Double Mutations in a Patient with Early-Onset Alzheimer's Disease in Korea: An APP Val551Met and a PSEN2 His169Asn.

The etiology of early-onset Alzheimer's disease (EOAD) is associated with alterations in the production of amyloid beta (Aß) species caused by mutations in the APP, PSEN1, and PSEN2 genes. Mutations affect intra- or inter-molecular interactions and processes between the γ-secretase complex and amyloid precursor protein (APP), leading to the aberrant sequential cleavage of Aß species. A 64-year-old woman presented with progressive memory decline, mild right hippocampal atrophy, and a family history of Alzheimer's dementia (AD). Whole exome sequencing was performed to evaluate AD-related gene mutations, which were verified by Sanger sequencing. A mutation-caused structural alteration of APP was predicted using in silico prediction programs. Two AD-related mutations, in APP (rs761339914; c.G1651A; p.V551M) and PSEN2 (rs533813519; c.C505A; p.H169N), were identified. The APP Val551Met mutation in the E2 domain may influence APP homodimerization through changes in intramolecular interactions between adjacent amino acids, altering Aß production. The second mutation was PSEN2 His169Asn mutation, which was previously reported in five EOAD patients from Korea and China, with a relatively high frequency in the East Asian population. According to a previous report, the presenilin 2 protein was predicted to result in a major helical torsion by PSEN2 His169Asn mutation. Notably, the co-existence of APP Val551Met and PSEN2 His169Asn may induce a synergistic effect by both mutations. Future functional studies are needed to clarify the pathological effects of these double mutations.

Reducing amount of contrast agent after compression of right brachial artery using a blood pressure cuff in computed tomography cerebrovascular angiography.

OBJECTIVE: To invastgate feasibility of low-dose contrast agent in cerebral computed tomography angiography (CTA) to alleviate side effects. METHOD: Siemens' Somatom Definition AS+CT scanner, Heine's blood pressure monitor G7-M237 (BP cuff) and Ultravist contrast agent (370 mg Iodine/ml) are used. CTA is acquired using following scan parameters including slice thickness of 1mm, image acquisition parameters of 128×0.6 mm, pitch size of 0.8 mm, 175 effective mAs, 120 kVp tube voltage, scan delay time of 3 seconds, and the scan time of 4 seconds. This study is conducted by securing the IV route in the left antecubital vein before injection of contrast agent, wrapping BP cuff around the branchial artery of the opposite right arm after setting the pressure to 200 mmHg. Then, the injection rate of the contrast agent is fixed at 4.5 cc/sec and contrast agent was injected in three different amounts (70, 80, and 100 cc). Bp cuff is released from this moment when HU value reachs 100. RESULT: In this study, the mean HU values measured from common carotid artery are 412.45±5.89 when injecting 80cc contrast agent and using BP cuff and 399.64±5.51 when injecting 100 cc contrast agenet and not using BP cuff, respectively. In middle cerebral artery M1, the mean HU values are 325.23±38.29 when injecting 80cc contrast agent and using BP cuff and 325.00±30.63 when injecting 100cc contrast agent blood and not using pressure cuff, respectively. Difference of mean HU values is not statistically significant (p > 0.05) with and without using BP cuff. CONCLUSION: This study demonstrates that reducing amount of contrast agent is possible when the right brachial artery is compressed using BP cuff. Study results indicate that reducing 20% injection of contrast agent in CT cerebrovascular angiography can still yield comparable imaging results with conventional contrast angent usage, which implies that less side effects are expected with a contrast agent injection. Thus, this study can serve as a reference for potential reducing side effect during CT cerebrovascular angiography.

Machine learning-based diagnostic method of pre-therapeutic 18F-FDG PET/CT for evaluating mediastinal lymph nodes in non-small cell lung cancer.

