超声在胃常见疾病及胃功能诊断中的应用

借助口服超声助显剂，胃壁及其病变得以清晰显示。本文就经腹超声诊断胃常见疾病和胃排空功能评估方面的一些体会与大家分享，希望经腹胃超声这种无创、实时的检查方式能更普及，使更多患者受益。     

干扰素在恶性淋巴瘤自体移植后早期干预的应用

目的:观察非霍奇金淋巴瘤（non-Hodgkin's lymphoma，NHL）患者自体造血干细胞移植（autologous hematopoietic stem cell transplantation，ASCT）术后应用重组人α-2b干扰素（α-2b IFN）进行早期干预治疗的临床疗效。方法:选取18例行ASCT的NHL患者为研究对象，移植前疾病评估均未达到完全缓解（complete remission，CR），试验组血象恢复后给予IFN 3 000 000 U次/隔日干预治疗，3个月后停用；对照组未行干扰素干预治疗，分析总体疗效及两组对比的生存情况。结果:随访中位时间为34（10~50）个月，患者中位生存时间为37（31~45）个月，3年总体无进展生存（progressive free survival，PFS）、总生存（overall survivial，OS）分别为54.7%、66.8%。ASCT后试验组1年内无疾病复发，2年内复发率为12.5%；对照组1年内复发率为20%，2年内复发率为30%。结论:NHL患者在ASCT后给予重组人α-2b IFN早期干预治疗，患者耐受性好，可能降低移植后早期复发率。     

Estimation of phase signal change in neuronal current MRI for evoke response of tactile detection with realistic somatosensory laminar network model

Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm³. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation.