Shape, margin, echogenicity, and presence of calcification are helpful criteria for the discrimination of malignant from benign nodules; the diagnostic accuracy of US criteria is dependent on tumor size.

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High-resolution ultrasound can be accurate in preoperative evaluation for extrathyroidal tumor extension and lateral lymph node metastasis. CT had greater sensitivity than ultrasound alone in the detection of central lymph node metastasis for all lesions. For papillary thyroid microcarcinoma, however, there was no significant difference in the diagnostic accuracy rates of ultrasound, CT, and the combination of ultrasound and CT.

Congenital anomalies of the central nervous system (CNS) often demonstrate aberrant white matter connections, which may be better characterized with diffusion-tensor imaging (DTI) and fiber tractography (FT) than with conventional magnetic resonance (MR) imaging. DTI-FT demonstrates abnormal hemispheric fiber connections in callosal agenesis or acquired disease of the corpus callosum. Decreased anisotropy of white matter adjacent to the malformed cortex and an aberrant course of major fiber pathways due to dysplastic white matter are common findings in cortical dysplasia. Increased anisotropy of dysplastic gray matter in heterotopia supports the hypothesis that developing neurons migrate from the ependyma to the cortex with a radial growth pattern. In periventricular leukomalacia, DTI-FT demonstrates an intact corticospinal tract and decreased thalamocortical sensory connections, which are responsible for the spasticity of cerebral palsy owing to impairment of inhibitory function. Joubert syndrome comprises malformation of the cerebellar vermis and an aberrant connection between the cerebellum and the cerebral cortex via an elongated and abnormally shaped superior cerebellar peduncle, which are well visualized with DTI-FT. In developmental CNS disease, DTI-FT demonstrates additional findings beyond those seen with conventional MR imaging. Future studies will focus on determining the significance of the aberrant fiber connections and their relationships to the clinical manifestations of CNS anomalies.

ObjectivesThe objective of this study was to review our experience in the surgical management of carotid body paragangliomas and evaluate the outcomes and complications according to the Shamblin classification.MethodsThirteen patients who had been diagnosed and surgically treated for carotid body tumors (CBTs) were enrolled in this study. We reviewed patient demographics, radiographic findings, and surgical outcomes collected from medical records.ResultsFifteen CBTs were found in 13 patients and 13 tumors were resected. Selective preoperative tumor embolization was performed on six patients. The median blood loss, operation time, and hospital stay for these patients were not significantly reduced compared to those without embolization. The median tumor size was 2.3 cm in Shamblin I and II and 4 cm in Shamblin III. The median intraoperative blood loss was 280 mL and 700 mL, respectively (P<0.05). Internal carotid artery ligation with reconstruction was accomplished on three patients (23%), and they all belonged to Shamblin III (38%). One Shamblin III patient (8%) developed transient cerebral ischemia, and postoperative stroke with death occurred in another Shamblin III patient. Postoperative permanent cranial nerve deficit occurred in three patients (23%) who were all in Shamblin III (P=0.03). There were no recurrences or delayed complications at the median follow up of 29 months.ConclusionShamblin III had a high risk of postoperative neurovascular complications. Therefore, early detection and prompt surgical resection of CBTs will decrease surgical morbidity.

The endovascular treatment of cerebral aneurysms with coils poses significant technical challenges, particularly with respect to wide-necked aneurysms. We present the results of our initial experiences in using a stent for endovascular treatment of aneurysms, with an emphasis on potential applications, technical aspects, and associated complications. Twenty-three wide-necked aneurysms from 22 patients were treated during the 13-month study period. Seven patients presented with subarachnoid hemorrhage. Aneurysms were located at the internal carotid artery (n=14), the vertebral artery (n=3), the basilar artery (n=5), and the middle cerebral artery (n=1). A Neuroform stent2 was used for stent-assisted procedures. Premedication with antithrombotic agents was available for unruptured cases. Postprocedural antithrombotic medication was prescribed for all patients. Nineteen aneurysms were primarily stented, followed by coil placement. For five of these aneurysms, stenting was performed subsequent to failure of an attempt to frame with an initial coil. Stenting for the remaining four aneurysms was performed as a rescue procedure to prevent the migration of previously placed coils. Complete occlusion was obtained in ten aneurysms, nearly complete occlusion (95% or more occluded) in 11 aneurysms, and partial occlusion (less than 95% occluded) in one aneurysm. In one aneurysm, we failed to navigate the microcatheter into the aneurysmal sac through the interstices of the stent. Stent thrombosis was noted during the procedure in one patient. Hemorrhagic complication on the 25th day after the procedure was noted in one patient. No procedure-related complications were observed during the procedure or during follow-up in the remaining 20 patients, including seven patients who did not receive antithrombotic agents prior to endovascular treatment owing to recent subarachnoid hemorrhage. To overcome the technical limitation in the coiling of wide-necked aneurysms, stent-assisted coil embolization may be a technically feasible and relatively safe method, even though longer periods of follow-up are required.

Background Glioma prognosis depends on the isocitrate dehydrogenase (IDH) mutation status. We aimed to predict the IDH status of gliomas from preoperative MR images using a fully automated hybrid approach with convolutional neural networks (CNNs) and radiomics. Methods We reviewed 1,166 preoperative MR images of gliomas (grades II-IV) from Severance Hospital (n=856, Severance Set), Seoul National University Hospital (n=107, SNUH set), and The Cancer Imaging Archive (n=203, TCIA set). The Severance set was subdivided into the development (n=727) and internal test (n=129) sets. Based on T1 postcontrast, T2, and fluid-attenuated inversion-recovery images, a fully automated model was developed that comprised a CNN for tumor segmentation (Model 1) and CNN-based classifier for IDH status prediction (Model 2) that uses a hybrid approach based on 2-dimensional tumor images and radiomic features from 3-dimensional tumor shape and loci guided by Model 1. The trained model was tested on internal (a subset of the Severance set) and external (SNUH and TCIA) test sets. Results The CNN for tumor segmentation (Model 1) achieved a dice coefficient of 0.86–0.92 across datasets. Our hybrid model achieved accuracies of 93.8%, 87.9%, and 78.8%; with areas under the receiver operating characteristic curves of 0.96, 0.94, and 0.86; and areas under the precision-recall curves of 0.88, 0.82, and 0.81 in the internal test, SNUH, and TCIA sets, respectively. Conclusions Our fully automated hybrid model demonstrated the potential to be a highly reproducible and generalizable tool across different datasets for the noninvasive prediction of the IDH status of gliomas.

To explore the effects of white matter in the absence of auditory input in the early deaf, we conducted a tract-based statistical analysis of the diffusion tensor anisotropy and the voxel-based morphometry in the white matter of 13 early deaf and 29 hearing individuals. Deaf individuals showed significant decreases in diffusion anisotropy and in regional volume reductions within the temporal white matter. Decreased anisotropy was also found at the internal capsule, superior longitudinal fasciculus, and the inferior frontal white matter. In contrast, the forceps major of the corpus callosum, where interhemispheric connections between visual cortices exist, showed increased anisotropy. We interpreted these white matter alterations in terms of both disuse-driven atrophy and compensatory plasticity in the early deaf.