• Journal of radiological science and technology
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• v.35 no.2
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• pp.151-156
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• 2012

$^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) causes a significant amount of radioactivity retention in kidneys and urinary tract and degrades image quality and diagnostic performance. Diuretics are used to perform tests and prevent the urinary tract retention of $^{18}F$-FDG. The purpose of the study is to investigate how the diuretics affect images and excretion rates of $^{18}F$-FDG. The study consists of a group using diuretics for patients with no primary tumors or transfer lesions in kidneys according to PET/CT images, a group using physiological saline and the control group injecting only $^{18}F$-FDG and SUVs are measured by configuring interested areas for each group. Also, SUVs are compared and evaluated depending on the lasix injection after basic inspection and injecting $^{18}F$-FDG for quantitative analysis. The study shows that images with decreased background radioactivity and increased urine excretion due to using diuretics. However, an opposite result that there is no change in the amount of radioactivity in urine appears. The study concludes that the diuretics may decrease background radioactivity in the images but may not affect the $^{18}F$-FDG excretion.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.66-67
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• 2007

POEMS syndrome is a rare disorder, also known as Crow-Fukase, PEP or Takatsuki syndrome. The acronym, POEMS, represents polyneuropathy, organomegaly, endocrinopathy, M protein and skin change. However, there are associated features not included in the acronym such as sclerotic bone lesions, Castleman disease, papilledema, thromobocytosis, peripheral edema, ascites, effusion, polycythemia, fatigue and clubbing. In most cases, osseous lesions in POEMS syndrome present as an isolated sclerotic deposit and that reveal as osteosclerotic myeloma. Several cases of $^{18}F-FDG$ PET in multiple myeloma involvements were reported, but there was no previous literature that reported FDG PET findings in POEMS syndrome. We describe here a 66-year-old patient with POEMS syndrome who underwent $^{18}F-FDG$ PET/CT image.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.357-360
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• 2009

Malignant mesothelioma of the peritoneum is a rare neoplasm with a rapidly fatal course. The tumour arises from the mesothelial cells lining the pleura and peritoneum or, rarely, in the pericardium or tunica vaginalis. This neoplasm is characterized by being difficult to diagnose, having a rapid evolution and a poor response to therapy. Mesothelioma is very glucose avid, and malignant pleural mesothelioma has been reported concerning the utility of F-18 FDG PET or PET/CT. But little has been known about the imaging finding of malignant peritoneal mesothelioma on F-18 FDG PET/CT. We report a case of malignant peritoneal mesothelioma mimicking peritoneal carcinomatosis of F-18 FDG PET/CT.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.79-80
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• 2008

Including malignancy, various disease can show abnormal uptake in bone marrow. We report a case of non-specific inflammatory FDG uptake in bone marrow mimicking malignancy. A 35-year old woman with fever of unknown origin (FUO) underwent $^{18}F$-FDG PET/CT to find out fever $^{18}F$-FDG and unknown malignancy. $^{18}F$-FDG was injected and imaged 1hr after injection with Discovery ST (GE, USA), $^{18}F$-FDG PET/CT whole body image showed abnormal uptake in lower extremities (Fig. 1). MRI and biopsy was also done in the sites of abnormal uptake. PET and MRI suspect malignancy (Fig. 2, 3), but biopsy result was non-specific inflammatory process (Fig. 4). The patient was improved her clinical condition after antibiotics therapy.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.505-507
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• 2009

A 60-year-old woman, who had non-small-cell lung cancer (NSCLC) in left lower lobe underwent brain F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for evaluation of cerebral metastasis. On follow-up FDG-PET/CT, only hypometaolic lesion was detected and progressed in right frontal lobe at 6 months and 10 months, later. Hypermetabolic metastasis was not detected even at last scan time of FDG-PET/CT. Brain MRI showed brain metastasis in right frontal lobe. As might be expected, the physician should take cerebral metastasis into consideration even though there is only hypometabolic change on subsequent FDG-PET/CT in patients with NSCLC.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.333-336
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• 2008

A 52-year-old woman with a history of general weakness, fatigue, weight loss, elevated serum levels of liver transaminase enzyme for three months underwent an F-18 FDG PET/CT scan to evaluate a cause of the hepatosplenomegaly found on abdominal ultrasonography. Initial PET/CT revealed markedly enlarged liver and spleen with intense FDG uptake. Otherwise, there were no areas of abnormal FDG uptake in whole body image. Histological evaluation by a hepatic needle biopsy demonstrated diffuse large B cell type lymphoma and final diagnosis for this patient was hepatosplenic B-cell lymphoma. She received five cycles of CHOP chemotherapy, and second PET/CT scan was followed after then. Follow-up PET-CT revealed normal sized liver with disappearance of abnormal FDG uptake. Hepatosplenic B-cell lymphoma is relatively rare and mostly presents as single or multiple nodules.1,2 Diffuse type hepatosplenic lymphoma is extremely rare and poorly recognized entity.3 The diagnosis is very difficult and complicated by the presence of misleading symptoms.4 In this rare hepatosplenic B-cell lymphoma case, F-18 FDG PET/CT scan provided a initial diagnostic clue of hepatosplenic lymphoma and an accurate chemotherapy response.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.444-450
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• 2008

