Alzheimer’s Disease Prediction Using Attention Mechanism with Dual‑Phase 18 F‑Florbetaben Images / 대한핵의학회잡지

Materials and Methods@#A total of 264 patients (74 CN and 190 AD), who underwent FBB imaging test and neuropsychological tests, were retrospectively analyzed. Early- and delay-phase FBB images were spatially normalized with an in-house FBB template. The regional standard uptake value ratios were calculated with the cerebellar region as a reference region and used as independent variables that predict the diagnostic label assigned to the raw image. @*Results@#AD positivity scores estimated from dual-phase FBB showed better accuracy (ACC) and area under the receiver operating characteristic curve (AUROC) for AD detection (ACC: 0.858, AUROC: 0.831) than those from delay phase FBB imaging (ACC: 0.821, AUROC: 0.794). AD positivity score estimated by dual-phase FBB (R: −0.5412) shows a higher correlation with psychological test compared to only dFBB (R: −0.2975). In the relevance analysis, we observed that LSTM uses different time and regions of early-phase FBB for each disease group for AD detection. @*Conclusions@#These results show that the aggregated model with dual-phase FBB with long short-term memory and attention mechanism can be used to provide a more accurate AD positivity score, which shows a closer association with AD, than the prediction with only a single phase FBB.

The Effect of Clinical Characteristics and Subtypes on Amyloid Positivity in Patients with Amnestic Mild Cognitive Impairment

BACKGROUND AND PURPOSE: Mild cognitive impairment (MCI) is a prodromal stage of dementia. Amyloid deposits in positron-emission tomography (PET) imaging of MCI patients imply a higher risk for advancing to dementia, with rates of 10%–15% yearly. The purpose of this study was to investigate the clinical characteristics of subgroups of amnestic MCI (aMCI) that may have a higher impact on amyloid positivity.METHODS: We recruited 136 aMCI patients. All patients underwent a 20-minute F-18 florbetaben or flutemetamol PET scan. We classified amyloid PET images as positive or negative according to a semi-quantitative method. We evaluated the amyloid positivity of subgroups of aMCI (early vs. late type, single vs. multiple amnestic type, verbal vs. verbal, and visual amnestic type), and compared baseline clinical characteristics including key risk factors, apolipoprotein E4 (apoE4) genotype, and neuropsychological assessments with amyloid positivity in aMCI.RESULTS: The amyloid positivity in total aMCI was 41%. The positivity rate according to subgroup of aMCI were as follow: Late aMCI (49%) vs. early aMCI (33%) (p=0.13), multiple aMCI (40%) vs. single aMCI (38%) (p=0.51), and verbal and visual aMCI (59%) vs. verbal aMCI (35%) (p=0.01), respectively. The mean age and the frequency of apoE4 allele of the amyloid-positive group was higher than that of the amyloid-negative group in aMCI (p< 0.01).CONCLUSIONS: We found that the amyloid positivity was related to patterns of clinical subtypes, characteristics, and risk factors in patients with aMCI.

Correlation of Early-Phase F-18 Florapronal PET with F-18 FDG PET in Alzheimer's Disease and Normal Brain / 대한핵의학회잡지

PURPOSE: F-18 florapronol (FPN) is the commercially recognized beta-amyloid positron emission tomography (PET) radiotracer in Korea. This study compared the early F-18 florapronol PET with F-18 fluorodeoxyglucose (FDG) PET between healthy controls (HC) and Alzheimer's dementia (AD) patients.METHODS: A total of 29 subjects (15 HC and 14 AD subjects) underwent F-18 FPN PET and F-18 FDG PET. F-18 FDG PET image was acquired from 30 to 60 min and F-18 FPN PET for 0 to 10 min. F-18 FPN and F-18 FDG images were spatially normalized with transformation matrices obtained from individual CTimages and standardized uptake value ration (SUVR) from cerebellum area, and the global mean was calculated using PMOD 3.6. Pearson's correlation coefficients between F-18 FDG and early F-18 FPN for predefined cortical brain regions were calculated.RESULTS: We compared the F-18 FDG and F-18 FPN for SUVR of a specific region in global mean normalization and cerebellum normalization, and most of the correlation coefficient was higher in global mean normalization. In global mean normalization, the correlation coefficient for SUVR of HC was higher than that of AD in all brain regions.CONCLUSIONS: Early F-18 FPN study can be used as a proxy marker for the F-18 FDG PET.