OBJECTIVES: We aimed to find the best machine learning (ML) model using 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for evaluating metastatic mediastinal lymph nodes (MedLNs) in non-small cell lung cancer, and compare the diagnostic results with those of nuclear medicine physicians. METHODS: A total of 1329 MedLNs were reviewed. Boosted decision tree, logistic regression, support vector machine, neural network, and decision forest models were compared. The diagnostic performance of the best ML model was compared with that of physicians. The ML method was divided into ML with quantitative variables only (MLq) and adding clinical information (MLc). We performed an analysis based on the 18F-FDG-avidity of the MedLNs. RESULTS: The boosted decision tree model obtained higher sensitivity and negative predictive values but lower specificity and positive predictive values than the physicians. There was no significant difference between the accuracy of the physicians and MLq (79.8% vs. 76.8%, p = 0.067). The accuracy of MLc was significantly higher than that of the physicians (81.0% vs. 76.8%, p = 0.009). In MedLNs with low 18F-FDG-avidity, ML had significantly higher accuracy than the physicians (70.0% vs. 63.3%, p = 0.018). CONCLUSION: Although there was no significant difference in accuracy between the MLq and physicians, the diagnostic performance of MLc was better than that of MLq or of the physicians. The ML method appeared to be useful for evaluating low metabolic MedLNs. Therefore, adding clinical information to the quantitative variables from 18F-FDG PET/CT can improve the diagnostic results of ML. KEY POINTS: • Machine learning using two-class boosted decision tree model revealed the highest value of area under curve, and it showed higher sensitivity and negative predictive values but lower specificity and positive predictive values than nuclear medicine physicians. • The diagnostic results from machine learning method after adding clinical information to the quantitative variables improved accuracy significantly than nuclear medicine physicians. • Machine learning could improve the diagnostic significance of metastatic mediastinal lymph nodes, especially in mediastinal lymph nodes with low 18F-FDG-avidity.

Face Recognition at a Distance for a Stand-Alone Access Control System.

Although access control based on human face recognition has become popular in consumer applications, it still has several implementation issues before it can realize a stand-alone access control system. Owing to a lack of computational resources, lightweight and computationally efficient face recognition algorithms are required. The conventional access control systems require significant active cooperation from the users despite its non-aggressive nature. The lighting/illumination change is one of the most difficult and challenging problems for human-face-recognition-based access control applications. This paper presents the design and implementation of a user-friendly, stand-alone access control system based on human face recognition at a distance. The local binary pattern (LBP)-AdaBoost framework was employed for face and eyes detection, which is fast and invariant to illumination changes. It can detect faces and eyes of varied sizes at a distance. For fast face recognition with a high accuracy, the Gabor-LBP histogram framework was modified by substituting the Gabor wavelet with Gaussian derivative filters, which reduced the facial feature size by 40% of the Gabor-LBP-based facial features, and was robust to significant illumination changes and complicated backgrounds. The experiments on benchmark datasets produced face recognition accuracies of 97.27% on an E-face dataset and 99.06% on an XM2VTS dataset, respectively. The system achieved a 91.5% true acceptance rate with a 0.28% false acceptance rate and averaged a 5.26 frames/sec processing speed on a newly collected face image and video dataset in an indoor office environment.

Prognostic value of lymphoscintigraphy in patients with gynecological cancer-related lymphedema.

BACKGROUND AND OBJECTIVES: We investigated the prognostic value of qualitative lymphoscintigraphy in gynecological cancer-related lymphedema, which is a common complication after treatment. METHODS: All 152 patients underwent (99m) Tc tin-colloid lymphoscintigraphy before complex decongestive therapy (CDT). We analyzed the uptake patterns of the inguinal lymph nodes, main lymphatic vessel and collateral lymphatic vessels, as well as dermal back flow. We compared these lymphoscintigraphic findings and other clinical variables between good and poor therapeutic responders using Pearson's Chi-squared test, Fisher's exact test and multiple logistic regression analysis. RESULTS: Eighty-nine patients (58.6%) had a poor therapeutic response to CDT. In univariate analysis, there were significant differences between good and poor responders in clinical stage (P < 0.001), therapy compliance (P < 0.001), main lymphatic vessel uptake pattern (P < 0.01), collateral lymphatic vessel uptake pattern (P < 0.01) and severity of dermal back flow (P < 0.001). After multivariate analysis, only severity of dermal back flow (P < 0.005), clinical stage (P < 0.05) and therapy compliance (P < 0.001) were found to be independent predictors of therapeutic response. CONCLUSIONS: Lymphoscintigraphy may be useful to predict the outcome of patients with gynecological cancer-related lymphedema undergoing CDT along with clinical stage and compliance.