Purpose: The aim of this study was to evaluate the usefulness of whole body positron emission tomography (PET) using $^{18}F-fluorodeoxyglucose$ ($^{18}F-FDG$) for cancer screening in asymptomatic subjects. Materials and Methods: The subjects were 1,762 men and 259 women who voluntarily underwent $^{18}F-FDG$ PET for cancer screening as a part of a routine health examination. Final diagnosis was decided by other diagnostic studies, pathological results or clinical follow-up for 1 year. Results: Of 2,021 subjects, 40 (2.0%) were finally proved to have cancer. Abnormal focal $^{18}F-FDG$ uptake suggesting malignancy was found in 102 subjects (5.0%). Among them, 21 subjects (1.0%) were proved to have cancer. Other tests in the routine health examination could not find 9 of 21 cancers (42.9%) detected by PET. The sensitivity, specificity, positive predictive value, and negative predictive value of PET for cancer screening were 52.5%, 95.9%, 20.6%, and 99.0%, respectively. Pathologies of cancers missed on PET were adenocarcinoma (n = 9; 3 colon cancers, 3 prostate cancers, 2 stomach cancers, and 1 rectal cancer), differentiated thyroid carcinoma (n = 6), bronchioalveolar cell carcinoma (n = 2), urinary bladder cancer (n = 1), and melanoma (n = 1). More than half of cancers which were not detected by PET were smaller than 1 cm in diameter. Conclusion: $^{18}F-FDG$ PET might be useful for cancer screening in asymptomatic subjects due to its high specificity and negative predictive value and playa supplementary role to the conventional health check-up, but it could not replace due to limited sensitivity for urological cancers, small-sized tumors and some hypometaboic cancers.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.253-255
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• 2008

A 61-year-old man had a F-18 FDG PET/CT scan for evaluation of a common bile duct cancer identified on CT. The PET/CT image showed a hypermetabolic mass in the common bile duct, and a focal area of increased F-18 FDG uptake in segment IV of the liver, which corresponded to a hypoattenuated lesion on non-enhanced CT, and was consistent with hepatic metastasis. The patient underwent choledochojejunostomy with hepatic resection, and pathologic findings were compatible with an eosinophilic abscess in the liver. This case demonstrates that F-18 FDG uptake by an eosinophilic abscess can mimic hepatic metastasis in a patient with a malignancy.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.32-39
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• 2005

Introduction: Currently, F-18 fluorodeoxyglucose positron emission tomography scans (FDG-PET) has been investigated in soft tissue tumor especially for tumor detection and noninvasive grading. However, the validity and the efficacy of FDG-PET are still unclear in clinical evaluation. The purpose of this study is to determine the efficacy of FDG-PET in compared to conventional diagnostic imaging studies currently used in the soft tissue tumor. Methods: Between March 2001 and March 2002, 29 patients (sixteen males, thirteen females, mean age, 47 years; a range from 4 to 73) diagnosed with soft tissue tumor were evaluated by both conventional diagnostic imaging and FDG-PET. Valid reference test of the local lesion was the histopathologic diagnosis, which was measured in all patients. The suspecting metastasis in the imaging studies was validated by pathology or follow up imaging for at least 6 months. Each imaging diagnosis was made independently. The accuracy of each diagnostic method was evaluated. The incremental cost accuracy ratio was determined in each diagnostic method. Results: For detection of local lesion, sensitivity, specificity, and accuracy for MRI and FDGPET scans were 91%, 57%, 83% and 95%, 43%, 83% respectively. For detection of distant lesion, sensitivity, specificity, accuracy for conventional diagnostic methods and FDG-PET scans were 77%, 89%, 87% and 92%, 94%, 93% respectively. The incremental cost accuracy ratio (ICAR) of FDG-PET for detection of distant lesion was 145,000won/%. According to ICAR for each tumor grade, PET strategy is most cost-effective at high grade tumors. Conclusions: For detection of local lesion such as recurrence or remnant tumor, FDG-PET scan was not more accurate than MRI. However, It was more accurate for detection of metastatic lesion than conventional methods. For detection of high grade tumor, PET was most costeffective than for detection of lower grade tumor.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.101-109
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• 2008

Cervix cancer is one of common gynecological cancers in the world, and staged with FIGO or TNM system. However, these clinical staging systems lack information about lymph node or distant metastases, thus imaging modalities are considered to make an appropriate therapeutic plan and enhance overall survival rate. In this context, FDG PET is recommended to pre-treatment stating and prognosis prediction, for it could noninvasively evaluate the status of lymph nodes, especially abdominal paraaortic nodes which are closely related with prognosis. Moreover, the degree of FDG uptake is correlated with prognosis. Although there is no consistent method for surveillance of cervix cancer, FDG PET seems a very important tool in detecting tumor recurrence because it is much more advantageous than conventional imaging modalities such as MRI for discerning recurrent tumor from fibrosis caused by radiation or surgery. Furthermore, FDG PET could be used to evaluate treatment response. On the other hand, recently introduced PET/CT is expected to play an ancillary role to FIGO staging by adding anatomical information, and enhance diagnostic performance of PET by decreasing false positive findings.