Periapical radiographic techniques during endodontic diagnosis and treatment

The objective of this article is to describe various radiographic projections which can be used during endodontic therapy. Changes to the angulation of the X-ray beam in relation to the teeth and film can help diagnosis and treatment by producing images which provide additional information not always visible on radiographs taken with standard angulations. For example, changes in angulation can be useful to determine the number and curvature of roots and canals, to identify superimposed roots and to distinguish between anatomical landmarks and apical pathology. Although use of such techniques increases the diagnostic yield of films, it must be appreciated that such views lead to images that are less distinct because of inherent image distortion. Nevertheless, use of the various techniques during endodontics can provide substantial benefit for clinicians in their daily practice.     

A Study on Extension－Flexion Dynamic Lumbar Spine Radiographsin Patients with Lumbar Intervertebral Disc Herniation

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Vanishing pleural fluid collections in cardiac failure simulating lung tumours

Vanishing fluid collections in interlobar fissures, associated with congestive cardiac failure, are uncommon but well-recognized. Previous studies have highlighted the occurrence of solitary vanishing ‘tumours’, but in the study reported here 7 out of 12 consecutive patients presented with more than one interlobar fluid collection simulating pulmonary tumours. In most cases a lateral radiograph confirmed the correct diagnosis and in all cases follow-up radiographs demonstrated resolution of all pleural fluid collections. In one case ultrasound was helpful. Making the correct diagnosis is very important inorder to prevent inappropriate investigations and treatment such as biopsy or surgery. It is suggested that unusual pleural fluid collections may be more common in communities where pleural disease following stab wounds or tuberculosis are more prevalent.     

Lacunar skull deformity and hydrocephalus in infants with myelomeningocele: is lacunar skull deformity a predictor of hydrocephalus development?

Objects We evaluated whether the presence of lacunar skull deformity (LSD) with myelomeningocele is a predictive factor for subsequent hydrocephalus development. Materials and methods We reviewed the clinical and radiological records of 18 infants with myelomeningocele, divided the patients into groups with (group A, n=9) and without (group B, n=9) ventriculomegaly at birth and assessed whether the presence of LSD was predictive of the necessity for ventriculoperitoneal shunt (VPS) placement. Results LSD was present in five group A patients. All nine group A patients underwent VPS placement. Among the group B patients, five had LSD; they underwent VPS placement. A significantly higher proportion of those with ventricle enlargement or LSD at birth required VPS placement (p=0.0001). Conclusion Adding to the ventriculomegaly at birth, the presence of LSD alerts to the necessity to monitor these infants closely to determine the necessity for VPS placement.     

Accuracy of Preoperative Templating in Total Hip Arthroplasty With Special Focus on Stem Morphology: A Randomized Comparison Between Common Digital and Three-Dimensional Planning Using Biplanar Radiographs

BackgroundAccurate preoperative planning is a key component of successful total hip arthroplasty (THA). The purpose of the present study was to compare the accuracy and reliability of three-dimensional (hipEOS) and common digital two-dimensional (TraumaCad) templating with special focus on stem morphology.Methods51 patients undergoing THA were randomized to two groups. Preoperative planning was performed on 23 patients with hipEOS (3D) and on 28 patients with TraumaCad (2D) planning software. Planning results were compared with the implanted component size. Inter- and intraobserver reliability as well as planning accuracy of both planning methods with special focus on straight and short stem design were recorded.ResultsIntraobserver reliability of both planning methods was good for component planning (ICC_2,1: 0.835-0.967). Interobserver ICC_2,1 for stem and cup planning were higher for 3D templating (3D ICC_2,1: 0.906-0.918 vs. 2D ICC_2,1: 0.835-0.843). Total stem and cup size predictions were within 2 sizes for 3D and within 3 sizes for 2D planning. Comparing short stem planning accuracy of both planning methods, absolute difference between implanted and planned component size was significantly lower in 3D planning (P = .029). There was no significant difference in straight stem (P = .935) and cup (P = .954) planning accuracy.ConclusionOur findings suggest that 3D templating with hipEOS software has a good overall reliability and may have a better planning accuracy of short stem prostheses than digital templating with TraumaCad software. Assuming that the number of implanted short stem prostheses will further increase in coming years, a more precise planning with 3D technique can contribute to improve surgery outcome.     

基于改进SLNC的2D-3D医学图像配准

介绍了一种基于改进SLNC(sum of local normalized correlation,SLNC)的2D-3D医学图像配准方法。首先对CT体积数据进行三线性插值,得到各向分辨率相同的体积数据,采用光线跟踪算法对其进行数字图像重建。针对不同位置和方向的重建图像,在灰度级压缩的基础上,用改进SLNC函数评价其与X线透视图像的相似性,利用与Brent相结合的Powell优化方法,搜索出相似性最大时的投影变换参数。将此方法用于移动数字X线投影设备——Biplanar 500采集的X线透视图像与相应CT体积数据的配准实验,得到较好的2D-3D图像配准效果。     

76例颞下颌关节紊乱病患者许氏位片中髁突位置的分析

目的通过颞下颌关节紊乱病(TMD)患者的许氏位片来分析患者的髁突位置变化。方法选取76例TMD患者为研究对象,男性30例,女性46例,年龄为17～53岁。采用Cohlmia法对76例患者的双侧颞下颌关节(TMJ)的牙尖交错位标准许氏位片进行测量分析。结果76例TMD患者左侧颞下颌关节的PO1(反映髁突矢状向位置)平均值为1.220±0.422,PO2(反映髁突垂直向位置)平均值为0.386±0.085,右侧颞下颌关节的PO1平均值为1.119±0.386,PO2平均值为0.397±0.098,左、右侧髁突位置及关节窝形态的差异均无统计学意义(P>0.05)。结论在颞下颌关节紊乱病患者的许氏位片中,髁突位置变化不明显,诊断意义不大。     

Measuring distortion of skeletal elements in Lodox Statscan‐generated images

Due to a scarcity of available skeletal material, anthropologists and other practitioners face difficulties with either the creation or validation of techniques used to estimate a biological profile in subadults. To address this problem, radiographic images of living individuals are often used in lieu of dry skeletal elements. However, radiographic images suffer from distortion. Some problems with metric analyses when using radiographic images may be addressed with the Lodox Statscan, an X‐ray machine that claims to produce minimal distortion along the scan‐axis due to a linear slot‐scanning design. The purpose of this research was to measure the distortion of skeletal elements in radiographic images generated from a Lodox Statscan. Skeletal elements subject to multiple imaging variables that affect distortion were radiographed, measured, and then compared to the dry bone measurements through multiple approaches. An 85% percent agreement within a ±1 mm range and a 97% agreement within a ±2 mm range was obtained. Percent difference results demonstrate that slot‐axis measurements incurred more distortion than scan‐axis measurements (11.8% and 2.7%, respectively). Inclusion of foam results in 4.5% more error than when foam is not included in the image. Angled scan‐axis measurements also incurred more distortion than either nonangled slot‐ and scan‐axis measurements. A Bland‐Altmanplot reveals an overall agreement between the radiographic and dry bonemeasurements, with most measurements falling within the upper and lower limits. Similar measurement error is found in Statscan radiographic and dry bone measurements; therefore, the Statscan offers a radiographic venue to collect metric data. Clin. Anat. 26:780–786, 2013. © 2013 Wiley Periodicals, Inc.