Prognostic Significance of 18F-FDG PET/CT Radiomics in Patients With Resectable Pancreatic Ductal Adenocarcinoma Undergoing Curative Surgery.

PURPOSE: This study aimed to investigate the prognostic significance of PET/CT radiomics to predict overall survival (OS) in patients with resectable pancreatic ductal adenocarcinoma (PDAC). METHODS: We enrolled 627 patients with resectable PDAC who underwent preoperative 18F-FDG PET/CT and subsequent curative surgery. Radiomics analysis of the PET/CT images for the primary tumor was performed using the Chang-Gung Image Texture Analysis toolbox. Radiomics features were subjected to least absolute shrinkage and selection operator (LASSO) regression to select the most valuable imaging features of OS. The prognostic significance was evaluated by Cox proportional hazards regression analysis. Conventional PET parameters and LASSO score were assessed as predictive factors for OS by time-dependent receiver operating characteristic curve analysis. RESULTS: During a mean follow-up of 28.8 months, 378 patients (60.3%) died. In the multivariable Cox regression analysis, tumor differentiation, resection margin status, tumor stage, and LASSO score were independent prognostic factors for OS (HR, 1.753, 1.669, 2.655, and 2.946; all P < 0.001, respectively). The time-dependent receiver operating characteristic curve analysis showed that the LASSO score had better predictive performance for OS than conventional PET parameters. CONCLUSION: The LASSO score using the 18F-FDG PET/CT radiomics of the primary tumor was the independent prognostic factor for predicting OS in patients with resectable PDAC and may be helpful in determining therapeutic and follow-up plans for these patients.

Dynamic blood flow imaging with 99mTc-hydroxymethylene diphosphonate as a therapeutic response marker in patients with Raynaud's phenomenon.

We evaluated the predictive value of dynamic blood flow scintigraphy with 99mTc-HDP (hydroxymethylene diphosphonate) for therapeutic response in patients with Raynaud's phenomenon (RP). Eighty patients who underwent dynamic blood flow scintigraphy using the one-hand chilling method were enrolled. We analyzed the quantitative variables as the ratio of chilled fingers to ambient fingers (CAfinger), that of the chilled hand to ambient hand (CAhand), and that of chilled fingers to ambient palm (FPR) (CAFPR) at 15 and 30 s after 99mTc-HDP bolus injection. Total cumulative radioactivity counts for 180 s were obtained. We evaluated the clinical utility of these quantitative parameters with other clinical variables, including RP severity, therapeutic compliance, types of RP, and scintigraphic interpretation of findings in patients with RP. Fifty-two patients showed poor therapeutic response. There were significant differences between good- and poor-therapeutic responder groups in RP intensity (p = 0.003), CAfinger15s (p = 0.008), CAfinger30s (p = 0.002), CAfinger180s (p = 0.011), CAhand15s (p = 0.008), CAhand30s (p = 0.007), CAhand180s (p = 0.017), CAFPR30s (p = 0.004), and CAFPR180s (p = 0.002). After multivariate logistic regression analysis, only CAfinger30s (p = 0.002) had an independent predictive value of the therapeutic response. 99mTc-HDP dynamic blood flow scintigraphy could be helpful in predicting the therapeutic response in patients with RP.

Pulmonary and Liver Toxocariasis Mimicking Metastatic Tumors in a Patient with Colon Cancer.

