BACKGROUND & AIMS: PURPOSE:To determine the clinical importance and relative value of reinterpreting brain CT imaging studies by subspecialty experts regarding changes in clinical management. METHODS:Computerized records were queried at two institutions during the years 2002-2003 for both primary interpretation by board-certified nonneuroradiologists and secondary interpretation by three neuroradiologists. A total of 1,081 cases were reviewed. Each case was initially interpreted as an emergent or urgent study. The reinterpreted studies were scored as concordant or discordant by the subspecialty experts. The discordant studies were then categorized as a "major discordance" if there was a change in clinical management, or as a "minor discordance" if there was no impact or change in clinical management. RESULTS:Of the 1,081 studies reviewed, 14 studies were identified as discordant (1.3%). Of those discordant studies, four were categorized as major discrepancies necessitating a change in clinical management (0.4 %). Ten were categorized as minor discrepancies (0.9%). There were no permanent adverse outcomes with respect to morbidity and mortality as a result of any discrepancy. CONCLUSION:The vast majority of interpreted head CT cases read by board-certified general radiologists do not result in discordant interpretations as verified by subspecialty experts. Discordant interpretations did not result in changes in clinical management in most cases. Double reading of head CTs by subspecialty experts appears to be an inefficient method of substantially improving imaging health quality outcomes.

背景与目标： 目的：确定亚专业专家对临床管理变化进行重新解释脑CT成像研究的临床重要性和相对价值。
方法：在2002年至2003年期间，在两家机构中查询了计算机记录，以获取由董事会认证的非神经放射科医生进行的主要解释和由三位神经放射科医生进行的次要解释。总共审查了1,081例。最初，每个案例都被解释为紧急研究。重新解释的研究被专业专家评定为一致或不一致。如果临床管理发生变化，则将不一致的研究分类为“重大不一致”，如果临床管理没有影响或发生变化，则将其分类为“轻微不一致”。
结果：在所审查的1,081项研究中，有14项研究被确定为不一致（1.3％）。在这些不一致的研究中，有四项被归类为需要改变临床管理的主要差异（0.4％）。十个分类为轻微差异（0.9％）。任何差异都不会在发病率和死亡率方面带来永久性的不良后果。
结论：经董事会认证的一般放射科医生阅读的绝大多数解释性头部CT病例，经专科专家验证，并不会导致不一致的解释。在大多数情况下，不一致的解释并不会导致临床管理的改变。专科专家对头颅CT进行双重读取似乎是一种实质上改善影像健康质量结果的无效方法。

BACKGROUND & AIMS: Transgenic mice expressing high levels of the BclxL or Bcl2 proteins in the male germinal cells show a highly abnormal adult spermatogenesis accompanied by sterility. This appears to result from the prevention of an early and massive wave of apoptosis in the testis, which occurs among germinal cells during the first round of spermatogenesis. In contrast, sporadic apoptosis among spermatogonia, which occurs in normal adult testis, is not prevented in adult transgenic mice. The physiological early apoptotic wave in the testis is coincident, in timing and localization, with a temporary high expression of the apoptosis-promoting protein Bax, which disappears at sexual maturity. The critical role played by the intracellular balance, probably hormonally controlled, of the BclxL and Bax proteins (Bcl2 is apparently not expressed in normal mouse testis) in this early apoptotic wave is shown by the occurrence of a comparable testicular syndrome in mice defective in the bax gene. The apoptotic wave appears necessary for normal mature spermatogenesis to develop, probably because it maintains a critical cell number ratio between some germinal cell stages and Sertoli cells, whose normal functions and differentiation involve an elaborate network of communication.

背景与目标： 在雄性生殖细胞中表达高水平BclxL或Bcl2蛋白的转基因小鼠表现出高度异常的成年精子发生并伴有不育。这似乎是由于防止了睾丸早期大量凋亡的结果，这种情况发生在第一轮精子发生过程中的生发细胞之间。相反，在成年转基因小鼠中，不能阻止正常成年人睾丸中发生的精原细胞中的偶发性细胞凋亡。睾丸中的生理性早期凋亡波在时间和位置上是一致的，具有促凋亡的蛋白Bax的临时高表达，该蛋白在性成熟时消失。 BclxL和Bax蛋白的细胞内平衡（可能是激素控制的）（在正常小鼠的睾丸中显然不表达Bcl2）在细胞内平衡中起着至关重要的作用，这是通过在小鼠体内出现类似的睾丸综合症而证明的。 bax基因。凋亡波似乎是正常成熟精子发生发展所必需的，这可能是因为它在某些生细胞阶段和支持细胞之间维持了关键的细胞数比，其正常功能和分化牵涉到复杂的交流网络。

