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: 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。

BACKGROUND & AIMS: The effect of bacteriorhodopsin (BR) on the percolation properties of dimyristoylphosphatidylcholine/distearoylphosphatidylcholine bilayers was examined by studying the quenching of a lipid-bound fluorophore by a lipid-bound quencher, and by spin-spin interactions of a nitroxide-labeled lipid using electron spin resonance (ESR). At the low concentrations of BR used, differential scanning calorimetry showed that although the transition enthalpy was reduced in a concentration-dependent manner by incorporation of BR, the solidus and fluidus phase boundaries and overall shape of the heat capacity profiles were essentially unchanged. However, fluorescence quenching and spin-label ESR data showed that the domain topology, as reflected in the percolation properties, is strongly affected by the protein. In contrast to our previous fluorescence data for the pure lipid mixtures, quenching in the coexistence region is independent of the fluid phase fraction when BR is present. In addition, the percolation threshold estimated by spin-label ESR is shifted in the presence of BR to a higher gel phase fraction at a given lipid composition. Both the fluorescence quenching and spin-label ESR data, together with the results of earlier simulations, strongly suggest that the fluid phase domains are substantially larger and/or less ramified in the presence of BR than in its absence. We have previously reported a similar effect of a transmembrane peptide, pOmpA (Escherichia coli outer membrane protein A signal peptide), on fluid domain connectivity in binary phosphatidylcholine mixtures.

背景与目标： 通过研究脂质结合的猝灭剂对脂质结合的荧光团的猝灭以及使用电子自旋的一氧化氮标记的脂质的自旋-自旋相互作用，研究了细菌视紫红质（BR）对二肉豆蔻酰基磷脂酰胆碱/二硬脂酰磷脂酰胆碱双层渗透特性的影响。共振（ESR）。在使用低浓度的BR时，差示扫描量热法显示，尽管通过掺入BR以一定的浓度依赖性降低了转变焓，但固相线和液相线的边界和热容曲线的总体形状基本不变。但是，荧光猝灭和自旋标记ESR数据表明，渗透特性所反映的域拓扑结构受到蛋白质的强烈影响。与我们以前的纯脂质混合物的荧光数据相反，当存在BR时，共存区域的猝灭与液相分数无关。另外，在给定脂质组成下，在BR存在下，自旋标记ESR估计的渗透阈值会转移到较高的凝胶相分数。荧光猝灭和自旋标记ESR数据以及早期模拟的结果都强烈表明，在存在BR的情况下，与不存在BR的情况相比，液相域的分支和/或分枝显着增加。我们以前曾报道过跨膜肽pOmpA（大肠杆菌外膜蛋白A信号肽）对二元磷脂酰胆碱混合物中的流体域连通性具有类似作用。

BACKGROUND & AIMS: Nodular regenerative hyperplasia (NRH) of the liver is a condition characterized by multiple monoacinar regenerative nodules in the absence of fibrous septa. When these nodules become confluent they may be seen with sonography or CT. The appearance of these pseudotumoral pattern of NRH has been scarcely described with MRI. We present the imaging findings of five patients with NRH and a pseudotumoral form at sonography. Sonography depicted hyperechoic lesions in four patients and hypoechoic lesions in another. Computed tomography showed hypodense lesions with little contrast enhancement in two patients. Three patients showed subtle focal liver lesions on MRIisointense in one, mildly hypointense in another, and minimally hyperintense in a patient with siderosis. The dynamic behavior at MRI was similar to the normal liver parenchyma. Hyperechoic lesions on sonography or hypodense lesions on CT, barely or not seen on MRI, can be indicative of NRH in an appropriate clinical setting.

背景与目标： 肝脏的结节性再生增生（NRH）是一种疾病，其特征是在没有纤维间隔的情况下出现了多个单腺泡再生结节。当这些结节汇合时，可以通过超声检查或CT看到。 MRI几乎没有描述这些NRH假瘤型的出现。我们在超声检查中介绍了5例NRH和假瘤形式的患者的影像学表现。超声检查显示四名患者出现高回声病变，另一名患者出现低回声病变。计算机断层扫描显示两名患者的低密度病变，对比增强很少。 3例患者在MRIisointense上显示出细微的局灶性肝损害，另一例患者表现为轻度低点，铁锈病患者显示为最低程度的高强度。 MRI的动态行为与正常肝实质相似。在适当的临床环境中，超声检查中的高回声病变或CT上的低密度病变（在MRI上几乎未见或未见）可指示NRH。

BACKGROUND & AIMS: :Isolated cleft mitral valve (ICMV) is a rare entity not known to be related to pulmonary atresia with ventricular septal defect (PA-VSD). This report describes the use of cardiovascular magnetic resonance (CMR) imaging to diagnose ICMV in a patient with repaired PA-VSD who presented with incidental severe mitral regurgitation (MR) on follow-up echocardiography. An associated pulmonary varix secondary to the severe MR also was shown by CMR.