Cerebral Amyloid Quantification in Cognitively Normal Korean Adults Using F-18 Florbetaben PET / 대한핵의학회잡지

PURPOSE: To investigate regional cerebral amyloid beta retention in cognitively normal Korean adults using F-18 florbetaben (FBB).METHODS: We prospectively analyzed F-18 FBB positron emission tomography (PET)/CT scans of 30 cognitively healthy adults (age range, 50??0 years) using automated quantification. The standardized uptake value ratios (SUVRs) of F-18 FBB were calculated for predefined regions by normalizing the regional count with cerebellar cortex.RESULTS: The distribution of amyloid beta for each brain region revealed no age-related trends (p > 0.05). From all subjects, mean SUVR of amyloid deposit was 1.30 ± 0.18. The right parietal lobe showed the highest SUVR value (1.46 ± 0.23), whereas the right frontal lobe and left precuneus showed the lowest SUVR (1.23 ± 0.25).CONCLUSIONS: We provide reference values of normative data obtained from healthy elderly Koreans and suggest its use for accurate diagnosis of patients with Alzheimer's disease.

Prediction of Alzheimer's Pathological Changes in Subjective Cognitive Decline Using the Self-report Questionnaire and Neuroimaging Biomarkers

BACKGROUND AND PURPOSE: Subjective cognitive decline (SCD) may be the first symptomatic stage of Alzheimer's disease (AD). Hence, a screening tool to characterize the patients' complaints and assess the risk of AD is required. We investigated the SCD neuroimaging biomarker distributions and the relevance between the self-report questionnaire and Alzheimer's pathologic changes. METHODS: Individuals aged 50 and above with consistent cognitive complaints without any objective cognitive impairments were eligible for the study. The newly developed questionnaire consisted of 2 parts; 10 questions translated from the ‘SCD-plus criteria’ and a Korean version of the cognitive failure questionnaire by Broadbent. All the subjects underwent physical examinations such as blood work, detailed neuropsychological tests, the self-report questionnaire, brain magnetic resonance imagings, and florbetaben positron emission tomography (PET) scans. Amyloid PET findings were interpreted using both visual rating and quantitative analysis. Group comparisons and association analysis were performed using SPSS (version 18.0). RESULTS: A total of 31 participants with SCD completed the study and 25.8% showed positive amyloid depositions. The degree of periventricular white matter hyperintensities (WMH) and hippocampal atrophy were more severe in amyloid-positive SCDs compared to the amyloid-negative group. In the self-reported questionnaire, the ‘informant's report a decline’ and ‘symptom's onset after 65 years of age’ were associated with more Alzheimer's pathologic changes. CONCLUSIONS: Amyloid-positive SCDs differed from amyloid-negative SCDs on WMH, hippocampal atrophy, and a few self-reported clinical features, which gave clues on the prediction of AD pathology.

Correlation of Early-Phase F-18 Florapronal PET with F-18 FDG PET in Alzheimer's Disease and Normal Brain / 대한핵의학회잡지

PURPOSE@#F-18 florapronol (FPN) is the commercially recognized beta-amyloid positron emission tomography (PET) radiotracer in Korea. This study compared the early F-18 florapronol PET with F-18 fluorodeoxyglucose (FDG) PET between healthy controls (HC) and Alzheimer's dementia (AD) patients.@*METHODS@#A total of 29 subjects (15 HC and 14 AD subjects) underwent F-18 FPN PET and F-18 FDG PET. F-18 FDG PET image was acquired from 30 to 60 min and F-18 FPN PET for 0 to 10 min. F-18 FPN and F-18 FDG images were spatially normalized with transformation matrices obtained from individual CTimages and standardized uptake value ration (SUVR) from cerebellum area, and the global mean was calculated using PMOD 3.6. Pearson's correlation coefficients between F-18 FDG and early F-18 FPN for predefined cortical brain regions were calculated.@*RESULTS@#We compared the F-18 FDG and F-18 FPN for SUVR of a specific region in global mean normalization and cerebellum normalization, and most of the correlation coefficient was higher in global mean normalization. In global mean normalization, the correlation coefficient for SUVR of HC was higher than that of AD in all brain regions.@*CONCLUSIONS@#Early F-18 FPN study can be used as a proxy marker for the F-18 FDG PET.

