Phase Error Correction in Time-Averaged 3D Phase Contrast Magnetic Resonance Imaging of the Cerebral Vasculature

Purpose

Volume flow rate (VFR) measurements based on phase contrast (PC)-magnetic resonance (MR) imaging datasets have spatially varying bias due to eddy current induced phase errors. The purpose of this study was to assess the impact of phase errors in time averaged PC-MR imaging of the cerebral vasculature and explore the effects of three common correction schemes (local bias correction (LBC), local polynomial correction (LPC), and whole brain polynomial correction (WBPC)).

Methods

Measurements of the eddy current induced phase error from a static phantom were first obtained. In thirty healthy human subjects, the methods were then assessed in background tissue to determine if local phase offsets could be removed. Finally, the techniques were used to correct VFR measurements in cerebral vessels and compared statistically.

Results

In the phantom, phase error was measured to be <2.1 ml/s per pixel and the bias was reduced with the correction schemes. In background tissue, the bias was significantly reduced, by 65.6% (LBC), 58.4% (LPC) and 47.7% (WBPC) (p < 0.001 across all schemes). Correction did not lead to significantly different VFR measurements in the vessels (p = 0.997). In the vessel measurements, the three correction schemes led to flow measurement differences of -0.04 ± 0.05 ml/s, 0.09 ± 0.16 ml/s, and -0.02 ± 0.06 ml/s. Although there was an improvement in background measurements with correction, there was no statistical difference between the three correction schemes (p = 0.242 in background and p = 0.738 in vessels).

Conclusions

While eddy current induced phase errors can vary between hardware and sequence configurations, our results showed that the impact is small in a typical brain PC-MR protocol and does not have a significant effect on VFR measurements in cerebral vessels.     

Non-Enhanced MR Imaging of Cerebral Aneurysms: 7 Tesla versus 1.5 Tesla

Purpose

To prospectively evaluate 7 Tesla time-of-flight (TOF) magnetic resonance angiography (MRA) in comparison to 1.5 Tesla TOF MRA and 7 Tesla non-contrast enhanced magnetization-prepared rapid acquisition gradient-echo (MPRAGE) for delineation of unruptured intracranial aneurysms (UIA).

Material and Methods

Sixteen neurosurgical patients (male n = 5, female n = 11) with single or multiple UIA were enrolled in this trial. All patients were accordingly examined at 7 Tesla and 1.5 Tesla MRI utilizing dedicated head coils. The following sequences were obtained: 7 Tesla TOF MRA, 1.5 Tesla TOF MRA and 7 Tesla non-contrast enhanced MPRAGE. Image analysis was performed by two radiologists with regard to delineation of aneurysm features (dome, neck, parent vessel), presence of artifacts, vessel-tissue-contrast and overall image quality. Interobserver accordance and intermethod comparisons were calculated by kappa coefficient and Lin''s concordance correlation coefficient.

Results

A total of 20 intracranial aneurysms were detected in 16 patients, with two patients showing multiple aneurysms (n = 2, n = 4). Out of 20 intracranial aneurysms, 14 aneurysms were located in the anterior circulation and 6 aneurysms in the posterior circulation. 7 Tesla MPRAGE imaging was superior over 1.5 and 7 Tesla TOF MRA in the assessment of all considered aneurysm and image quality features (e.g. image quality: mean MPRAGE7T: 5.0; mean TOF7T: 4.3; mean TOF1.5T: 4.3). Ratings for 7 Tesla TOF MRA were equal or higher over 1.5 Tesla TOF MRA for all assessed features except for artifact delineation (mean TOF7T: 4.3; mean TOF1.5T 4.4). Interobserver accordance was good to excellent for most ratings.

Conclusion

7 Tesla MPRAGE imaging demonstrated its superiority in the detection and assessment of UIA as well as overall imaging features, offering excellent interobserver accordance and highest scores for all ratings. Hence, it may bear the potential to serve as a high-quality diagnostic tool for pretherapeutic assessment and follow-up of untreated UIA.     

