Objective To study the imaging apperances and the diagnostic value of conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in differentiating histopathological types of small hepatocellular carcinoma (sHCC).Methods 40 sHCC confirmed by histopathology were classified into 4 groups according to their degree of differentiation:well (n=6),well-moderate (n=5),moderate (n=27) and moderate-poor (n =2).All patients received conventional MRI and DWI (1.5T,b =0 and 600 s/mm2) before the operation.The ADC values of the sHCC were measured and compared.Results On T1WI,32 lesions showed hypointensity,4 hyperintensity (well) and 4 isointensity (well-moderate =2,moderate =2).On T2WI,hyperintensity was observed in 39 lesions and isointensity in 1 lesion (well).Steatosis in the sHCC was seen in 17 of 40lesions (17/40,42.5 ％,well=4,well-moderate=1 and moderate=12).A pseudocapsule was seen in 67.5 ％ sHCC (27/40,well=4,well-moderate=3,moderate=18 and moderate-poor=2).32 lesions showed hypervascularity on arterial phase,and 8 lesions showed hypovascularity (well=3,moderate =4,moderate-poor=1).On DWI,37 lesions showed hyperintensity,except for 3 lesions with welldifferentiated sHCC which showed isointensity (50％,3/6).The mean ADC values±S.D.of sHCC in the well,well-moderate,moderate and moderate-poor groups were (1.757 ± 0.337) × 10-3,(1.917±0.574)×103,(1.816±0.545)×103 and (1.723±0.217)×10-3,respectively.There were no significant differences among the 4 groups.Conclusion The imaging appearances of wellmoderate,moderate and moderate-poor sHCC on conventional MRI were classical which make diagnosis easy.Hyperintensity on DWI contributed to diagnosis.However,the imaging appearances of some well-differentiated sHCC were atypical.The lesions could be isointensity or hyperintensity on DWI.The combination of conventional MRI and DWI contributed to better diagnosis of sHCC,especial for atypical sHCC.

BACKGROUND: Managing acute postoperative pain is challenging for anesthesiologists, surgeons, and patients, leading to adverse events despite making significant progress. Patient-controlled intravenous analgesia (PCIA) is a recommended solution, where oxycodone has depicted unique advantages in recent years. However, controversy still exists in clinical practice and this study aimed to compare two drugs in PCIA. METHODS: We performed a literature search in PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, Chinese National Knowledge Infrastructure, Wanfang, and VIP databases up to December 2020 to select specific randomized controlled trials (RCTs) comparing the efficacy of oxycodone with sufentanil in PCIA. The analgesic effect was the primary outcome and the secondary outcome included PCIA consumption, the Ramsay sedation scale, patients' satisfaction and side effects. RESULTS: Fifteen RCTs were included in the meta-analysis. Compared with sufentanil, oxycodone showed lower Numerical Rating Scale scores (mean difference [MD] = -0.71, 95% confidence interval [CI]: -1.01 to -0.41; P < 0.001; I2 = 93%), demonstrated better relief from visceral pain (MD = -1.22, 95% CI: -1.58 to -0.85; P < 0.001; I2 = 90%), promoted a deeper sedative level as confirmed by the Ramsay Score (MD = 0.77, 95% CI: 0.35-1.19; P < 0.001; I2 = 97%), and resulted in fewer side effects (odds ratio [OR] = 0.46, 95% CI: 0.35-0.60; P < 0.001; I2 = 11%). There was no statistical difference in the degree of patients' satisfaction (OR = 1.13, 95% CI: 0.88-1.44; P = 0.33; I2 = 72%) and drug consumption (MD = -5.55, 95% CI: -14.18 to 3.08; P = 0.21; I2 = 93%). CONCLUSION: Oxycodone improves postoperative analgesia and causes fewer adverse effects, and could be recommended for PCIA, especially after abdominal surgeries. REGISTRATION PROSPERO; https://www.crd.york.ac.uk/PROSPERO/; CRD42021229973.
Humans ; Oxycodone/therapeutic use* ; Sufentanil/therapeutic use* ; Randomized Controlled Trials as Topic ; Pain, Postoperative/drug therapy* ; Drug-Related Side Effects and Adverse Reactions ; Analgesia, Patient-Controlled