Robust rigid registration of retinal angiograms through optimization

Retinal fundus photographs are employed as standard diagnostic tools in ophthalmology. Serial photographs of the flow of fluorescein and indocyanine green (ICG) dye are used to determine the areas of the retinal lesions. For objective measurements of features, the registration of the images is a necessity. In this paper, we employ optimization techniques for registration with the help of 2-parameter translational motion model of retinal angiograms, based on non-linear pre-processing (Wiener filtering and morphological gradient) and computation of the similarity criteria for the alignment of the two gradient images for any given rigid transformation. The optimization methods are effectively employed to minimize the similarity criterion.

The presence of noise, the variations in the background and the temporal variation of the fluorescence level pose serious problems in obtaining a robust registration of the retinal images. Moreover, local search strategies are not robust in the case of ICG angiograms, even if one uses a multiresolution approach.

The present work makes a systematic comparison of different optimization techniques, namely the minimization method derived from the optical flow formulation, the Nelder-Mead local search and the HCIAC ant colony metaheuristic, each optimizing a similarity criterion for the gradient images. The impact of the resolution and median filtering of gradient image is studied and the robustness of the approaches is tested through experimental studies, performed on macular fluorescein and ICG angiographies.

Our proposed optimization techniques have shown interesting results especially for high resolution difficult registration problems. Moreover, this approach seems promising for affine (6-parameter motion model) or elastical registrations.     

Diagnostic accuracy of the Retinal Thickness Analyser: differentiation between normal eyes and eyes with glaucoma or macular pathologies

Background The Retinal Thickness Analyser (RTA) is intended to detect glaucomatous changes as well as macular pathologies at the posterior pole. We determined the diagnostic accuracy for eyes with manifest glaucoma or macular diseases.Methods We examined 71 eyes with long-term, established eye conditions. Included were 28 eyes with glaucoma, 21 with different macular diseases and 22 normal eyes. All examinations were evaluated in a blind-test by RTA experts without any clinical information on the patients. After comparison of the RTA interpretation with the clinical diagnosis, we determined sensitivity, specificity, positive and negative predictive values.Results Of 71 examinations, 15 (21%) were not interpretable. If these results are excluded, the following diagnostic accuracy values were calculated for glaucoma and macular disorders respectively: sensitivity 75 and 59%, specificity 55 and 97%, positive predictive value 48 and 90% and negative predictive value 80 and 84%. These values were not significantly different when both eyes of each patient were included in the final analysis (n=133).Conclusion The diagnostic values of the RTA determined in this case control study were not satisfactory. However, no clinical information was used in the assessment. The extent to which additional clinical information increases the diagnostic value remains to be determined.     

剖宫产术后下肢深静脉血栓的护理

目的探讨剖宫产术后深静脉血栓的护理经验。方法将2003年1月～2005年12月行剖宫产术的产妇76例，采取护理干预，加强饮食指导、抗凝血及溶栓护理。结果70例患者治愈，4例留有后遗症，2例转院，未跟踪报告。结论剖宫产术后易发生深静脉血栓；而高龄、经产、多胎、有产科并发症是其高危因素；应用护理措施进行积极干预，起到较好的预防作用，能保证产妇生命安全，提高产科护理质量。     

Percutaneous Endovascular Treatment for Stenoses and Occlusions of Infrarenal Aorta and Aortoiliac Bifurcation: Midterm Results

OBJECTIVE: evaluation and comparison of the endovascular treatment of isolated aortic and aortoiliac atherosclerotic lesions (stenoses and occlusions). METHODS: a percutaneous endovascular procedure was performed in 52 patients (38 men and 14 women) with a mean age of 52 years (range, 25-85 years). The baseline angiogram showed 35 aortic lesions (31 stenoses, 4 occlusions) and 17 aortoiliac lesions (14 stenoses, 3 occlusions). Percutaneous techniques used in this series included variable combinations of transluminal angioplasty and stenting. All stents placements were performed over-the-wire using the transfemoral route (most often bilateral approach). Clinical examination and Duplex-scan were performed at discharge, 1 month, 6 months, 12 months, and then yearly. RESULTS: technical success was 100% for aortic and aortoiliac lesions. Angiographic success rates were comparable for aortic (91%) and aortoiliac (94%) lesions. No death occurred during or early after the endovascular intervention. Duplex-scan confirmed 100% patency rate at discharge. There was no significant difference between the aortic (94%) and aortoiliac (96%) groups regarding immediate clinical improvement. Mean follow-up was 34+/-31 months (range, 0-130 months). The cumulative primary patency rate at 36 months was 85% in the aortic group and 86% in the aortoiliac group. Clinical success, defined as a symptom-free status at the end of follow-up, was also similar in both groups. CONCLUSION: endovascular treatment of isolated aortic lesions of the infra-renal aorta has favorable outcomes comparable to those of aortoiliac lesions.     