背景与目标： ：孤立的二尖瓣裂开（ICMV）是一种罕见病，未知与室间隔缺损的肺动脉闭锁（PA-VSD）相关。本报告介绍了在后续超声心动图检查中出现偶发性严重二尖瓣关闭不全（MR）的PA-VSD修复患者中，使用心血管磁共振（CMR）成像诊断ICMV的情况。 CMR还显示了继发于严重MR的相关肺静脉曲张。

BACKGROUND & AIMS: :A new optical method is proposed to investigate the reflectance of structurally coloured objects, such as Morpho butterfly wing scales and cholesteric liquid crystals. Using a reflected-light microscope and a digital single-lens reflex (DSLR) camera, we have successfully measured the two-dimensional reflection pattern of individual wing scales of Morpho butterflies. We demonstrate that this method enables us to measure the bidirectional reflectance distribution function (BRDF). The scattering image observed in the back focal plane of the objective is projected onto the camera sensor by inserting a Bertrand lens in the optical path of the microscope. With monochromatic light illumination, we quantify the angle-dependent reflectance spectra from the wing scales of Morpho rhetenor by retrieving the raw signal from the digital camera sensor. We also demonstrate that the polarization-dependent reflection of individual wing scales is readily observed using this method, using the individual wing scales of Morpho cypris. In an effort to show the generality of the method, we used a chiral nematic fluid to illustrate the angle-dependent reflectance as seen by this method.

背景与目标： ：提出了一种新的光学方法来研究结构上有色物体的反射率，例如Morpho蝴蝶翼鳞和胆甾型液晶。使用反射光显微镜和数字单镜反光（DSLR）相机，我们已经成功地测量了Morpho蝴蝶单个机翼尺度的二维反射图案。我们证明了这种方法使我们能够测量双向反射率分布函数（BRDF）。在物镜的后焦平面上观察到的散射图像通过在显微镜的光路中插入一个Bertrand透镜而投射到相机传感器上。利用单色光照明，我们通过从数码相机传感器中检索原始信号，从Morpho rhetenor的机翼尺度上量化了与角度相关的反射光谱。我们还证明，使用这种方法，使用蓝蝶的单个机翼鳞片，很容易观察到单个机翼鳞片的偏振依赖性反射。为了说明该方法的一般性，我们使用手性向列液来说明该方法所见的角度依赖性反射率。

BACKGROUND & AIMS: BACKGROUND AND PURPOSE:Imaging of bisphosphonate-induced osteonecrosis of the jaw is essential for surgical planning. We compared the extent of BONJ on contrast-enhanced MR imaging, [(18)F] fluoride PET/CT, and panoramic views derived from standard conebeam CT with clinical pre- and intraoperative examinations. MATERIALS AND METHODS:Between February 2011 and January 2012, ten subjects with written informed consent (9 women; mean, 69.6 years; range, 53-88 years) were included in this prospective ethics-board-approved study. Patients underwent CEMR imaging, [(18)F] fluoride PET/CT, and CBCT and were clinically examined pre- and intraoperatively. Surgery was performed, and BONJ was histologically confirmed in 9 patients. Location and extent of BONJ on different modalities/examinations were graphically compared (0 = no pathologic finding, 1 = smallest, 5 = largest extent of BONJ). Rank tests were used to assess overall and paired differences of ratings in 9 patients. A P value <.05 was considered statistically significant. RESULTS:Significant differences in BONJ extent among different modalities and examinations were found (P < .001). The highest median rank was seen in PET/CT (4 ± 1.12) and CEMR imaging (4 ± 1.01), followed by intraoperative examinations (3 ± 0.71), CBCT (2 ± 0.33), and preoperative examinations (1 ± 0). No significant differences were found between PET/CT and CEMR imaging (P = .23), except when comparing PET/CT to either CBCT, pre- and intraoperative examinations (all P < .05). Preoperative examinations showed significantly less extensive disease than all other modalities/examinations (all P < .05). CONCLUSIONS:[(18)F] fluoride PET/CT and CEMR imaging revealed more extensive involvement of BONJ compared with panoramic views from CBCT and clinical examinations.