Screening for Unruptured Intracranial Aneurysms in Autosomal Dominant Polycystic Kidney Disease: A Survey of 420 Nephrologists

BackgroundDespite a high prevalence of intracranial aneurysm (ICA) in autosomal dominant polycystic kidney disease (ADPKD), rupture events are rare. The current recommendations for ICA screening are based on expert opinions and studies with low levels of evidence.ObjectivesThe aim of our study was to describe the attitudes of practicing nephrologists in Europe towards screening for ICA using magnetic resonance angiography (MRA).MethodsWe conducted a web-based survey among 1315 European French-speaking nephrologists and nephrology residents. An anonymous, electronic questionnaire including 24 independent questions related to ICA screening modalities, indications and participant profiles was sent by email between September and December 2014. Four hundred and twenty nephrologists (mostly from France) participated, including 31 nephrology residents; the response rate was 32%.ResultsSystematic screening for ICA was advocated by 28% of the nephrologists. A family history of ICA rupture, sudden death, stroke and migraine were consensual indications for screening (> 90% of the panel). In other clinical situations largely not covered by the recommendations (pregnancy, nephrectomy, kidney transplantation, cardiac or hepatic surgery, uncontrolled hypertension, lack of familial ADPKD history, at-risk activity, tobacco use), the attitudes towards screening were highly divergent. ICA screening was influenced by nephrologists experience with ADPKD and by their practice setting. The majority of participants (57%) would not repeat a normal ICA screening. Only a few participants (22%) knew that non-contrast MRA was the reference diagnostic tool for ICA screening, whereas most participants thought that contrast enhancement was necessary to screen for ICA. The results from the nephrology residents were analyzed separately and yielded similar results.ConclusionThis practice survey revealed that most nephrologists follow the current recommendations for the initial screening of ICAs. However, more than a quarter of the panel was in favor of systematic ICA screening, most nephrologists did not know that contrast medium was not necessary to screen for ICA using MRA, and many areas of uncertainty remain.     

Otomycosis in the South of Iran with a High Prevalence of Tympanic Membrane Perforation: A Hospital-Based Study

Mycopathologia - Otomycosis is a superficial infection of the external ear caused by fungal pathogens. The genera Aspergillus and Candida are considered the main fungal causative agents, with the...     

影像诊断在颅内动脉瘤中的研究进展

颅内动脉瘤(intracranial aneurysms,ICA)是由于脑血管局部异常改变而产生的血管瘤样突起,世界2%的人口患有颅内动脉瘤。颅内动脉瘤是引起脑卒中的第三大病因,仅次于脑血栓形成和高血压脑出血,脑卒中病死率、致残率极高,总病死率约为40~50%,早期诊断ICA对预防脑卒中意义重大。颅内动脉瘤的早期诊断主要依赖于影像学检查,近年多层螺旋CT、MRI及DSA技术的迅猛发展对颅内动脉瘤的早期诊断有很大帮助,本文就CT以及MRI功能成像在颅内动脉瘤的应用研究进展进行综述。     

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients ≤55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged ≤55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.     

三维DSA在颅内动脉瘤中的应用

目的探讨三维数字减影血管造影(3D DSA)在颅内动脉瘤中的应用价值。方法使用GE Innova 3100平板血管造影机对40例疑似颅内动脉瘤患者行双侧颈内、外动脉和双侧椎动脉正、侧位2D DSA,进一步对感兴趣血管行3D DSA,通过容积再现(VR)进行颅内血管重建。结果 3D DSA检出39例动脉瘤患者,47枚动脉瘤,2D DSA检出31例动脉瘤患者,35枚动脉瘤,二者检出动脉瘤的长、短径无统计学差异(P>0.05),图像质量有统计学差异(P<0.05)。2D DSA出现假阳性动脉瘤3枚,假阴性动脉瘤15枚,评估颅内动脉瘤的灵敏度为78.9%,特异性为85.2%;3D DSA没有出现假阳性、假阴性动脉瘤,评估颅内动脉瘤的灵敏度为100%,特异性为100%。在动脉瘤形态、瘤颈尺寸及与相邻血管间的关系的显示上,3D DSA明显优于2D DSA。结论 3D DSA作为脑动脉造影中2D DSA的进一步补充,对颅内动脉瘤的诊断与治疗具有重要价值。     

