Diagnosis of Metastatic Lymph Nodes in Patients With Hepatocellular Carcinoma Using Dual-Energy Computed Tomography.

OBJECTIVE: Our study aimed to investigate the role of quantitative parameters derived from dual-energy computed tomography (DECT) in discriminating metastatic from nonmetastatic lymph nodes in hepatocellular carcinoma (HCC). METHODS: Forty-two patients (34 males; mean age, 53.7 years) with HCC underwent unenhanced computed tomography scans and triple-phase DECT scans of the upper abdomen. A total of 72 suspected lymph nodes were resected, including 43 nonmetastatic and 29 metastatic lymph nodes. The maximum short-axis diameter of the lymph nodes, iodine concentration, normalized iodine concentration (NIC), and slope of the spectral curve were analyzed for the HCC primary lesions and the suspected lymph nodes. Lymph node metastasis was confirmed by pathologic examination. RESULTS: A maximum short-axis diameter of >10 mm had a sensitivity and a specificity of 75.9% (22/29) and 53.5% (23/43) in diagnosing metastatic lymph nodes. The iodine concentration, NIC, and slope of the spectral curve of the nonmetastatic lymph nodes were significantly higher than those of the primary HCC lesions and the metastatic lymph nodes (all P < 0.05). Among all the analyzed spectral parameters, the NIC in the arterial phase had the highest sensitivity and specificity of 88.4% and 86.2% in diagnosing metastatic lymph nodes. CONCLUSIONS: The arterial phase NIC of DECT has superior diagnostic performance than the traditional lymph node size in diagnosing metastatic lymph nodes in HCC.

'Stateful' threshold switching for neuromorphic learning.

Memristors have promising prospects in developing neuromorphic chips that parallel the brain-level power efficiency and brain-like computational functions. However, the limited available ON/OFF states and high switching voltage in conventional resistive switching (RS) constrain its practical and flexible implementations to emulate biological synaptic functions with low power consumption. We present 'stateful' threshold switching (TS) within the millivoltage range depending on the resistive states of RS, which originates from the charging/discharging parasitic elements of a memristive circuit. Fundamental neuromorphic learning can be facilely implemented based on a single memristor by utilizing four resistive states in 'stateful' TS. Besides the metaplasticity of synaptic learning-forgetting behaviors, multifunctional associative learning, involving acquisition, extinction, recovery, generalization and protective inhibition, was realized with nonpolar operation and power consumption of 5.71 pW. The featured 'stateful' TS with flexible tunability, enriched states, and ultralow operating voltage will provide new directions toward a massive storage unit and bio-inspired neuromorphic system.

Correction: 'Stateful' threshold switching for neuromorphic learning.

Correction for ''Stateful' threshold switching for neuromorphic learning' by Zhijian Zhong et al., Nanoscale, 2022, DOI: 10.1039/d1nr05502j.

Imaging features of intrahepatic cholangiocarcinoma mimicking a liver abscess: an analysis of 8 cases.

BACKGROUND: In rare cases, intrahepatic cholangiocarcinoma can present as a pyogenic liver abscess and are often misdiagnosed. This study aimed to analyze the imaging features of intrahepatic cholangiocarcinoma mimicking a pyogenic liver abscess. METHODS: The clinical data and imaging results of eight patients with pathologically confirmed intrahepatic cholangiocarcinoma mimicking a liver abscess were retrospectively collected. RESULTS: The mean age was 58 years with a range of 46-68 years. Fever and leukocytosis were present in six patients. All the eight lesions were a single mass. Air-liquid levels were present in two patients. Only one patient showed hepatic lobar atrophy and hepatic capsule retraction. The double target sign of liver abscess was not noticed in the CT/MRI images of all eight patients. The inner wall of the lesion was rough and irregular, with multiple dot/patchy and wall nodule enhancements. The abscess wall and the marginal parenchyma were supplied by the hepatic artery in four patients, and the intralesional arteries were rough and disrupted. Bile duct dilatation was seen adjacent to the lesion. In seven patients, diffusion-weighted images showed irregular patchy restricted diffusion in the marginal parenchyma of the necrotic area in addition to the prominent restricted diffusion in the necrotic area. Two patients with cholangiolithiasis showed patchy slight CT hypodensity, slight T1 hypointensity, slight T2 hyperintensity, and patchy delayed enhancement. Multiple lymph nodes enlargement in the hepatic hilar area and the retroperitoneal space were seen in five patients. CONCLUSION: Intrahepatic cholangiocarcinoma mimicking a pyogenic liver abscess have unique imaging features and require careful image examination to avoid misdiagnosis.