Solid pseudopapillary tumor (SPT) of the pancreas is a neoplasm with low malignant potential. It is often challenging to diagnose SPT due to its nonspecific clinical and radiological features, and ­[18F]FDOPA is effective in diagnosing SPT, particularly in differentiating SPT from benign conditions such as splenosis. A 55-year-old woman underwent distal pancreatectomy and splenectomy for histologically confirmed SPT. She was also initially diagnosed with splenosis. During follow-up, sizes of multiple nodular lesions were increased, raising the possibility of peritoneal seeding of SPT. For diagnosis, a spleen scan and SPECT/CT were performed using 99mTc-labeled damaged red blood cells, which showed no uptake in the peritoneal nodules. Subsequent ­[18F]FDOPA PET/CT revealed ­[18F]FDOPA-avidity of the nodules. The patient underwent tumor resection surgery, and the nodules were pathologically confirmed as SPT.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

The central type of Tapia’s syndrome is an extremely rare presentation, characterized by unilateral paralysis of the vagal and hypoglossal nerves, contralateral hemiparesis, or hemihypesthesia. This report describes a case of a middle-aged patient who developed central Tapia’s syndrome due to a right vertebral artery dissecting aneurysm (VADA). The patient complained about swallowing difficulty and odynophagia. Right vocal cord paralysis, mild tongue deviation to the right side, left hypesthesia, and decreased temperature sensation with left hemiparesis were observed in neurologic exams. A right VADA and compression of the medulla oblongata due to the VADA were diagnosed on magnetic resonance imaging. Endovascular flow diversion of the right VADA was performed. After 1 year, all neurological symptoms and vocal cord paralysis were nearly resolved, but left hypesthesia remained with decreased nociception. We present and discuss how a VADA caused those symptoms and propose endovascular flow diversion as a treatment option.

Pheochromocytoma and paraganglioma (PPGLs) are rare catecholamine-secreting neuroendocrine tumors but can be life-threatening. Although most PPGLs are benign, approximately 10% have metastatic potential. Approximately 40% cases are reported as harboring germline mutations. Therefore, timely and accurate diagnosis of PPGLs is crucial. For more than 130 years, clinical, molecular, biochemical, radiological, and pathological investigations have been rapidly advanced in the field of PPGLs. However, performing diagnostic studies to localize lesions and detect metastatic potential can be still challenging and complicated. Furthermore, great progress on genetics has shifted the paradigm of genetic testing of PPGLs. The Korean PPGL task force team consisting of the Korean Endocrine Society, the Korean Surgical Society, the Korean Society of Nuclear Medicine, the Korean Society of Pathologists, and the Korean Society of Laboratory Medicine has developed this position statement focusing on the comprehensive and updated diagnosis for PPGLs.

The central type of Tapia’s syndrome is an extremely rare presentation, characterized by unilateral paralysis of the vagal and hypoglossal nerves, contralateral hemiparesis, or hemihypesthesia. This report describes a case of a middle-aged patient who developed central Tapia’s syndrome due to a right vertebral artery dissecting aneurysm (VADA). The patient complained about swallowing difficulty and odynophagia. Right vocal cord paralysis, mild tongue deviation to the right side, left hypesthesia, and decreased temperature sensation with left hemiparesis were observed in neurologic exams. A right VADA and compression of the medulla oblongata due to the VADA were diagnosed on magnetic resonance imaging. Endovascular flow diversion of the right VADA was performed. After 1 year, all neurological symptoms and vocal cord paralysis were nearly resolved, but left hypesthesia remained with decreased nociception. We present and discuss how a VADA caused those symptoms and propose endovascular flow diversion as a treatment option.

Pheochromocytoma and paraganglioma (PPGLs) are rare catecholamine-secreting neuroendocrine tumors but can be life-threatening. Although most PPGLs are benign, approximately 10% have metastatic potential. Approximately 40% cases are reported as harboring germline mutations. Therefore, timely and accurate diagnosis of PPGLs is crucial. For more than 130 years, clinical, molecular, biochemical, radiological, and pathological investigations have been rapidly advanced in the field of PPGLs. However, performing diagnostic studies to localize lesions and detect metastatic potential can be still challenging and complicated. Furthermore, great progress on genetics has shifted the paradigm of genetic testing of PPGLs. The Korean PPGL task force team consisting of the Korean Endocrine Society, the Korean Surgical Society, the Korean Society of Nuclear Medicine, the Korean Society of Pathologists, and the Korean Society of Laboratory Medicine has developed this position statement focusing on the comprehensive and updated diagnosis for PPGLs.