Accuracy and Reliability of Pallor for Detecting Anaemia: A Hospital-Based Diagnostic Accuracy Study

Background

Anaemia is a common disorder. Most health providers in resource poor settings rely on physical signs to diagnose anaemia. We aimed to determine the diagnostic accuracy of pallor for anaemia by using haemoglobin as the reference standard.

Methodology/Principal Findings

In May 2007, we enrolled consecutive patients over 12 years of age, able to consent and willing to participate and who had a haemoglobin measurement taken within a day of assessment of clinical pallor from outpatient and medicine inpatient department of a teaching hospital. We did a blind and independent comparison of physical signs (examination of conjunctivae, tongue, palms and nailbed for pallor) and the reference standard (haemoglobin estimation by an electronic cell counter). Diagnostic accuracy was measured by calculating likelihood ratio values and 95% confidence intervals (CI) at different haemoglobin thresholds and area under the receiver operating characteristic curve. Two observers examined a subset of patients (n = 128) to determine the inter-observer agreement, calculated by kappa statistics. We studied 390 patients (mean age 40.1 [SD 17.08] years); of whom 48% were women. The haemoglobin was <7 g/dL in 8% (95% confidence interval, 5, 10) patients; <9 g/dL in 21% (17, 26) patients and <12 g/dL in 64% (60, 70) patients. Among patients with haemoglobin <7 g/dL, presence of severe tongue pallor yielded a LR of 9.87 (2.81, 34.6) and its absence yielded a LR of 0. The tongue pallor outperformed other pallor sites and was also the best discriminator of anaemia at haemoglobin thresholds of 7 g/dL and 9 g/dL (area under the receiver operating characteristic curves (ROC area  = 0.84 [0.77, 0.90] and 0.71[0.64, 0.76]) respectively. The agreement between the two observers for detection of anaemia was poor (kappa values  = 0.07 for conjunctival pallor and 0.20 for tongue pallor).

Conclusions/Significance

Clinical assessment of pallor can rule out and modestly rule in severe anaemia.     

157例颅内动脉瘤患者CT血管成像与DSA临床分析

目的:探讨CT血管成像(CTA)在临床诊断颅内动脉瘤的价值。方法:回顾性分析本院157例经影像学检查或手术后确诊为颅内动脉瘤的患者,所有病例均依次行头颅CTA及DSA检查,由A、B两组医生(各三名),对CTA及DSA检查的结果进行独立的双盲判读确定,评估CTA和DSA对颅内动脉瘤诊断的敏感性,特异性;在CTA及DSA图像上分别测得瘤体最长径,比较两种检查在瘤体最长径测量上的结果差异;对颅内微动脉瘤(瘤体直径D3 mm)检出的敏感性比较。结果:1头颅CTA检出148例(94%),假阴性9例,DSA检出151例(96%),假阴性6例,两者特异性比较,无显著差异(P0.05)。2在CTA图像上测得瘤体最长径均数D=5.495 mm,在DSA图像上测得瘤体最长径均数D=5.503 mm,两种测量的测量值之间比较,无显著差异(P0.05)。3在微动脉瘤敏感性上,157例患者共有37个微动脉瘤,CTA检出35个,DSA检出33个,两种检查方法比较,无显著差异(P0.05)。结论:头颅CTA和DSA在颅内动脉瘤的诊断上具有相同的敏感性和特异性,可作为颅内动脉瘤的首选筛查。     

Intervention for Diagnosis of Deep Vein Thrombosis in Acute Stroke Patients: A Hospital-Based Study

Background

Immobile stroke patients are at high risk of deep vein thrombosis (DVT). Demographic studies suggest a low incidence of DVT in Asian patients, but that might be underestimated.