背景与目标： 背景与目的：双膦酸盐诱发的颌骨骨坏死的成像对于手术计划至关重要。我们将BONJ在对比增强MR成像，[（18）F]氟化物PET / CT和标准锥束CT的全景图与临床术前和术中检查之间进行了比较。
材料与方法：在2011年2月至2012年1月之间，该前瞻性伦理委员会批准的研究包括十名获得书面知情同意的受试者（9名女性；平均69.6岁；范围53-88岁）。患者接受了CEMR成像，[（18）F]氟化物PET / CT和CBCT，并在术前和术中接受了临床检查。进行了手术，并在组织学上证实了9例患者的BONJ。以图形方式比较了BONJ在不同模态/检查中的位置和程度（0 =无病理发现，1 =最小，5 =最大程度的BONJ）。等级检验用于评估9位患者的总体和配对等级差异。 P值<.05被认为具有统计学意义。
结果：在不同的方式和检查之间，BONJ范围存在显着差异（P <.001）。 PET / CT（4±1.12）和CEMR成像（4±1.01），手术中检查（3±0.71），CBCT（2±0.33）和术前检查（1±0）最高。除了将PET / CT与CBCT，术前和术中检查进行比较（所有P <.05）之外，PET / CT和CEMR成像之间没有发现显着差异（P = 0.23）。术前检查显示，与所有其他方式/检查相比，病灶明显更少（所有P <.05）。
结论：[（18）F]氟化物PET / CT和CEMR成像显示，与CBCT和临床检查的全景图相比，BONJ的介入程度更大。

BACKGROUND & AIMS: :In a prospective magnetic resonance imaging and cognitive study of 38 demented patients and 15 control subjects, 11 of 27 patients with Alzheimer's disease and 8 of 11 patients with vascular dementia had significant periventricular hyperintensities. Memory and language testing in the early investigation of dementia is useful to distinguish patients with or without periventricular hyperintensities on magnetic resonance imaging. Patients without periventricular hyperintensities are worse on memory and conceptualization tests than patients with periventricular hyperintensities, who tend to be worse on comprehension and attention tests. These differences in cognitive pattern are present between patients with different pathogenesis who are otherwise matched for dementia severity. Language and some nonverbal cognitive deficits correlate with the extent of cortical and ventricular atrophy in Alzheimer's disease.

背景与目标： ：在一项针对38名痴呆患者和15名对照受试者的前瞻性磁共振成像和认知研究中，27名阿尔茨海默氏病患者中的11名和11名血管性痴呆患者中的8名出现了明显的脑室高信号。痴呆症早期调查中的记忆和语言测试有助于区分磁共振成像中是否伴有脑室高信号的患者。没有脑室高信号的患者在记忆力和概念化测试方面比脑室高信号的患者在理解和注意力测试方面更差。这些认知模式上的差异存在于具有不同发病机制的患者之间，这些患者在其他方面因痴呆症的严重程度而匹配。语言和一些非语言认知缺陷与阿尔茨海默氏病的皮质和心室萎缩程度有关。

BACKGROUND & AIMS: :We investigated the effect of homogeneous and inhomogeneous static magnetic field (SMF) exposure on the thermal nociceptive threshold of snail in the hot plate test (43 °C). Both homogeneous (hSMF) and inhomogeneous (iSMF) SMF increased the thermo-nociceptive threshold: 40.2%, 29.2%, or 41.7% after an exposure of 20, 30, or 40 min hSMF by p < 0.001, p < 0.0001, or p < 0.001, and 32.7% or 46.2% after an exposure of 20 or 40 min iSMF by p < 0.05 or p < 0.0001. These results suggest that SMF has an antinociceptive effect in snail. On the other hand, naloxone as an atypical opioid antagonist in an amount of 1 μg/g was found to significantly decrease the thermo-nociceptive threshold (41.9% by p < 0.002), which could be antagonized by hSMF exposure implying that hSMF exerts its antinociceptive effect partly via opioid receptors.

