Development of Automated Image Stitching System for Radiographic Images

Standard X-ray images using conventional screen-film technique have a limited field of view that is insufficient to show the full bone structure of large hands on a single frame. To produce images containing the whole hand structure, digitized images from the X-ray films can be assembled using image stitching. This paper presents a new medical image stitching method that utilizes minimum average correlation energy filters to identify and merge pairs of hand X-ray medical images. The effectiveness of the proposed method is demonstrated in the experiments involving two databases which contain a total of 40 pairs of overlapping and non-overlapping hand images. The experimental results are compared with that of the normalized cross-correlation (NCC) method. It is found that the proposed method outperforms the NCC method in classifying and merging the overlapping and non-overlapping medical images. The efficacy of the proposed method is further indicated by its average execution time, which is about five times shorter than that of the other method.     

肿瘤疾病中信息管理的应用与发展概况

对目前国内信息管理工具在肿瘤疾病领域的应用与发展进行简要综述，总结此领域中信息管理软件应用的优势和不足，发现信息管理的应用为肿瘤疾病的管理带来极大的方便，在肿瘤的注册登记、随访、防治、数据管理和专项数据库建设方面尤为突出，但仍缺少功能全面的一体化的管理软件。随着肿瘤诊疗水平的不断进步和中医综合治疗在肿瘤治疗中地位的提升，急需探索开发能够体现中医综合治疗特色和满足肿瘤临床、科研和管理工作的需求的肿瘤信息管理应用软件。     

A clinical validation study for the feasibility and reliability of three-dimensional ultrasound-ultrasound automatic image registration

Abstract

Purpose: The purpose of our study was to assess the feasibility and reliability of 3D ultrasound-ultrasound (US-US) automatic registration-based analysis of the hepatic vessel tree (VT) (3D VT-based automatic registration) in clinical applications. Materials and methods: A total of 70 pairs of 3D ultrasound data were acquired from the livers of 10 healthy volunteers enrolled in the study. An automatic registration method was applied to the acquired volumetric data pairs, and anatomic landmarks were picked by an experienced sonographer as ‘ground truth’. The influences of respiration phase, subject posture, and liver lobe on data acquisition and scan volumetric angle on the registration accuracy and robustness were investigated. The registration time, success rate, median registration error distance, and sonographer’s subjective feedback were assessed. Results: The time required for the 3D VT-based automatic registration was approximately 15～20?s. Overall, the success rate for the hepatic vessel-based registration was 71% (50/70), and the median registration error distance was 1.72?mm (0.57～4.71?mm). When the influential factors were well controlled, the optimal registration accuracy (median registration error distance?=?1.22?mm) could be obtained with an excellent success rate of 100% (10/10). According to the subjective assessment of the sonographer, over 90% (45/50) of the automatic registration results were not inferior to the ground truth. Among them, 42% (21/50) were superior to the fusion results from the ground truth. Conclusions: The results suggest that the 3D VT-based automatic registration is feasible and reliable and has potential for guidance and evaluation of intraoperative ablation of hepatocellular carcinoma.     

Population based ranking of frameless CT-MRI registration methods

BackgroundClinical practice often requires simultaneous information obtained by two different imaging modalities. Registration algorithms are commonly used for this purpose. Automated procedures are very helpful in cases when the same kind of registration has to be performed on images of a high number of subjects. Radiotherapists would prefer to use the best automated method to assist therapy planning, however there are not accepted procedures for ranking the different registration algorithms.PurposeWe were interested in developing a method to measure the population level performance of CT-MRI registration algorithms by a parameter of values in the [0,1] interval.Materials and MethodsPairs of CT and MRI images were collected from 1051 subjects. Results of an automated registration were corrected manually until a radiologist and a neurosurgeon expert both accepted the result as good. This way 1051 registered MRI images were produced by the same pair of experts to be used as gold standards for the evaluation of the performance of other registration algorithms. Pearson correlation coefficient, mutual information, normalized mutual information, Kullback-Leibler divergence, L₁ norm and square L₂ norm (dis)similarity measures were tested for sensitivity to indicate the extent of (dis)similarity of a pair of individual mismatched images.ResultsThe square Hellinger distance proved suitable to grade the performance of registration algorithms at population level providing the developers with a valuable tool to rank algorithms.ConclusionsThe developed procedure provides an objective method to find the registration algorithm performing the best on the population level out of newly constructed or available preselected ones.     