Objective

Intervention by in-hospital case management for diagnosis of DVT in patients with acute stroke.

Patients and Methods

Intervention was defined as: recommendation of D-dimer test for patients who are immobile by day 4 after stroke onset and compression ultrasonography if the level of D-dimer is ≥500 ng/ml. Treating physicians were notified by case managers before they failed to do so for qualified patients. Data of patients hospitalized 12 months before and 8 months after the intervention, including basic demographics, Glasgow Coma Scale score, National Institute of Health Stroke Scale (NIHSS) score, laboratory results, and examination reports, was retrieved from electronic medical records for analysis by code searches for acute stroke.

Results

A total of 2523 patients were identified. 1528 were before and 995 after intervention. More patients after intervention had D-dimer test and ultrasound examination than that before intervention (22.1% vs 8.6%, P<0.001 and 15.1% vs 1.2%, P<0.001, respectively). Ultrasound diagnosis of DVT was significantly more after than before intervention (2.0% vs 0.3%, P<0.001). DVT was 55.7 per 1000 in patients with a NIHSS score≧18. Male sex (Odds ratio 0.33, 95% confidence intervals: 0.11–0.98), NIHSS score (Odds ratio 1.05, 95% confidence intervals: 1.00–1.09), and intervention (Odds ratio 5.39, 95% confidence intervals: 1.88–15.44) were independent predictors of ultrasound diagnosis of DVT.

Conclusions

Intervention by in-hospital case management may be an effective strategy for improvement of under-diagnosis of DVT in acute stroke patients.     

Episcopic 3D Imaging Methods: Tools for Researching Gene Function

This work aims at describing episcopic 3D imaging methods and at discussing how these methods can contribute to researching the genetic mechanisms driving embryogenesis and tissue remodelling, and the genesis of pathologies. Several episcopic 3D imaging methods exist. The most advanced are capable of generating high-resolution volume data (voxel sizes from 0.5x0.5x1 µm upwards) of small to large embryos of model organisms and tissue samples. Beside anatomy and tissue architecture, gene expression and gene product patterns can be three dimensionally analyzed in their precise anatomical and histological context with the aid of whole mount in situ hybridization or whole mount immunohistochemical staining techniques. Episcopic 3D imaging techniques were and are employed for analyzing the precise morphological phenotype of experimentally malformed, randomly produced, or genetically engineered embryos of biomedical model organisms. It has been shown that episcopic 3D imaging also fits for describing the spatial distribution of genes and gene products during embryogenesis, and that it can be used for analyzing tissue samples of adult model animals and humans. The latter offers the possibility to use episcopic 3D imaging techniques for researching the causality and treatment of pathologies or for staging cancer. Such applications, however, are not yet routine and currently only preliminary results are available. We conclude that, although episcopic 3D imaging is in its very beginnings, it represents an upcoming methodology, which in short terms will become an indispensable tool for researching the genetic regulation of embryo development as well as the genesis of malformations and diseases.Key Words: 3D modelling, episcopic microscopy, imaging, embryo, development, gene expression.     

Assessment of Prosthesis Alignment after Revision Total Knee Arthroplasty Using EOS 2D and 3D Imaging: A Reliability Study

Introduction

A new low-dose X-ray device, called EOS, has been introduced for determining lower-limb alignment in 2D and 3D. Reliability has not yet been assessed when using EOS on lower limbs containing a knee prosthesis. Therefore purpose of this study was to determine intraobserver and interobserver reliability of EOS 2D and 3D knee prosthesis alignment measurements after revision total knee arthroplasty (rTKA).

