Differentiation of Parkinson's Disease and Essential Tremor on I-123 IPT(I-123-N-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta(4-cholorophenyl) tropane) Brain SPECT / 핵의학분자영상

PURPOSE: The study was to assess I-123-N-(3-iodopropen-2-yl)-2[beta]-carbomethoxy-3[beta]-(4-cholorophenyl) tropane (IPT) SPECT in differential diagnosis among early stage of Parkinson's disease(PD) and essential tremor(ET) and normal control(NL) groups quantitatively. MATERIALS AND METHODS: I-123 IPT brain SPECT of 50 NL, 20 early PD, 30 advanced PD, and 20 ET were performed at 20 minutes and 2 hours. Specific/nonspecific binding of striatum was calculated by using right and left striatal specific to occipital non-specific uptake ratio (striatum-OCC/OCC). RESULTS: Mean value of specific/nonspecific binding ratio was significantly different between advanced PD group and NL group. However, significant overlap of striatal specific/nonspecific binding ratio was observed between PD group and ET group. Bilateral striatal specific/nonspecific binding ratios were decreased in advanced PD. Lateralized differences in the striatal uptake of I-123 IPT correlated with asymmetry in clinical findings in PD group. CONCLUSION: I-123 IPT SPECT may be a useful method for the diagnosis of PD and objective evaluation of progress of clinical stages. Care should be made in the differential diagnosis of early stage of PD and other motor disturbances mimicking PD such as ET in view of significant overlap in striatal I-123 specific/nonspecific binding ratio.

Tc-99m MDP-induced Acute Hepatitis in a Hemodialysis Patient / 대한신장학회지

Bone scan is one of the most frequently performed studies in nuclear medicine with few adverse reactions for the examination of pathologic conditions of bone. Diffuse liver uptake of Technetium-99m methylene diphosphonate (Tc-99m MDP) is a rare occurrence with only a few reports in the literature. Furthermore, there is no report of Tc-99m MDP-induced liver injury. Here we report a case of acute hepatitis with diffusely increased uptake of Tc-99m MDP in a hemodialysis patient.

Hypermetabolism of Compensatory Laryngeal Muscles in Unilateral Vocal Cord Palsy: Comparison Study between Speech and Silence with Normal Subjects by Co-registered PET-CT Fusion Images / 핵의학분자영상

PURPOSE: There are a few case reports on asymmetric vocal cord uptake on FDG-PET in patients with unilateral vocal cord paralysis, which could be a potential pitfall in the interpretation of FDG-PET images. We evaluated the metabolic activity of laryngeal muscles of patients with unilateral vocal cord paralysis in comparison to normal controls during both speech and silence. METHODS: Eleven patients with unilateral vocal cord palsy (thyroidectomy=7, lung cancer=1, others=3) and 12 normal controls underwent FDG-PET with usual protocol. They were divided into two groups respectively; one group read books aloud for 20 minutes (phonation group) and the other kept silence (non-phonation groups) after FDG injection. Recent neck CT scan were co-registered with FDG-PET to produce PET-CT fusion images to elaborate small laryngeal muscles. RESULTS: In patients with unilateral vocal cord palsy, contralateral non-paralyzed vocal cord showed hypermetabolism mainly on thyroarytenoid muscle, more intensely with phonation group (SUV=5.88+/-2.65) than with non-phonation group (SUV=2.30+/-0.39). Normal control subjects showed hypermetabolism (3.68+/-0.96) in interarytenoid muscle and symmetric mild hypermetabolism in both lateral cricoarytenoid muscles in only phonation group. CONCLUSION: FDG-PET with fusion images using CT scan in patients with unilateral vocal cord paralysis showed hypermetabolism of contralateral non-paralyzed thyroarytenoid muscle, suggesting compensatory action during phonation. Phonation during FDG-PET study enhanced FDG uptake on different laryngeal muscles between patients with unilateral vocal cord paralysis and normal subjects.

F-18 FDG PET Scan findings in Patients with Pulmonary Involvement in the Hypereosinophilic Syndrome / 대한핵의학회잡지