Purpose: EGFR-mutation (EGFR-mt) is a major oncogenic driver mutation in lung adenocarcinoma (ADC) and is more oftenobserved in Asian population. In lung ADC, some radiomics parameters of FDG PET have been reported to be associated withEGFR-mt. Here, the associations between EGFR-mt and PET parameters, particularly asphericity (ASP), were evaluated inAsian population. Methods: Lung ADC patients who underwent curative surgical resection as the first treatment were retrospectively enrolled.EGFR mutation was defined as exon 19 deletion and exon 21 point mutation and was evaluated using surgical specimens. OnFDG PET, image parameters of maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesionglycolysis (TLG), and ASP were obtained. The parameters were compared between EGFR-mt and wild type (EGFR-wt) groups,and the relationships between these PET parameters and EGFR-mt were evaluated. Results: A total of 64 patients (median age 66 years, M:F = 34:30) were included in the analysis, and 29 (45%) patients showedEGFR-mt. In EGFR-mt group, all the image parameters of SUVmax, MTV, TLG, and ASP were significantly lower than inEGFR-wt group (all adjusted P< 0.050). In univariable logistic regression, SUVmax (P= 0.003) and ASP (P= 0.010) weresignificant determinants for EGFR-mt, whereasMTV was not (P= 0.690). Multivariate analysis revealed that SUVmax and ASPare independent determinants for EGFR-mt, regardless of inclusion of MTV in the analysis (P< 0.05). Conclusion In Asian NSCLC/ADC patients, SUVmax, MTV, and ASP on FDG PET are significantly related to EGFR mutationstatus. Particularly, low SUVmax and ASP are independent determinants for EGFR-mt.

Purpose: The precise quantification of dopamine transporter (DAT) density on N-(3-[18F]Fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane positron emission tomography ([18F]FP-CIT PET) imaging is crucial to measure the degree of striatal DAT loss in patients with parkinsonism. The quantitative analysis requires a spatial normalization process based on a template brain. Since the spatial normalization method based on a delayed-phase PET has limited performance, we suggest an early-phase PET-based method and compared its accuracy, referring to the MRI-based approach as a gold standard. Methods: A total of 39 referred patients from the movement disorder clinic who underwent dual-phase [18F]FP-CIT PET and took MRI within 1 year were retrospectively analyzed. The three spatial normalization methods were applied for quantification of [18F]FP-CIT PET-MRI-based anatomical normalization, PET template-based method based on delayed PET, and that based on early PET. The striatal binding ratios (BRs) were compared, and voxelwise paired t tests were implemented between different methods. Results: The early image-based normalization showed concordant patterns of putaminal [18F]FP-CIT binding with an MRI-based method. The BRs of the putamen from the MRI-based approach showed higher agreement with early image- than delayed image-based method as presented by Bland-Altman plots and intraclass correlation coefficients (early image-based, 0.980; delayed image-based, 0.895). The voxelwise test exhibited a smaller volume of significantly different counts in putamen between brains processed by early image and MRI compared to that between delayed image and MRI. Conclusion The early-phase [18F]FP-CIT PET can be utilized for spatial normalization of delayed PET image when the MRI image is unavailable and presents better performance than the delayed template-based method in quantitation of putaminal binding ratio.

Objective: Microsurgical treatment could be a good alternative for the treatment of recurrent cerebral aneurysm after coil embolization. The purpose of this study was to present our experience of microsurgical treatment for recurrent cerebral aneurysm previously treated using coil embolization. Methods: From June 2012 to May 2019, 34 patients consecutively received microsurgical treatment for a recurrent cerebral aneurysm previously treated using coil embolization after it ruptured. Results: Of the 34 patients with aneurysm, 33 had the aneurysm located in the anterior circulation. The most common location was the anterior communicating artery (13 cases). Immediate radiologic outcome at coil embolization was completed (n=6), residual neck (n=26), and residual sac (n=2). The reason for microsurgical treatment included rebleeding (n=12), persistent residual sac (n=1), and recurrence on follow-up study (n=21). Rebleeding occurred within 10 days after coil embolization in 10 cases, and the other 2 were due to regrowth. In the 20 recurred and saccular aneurysms, coil compaction was present in 11 aneurysms and regrowth in 9 aneurysms. Simple neck clipping (n=29) and clipping with coil mass extraction (n=3) was possible in the saccular aneurysms. The blood blister like aneurysm (n=2) were treated using bypass and endovascular internal carotid artery trapping. In the follow-up study group after microsurgical treatment there were no severe complications due to the treatment. Age, cause of retreatment, and modified Rankin Scale before microsurgery were associated with good outcome (p<0.001). Conclusions Microsurgical treatment may be a viable and effective option for treating recurrent aneurysms previously treated by endovascular techniques.

PURPOSE: Although quantification of amyloid positron emission tomography (PET) is important for evaluating patients with cognitive impairment, its routine clinical use is hampered by complicated preprocessing steps and required MRI. Here, we suggested a one-step quantification based on deep learning using native-space amyloid PET images of different radiotracers acquired from multiple centers. METHODS: Amyloid PET data of the Alzheimer Disease Neuroimaging Initiative (ADNI) were used for this study. A training/validation consists of 850 florbetapir PET images. Three hundred sixty-six florbetapir and 89 florbetaben PET images were used as test sets to evaluate the model. Native-space amyloid PET images were used as inputs, and the outputs were standardized uptake value ratios (SUVRs) calculated by the conventional MR-based method. RESULTS: The mean absolute errors (MAEs) of the composite SUVR were 0.040, 0.060, and 0.050 of training/validation and test sets for florbetapir PETand a test set for florbetaben PET, respectively. The agreement of amyloid positivity measured by Cohen's kappa for test sets of florbetapir and florbetaben PET were 0.87 and 0.89, respectively. CONCLUSION We suggest a one-step quantification method for amyloid PET via a deep learning model. The model is highly reliable to quantify the amyloid PET regardless of multicenter images and various radiotracers.