Methods

Forty anteroposterior and lateral images of 37 rTKA patients were included. Two observers independently performed measurements on these images twice. Varus/valgus angles were measured in 2D (VV2D) and 3D (VV3D). Intraclass correlation coefficients and the Bland and Altman method were used to determine reliability. T-tests were used to test potential differences.

Results

Intraobserver and interobserver reliability were excellent for VV2D and VV3D. No significant difference or bias between the first and second measurements or the two observers was found. A significant mean and absolute difference of respectively 1.00° and 1.61° existed between 2D and 3D measurements.

Conclusions

EOS provides reliable varus/valgus measurements in 2D and 3D for the alignment of the knee joint with a knee prosthesis. However, significant differences exist between varus/valgus measurements in 2D and 3D.     

A Comparison of 4D Time-Resolved MRA with Keyhole and 3D Time-of-Flight MRA at 3.0 T for the Evaluation of cerebral Aneurysms

ABSTRACT: OBJECTIVE: To evaluate the feasibility of 4D time-resolved MRA with keyhole (4D-TRAK) for the diagnostic accuracy and reliability of the detection and characterization of cerebral aneurysms (CAs), with a comparison of 3D time-of-flight MRA (3D-TOF-MRA) by using DSA as a reference. Materials and methods 3D-TOF-MRA, 4D-TRAK and 3D-DSA were performed sequentially in 52 patients with suspected CAs. 4D-TRAK was acquired using a combination of sensitivity encoding (SENSE) and CE timing robust angiography (CENTRA) k-space sampling techniques at a contrast dose of 10 ml at 3 T. Accuracy, sensitivity, specificity of 4D-TRAK and 3D-TOF-MRA were calculated and compared for the detection of CAs on patient-based and aneurysm-based evaluation using 3D-DSA as a reference. RESULTS: The overall image quality of 4D-TRAK with a contrast dose of 10 ml was in the diagnostic range but still cannot be compared with that of 3D-TOF-MRA. In 52 patients with suspected CAs, fifty-eight CAs were confirmed on 3D-DSA finally. Fifty-one (with 2 false-positives and 9 false-negatives) and 58 (with 1 false-positive and 1 false-negative) CAs were visualized on 4D-TRAK and 3D-TOF-MRA, respectively. Accuracy, sensitivity and specificity on patient-based evaluation of 4D-TRAK and 3D-TOF-MRA were 92.31 %, 93.33 %, 85.71 % and 98.08 %, 100 %, 85.71 %, respectively, and 74.07 %, 75.00 %, 66.67 % and 96.30 %, 95.83 %, 100 % on aneurysm-based evaluation in patients with multiple CAs, respectively. Subgroup analysis revealed that for 19 very small CAs (maximal diameter <3 mm, measured on 3D-DSA), 9 were missed on 4D-TRAK and 1 on 3D-TOF-MRA (P?=?0.008). However, for 39 CAs with maximal diameter ? 3 mm, the diagnostic accuracy is equally (39 on 4D-TRAK vs. 39 on 3D-TOF-MRA) (P?=?1). In four larger CAs with maximal diameter ? 10 mm, 4D-TRAK provided a better characterization of morphology than 3D-TOF-MRA. CONCLUSION: 4D-TRAK at a lower contrast dose of 10 ml with a combination of SENSE and CENTRA at 3 T could provide similar diagnostic accuracy rate for CAs with maximal diameter???3 mm, and a better characterization of morphology for larger CAs with maximal diameter???10 mm compared to 3D-TOF-MRA. However, further study is still needed to improve the ?vascular edge? artifact and the compromise in spatial resolution in depiction of CAs with maximal diameter?3 mm.     