Cerebral Amyloid Quantification in Cognitively Normal Korean Adults Using F-18 Florbetaben PET / 대한핵의학회잡지

PURPOSE@#To investigate regional cerebral amyloid beta retention in cognitively normal Korean adults using F-18 florbetaben (FBB).@*METHODS@#We prospectively analyzed F-18 FBB positron emission tomography (PET)/CT scans of 30 cognitively healthy adults (age range, 50??0 years) using automated quantification. The standardized uptake value ratios (SUVRs) of F-18 FBB were calculated for predefined regions by normalizing the regional count with cerebellar cortex.@*RESULTS@#The distribution of amyloid beta for each brain region revealed no age-related trends (p > 0.05). From all subjects, mean SUVR of amyloid deposit was 1.30 ± 0.18. The right parietal lobe showed the highest SUVR value (1.46 ± 0.23), whereas the right frontal lobe and left precuneus showed the lowest SUVR (1.23 ± 0.25).@*CONCLUSIONS@#We provide reference values of normative data obtained from healthy elderly Koreans and suggest its use for accurate diagnosis of patients with Alzheimer's disease.

Role of Positron Emission Tomography as a Biologic Marker in the Diagnosis of Primary Progressive Aphasia: Two Case Reports / 대한핵의학회잡지

Primary progressive aphasia (PPA) is a heterogenous neurodegenerative disorder characterized by declining language and speech ability. Various underlying neuropathologies can induce PPA, and the disorder is divided into three subtypes—progressive non-fluent aphasia, semantic variant aphasia, and logopenic aphasia—according to clinical features. Accurate disease classification and prediction of underlying diseases are necessary for appropriate treatment, but proper use of imaging tests is important because clinical information alone often makes it difficult to make accurate decisions. Because there is a characteristic metabolic pattern according to the subtypes, F-18 fluorodeoxyglucose positron emission tomography (PET) can indicate subtype classification. In addition, PETstudies for imaging amyloid or dopamine transporters play an important role in demonstrating underlying disease. The present case showed that PET imaging studies are useful in diagnosis and could be used as a biomarker in PPA.

Role of Positron Emission Tomography as a Biologic Marker in the Diagnosis of Primary Progressive Aphasia: Two Case Reports / 대한핵의학회잡지

Primary progressive aphasia (PPA) is a heterogenous neurodegenerative disorder characterized by declining language and speech ability. Various underlying neuropathologies can induce PPA, and the disorder is divided into three subtypes—progressive non-fluent aphasia, semantic variant aphasia, and logopenic aphasia—according to clinical features. Accurate disease classification and prediction of underlying diseases are necessary for appropriate treatment, but proper use of imaging tests is important because clinical information alone often makes it difficult to make accurate decisions. Because there is a characteristic metabolic pattern according to the subtypes, F-18 fluorodeoxyglucose positron emission tomography (PET) can indicate subtype classification. In addition, PETstudies for imaging amyloid or dopamine transporters play an important role in demonstrating underlying disease. The present case showed that PET imaging studies are useful in diagnosis and could be used as a biomarker in PPA.

Detection of BRAF(V600E) Mutation using Peptide Nucleic Acid-Mediated PCR Clamping Method in Fine Needle Aspiration Cytology / 대한내분비외과학회지

PURPOSE: The aim of this study was to evaluate the diagnostic value of a peptide nucleic acid (PNA)-mediated PCR clamping method for the detection of BRAFV600E mutations in fine needle aspiration cytology (FNAC). METHODS: One hundred sixty four patients underwent FNAC to evaluate BRAFV600E mutations between April 2011 and November 2011. Among them, forty-two patients were diagnosed with papillary thyroid carcinoma in a permanent pathologic specimen. A PNA-mediated PCR clamping method and a Dual-Priming Oligonucleotide (DPO)-based Real-time PCR method were used to detect the BRAFV600E mutation. We compared the result of mutation between the two methods. RESULTS: A BRAF mutation was found in 31 samples created by the PNA-mediated PCR clamping method, and in 28 samples in the DPO-based Real-time PCR method. The rate of BRAF mutation was 73.8% in association with the PNA-mediated PCR clamping method, and 66.7% in association with the DPO-based Real-time PCR method. There was no statistical differences between the two methods (P>0.05). CONCLUSION: The PNA-mediated PCR clamping method may be an alternative to the DPO-based Real-Time PCR method for detection of BRAF mutations in thyroid nodules.

