cells of the neural sheath. Most schwannomas occur in the head and neck, and extremities and rarely in the retroperitoneal space. The differentiation of a schwannoma from other malignant tumor or benign tumor is very difficult on a preoperative examination with ultrasonography, computed tomography or magnetic resonance imaging. Furthermore, the lesion with increased fluorodeoxyglucose uptake in PET-CT cannot exclude malignant tumor. Therefore, this lesion needs surgical excision and a histological examination with immunohistochemical staining. We report a case of schwannoma occuring in the retroperitoneal space that incidentally discovered by PET-CT for health-check up. Pathologic confirmation by laparoscopic excision was done.
Aged ; Diagnosis, Differential ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Male ; Neurilemmoma/*diagnosis/pathology/surgery ; Positron-Emission Tomography ; Retroperitoneal Neoplasms/*diagnosis/pathology/surgery ; Tomography, X-Ray Computed