背景与目标： ：我们在热板测试（43°C）中研究了均匀和不均匀的静磁场（SMF）暴露对蜗牛的热伤害感受性阈值的影响。均质（hSMF）和不均质（iSMF）SMF均可在暴露20、30或40分钟的hSMF时通过p <0.001，p <0.0001或p提高热伤害感受性阈值：40.2％，29.2％或41.7％ iSMF暴露p≤0.05或p≤0.0001后，<0.001，以及32.7％或46.2％。这些结果表明，SMF对蜗牛具有镇痛作用。另一方面，发现纳洛酮作为一种非典型的阿片类药物拮抗剂，可显着降低热伤害感受性阈值（41.9％，p <0.002），可被hSMF暴露所拮抗，暗示hSMF发挥了其作用。部分通过阿片样物质受体产生抗伤害感受作用。

BACKGROUND & AIMS: BACKGROUND:Evidence-based guidelines recommend limited perioperative diagnostic imaging for new breast cancer diagnoses. For patients aged >65 years, conventional imaging use (mammography, plain radiographs, and ultrasound) has remained stable, whereas advanced imaging (computed tomography [CT], nuclear medicine scans [positron emission tomography/bone scans], and magnetic resonance imaging [MRI]) use has increased. In this study, the authors evaluated traditional and advanced imaging use among younger patients (aged ≤ 65 years) undergoing breast cancer surgery. METHODS:The MarketScan Commercial Claims and Encounters Research Database from 2005 through 2008 was analyzed to evaluate the use of conventional and advanced diagnostic imaging associated with surgery for ductal carcinoma in situ (DCIS) or stage I through III invasive breast cancer. RESULTS:The study cohort included 52,202 women (13% with DCIS and 87% with stage I-III breast cancer). The proportion of patients undergoing conventional imaging remained stable, whereas the average number of conventional imaging tests per patient increased from 4.21 tests in 2005 to 4.79 tests per patient in 2008 (P < .0001). For advanced imaging, the proportion of women who underwent imaging increased from 48.8% in 2005 to 68.8% in 2008 (P < .0001), as did the number of tests per patient (from 1.53 tests in 2005 to 1.98 tests in 2008; P < .0001). MRI examinations accounted for nearly all of the increase in advanced imaging. Patients who underwent MRI examinations received significantly more traditional imaging tests compared with to those who did not, indicating that these tests are additive and are not replacing traditional imaging. CONCLUSIONS:The current results demonstrate that the use of perioperative breast MRI has increased among women aged <65 years. Further study is indicated to determine whether the benefits of this procedure justify increased use.

背景与目标： 背景：基于证据的指南建议对新的乳腺癌诊断进行有限的围手术期诊断成像。对于65岁以上的患者，传统的影像学检查（乳房X线照片，X线平片和超声检查）保持稳定，而高级影像学（计算机断层扫描[CT]，核医学扫描[正电子发射断层扫描/骨扫描]和磁共振成像[ MRI]）的使用有所增加。在这项研究中，作者评估了接受乳腺癌手术的年轻患者（≤65岁）的传统和高级成像使用情况。
方法：对2005年至2008年的MarketScan商业索赔和遭遇研究数据库进行了分析，以评估与导管原位癌（DCIS）或I至III期浸润性乳腺癌手术相关的常规和高级诊断成像的使用。
结果：该研究队列包括52,202名妇女（13％的DCIS患者和87％的I-III期乳腺癌患者）。接受常规影像学检查的患者比例保持稳定，而每名患者的常规影像学检查的平均次数从2005年的4.21次检查增加到2008年的4.79次检查（P <.0001）。对于高级影像学，接受影像学检查的女性比例从2005年的48.8％增加到2008年的68.8％（P <.0001），每位患者的检查次数也从2005年的1.53次增加到2008年的1.98次； P <.0001）。 MRI检查几乎占了高级影像学增长的全部。与未接受MRI检查的患者相比，接受过MRI检查的患者接受的传统成像检查要多得多，这表明这些检查是相加的，并且不能替代传统成像。
结论：目前的结果表明，<65岁的女性围手术期乳房MRI的使用有所增加。指示需要进一步研究以确定该程序的益处是否可证明增加使用量是合理的。