BACKGROUND & AIMS: STUDY DESIGN:A cross-sectional study of the spine in 40 young adults after solid organ transplantation in childhood. OBJECTIVE:To evaluate the impact of organ transplantation and long-term immunosuppressive treatment on growing spine using magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA:A review of the current literature reveals no systematic evaluation of the spine after transplantation in childhood. METHODS:A total of 40 adult patients (mean age 22.1 years, range, 16.0-27.0), who received either kidney, liver, or heart transplant as children, were evaluated. Mean follow-up after transplantation was 11.2 years (range 3.0-18.0). All patients filled in a questionnaire, underwent an interview and physical examination, as well as had MRI of the spine. Standing spinal radiographs were taken from patients with a rib hump > or = 6 degrees. RESULTS:There were 8 (20%) patients who had a history of vertebral fracture. Eleven (28%) patients reported frequent back pain at rest. There were 15 (38%) patients who had scoliosis > 10 degrees (range 10 degrees -69 degrees ). On MRI, narrowed disc spaces were noted in 32 (80%) patients, and irregular endplates were noted in 24 (60%). There were 14 (35%) patients who had at least 1 compressed or wedged vertebra (> 20%). Patients treated for acute rejection had wedged vertebrae, speckled or black disc spaces, and irregular endplates more often than patients without rejections. Males had wedged vertebrae more often than females (P = 0.0067). CONCLUSIONS:Back pain, scoliosis, wedged vertebrae, and narrowed, degenerated disc spaces are common after solid organ transplantation in childhood.

背景与目标： 研究设计：儿童实体器官移植后对40位年轻人的脊柱进行的横断面研究。
目的：利用磁共振成像（MRI）评估器官移植和长期免疫抑制治疗对生长中脊柱的影响。
背景资料摘要：对当前文献的回顾表明，儿童期移植后没有对脊柱进行系统评价。
方法：总共评估了40名成年患者（平均年龄22.1岁，范围16.0-27.0），他们从小就接受了肾脏，肝脏或心脏移植手术。移植后的平均随访时间为11.2年（范围3.0-18.0）。所有患者均填写了问卷，接受了访谈和体格检查，并对脊柱进行了MRI检查。肋骨隆起>或= 6度的患者拍摄站立式脊柱X光片。
结果：有8例（20％）有椎体骨折病史。 11名（28％）患者报告休息时经常出现背痛。脊柱侧弯> 10度（范围10度-69度）的患者为15（38％）。在MRI上，发现32例（80％）患者的椎间盘间隙变窄，发现24例（60％）的不规则端板。有14名（35％）患者至少有1块受压或楔入的椎骨（> 20％）。接受急性排斥反应的患者比没有排斥反应的患者更经常出现椎体楔形，斑点或黑色椎间盘间隙以及不规则的终板。男性比女性更经常楔住椎骨（P = 0.0067）。
结论：儿童实体器官移植后，背部疼痛，脊柱侧弯，椎骨楔形和椎间盘狭窄变窄是常见的。

BACKGROUND & AIMS: Magnetic resonance has assumed a preeminent role in the imaging evaluation of the spine. Owing to its multiplanar capability and superior soft tissue contrast, magnetic resonance imaging is the procedure of choice for a host of spinal disorders including degenerative disc disease, tumor evaluation, trauma, and spinal deformities. It represents the most accurate means of distinguishing between recurrent disc herniation and epidural fibrosis, and it excels at the assessment of many postoperative abnormalities such as infection, adjacent segment disc degeneration, and arachnoiditis. Magnetic resonance imaging is also helpful in the evaluation of numerous diagnostic challenges that are less well resolved by other means. This includes the distinction between disc herniation and epidural hematoma, synovial cyst from nonspecific fibrous thickening of a facet capsule, and the evaluation of numerous other soft tissue abnormalities. Computed tomography, computed tomography myelography, and scintigraphy continue to be useful for numerous specific disorders and in those patients with metal hardware or contraindications to magnetic resonance scanning. Overall, however, magnetic resonance is the imaging procedure preferred for many spinal disorders. This article is the first installment of a 3-part series discussing the role of magnetic resonance imaging of spinal disorders. Section 1 will describe the varying imaging modalities available and their relative advantages and disadvantages. A consideration of magnetic resonance imaging techniques will follow, followed by a discussion of the imaging manifestations of early degenerative disc disease. Section 2 will be devoted to an in depth discussion of specific pathologic processes encountered in patients with degenerative disc disease. Section 3 will end the series with a consideration of postoperative imaging followed by a discussion of spinal deformities, trauma, and neoplasms.

背景与目标： 磁共振在脊柱的成像评估中发挥了重要作用。由于其多平面能力和出色的软组织对比度，磁共振成像是许多脊柱疾病（包括退行性椎间盘疾病，肿瘤评估，创伤和脊柱畸形）的首选程序。它代表了区分复发性椎间盘突出症和硬膜外纤维化的最准确方法，并且擅长评估许多术后异常，例如感染，邻近节段性椎间盘退变和蛛网膜炎。磁共振成像还有助于评估许多诊断挑战，而这些挑战很难通过其他方式解决。这包括区分椎间盘突出症和硬膜外血肿，小囊囊的非特异性纤维增厚引起的滑膜囊肿，以及许多其他软组织异常的评估。计算机体层摄影术，计算机体层摄影术脊髓造影和闪烁显像术继续对许多特定疾病以及那些具有金属硬件或磁共振扫描禁忌症的患者有用。但是，总的来说，磁共振是许多脊柱疾病首选的成像方法。本文是由三部分组成的系列文章的第一部分，该系列讨论了磁共振成像对脊柱疾病的作用。第1节将描述可用的各种成像方式及其相对优缺点。随后将考虑磁共振成像技术，然后讨论早期退行性椎间盘疾病的成像表现。第2节将专门讨论变性椎间盘疾病患者遇到的特定病理过程。第三部分将在结束本系列文章时考虑术后影像学，然后讨论脊柱畸形，创伤和肿瘤。