Characteristics of Brain Perfusion in Patients of Parkinson's Disease / 핵의학분자영상

PURPOSE: It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. METHODS AND MATERIALS: Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9+/-6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4+/-9.2 y/o) as normal controls who had no past illness history were performed (99m)Tc-HMPAO brain perfusion SPECT and neuropsychological test. RESULTS: At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood perfusion in 32 (14.7%) of 219 patients with PD, decreased perfusion on the frontal lobe in 45 patients (20.6%), the temporal lobe in 38 patients (17.4%), the parietal lobe in 39 patients (17.9%), the occipital lobe in 40 patients (18.3%), diffuse area in 14 patients (6.4%) and unclassified in 10 patients (4.6%). Fifthly, we compared the results of the neuropsychological test and cerebral perfusion pattern. There was no correlation between two tests except visuospatial function. CONCLUSION: Various perfusion state were found in patients with PD according to the age and sex. Also we were able to classify perfusion state into several groups and compare the neuropsychological test with cerebral perfusion.

A case of parathyroid carcinoma with acute renal failure and microscopic nephrocalcinosis / 대한내과학회지

Parathyroid carcinoma is a very rare disease in patients with primary hyperparathyroidism. Renal impairment and bone disease in the case of parathyroid carcinoma is common due to hypercalcemia. Renal diseases, including nephrocalcinosis, nephrolithiasis, and renal failure are frequent compared with those of benign parathyroid tumors. Nephrocalcinosis is a disorder of increased calcium content and deposition within renal parenchyma. Most cases reporting parathyroid carcinoma have shown medullary calcinosis on radiologic images, but there has been no definitive report of microscopic nephrocalcinosis which does not have a positive radiologic finding. In the case reported herein, a 50-year-old woman had experienced general weakness and a decline in vision. She had hypercalcemia and acute renal failure and the renal biopsy revealed nephrocalcinosis. The PTH level was elevated (940.47 pg/mL) and the parathyroid tumor was localized based on several radiologic findings. Capsular invasion was noted at the time right parathyroidectomy, indicative of parathyroid carcinoma, thus we carried out ipsilateral thyroidectomy. Hypercalcemia was improved after surgery, but renal function was not improved completely due to microscopic nephrocalcinosis.

Severe Episodic Memory Impairment in a Patient With Clinical Features Compatible With Corticobasal Degeneration

Corticobasal degeneration (CBD) is a progressive neurodegenerative disorder characterized by asymmetric parkinsonism associated with apraxia, cortical sensory loss, and alien-limb phenomenon. Neuropsychological testing in patients with CBD typically shows deficits in executive functions, praxis, language, and visuospatial functioning, but not in memory. We report a CBD patient with severely impaired memory function but relatively mild motor symptoms. Detailed neuropsychological assessment showed significant verbal and visual memory deficits accompanied by frontal executive dysfunctions. Our observations indicate that CBD can in rare cases present with severe episodic memory impairment associated with frontal executive dysfunctions in the early stage of illness.

Differences of Tc-99m HMPAO SPECT Imaging in the Early Stage of Subcortical Vascular Dementia Compared with Alzheimer's Disease / 핵의학분자영상

PURPOSE: The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVaD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. MATERIALS AND METHODS: Sixteen SVaD, 46 AD and 12 control subjects participated in this study. We included the patients with SVaD and AD according to NINCDS-ADRDA and NINDS-AIREN criteria. They were all matched for age, education and clinical dementia rating scores. Three groups were evaluated by Tc-99m HMPAO SPECT using statistical parametric mapping (SPM) for measuring rCBF. The SPECT data of patients with SVaD and AD were compared with those of normal control subjects and then compared with each other. RESULTS: SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyri in patients with SVaD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in AD compared with control subjects (uncorrected p<0.01). SVaD patients revealed significant hypoperfusion in the right parahippocampal gyrus with cingulated gyrus, left insula and both frontal subgyral regions compared with AD (uncorrected p<0.01). CONCLUSION: Our study shows characteristic and different pattern of perfusion deficits in patients with SVaD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness.

Comparison between PET and CT Findings for 7 Patients with a Pulmonary Lymphangitic Metastasis

PURPOSE: This study was conducted to compare the PET and CT findings for patients with a pulmonary lymphangitic metastasis. MATERIALS AND METHODS: We retrospectively reviewed the PET and CT findings of seven patients diagnosed with a pulmonary lymphangitic metastasis between May 2005 and May 2007. RESULTS: All patients had interstitial thickening, as seen on a CT scan, while the PET scans showed abnormal findings in only three patients. In these three patients, one patient had interlobular septal thickening of more than 10, another patient had interlobular septal thickening of more than 5 but less than 10, and another patient had interlobular septal thickening of less than 5. All of the patients had bronchovascular bundle thickening. However, among the four patients that had normal FDG uptake, no patient had interlobular septal thickening of more than 10, two of the patients had interlobular septal thickening of more than 5 but less than 10, and the remaining patients had interlobular septal thickening of less than 5. Only two of the patients had bronchovascular bundle thickening. CONCLUSION: All patients with pulmonary lymphangitic metastasis have typical CT findings, but some of the patients had FDG uptake, as seen in the PET scans. Thus, CT is a more useful modality for diagnosis for pulmonary lymphangitic metastases.