PURPOSE: Hypereosinophilic syndrome (HES) is an infiltrative disease of eosinophils affecting multiple organs including the lung. F-18 2-fluoro-2-deoxyglucose (F-18 FDG) may accumulate at sites of inflammation or infection, making interpretation of whole body PET scan difficult in patients with cancer. This study was to evaluate the PET findings of HES with lung involvement and to find out differential PET features between lung malignancy and HES with lung involvement. MATERIAL AND METHODS: F-18 FDG PET and low dose chest CT scan was performed for screening of lung cancer. Eight patients who showed ground-glass attenuation (GGA) and consolidation on chest CT scan with peripheral blood eosinophilia were included in this study. The patients with history of parasite infection, allergy and collagen vascular disease were excluded. CT features and FDG PET findings were meticulously evaluated for the distribution of GGA and consolidation and nodules on CT scan and mean and maximal SUV of abnormalities depicted on F-18 FDG PET scan. In eight patients, follow-up chest CT scan and FDG PET scan were done one or two weeks after initial study. RESULTS: F-18 FDG PET scan identified metabolically active lesions in seven out of eight patients. Maximal SUV was ranged from 2.8 to 10.6 and mean SUV was ranged from 2.2 to 7.2. Remaining one patient had maximal SUV of 1.3. On follow-up FDG PET scan taken on from one to four weeks later showed decreased degree of initially noted FDG uptakes or migration of previously noted abnormal FDG uptakes. CONCLUSIONS: Lung involvement in the HES might be identified as abnormal uptake foci on FDG PET scan mimicking lung cancer. Follow-up FDG PET and CT scan for the identification of migration or resolution of abnormalities and decrement of SUV would be of help for the differentiation between lung cancer and HES with lung involvement.

Accuracy of Ventricular Volume and Ejection Fraction Measured by Gated Tl-201 Perfusion Single Photon Emission Tomography / 대한핵의학회잡지

Electrocardiogram-gated single photon emission computed tomography (SPECT) provides valuable information in the assessment of both myocardial perfusion and ventricular function. Tl-201 is a suboptimal isotope for gating. Tl-201 images are more blurred compared with Tc-99m tracers due to the increased amount of scattered photons and use of a smooth filter. The average myocardial count densities are approximately one-half those of conventional technetium tracers. However, Tl-201 is still widely used because of its well-established utility for assessing myocardial perfusion, viability and risk stratification. Gated SPECT with Tl-201 enables us to assess both post-stress and rest left ventricular volume and function. Previous studies with gated Tl-201 SPECT measurements of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) have shown high correlation with first-pass radionuclide angiography, gated blood pool scan, Tc-99m-MIBI gated SPECT, contrast ventriculography, echocardiography, and 3-dimensional magnetic resonance imaging. However, problems related to these studies include few agreement data of EDV and ESV, use of a reference method that is likely to have the same systemic errors (gated Tc-99m-MIBI SPECT), and other technical factors related to the count density of gated SPECT. With optimization of gated imaging protocols and more validation studies, gated Tl-201 SPECT would be an accurate method to provide perfusion and function information in patients with coronary artery disease.

Colonic Uptake Patterns of F-18-FDG PET in Asymptomatic Adults: Comparison with Colonoscopic Findings / 대한핵의학회잡지

PURPOSE: Physiologic intestinal FDG uptake is frequently observed in asymptomatic individuals for cancer screening FDG PET. Colonic FDG accumulation is a well-known confusing findings that interfere true cancer detection or cause false positive. The aim of this study was to evaluate the pattern and intensity of colonic uptake in whole body FDG PET in asymptomatic healthy adults and to correlate them with colonoscopic findings. MATERIALS AND METHODS: We reviewed retrospectively 64 subjects (age: 27-87, M: F = 31: 33 ) who underwent both FDG PET and colonoscopy for cancer screening. FDG uptake patterns were classified as focal, segmental and diffuse. Maximum SUV were measured. The PET results were compared with colonoscopic and histologic findings. RESULTS: In 13 patients FDG bowel uptake was interpreted as focal, in 17 patients as segmental and in 34 patients as diffuse uptake. Six adenomas (17.6%, average diameter =5.0 mm) were found in diffuse pattern, 7 adenomas (41.1%, 5.6 mm) in segmental and 4 adenomas and 1 adenocarcinoma (38.5%, 16.4 mm) in focal uptake pattern. In patients with focal uptake, four were non-adenomatous pathologic lesions (30.8%, 2 intestinal tuberculosis, 2 mucosal ulcer). There is no difference of mean SUV between patients with adenoma and with negative colonoscopic results in each group of intestinal FDG pattern (Diffuse: 1.7 +/- 0.1 vs. 1.9 +/- 0.5, Segmental: 4.8 +/- 3.6 vs. 4.2 +/- 1.2, Focal: 6.5 +/- 4.7 vs. 3.5 +/- 1.3). Large adenomas (> 1 cm) can be detected more in the focal uptake pattern (4 out of 5) rather than in segmental (1 out of 7) or diffuse uptake (none) and had higher SUV (6.3 +/- 4.8) than small adenomas (3.5 +/- 3.0) (statistically insignificant). CONCLUSION: Focal FDG uptake is associated more often with large adenoma and other pathologic findings in colonoscopy. Segmental uptake cannot discriminate presence of adenoma from negative results, while diffuse pattern may have more chance to be normal.

