A hepatic angiomyolipoma is a rare benign tumor mainly composed of blood vessels, smooth muscle cells and fat cells in varying proportion. Hepatic angiomyolipoma is often misdiagnosed as a hepatocellular carcinoma in preoperative imaging work-up. To date, there has been little published data describing PET findings of hepatic angiomyolipoma. We report one case of hepatic angiomyolipoma that showed a high acetate and relatively low FDG uptake on PET images.
Adipocytes ; Angiomyolipoma ; Blood Vessels ; Carcinoma, Hepatocellular ; Liver ; Myocytes, Smooth Muscle

An esophageal leiomyoma is the most common benign tumor of the esophagus mainly occurred in intramural portion. Occasionaly, it is difficult to discriminate esophageal malignancy from large leiomyoma. Although F-18 FDG PET has been used for differentiating malignant from benign disease, false-positive cases have been reported. Recently, uterine leiomyoma has been reported to have relatively high F-18 FDG uptake in some patients but little is known about how an esophageal leiomyoma might be showed on F-18 FDG PET. We report a case of esophageal leiomyoma that showed high FDG uptake on PET images.
Esophagus ; Humans ; Leiomyoma

It is well known that F-18 FDG PET/CT is a highly sensitive diagnostic modality for cancer patients. However, false positive cases resulting from benign disease such as tuberculosis in the endemic area often compromise the diagnostic accuracy of F-18 FDG PET/CT. Nasopharyngeal tuberculosis is a rare disease although extrapulmonary tuberculosis can involve any region in the body. We report one case of nasopharyngeal tuberculosis incidentally detected on F-18 FDG PET/CT.
Humans ; Rare Diseases ; Tuberculosis

A rectal cancer was found in a 67-year-old man with a history of neurofibromatosis type 1. A low anterior resection was performed, and he received concurrent chemoradiation for 6 months. Twelve months after the surgery, a tumor was found at the anastomotic site by positron emission tomography-computed tomography and colonoscopy and was mistaken as anastomotic site recurrence. The tumor was confirmed as an inflammatory myofibroblastic tumor through transanal excision.
Aged ; Colonoscopy ; Colorectal Neoplasms ; Electrons ; Humans ; Myofibroblasts ; Neurofibromatoses ; Neurofibromatosis 1 ; Rectal Neoplasms ; Recurrence

Head and neck cancers are the sixth most common type of human cancer worldwide. Squamous cell carcinomas are the most common cancer of the head and neck. Due to the higher glycolytic rates of squamous cell carcinomas relative to normal tissue, the glucose analog 18F-FDG can be used to detect umors, and 18F-FDG PET has been used inpatients with head and neck cancers for initial staging, management of recurrent cancers, and therapeutic onitoring. We reviewed the clinical application and diagnostic usefulness of 18F-FDG PET in the management of head and neck cancer.
Carcinoma, Squamous Cell ; Fluorodeoxyglucose F18 ; Glucose ; Head and Neck Neoplasms* ; Head* ; Humans ; Inpatients ; Neck

PURPOSE: This study investigated the correlative relationship between metabolic parameters estimated from dual time point 2-deoxy-2-[¹⁸F] fluoro-D-glucose (¹⁸F-FDG) positron emission tomography/computerized tomography (PET/CT) and the clinical tools predicting the outcome of a lymphoma. We also measured metabolic and volumetric alterations between early and delayed ¹⁸F-FDG PET/CT in patients with high grade lymphoma (HGL).METHODS: The samples were 122 lymph nodes and extralymphatic lesions from 26 patients diagnosed with HGL. All patients were applied to the International Prognostic Index (IPI), Ann Arbor stage, and revised IPI as clinical prognostic parameters. ¹⁸F-FDG dual time point PET/ CT (DTPFP) consisted of an early scan 1 h after ¹⁸F-FDG injection and a delayed scan 2 h after the early scan. Based on an analysis of DTPFP, we estimated the standardized uptake value (SUV) of tumors from the early and delayed scans, retention index (RI) representing the percentage change between early and delayed SUV, and metabolic volume different index (MVDI) calculated using metabolic tumor volumes (MTV).RESULTS: RI(max) showed a multiple positive correlative relationship with stage and IPI in lesion-by-lesion analysis (p < 0.01). In the case of IPI, the high risk group exhibited higher RI(max) than the low risk group (p = 0.004). In the case of revised IPI, the RI(max) of the low risk group were significantly lower than the intermediate and high risk groups, respectively (p < 0.01). The MVDIs of the best outcome group were decreased in comparison to the moderate outcome group (p = 0.029). There was a significant negative correlative relationship between RI(max) and MVDI, and the inclinations for decreased MVDIs were slightly associated with increased RIs.CONCLUSIONS: RI(max) extracted from DTPFP had a significant relationship to extranodal involvement, staging, IPI, and revised IPI. MVDI showed significant negative correlation with RI(max). Further large scale studies are warranted to support and extend these preliminary results.
Electrons ; Humans ; Lymph Nodes ; Lymphoma ; Pilot Projects ; Positron-Emission Tomography and Computed Tomography

INTRODUCTION: Distant metastases of mucoepidermoid carcinoma (MEC) are reported with the most common sites being the soft tissue of skin, lung, liver, and bone. We report here a very rare case of MEC with multiple metastases to the kidney, adrenal gland, skull and gluteus maximus muscle. CASE REPORT: A 63-year-old male patient presented with left-sided headache. Radiologic evaluations including CT and MRI showed ill-defined soft tissue lesion involving the left infratemporal fossa and left sphenoid sinus, and multiple enlarged lymph nodes in neck and mediastinum. PET-CT demonstrated multiple hypermetabolic lesions in and around the left kidney, left adrenal gland, right ischium, right gluteus maximus and skull base. These lesions were confirmed as MEC with multiple metastases through biopsy. DISCUSSION: Only one case of metastasis to the skull has been previously reported, and moreover, there has not been a case of metastatic MEC to the kidney, adrenal gland and gluteus maximus muscle so far in the medical literature. It is important to acknowledge the possibility of every unusual MEC metastases, since the presence of metastasis has statistically significant influence on the survival of MEC.
Adrenal Glands* ; Biopsy ; Carcinoma, Mucoepidermoid* ; Headache ; Humans ; Ischium ; Kidney* ; Liver ; Lung ; Lymph Nodes ; Magnetic Resonance Imaging ; Male ; Mediastinum ; Middle Aged ; Neck ; Neoplasm Metastasis* ; Positron-Emission Tomography ; Skin ; Skull Base ; Skull* ; Sphenoid Sinus

Superior vena cava syndrome (SVCS) is usually caused by extrinsic compression or invasion of the superior vena cava (SVC) by malignant tumors involving mediastinal structures. Although thymomas are well-known causes of SVCS, cases of SVCS caused by malignant thymomas protruding into adjacent vessels draining the SVC with thrombosis have been very rarely reported worldwide. We experienced a 39-year-old female patient with SVCS that developed after the direct invasion of the left brachiocephalic vein (LBCV) and SVC by an anterior mediastinal mass with a high maximum standardized uptake value on the chest computed tomography (CT) and positron emission tomography-CT. Based on these results, she underwent en bloc resection of the tumor, including removal of the involved vessels, and was eventually diagnosed as having a type B2 thymoma permeating into the LBCV and SVC. We present this case as a very rare form of SVCS caused by an invasive thymoma.
Adult ; Brachiocephalic Veins ; Electrons ; Female ; Humans ; Positron-Emission Tomography ; Superior Vena Cava Syndrome* ; Thorax ; Thrombosis ; Thymoma* ; Vena Cava, Superior*

PURPOSE: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using (99m)Tc-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). MATERIAL AND METHODS: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. RESULTS: Seventeen patients (M:F=12:5, mean age: 53+/-2yr) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p=0.003) and decreased to the preoperative level at 3-6 months (p=0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. CONCLUSION: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.
Acetazolamide ; Atherosclerosis ; Brain ; Carotid Artery, Internal ; Cerebellum ; Cerebral Arteries ; Cerebral Revascularization ; Follow-Up Studies ; Hemodynamics ; Humans ; Middle Cerebral Artery ; Perfusion ; Postoperative Period ; Stroke ; Tomography, Emission-Computed, Single-Photon

PURPOSE: Dopamine transporter imaging is suggested to be a useful imaging biomarker for Parkinson's disease (PD) progression and monitoring drug effects.We investigated the longitudinal decline characteristics of striatal [¹⁸F]FP-CIT uptake in PD.METHODS: We retrospectively reviewed 35 PD patients and 9 non-PD patients. All patients underwent [¹⁸F]FP-CIT PET at the initial diagnosis and follow-up. PET images were spatially normalized and analyzed with eight striatal and one occipital VOI templates. We measured the specific to non-specific binding ratio (SNBR) of the striatal subregions and calculated the absolute annual reduction (AAR) and relative annual reduction (%RAR) of the SNBRs.RESULTS: Total striatal SNBRs in PD patients were significantly lower than those in non-PD patients, with the most significant difference in the posterior putamen. Both AAR (0.26 ± 0.14 vs. 0.09 ± 0.19, p < 0.05) and %RAR (6.9 ± 3.5 vs. 1.2 ± 2.7, p < 0.001) of total striatal SNBRs were significantly greater in PD than non-PD patients. There were no significant differences in the AAR and %RAR of total striatal SNBRs between elderly and young onset PD. The AARs of the posterior putamen were higher in early PD than in advanced PD. Conversely, the %RARs were not significantly different between early and more advanced PD. The disease duration was significantly negatively correlated with the AAR but not with the %RAR of the posterior putamen.CONCLUSIONS: The longitudinal decline of striatal [¹⁸F]FP-CIT uptake in PD was nonlinear and significantly faster than that in non-PD, with a different rate of decline among the striatal subregions.
Aged ; Diagnosis ; Dopamine Plasma Membrane Transport Proteins ; Follow-Up Studies ; Humans ; Parkinson Disease ; Putamen ; Retrospective Studies