Pediatric patients with achondroplasia: CT evaluation of the craniocervical junction

Twenty-six patients (4 months to 6 years old) with achondroplasia complicated by sleep apnea and/or other neurologic manifestations underwent plain computed tomography (CT) of the craniocervical junction; six also underwent CT myelography. For objectification, multiplanar reconstruction was used to complement axial plane measurements by providing coronal and sagittal measurements; multiplanar reconstruction also improved perception of the longitudinal relationships between the brain stem and subarachnoid space. A narrow subarachnoid space was found in all 26 patients; marked cord compression was present in nine, six of whom underwent CT myelography. These six had marked focal obliteration of the subarachnoid space on both plain CT and CT myelography. Since the subarachnoid space immediately above and below the craniocervical junction is normally capacious, when marked constriction was present, no additional information could have been gained from CT myelography. Thus, plain CT was shown to be sufficient for surgical planning (suboccipital decompression) in nine patients with cord compression due to achondroplasia.     

Thrombosis at venous insertion sites after inferior vena caval filter placement

Color Doppler flow imaging or compression ultrasound (US) was used to prospectively determine frequency of thrombosis at 54 venous insertion sites (47 in common femoral veins, seven in right internal jugular veins) after percutaneous placement of Greenfield filters for interruption of the inferior vena cava. Fifty-one filters were successfully placed in 51 patients with a dilator set or a balloon angioplasty catheter. Nine focal thrombi were detected in the common femoral vein (19%) and one in the right internal jugular vein (14%). Use of dilators induced eight thrombi (24%), compared with two (10%) from balloon catheters. The left common femoral vein had a high frequency of thrombosis, regardless of dilation technique (five of nine). Of nine patients with acute common femoral vein thrombosis, four became symptomatic within 10 days after the procedure. Patients may remain asymptomatic or have delayed symptoms; thus, US is valuable for determining patients at risk of thrombosis of the common femoral vein.     

Digital imaging of the chest

During the past several years, image acquisition in nuclear medicine, computed tomography, ultrasonography, subtraction angiography, and magnetic resonance has been by digitization. Despite these advances, research in the development of digital imaging in conventional radiography has lagged behind. Although studies with a variety of digital techniques have been carried out on several fronts, we still do not possess a method that has captured the imagination of the majority of radiologists and other physicians to a point where it could replace conventional screen-film imaging. This article reviews the current status and general principles of the technology, focusing on the four digital radiographic techniques that have shown the greatest promise - film digitization, an image intensifier - based system, photostimulable phosphor plates, and a scanned projection system. The physical aspects of each of the four systems and the clinical results that have been reported to date, as well as the advantages and disadvantages of each system, are presented.     

MR imaging of facial nerve enhancement in Bell palsy or after temporal bone surgery

The authors evaluated magnetic resonance (MR) images obtained with intravenously administered gadolinium in ten patients who had facial paralysis and no facial nerve tumor. In patients with either Bell palsy (four patients) or facial paralysis after temporal bone surgery (six patients), intratemporal facial nerve enhancement was seen. Facial nerve enhancement on MR images proved to be a nonspecific finding.     

N-乙酰半胱氨酸对脑死亡状态巴马小型猪肾脏结构、功能与核转录因子κB表达的影响

目的：观察核转录因子κB活性抑制剂N-乙酰半胱氨酸对脑死亡状态下巴马小型猪肾脏结构、功能与核转录因子κB mRNA其蛋白表达的影响，以期提高脑死亡供肾的肾移植效果。方法：实验于2003—08／2004—12在河南省实验动物中心及河南省病理学重点实验室完成。①实验分组及方法：将15只巴马小型猪按随机数字表法分为3组（n=5），即脑死亡组、N-乙酰半胱氨酸组及对照组。脑死亡组和N-乙酰半胱氨酸组均应用改进的缓慢间断颅内加压法建立脑死亡模型，脑死亡组不行药物干预；N-乙酰半胱氨酸组分别于初次确认脑死亡后1h，12h给予N-乙酰半胱氨酸。对照组动物麻醉后仅行开颅与开关腹手术。②实验评估：分别于首次判定脑死亡后3，6，12，18和24h检测动物血清中尿素氮、肌酐、白细胞介素1β、白细胞介素6、肿瘤坏死因子α水平。于脑死亡后3，6，12及24h开腹取相同部位肾组织，苏木精-伊红染色后观察肾组织结构变化，应用免疫组化染色观察核转录因子κB蛋白的表达水平，应用反转录-聚合酶链反应法检测核转录因子κB mRNA动态变化。结果：15只猪均进入结果分析。①自首次判定脑死亡后12h开始，脑死亡组和N-乙酰半胱氨酸组尿素氮和肌酐水平逐渐升高（P〈0．05），相同时间点比较N-乙酰半胱氨酸组显著低于脑死亡组（P〈0．05）。②自首次判定脑死亡3h开始，脑死亡组及N-乙酰半胱氨酸组白细胞介素1β、白细胞介素6、肿瘤坏死因子α逐渐升高（P〈0．05），相同时间点比较N-乙酰半胱氨酸组显著低于脑死亡组（P〈0．05）。③自脑死亡后3h开始，脑死亡组及N-乙酰半胱氨酸组肾组织NF-κB mRNA其蛋白表达水平逐渐升高（P〈0．05），相同时间点比较N-乙酰半胱氨酸组显著低于脑死亡组（P〈0．05）。④N-乙酰半胱氨酸组和脑死亡组动物脑死亡后12h可见肾脏结构变化，N-乙酰半胱氨酸组变化程度明显轻于脑死亡组。结论：N-乙酰半胱氨酸可能通过抑制核转录因子κB mRNA其蛋白的表达，减少炎症介质的释放，从而保护脑死亡状态下肾脏的功能及结构，提高脑死亡供肾肾移植效果。