Toxocariasis is an uncommon cause of multiple cavitary lung lesions and an ill-defined liver lesion. We herein report a patient with lung and liver toxocariasis, which mimicked metastatic lesions of colon cancer on 18F-FDG PET-CT and chest and abdominal CT performed for cancer staging after diagnosis of colon cancer. The patient was diagnosed with lung and liver toxocariasis by a positive enzyme-linked immunosorbent assay. Lung toxocariasis may occur as multiple cavitary lung lesions, and liver toxocariasis may appear as a solitary ill-defined nodule, which may be misdiagnosed as metastatic tumors. Clinicians should consider toxocariasis when multiple cavitary lung lesions and a solitary ill-defined focal liver lesion are detected, especially in a patient with cancer.

18F-FDG PET/CT and Whole-Body Bone Scan Findings in Gorlin-Goltz Syndrome.

Gorlin-Goltz syndrome (basal cell nevus syndromes) is an uncommon, autosomal dominant inherited disorder characterized by developing basal cell carcinomas from a young age. Other distinct clinical features include keratocystic odontogenic tumors, dyskeratotic palmar and plantar pitting, and skeletal abnormalities. Clinicopathological findings of the syndrome are very diverse, and many symptoms manifest during a certain period of life. We present the compelling whole-body bone scan and 18F-FDG PET/CT findings in a 32-year-old man with odontogenic keratocyst, early-onset basal cell carcinoma, multiple ectopic calcifications in extremities, calcified falx cerebri, spinal scoliosis, macrocephaly, and ocular hypertelorism.

Enhanced Computed Tomography and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Uncommon Histiocytic Sarcoma of Small Intestine Arising after Gastric Large B-Cell Lymphoma.

Histiocytic sarcoma (HS) is an extremely rare and aggressive malignant neoplasm of hematopoietic origin that shows morphologic and immunophenotypic evidence of histiocytic differentiation. In approximately 25% of the cases, presumed transdifferentiation of a preexisting hematolymphoid disorder can be demonstrated. Various extranodal sites, particularly the gastrointestinal tract, soft tissue, skin, and spleen, can be involved. Enhanced CT and FDG PET/CT findings of extranodal histiocytic sarcoma have been barely reported. We present a case with extranodal HS originating in the small intestine after gastric large B-cell lymphoma, mistaken for prostate cancer metastasis in a 76-year-old man.

A Case Report of Early-Onset Alzheimer's Disease Using 18F-FDG PET and 18F-FBB PET.

We describe a 40-year-old female patient who presented with sleep disturbance, intermittent headache, and gradual subjective cognitive decline. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed mild FDG hypometabolism in bilateral parietal and temporal lobes. However, 18F-florbetaben (FBB) amyloid PET revealed diffuse amyloid retention in the lateral temporal cortex, frontal cortex, posterior cingulate cortex/precuneus, parietal cortex, and cerebellum. This finding supports the clinical significance of amyloid imaging in diagnostic work-up of early-onset Alzheimer's disease (EOAD).

Radiomics Analysis of 18F-FDG PET/CT for Prognosis Prediction in Patients with Stage III Non-Small Cell Lung Cancer Undergoing Neoadjuvant Chemoradiation Therapy Followed by Surgery.

We investigated the prognostic significance of radiomic features from 18F-FDG PET/CT to predict overall survival (OS) in patients with stage III NSCLC undergoing neoadjuvant chemoradiation therapy followed by surgery. We enrolled 300 patients with stage III NSCLC who underwent PET/CT at the initial work-up (PET1) and after neoadjuvant concurrent chemoradiotherapy (PET2). Radiomic primary tumor features were subjected to LASSO regression to select the most useful prognostic features of OS. The prognostic significance of the LASSO score and conventional PET parameters was assessed by Cox proportional hazards regression analysis. In conventional PET parameters, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of each PET1 and PET2 were significantly associated with OS. In addition, both the PET1-LASSO score and the PET2-LASSO score were significantly associated with OS. In multivariate Cox regression analysis, only the PET2-LASSO score was an independently significant factor for OS. The LASSO score showed better predictive performance for OS regarding the time-dependent receiver operating characteristic curve and decision curve analysis than conventional PET parameters. Radiomic features from PET/CT were an independent prognostic factor for the estimation of OS in stage III NSCLC. The newly developed LASSO score using radiomic features showed better prognostic results for individualized OS estimation than conventional PET parameters.