A new method to optimize resection area using a radiation treatment planning system and deformable image registration for breast-conserving surgery after neoadjuvant chemotherapy

BackgroundWe devised a breast-conserving surgery (BCS) utilizing a new image-processing and projection technique using a radiation treatment planning system (RTPS) and deformable image registration (DIR) for patients with breast cancer after neoadjuvant chemotherapy (NAC). RTPSs and DIR are commonly used in planning radiation treatment. The purpose of this pilot study was to evaluate the feasibility of our procedure.Patients and methodsTwenty-six patients diagnosed with breast cancer underwent NAC and BCS between November 2014 and May 2020. Multidetector-row computed tomography was performed in the same position used for surgery before and after NAC. In the DIR, CT before NAC was fused to CT after NAC. The RTPS simulated the design of tumor excision, and excision area was projected onto the breast skin utilizing an irradiation device.ResultsIn 26 patients with breast cancer after NAC, BCS was performed using the processing and projection technique of the RTPS with DIR. Only 1 of 26 patients showed carcinoma present in the surgical margins, and subsequently developed ipsilateral breast tumor recurrence. Mean excised volume was 33.5 cm³ (range, 12.8–62.8 cm³), and percent breast volume excised was 6.8% (range, 2.5–15.7%).ConclusionsThis pilot study confirmed the simplicity and utility of our procedure for minimally invasive BCS in patients with breast cancer after NAC. We will keep evaluating the safety and efficacy of our procedure in more patients.     

Endovascular image-guided navigation - validation of two volume-volume registration algorithms

Abstract

The limited volume covered by intraoperatively acquired CT scans makes the use of navigation systems difficult. Preoperative images cover a larger volume of interest. Hence, reliable registration of high quality preoperative to intraoperative CT will provide the necessary image information required for navigation. This study evaluates two algorithms (Siemens, CAMP) for volume-volume registration for usage during endovascular navigation. Twenty patients treated for abdominal aortic aneurysm were scanned with pre-, intra- and postoperative CT. Six data sets were excluded due to variations in image acquisition parameters and severe artifacts. Fourteen intra- and postoperative datasets were registered ten times with both algorithms, altogether 140 registrations for each program. In all data sets five specified landmarks placed by two radiologists were used to evaluate registration accuracy. The distance between the paired landmarks in the registered intra- and postoperative volumes was measured and the root mean square value calculated. Reference registrations were based on rigid body registration of the five landmarks in the intra- and postoperative volumes. Registration accuracy (mean ± SD) was for Siemens 5.05 ± 4.74 mm, for CAMP 4.02 ± 1.52 mm and for the reference registrations 2.72 ± 1.18 mm. The registration algorithms differed significantly, p < 0.001.     

基于图像形变配准的宫颈癌放疗累积剂量学研究

目的 比较两种不同累积方式下宫颈癌放疗累积剂量,并分析直肠累积剂量与放射性直肠炎严重程度相关性。方法 回顾分析278例已完成放疗的宫颈癌患者资料,对其中发生放射性直肠炎的49例患者分别采用直接“剂量-体积”直方图参数累积方法(S-DVH组)与图像形变配准方法(DIR组)获得累积剂量(EQD2Gy),并统计该278例患者S-DVH法的直肠累积剂量(D2.0cm³、D1.0cm³、D0.1cm³)。采用Spearman法进行相关分析。结果 S-DVH组较DIR组的高危临床靶体积D90%高2 Gy[(88.66±5.75) Gy∶(86.66±5.54) Gy, P<0.05],膀胱D2.0cm³、D1.0cm³分别高2.13Gy[(82.46±6.91) Gy∶(80.33±6.86) Gy,P<0.05]、2.35 Gy[(88.46±4.37) Gy∶(86.11±3.93) Gy,P<0.05],直肠D2.0cm³、D1.0cm³分别高[1.99 Gy (72.49±5.17) Gy∶(70.50±5.03) Gy,P<0.05]、2.71 Gy[(78.87±4.50) Gy∶(76.16±4.14) Gy,P<0.05]。直肠D2.0cm³、D1.0cm³、D0.1cm³与放射性直肠炎严重程度呈正相关。结论 两组累积剂量不同但均在可接受范围,临床上为了简便可用S-DVH法评估。直肠D2.0cm³、D1.0cm³、D0.1cm³可用于预测直肠放疗不良反应。     

军队医疗机构非PVC软包装输液袋配制注册申请的准备与实施

目的探索军队医疗机构非PVC软包装输液袋配制注册申请准备工作及注意事项。方法参照《直接接触药品包装材料和容器管理办法》,进行报批各项准备工作。结论通过系统总结我院非PVC软包装输液袋配制注册申请经验做法,为军队医疗机构申报单位提供参考。