BACKGROUND & AIMS: :Bacterial populations exhibit a range of metabolic states influenced by their environment, intra- and interspecies interactions. The identification of bacterial metabolic states and transitions between them in their native environment promises to elucidate community behavior and stochastic processes, such as antibiotic resistance acquisition. In this work, we employ two-photon fluorescence lifetime imaging microscopy (FLIM) to create a metabolic fingerprint of individual bacteria and populations. FLIM of autofluorescent reduced nicotinamide adenine dinucleotide (phosphate), NAD(P)H, has been previously exploited for label-free metabolic imaging of mammalian cells. However, NAD(P)H FLIM has not been established as a metabolic proxy in bacteria. Applying the phasor approach, we create FLIM-phasor maps of Escherichia coli, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus epidermidis at the single cell and population levels. The bacterial phasor is sensitive to environmental conditions such as antibiotic exposure and growth phase, suggesting that observed shifts in the phasor are representative of metabolic changes within the cells. The FLIM-phasor approach represents a powerful, non-invasive imaging technique to study bacterial metabolism in situ and could provide unique insights into bacterial community behavior, pathology and antibiotic resistance with sub-cellular resolution.

背景与目标： ：细菌种群表现出一系列受其环境，种内和种间相互作用影响的代谢状态。细菌代谢状态及其在自然环境中之间的过渡的鉴定有望阐明社区行为和随机过程，例如获得抗生素抗药性。在这项工作中，我们采用双光子荧光寿命成像显微镜（FLIM）来创建单个细菌和种群的代谢指纹。自发荧光还原烟酰胺腺嘌呤二核苷酸（磷酸）的FLIM NAD（P）H先前已被用于哺乳动物细胞的无标记代谢成像。但是，NAD（P）H FLIM尚未被确定为细菌中的代谢替代物。应用相量方法，我们在单个细胞和群体水平上创建了大肠杆菌，肠炎沙门氏菌血清型鼠伤寒杆菌，铜绿假单胞菌，枯草芽孢杆菌和表皮葡萄球菌的FLIM相量图。细菌相量对环境条件敏感，例如抗生素暴露和生长期，这表明所观察到的相量变化代表细胞内代谢变化。 FLIM相量方法代表了一种强大的，非侵入性的成像技术，可用于原位研究细菌代谢，并且可以通过亚细胞分辨率为细菌群落行为，病理学和抗生素耐药性提供独特的见解。

BACKGROUND & AIMS: :Diffusion magnetic resonance imaging (MRI) provides a sensitive indicator of cerebral hypoxia. We investigated if apparent diffusion coefficient (ADC) and transverse relaxation (T(2)) predict symptoms of acute mountain sickness (AMS), or merely indicate the AMS phenotype irrespective of symptoms. Fourteen normal subjects were studied in two groups; unambiguous AMS and no-AMS at 3,800 m altitude (intermediate AMS scores were excluded). T(2) relaxation was estimated from a T(2) index of T(2)-weighted signal normalized by cerebrospinal fluid signal. Measurements were made in normoxia and repeated after 2 days sustained hypoxia (AMS group symptomatic and no-AMS group asymptomatic) and after 7 days hypoxia (both groups asymptomatic). Decreased ADC directly predicted AMS symptoms (P<0.05). Apparent diffusion coefficient increased in asymptomatic subjects, or as symptoms abated with acclimatization. This pattern was similar in basal ganglia, white matter, and gray matter. Corpus callosum behaved differently; restricted diffusion was absent (or rapidly reversed) in the splenium, and was sustained in the genu. In symptomatic subjects, T(2,index) decreased after 2 days hypoxia and further decreased after 7 days. In asymptomatic subjects, T(2,index) initially increased after 2 days, but decreased after 7 days. T(2,index) changes were not predictive of AMS symptoms. These findings indicate that restricted diffusion, an indicator of diminished cerebral energy status, directly predicts symptoms of AMS in humans at altitude.