The hazardous interactions of copper-dyed patient gowns with MRI: Two cases of superficial abdominal burns.

Magnetic resonance imaging is a commonly used imaging modality in medical procedures. Despite its prevalent use, unexpected adverse events such as burns can occur during an MRI procedure. The majority of the transmitted Radio Frequency power can be converted into heat within the patient's tissue due to resistive losses, leading to such incidents. In this study, we present an intriguing case of a patient who experienced an MRI-induced burn, presumably caused by the copper dye in the patient's gown. Notably, we observed frequent distortion of the MR image due to the patient's gown. The awareness and understanding of such potential adverse events are critical for clinicians and technicians to prevent future occurrences. Through this study, we aim to contribute to this critical area of patient safety during MRI procedures.

Prognostic significance of volume-based metabolic parameters in uterine cervical cancer determined using 18F-fluorodeoxyglucose positron emission tomography.

OBJECTIVE: We compared the prognostic value of volume-based metabolic parameters determined using fluorine 18 (F) fluorodeoxyglucose (FDG) positron emission tomography (PET) (F-FDG PET) (with other prognostic parameters in uterine cervical cancer. METHODS: The subjects were 73 female patients who had an initial diagnosis of uterine cervical cancer and who underwent F-FDG PET. Various metabolic or volume-based PET parameters including maximum and average standardized uptake values, metabolic tumor volume, and total lesion glycolysis (TLG) were measured in primary cervical tumors. Survival analysis for disease-free survival or progression-free survival was performed with a Kaplan-Meier method using PET parameters and other clinical variables. For determining independent prognostic factors, Cox regression analysis was performed. RESULTS: Recurrence or disease progression occurred in 23 patients (31.5%). In univariate analysis, patient age (cutoff, 57 years, P < 0.05), International Federation of Gynecology and Obstetrics stage (P = 0.07), primary tumor size (cutoff, 6.7 cm; P < 0.05), lymph node status on PET (P < 0.005), treatment method (P < 0.01), metabolic tumor volume (cutoff, 82 cm; P = 0.001), and TLG (cutoff, 7600; P = 0.005) were significant predictors of recurrence or progression. In multivariate analysis, both lymph node status on PET (hazard ratio, 1.042 [negative vs intrapelvic metastasis only], 7.008 [negative vs extrapelvic metastasis]; P < 0.001) and TLG (cutoff, 7600; hazard ratio, 2.981; P < 0.05) were independent prognostic factors for predicting recurrence. CONCLUSIONS: In uterine cervical cancer, TLG, a volume-based metabolic parameter, and lymph node status on PET may be significant independent prognostic factors for event-free survival.

Differential diagnosis of patients with atypical Parkinsonian syndrome using 18F-FDG and 18F-FP CIT PET: A report of five cases.

We describe 5 cases of patients who presented atypical parkinsonian syndrome (APS), including gait disturbance, postural instability, decreasing facial expression, dyskinesia, and subjective cognitive impairment. The patients underwent 18F-FP-CIT PET and 18F-FDG PET consecutively for differential diagnosis of APS. Through PET imaging examination, it was possible to offer a suggestive diagnosis and determine individual strategic management for patients with APS.

A Case Report of a Gluteus Hematoma Detected on 99mTc-MDP Bone Scan.

This is a case report of a gluteal hematoma detected on 99mTc-methylene diphosphonate (MDP) whole-body bone scan in a 77-year-old male who had experienced a road traffic accident.

Visualization of Dialysis-Related Amyloid Arthropathy on 18F-FDG PET-CT Scan.