新型口服超顺磁性磁共振对比剂-NK50的体外试验研究

目的:研究一种由纳米磁性原料研制成功的口服磁共振胃肠对比剂-NK50,为磁共振造影提供一种新型材料。方法:按照新药研究的方法,进行了毒理、代谢、动力学、动物体内磁共振成像试验,并对其进行了效果分析。结果:家兔服用NK-50前后,血清铁无明显变化,MRI胃肠道显示率由5～15%提高到80～100%。结论:这种对比剂易于接受,安全性好,成像浓度范围宽,性能稳定,成本低,有优良超顺磁的性阴性对比效果和临床应用前景。     

Major Enteropathogenic Bacteria Isolated from Diarrheal Patients in Bolivia: A Hospital-Based Study

A total of 1,234 fecal samples from diarrhea cases were examined for etiological bacterial agents at medical facilities in La Paz and Sucre, Bolivia. Eighty strains of Shigella spp., 39 strains of Salmonella spp., 29 strains of Vibrio cholerae, and 222 strains of enteropathogenic Escherichia coli (139 EPEC, 55 ETEC, 29 EIEC, and 1 EHEC) were isolated. With regard to the serovars of Shigella, S. flexneri 2a, 3a, and 1b were predominant. In the case of Salmonella, S. enteritidis was the most common, followed by S. typhi, S. poona, and S. paratyphi B. Out of 29 cholera strains, 25 belonged to biovar El Tor, serovar Ogawa while the remaining 4 were serovar Inaba. Among 55 strains of ETEC serotypes, 5 showed ST producers but none showed LT producers. Likewise, among 55 strains of enterohemorrhagic serotypes, only one strain (O157:H7) produced verocytotoxin (VT 2). The results of drug sensitivity tests revealed the predominance of Shigella, EPEC, and ETEC strains resistant to aminobenzil-penicillin (ABPC) and trimethoprim. Since diarrheal patients in Bolivia are treated mainly with ABPC or sulfamethoxazole/trimethoprim (SXT) and rarely with gentamicin, kanamycin, or other drugs, it is possible that ABPC- and SXT-resistant strains will increase and persist in the near future.     

Magnetic Resonance Imaging of Cerebral Aspergillosis: Imaging and Pathological Correlations

Cerebral aspergillosis is associated with a significant morbidity and mortality rate. The imaging data present different patterns and no full consensus exists on typical imaging characteristics of the cerebral lesions. We reviewed MRI findings in 21 patients with cerebral aspergillosis and correlated them to the immune status of the patients and to neuropathological findings when tissue was available. The lesions were characterized by their number, topography, and MRI signal. Dissemination to the brain resulted from direct spread from paranasal sinuses in 8 patients, 6 of them being immunocompetent. Hematogenous dissemination was observed in 13 patients, all were immunosuppressed. In this later group we identified a total of 329 parenchymal abscesses involving the whole brain with a predilection for the corticomedullary junction. More than half the patients had a corpus callosum lesion. Hemorrhagic lesions accounted for 13% and contrast enhancement was observed in 61% of the lesions. Patients with hematogenous dissemination were younger (p = 0.003), had more intracranial lesions (p = 0.0004) and had a higher 12-week mortality rate (p = 0.046) than patients with direct spread from paranasal sinuses. Analysis of 12 aneurysms allowed us to highlight two distinct situations. In case of direct spread from the paranasal sinuses, aneurysms are saccular and located on the proximal artery portions, while the hematogenous dissemination in immunocompromised patients is more frequently associated with distal and fusiform aneurysms. MRI is the exam of choice for cerebral aspergillosis. Number and type of lesions are different according to the mode of dissemination of the infection.     