Immunohistochemical Expression of the Sodium/Iodide Symporter in Patients with Primary Lung Cancer

BACKGROUND: The sodium/iodide symporter (NIS) is a membrane glycoprotein that facilitates the uptake of iodine by thyroid follicular cells. Although the use of radioiodide is essential for the diagnosis and treatment of thyroid diseases, few studies have been conducted to investigate the use of NIS-mediated radioiodide accumulation in lung cancer. We evaluated the expression of NIS by immunohistochemistry in order to examine the diagnostic or therapeutic feasibility of using radioiodide in the treatment of primary lung cancer. METHODS: Immunohistochemistry for NIS was performed in 139 lung cancers. The expression pattern of NIS was compared with the clinicopathological characteristics of the tumors. RESULTS: NIS immunoreactivity was detected in 75 (54.0%) of the 139 cases. Twenty-three (37.7%) of the 61 squamous cell carcinomas, 49 (76.6%) of the 64 adenocarcinomas, 2 (40.0%) of the 5 small cell carcinomas, and 3 (33.3%) of the 9 other carcinomas showed positive NIS immunoreactivity. The expression of NIS was significantly associated with the histologic type (p<0.001), but it did not correlate with tumor size, lymphovascular invasion or lymph node metastasis. CONCLUSIONS: The presence of NIS was detected in lung cancer tissue using immunohistochemistry. Lung cancer potentially could be targeted with radioiodide for both diagnosis and treatment, especially in cases of adenocarcinoma.

Colon Cancer Mimicking Physiologic FDG Uptake: with Using of Negative Oral Contrast / 핵의학분자영상

A 64-year-old female with glioblastoma multiforme (GBM) was assigned to our department for whole body PET/CT scan. She ingested 1 liter of pure water as negative oral contrast just before PET/CT examination. FDG-PET/CT images showed a very intense hypermetabolic, focal lesion in the abdominal cavity around descending colon. The SUVmax of the lesion was 17.2. But there was no abnormal lesion corresponded to the area of PET scan in the combined contrast enhanced CT scan. We suggested considering a malignant lesion due to very intense glycolytic activity. Conventional abdominal CT scan and colonoscopy were accomplished within one week after PET/CT evaluation. There was no abnormality in both examinations. We executed follow-up PET/CT evaluation after 1 month and couldn't find any abnormality around the corresponding area. So we concluded the hypermetabolism was colonic physiologic uptake. A colonic physiologic uptake is a well known cause of false positive finding. Nuclear physicians should be considered the possibility of malignancy when interpret focal colonic uptake, especially incidental finding.1-3) There are a few reports that using of negative oral contrast is able to reduce gastrointestinal physiologic uptakes.4,5) But as we can see in this case, although we used negative oral contrast, intense physiologic uptake is detected and maxSUV is able to up to 17.2. So, it is important to keep a fact in mind. Even though there is a colonic physiologic uptake in PET/CT image, it may be able to show very intense hypermetabolism regardless of using negative oral contrast.

The Effect of Intravenous Contrast on SUV Value in 18F-FDG PET/CT using Diagnostic High Energy CT / 핵의학분자영상