We report a case of dialysis-related amyloid arthropathy in a patient with end-stage renal disease. It presented in our patient as moderately increased FDG uptake in the amyloid deposition in the periarticular tissues and eroding into adjacent bones.

Septic Pulmonary Emboli Detected by 18F-FDG PET/CT in a Patient with Central Venous Catheter-Related Staphylococcus aureus Bacteremia.

We describe a case of 18F-FDG PET/CT detecting septic pulmonary emboli in a patient with Staphylococcus aureus catheter-related bloodstream infection (CRBSI). The patient, who had an implantable venous access port for chemotherapy, underwent 18F-FDG PET/CT to diagnose unsuspected infectious foci. The PET/CT examination made it possible to offer a suggestive diagnosis and yielded metastatic infectious foci.

Diagnostic Performance for Differential Diagnosis of Atypical Parkinsonian Syndromes from Parkinson's Disease Using Quantitative Indices of 18F-FP-CIT PET/CT.

We are aimed to evaluate the diagnostic performances of quantitative indices obtained from dual-phase 18F-FP-CIT PET/CT for differential diagnosis of atypical parkinsonian syndromes (APS) from Parkinson's disease (PD). We analyzed 172 subjects, including 105 non-Parkinsonism, 26 PD, 8 PSP, 1 CBD, 8 MSA-P, 9 MSA-C, and 15 DLB retrospectively. Two sequential PET/CT scans were acquired at 5 min and 3 h. We compared subregional binding potentials, putamen-to-caudate nucleus ratio of the binding potential, asymmetry index, and degree of washout. To differentiate APS, all BPs in both early and late phases (except late BPbrainstem) and all factors of the percent change except for putamen in APS significantly differed from PD. When a cut-off for early BPcerebellum was set as 0.79, the sensitivity, specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and accuracy for differentiating APS 73.2%, 91.7%, 93.8%, 66.7%, and 80.0%. The early BPcerebellum showed significantly greater SP and PPV than the late quantitative indices. Combined criteria regarding both early and late indices exhibited only greater NPV. The quantitative indices showed high diagnostic performances in differentiating APS from PD. Our findings provide the dual-phase 18F-FP-CIT PET/CT would be useful for differentiating APS from PD.

Lymphoma total lesion glycolysis leads to hyperlactatemia and reduction of brain glucose utilization.

Clarifying the mechanism of lymphoma-associated hyperlactatemia could help identify patients at risk. Here, 129 non-Hodgkin's lymphoma patients suspected of blood lactate elevation underwent blood measurement and 18F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) on the same day. Blood lactate elevation was mild (1.0-2.5 mmol/L) in 60, moderate (2.5-4.0 mmol/L) in 46, and severe (≥ 4.0 mmol/L) in 23 subjects. Subjects with severe lactate elevation had higher lymphoma stage, worse IPI risk, poorer ECOG performance, and higher tumor TLG. Furthermore, there was a linear correlation between blood lactate concentration and lymphoma TLG (Spearman's r = 0.367; P < 0.0001). Brain FDG uptake was low (SUVave < 4.0) in 81 patients that were older, had greater stage and IPI risk, worse ECOG performance, and higher blood lactate. Brain SUVave showed inverse correlation with blood lactate (Spearman's r = - 0.564; P < 0.0001) and lymphoma TLG (Spearman's r = - 0.252; P = 0.0066), as well as with stage, ECOG score, and IPI risk. Multivariable regression analysis confirmed increased blood lactate and lymphoma TLG as significant explanatory variables for reduced brain SUVave (both P < 0.0001). Hence, blood lactate elevation in lymphoma patients is the result of glycolytic tumor burden. Since brain cells prefer lactate over glucose as energy source when blood lactate level is increased, this causes proportional reductions of brain FDG uptake. FDG PET/CT can therefore identify high glycolytic lymphoma burden at risk of hyperlactatemia and may provide estimates of its severity by reductions in brain uptake.