背景与目标： ：扩散磁共振成像（MRI）提供了脑缺氧的敏感指标。我们调查了表观扩散系数（ADC）和横向弛豫（T（2））是否可预测急性高山病（AMS）的症状，还是仅指示AMS表型，而与症状无关。 14个正常受试者分为两组进行研究；在3,800 m的高度进行明确的AMS和无AMS（不包括中级AMS分数）。根据脑脊髓液信号归一化的T（2）加权信号的T（2）指数估算T（2）弛豫。在常氧状态下进行测量，并在持续缺氧2天（AMS组有症状和无AMS组无症状）和缺氧7天（两组无症状）后重复进行。 ADC降低直接预测AMS症状（P <0.05）。无症状受试者的表观弥散系数增加，或者随着适应环境的减轻症状逐渐减轻。这种模式在基底神经节，白质和灰质中相似。 call体表现不同。脾中不存在（或迅速逆转）受限制的扩散，并且在脾中持续存在。在有症状的受试者中，缺氧2天后T（2，index）下降，而在7天后T（2，index）进一步下降。在无症状受试者中，T（2，index）最初在2天后升高，但在7天后降低。 T（2，index）的变化不能预测AMS症状。这些发现表明，限制扩散是大脑能量状态减弱的指标，可直接预测高海拔地区人类的AMS症状。

BACKGROUND & AIMS: :The solution of the forward problem in fluorescence molecular imaging strongly influences the successful convergence of the fluorophore reconstruction. The most common approach to meeting this problem has been to apply the diffusion approximation. However, this model is a first-order angular approximation of the radiative transfer equation, and thus is subject to some well-known limitations. This manuscript proposes a methodology that confronts these limitations by applying the radiative transfer equation in spatial regions in which the diffusion approximation gives decreased accuracy. The explicit integro differential equations that formulate this model were solved by applying the Galerkin finite element approximation. The required spatial discretization of the investigated domain was implemented through the Delaunay triangulation, while the azimuthal discretization scheme was used for the angular space. This model has been evaluated on two simulation geometries and the results were compared with results from an independent Monte Carlo method and the radiative transfer equation by calculating the absolute values of the relative errors between these models. The results show that the proposed forward solver can approximate the radiative transfer equation and the Monte Carlo method with better than 95% accuracy, while the accuracy of the diffusion approximation is approximately 10% lower.

背景与目标： ：荧光分子成像中前向问题的解决方案强烈影响荧光团重建的成功收敛。解决此问题的最常用方法是应用扩散近似。但是，该模型是辐射传递方程的一阶角近似，因此受到一些众所周知的限制。该手稿提出了一种通过在空间区域应用辐射传递方程来解决这些局限性的方法，其中扩散近似会降低精度。通过应用Galerkin有限元逼近法解决了表达该模型的显式积分微分方程。通过Delaunay三角剖分实现了所研究域的所需空间离散化，而方位角离散化方案则用于角空间。该模型已在两种模拟几何条件下进行了评估，并通过计算这些模型之间相对误差的绝对值，将结果与独立的蒙特卡洛方法和辐射传递方程的结果进行了比较。结果表明，所提出的前向求解器可以近似于95％的精度近似辐射传递方程和蒙特卡罗方法，而扩散近似的精度则低约10％。

BACKGROUND & AIMS: :The imaging of breast cancer has undergone significant progression in recent years. A multimodality approach is often required, with ongoing developments in mammography, ultrasound, magnetic resonance and nuclear medicine all contributing to breast cancer imaging. Here we review the literature to assess how advances in well-established technologies, such as mammography, have brought added benefits both in terms of diagnostic and practical benefits, as well as allowing the application of derived technologies, such as tomosynthesis and contrast-enhanced mammography. We consider how these newer technologies may fit into clinical practice, both in terms of general population screening as well as use as problem solving tools in specific patient groups, and where the limitations for these may lie. We aim to highlight some of the promising advances in imaging that are still in earlier stages, such as magnetic resonance elastography, as well as reviewing techniques that are already becoming incorporated into clinical practice.

背景与目标： ：近年来，乳腺癌的影像学经历了重大进展。通常需要一种多模态方法，随着乳房X线照片，超声，磁共振和核医学的不断发展，所有这些都有助于乳腺癌的成像。在这里，我们回顾文献以评估诸如乳房X线照相术等成熟技术的进步如何在诊断和实际获益方面带来了额外的好处，以及如何允许诸如断层合成和对比增强的X线照相术等衍生技术的应用。我们从总体人群筛查以及在特定患者群体中用作问题解决工具的角度考虑这些更新技术如何适合临床实践，以及这些方法可能存在的局限性。我们的目标是突出显示仍处于早期阶段的一些有希望的成像进展，例如磁共振弹性成像以及已经纳入临床实践的检查技术。