妊高征与眼底视网膜病变的临床探讨

目的 :探讨妊高征患者临床特征与视网膜病变的关系。方法 :观察 2 2 0例妊高征患者的眼底情况。结果 :视网膜病变与水肿关系不密切 ,与平均动脉压、蛋白尿的严重程度、病程及红细胞压积有密切关系 ;有眼底改变者 118例 ,占 5 0 .3%。结论 :眼底镜检查是临床上借以了解视网膜血管的常用方法 ,并可反映妊高征病情的程度 ,为产程处理提供依据     

经导管局部溶栓治疗髂-股静脉血栓:58例回顾性分析

目的　探讨经导管局部溶栓治疗髂 股静脉血栓的效果及临床应用中的有关问题。资料与方法　对 5 8例髂 股静脉血栓形成患者 (病程 <4周 4 5例 ,>4周 13例 ) ,采取经导管血栓局部灌注尿激酶 ,尿激酶先团注2 5 0 0 0 0U ,然后以 12 5 0 0 0～ 15 0 0 0 0U/h持续灌注。结果　全组溶栓治疗时间 4～ 5 6h ,平均 36h ,尿激酶用量75 0 0 0 0～ 72 5 0 0 0 0U ,平均 4 70 0 0 0 0U。阻塞段完全开通 (残存狭窄率 <30 % )者 30例 ,部分开通者 2 3例 ,无效 5例 ,有效率达 91.4 %。对残存狭窄率 >30 %的 2 3例 ,14例行经皮球囊血管成形术 (PTA)治疗 ,9例行PTA及内支架治疗。 6例溶栓前放置下腔静脉过滤器。本组无严重并发症及肺栓塞发生。结论　经导管血栓局部灌注尿激酶是治疗髂 股静脉血栓的安全、有效方法。溶栓术后继续肝素全身抗凝治疗可增强溶栓疗效     

Transarterial embolization of vein of Galen aneurysmal malformation after unsuccessful stereotactic radiosurgery

The authors present three cases of vein of Galen aneurysmal malformations (VGAMs) diagnosed in infancy and submitted by the referring teams for stereotactic radiosurgery as the initial therapy (therapeutic doses ranging between 20–25 Gy and 40–50 Gy to the peak dose). After the conventional follow-up of 18–24 months, no change could be detected in the angioarchitecture of the lesions. All three cases were then referred for endovascular treatment and underwent embolization by the transarterial route using liquid adhesives (N-butyl cyanoacrylate). This resulted in complete anatomical exclusion of the lesion. Regardless of the theoretical efficiency of radiosurgery in the management of brain arteriovenous malformations, the present authors believe that transarterial embolization remains the treatment of choice in VGAMs. It offers a high rate of morphological cure and the best chances for normal neurocognitive development. The time required by radiosurgery to achieve a significant result is too long for developing and maturing brain and may not prevent the negative effects of the lesion, mainly in regard to hemo- and hydrodynamic disorders (atrophy, subcortical calcifications, etc.) created by the VGAM, thus leading to irreversible mental retardation.     

老年人视网膜中央血管在前部视神经的解剖特征

目的：观察老年人前部视神经视网膜中央血管的解剖特征。 方法：通过组织连续切片和计算机影像分析，观察60~82岁老年人的18只眼球标本中无解剖变异的视网膜中央动脉(CRA)15条，视网膜中央静脉（CRV）23条在筛板前、筛板区及筛板后的管径变化。 结果：老年人筛板前、筛板区、筛板后CRA平均面积的均值分别为（12.70,17.40,18.00）×10^-3mm^2_;平均周长的均值分别为0.56，0.56，0.57mm，平均周长之间相比无显著差异。CRV平均面积的均值分别为（7.00，5.40，7.90）×10^-3mm²；平均周长的均值分别为0.44，0.38，0.41mm；CRV平均周长筛板前与筛板区相比，筛板区与筛板后相比均有显著差异。 结论：老年人CRA眼球内外管径一致；CRV在筛板区管径最小。 （中华眼底病杂志，1997，13：213-214）