10-Year Overview of the Hospital-Based Prevalence and Treatment of Congenital Cataracts: The CCPMOH Experience

A review of 6 years of hospitalization charts from Zhongshan Ophthalmic Center (ZOC) revealed that congenital cataracts (CC) accounted for 2.39% of all cataract in-patient cases and that the age at surgery was decreasing before the establishment of the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH) in December 2010. We aimed to investigate data from the 4 years (January 2011 to December 2014) following the establishment of the CCPMOH, compared, and combined with data from the previous study period (January 2005 to December 2010) to generate a 10-year overview of the hospital-based prevalence and treatment of CC. In the 4-year period after CCPMOH establishment, the prevalence of CC was 2.01% in all hospitalizations, and was 2.78% in all cataract in-patients. Most of the eligible CC in-patients (71%) lived in south China. The ratio of boys to girls was 1.42:1. Nearly 2/3 of the patients underwent cataract extraction with primary intraocular lens (IOL) implantation at a mean age of 78.40±51.45 months, and cataract extraction surgeries without IOL implantation were performed in the remaining 1/3 of patients at a mean age of 10.03±15.92 months. After CCPMOH establishment, an increased incidence of CC was revealed, and the CC in-patients were younger than the patients in the previous period. The 10-year overview (2421 CC in-patients from 206630 hospitalizations) revealed upward trends in both the number and the prevalence of CC and a further reduction in age at surgery. In conclusion, the data from 4-year period after CCPMOH establishment and the 10-year overview showed upward trends in the hospital-based prevalence of CC cases and a further reduction in age at surgery, likely reflecting the effects of the CCPMOH establishment and providing useful information for further CC studies and a valuable foundation for the prevention and treatment of this cause of childhood blindness.     

In-Line Phase Contrast Imaging of Hepatic Portal Vein Embolization with Radiolucent Embolic Agents in Mice: A Preliminary Study

It is crucial to understand the distribution of embolic agents inside target liver during and after the hepatic portal vein embolization (PVE) procedure. For a long time, the problem has not been well solved due to the radiolucency of embolic agents and the resolution limitation of conventional radiography. In this study, we first reported use of fluorescent carboxyl microspheres (FCM) as radiolucent embolic agents for embolizing hepatic portal veins. The fluorescent characteristic of FCM could help to determine their approximate location easily. Additionally, the microspheres were found to be fairly good embolizing agents for PVE. After the livers were excised and fixed, they were imaged by in-line phase contrast imaging (PCI), which greatly improved the detection of the radiolucent embolic agents as compared to absorption contrast imaging (ACI). The preliminary study has for the first time shown that PCI has great potential in the pre-clinical investigation of PVE with radiolucent embolic agents.     

Characteristics of Spondylotic Myelopathy on 3D Driven-Equilibrium Fast Spin Echo and 2D Fast Spin Echo Magnetic Resonance Imaging: A Retrospective Cross-Sectional Study

In patients with spinal stenosis, magnetic resonance imaging of the cervical spine can be improved by using 3D driven-equilibrium fast spin echo sequences to provide a high-resolution assessment of osseous and ligamentous structures. However, it is not yet clear whether 3D driven-equilibrium fast spin echo sequences adequately evaluate the spinal cord itself. As a result, they are generally supplemented by additional 2D fast spin echo sequences, adding time to the examination and potential discomfort to the patient. Here we investigate the hypothesis that in patients with spinal stenosis and spondylotic myelopathy, 3D driven-equilibrium fast spin echo sequences can characterize cord lesions equally well as 2D fast spin echo sequences. We performed a retrospective analysis of 30 adult patients with spondylotic myelopathy who had been examined with both 3D driven-equilibrium fast spin echo sequences and 2D fast spin echo sequences at the same scanning session. The two sequences were inspected separately for each patient, and visible cord lesions were manually traced. We found no significant differences between 3D driven-equilibrium fast spin echo and 2D fast spin echo sequences in the mean number, mean area, or mean transverse dimensions of spondylotic cord lesions. Nevertheless, the mean contrast-to-noise ratio of cord lesions was decreased on 3D driven-equilibrium fast spin echo sequences compared to 2D fast spin echo sequences. These findings suggest that 3D driven-equilibrium fast spin echo sequences do not need supplemental 2D fast spin echo sequences for the diagnosis of spondylotic myelopathy, but they may be less well suited for quantitative signal measurements in the spinal cord.