F-18-FDG Imaging Using Dual-Head Coincidence Positron Emission Tomography in Patients with Head and Neck Cancer / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: An accurate, preoperative assessment of tumor extent and lymph node involvement is necessary to plan and tailor therapy for patients with head and neck cancer. Metabolic imaging with tluorine-18-fluorodeoxyglucose (FDG) is a good method to detect primary cancers in the head and neck and to assess the involvement of lymph nodes, but it is not widely available because of high cost of positron emission tomography (PET). Recently, an alternative method for using FDG was developed: the coincidence detection PET (CoDe PET) using a gamma camera. The aim of this study was to evaluate the clinical utility of FDG CoDe PET using a gamma camera in patients with head and neck cancer. MATERIALS AND METHODS: Thirty FDG CoDe PET studies were performed in 7 patients before therapy and 19 patients after therapy with various head and neck cancers (Age : 25- 79 years, mean age : 50+/-13 years, 18 men, 8 women). All patients had fasted for 6 to 12 hours and were injected 1 1 l to 370 MRq of F-18-FDG 1 hour before imaging. With the exception of the physiological FDG uptake, all visually detectable focal FDC uptake in the primary cancer site or in the neck was considered positive. FDG CoDe PET studies were correlated with CT/MRI. The standard procedure for detecting the presence of disease was the combinations of repeated MRIs, 3 months of follow-up clinical evaluation and the result of a needle aspiration cytology or biopsy. RESULTS: FDG CoDe PET had a detcction rate that was comparable to that of CT/MRI in the pre-therapy group. However, in the post-therapy group, FDG CoDe PET could differentiate residual/recurrence of tumor from radiation change more accurately than could MRI. But, it had a less accurate detection rate for cervical metastases because of asymmetric neck muscle uptake. CONCLUSION: FDG CoDe PET is a sensitive and cost-effective method to detect primary tumor and lymph node involvement in primary head and neck cancers. It is also useful in differentiating residual tumor or tumor recurrence from post-therapy changes in patients with head and neck cancers.

F-18-FDG Whole Body Scan using Gamma Camera equipped with Ultra High Energy Collimator in Cancer Patients: Comparison with FDG Coincidence PET / 대한핵의학회잡지

PURPOSE: The aim of this study is to demonstrate the feasibility of 2-[fluorine-18] fluoro-2-deoxy-D-glucose (F-18-FDG) whole body scan (FDG W/B Scan) using dual-head gamma camera equipped with ultra high energy collimator in patients with various cancers, and compare the RESULTS with those of coincidence imaging. MATERIALS AND METHODS: Phantom studies of planar imaging with ultra high energy and coincidence tomography (FDG CoDe PET) were performed. Fourteen patients with known or suspected maligancy were examined. F-18-FDG whole body scan was performed using dual-head gamma camera with high energy (511 keV) collimators and regional FDG CoDe PET immediately followed it. Radiological, clinical follow up and histologic RESULTS were correlated with F-18-FDG finding. RESULTS: Planar phantom study showed 13.1 mm spatial resolution at 10 cm with a sensitivity of 2638 cpm/MBq/ml. In coincidence PET, spatial resolution was 7.49 mm and sensitivity was 5351 cpm/MBq/ml. Eight out of 14 patients showed hypermetabolic sites in primary or metastatic tumors in FDG CoDe PET. The lesions showing no hypermetabolic uptake of FDG in both methods were all less than 1 cm except one lesion of 2 cm sized metastatic lymph node. The metastatic lymph nodes of positive FDG uptake were more than 1.5 cm in size or conglomerated lesions of lymph nodes less than 1 cm in size. FDG W/B scan showed similar RESULTS but had additional false positive and false negative cases. FDG W/B scan not visualize liver metastasis in one case that showed multiple metastatic sites in FDG CoDe PET. CONCLUSION:S: FDG W/B scan with specially designed collimators depicted some cancers and their metastatic sites, although it had a limitation in image quality compared to that of FDG CoDe PET. This study suggests that F-18-FDG positron imaging using dual-head gamma camera is feasible in oncology and helpful if it should be more available by regional distribution of FDG.

Evaluation of Spontaneous Intracranial Hypotension Using Radionuclide Cisternography / 대한핵의학회잡지

We report four cases of spontaneous intracranial hypotension that were investigated by radionuclide cisternography Tc-99m-diethylenetriamine pentaacetic acid radionuclide cisternography of all our patients showed direct sign of cerebrospinal fluid leakage as well as indirect signs of less activity than expected over the cerebral convexities and rapid appearance of bladder activity. The headache of all patients was eventually controlled with bed rest and hydration.