PURPOSE: According to the development of CT scanner in PET/CT system, the role of CT unit as a diagnostic tool has been more important. To improve the diagnostic ability of CT scanner, it is a key aspect that CT scanning has to be performed with high dose energy and intravenous (IV) contrast. So we investigated the effect of IV contrast media on the maximum SUV (maxSUV) of normal tissues and pathologic lesions using PET/CT scanner with high dose CT scanning. MATERIALS AND METHODS: The study enrolled 13 patients who required PET/CT evaluation. At first, the patients were performed whole body non-contrast CT (NCCT - 120 kVp, 130 mAs) scan. Then contrast enhanced CT (CECT) scan was performed immediately. Finally PET scan was followed. The PET emission data were reconstructed twice, once with the NCCT and again with the CECT. We measured the maxSUV of 10 different body regions that were considered as normal in all patients. Also pathologic lesions were investigated. RESULTS: There were not seen focal artifacts in PET images based on CT with IV contrast agent. Firstly, 130 normal regions in 13 patients were evaluated. The maxSUV was significantly different between two PET images (p<0.001). The maxSUV was 1.1+/-0.5 in PET images with CECT-corrected attenuation and 1.0+/-0.5 in PET images with NCCT-corrected attenuation. The limit of agreement was 0.1+/-0.3 in Bland-Altman analysis. Especially there were significant differences in 6 of 10 regions, apex and base of the right lung, ascending aorta, segment 6 and segment 8 of the liver and spleen (p<0.05). Secondly, 39 pathologic lesions were evaluated. The maxSUV was significantly different between two PET images (p<0.001). The maxSUV was 4.7+/-2.0 in PET images with CECT-corrected attenuation and 4.4+/-2.0 in PET images with NCCT-corrected attenuation. The limit of agreement was 0.4+/-0.8 in Bland-Altman analysis. CONCLUSION: Although there were increases of maxSUVs in the PET images based on CT with IV contrast agent, it was very narrow in the range of limit of agreement. So there was no significant effect to clinical interpretation for PET images that were corrected attenuation with high dose CT using IV contrast.

Comparison of Na+/I- Symporter Expression Rate in Malignant and Benign Thyroid Diseases: Immunohistochemical Study / 핵의학분자영상

PURPOSE: Previous studies have not showed consistent results for the level of expression of sodium/iodide symporter (NIS) in thyroid diseases, especially malignant tumor. We undertook this study to evaluate the distribution of NIS expression in malignant thyroid diseases and compare with that in benign thyroid disease. MATERIALS AND METHODS: Total patients were 119 cases (Men 15, 48+/-13 yrs). Total number of samples were 205 pieces. In malignant thyroid disease, there were 153 samples: 90 in papillary carcinoma, 4 in follicular carcinoma, 2 in medullary carcinoma and 57 in metastatic lymph node. In benign thyroid disease, there were 52 samples: 36 in goiter/cyst, 11 in thyroiditis and 5 in follicular adenoma. Using immunohistochemical methods, we probed 205 samples with monoclonal anti-NIS Ab. Grading of staining was scored as 0 (negative or absent), 1 (weakly positive), 2 (moderately positive) or 3 (strongly positive). Expression rate (ER) of NIS positivity in individual disease entity was expressed as percentage of total number divided by number in 2 plus 3 grade. RESULTS: ERs of malignant thyroid diseases were 63% in papillary carcinoma, 81% in metastatic lymph node, 71% in follicular carcinoma and 100% in medullary carcinoma. ERs of benign thyroid disease were 53% in goiter/cyst, 64% in thyroiditis and 40% in follicular adenoma. ER of malignant thyroid diseases was higher than benign thyroid diseases (71% vs 54%). Grading of NIS expression in papillary carcinoma or goiter/cyst was heterogeneously distributed in considerable cases. Normal tissue also showed heterogeneous distribution of NIS expression, which was not correlated with that of primary lesion. CONCLUSION: In papillary thyroid carcinoma, distribution of NIS expression was heterogeneous and increased, and not different compared with that of benign thyroid disease.

A Case of Aorto-femoral bypass Graft Infection Complicated with Infective Endocarditis

Prosthetic vascular graft infection (PVGI) is a relatively uncommon complication of peripheral vascular surgery and although rare, is the most severe complication in reconstructive vascular surgery. The early diagnosis of this complication can reduce the mortality. We report a case of aorto-femoral bypass graft infection, which was diagnosed by Tc-99m HMPAO WBC scan, complicated with infective endocarditis. A 60-year-old man had been operated with aortofemoral bypass graft because of aortojejunal fistula due to abdominal aortic aneurysm. Nine months later, he was admitted with fever of two months' duration. On echocardiolography, aortic regurgitation and vegetation were observed, and then he was diagosed with infective endocarditis. He was treated with antibiotics for 6 weeks. Recurrent bacteremia of unknown origin persisted despite antibiotic therapy. Multiple microorganisms were separately isolated from the blood cultures. He complained of intermittent right groin pain. Imaging study (CT, MRI, US) showed no definite evidence of graft infection. However, Tc-99m HMPAO WBC scan demonstrated uptake in the aortofemoral bypass graft site. The patient underwent emergent aortofemoral graft removal with axillobifemoral bypass and right femoropopliteal bypass.