Enamel and dentin mineralization in familial hypophosphatemic rickets: a micro-CT study

Objectives:

The aim of the present study was to analyse the mineralization pattern of enamel and dentin in patients affected by X-linked hypophosphatemic rickets (XLHR) using micro-CT (µCT), and to associate enamel and dentin mineralization in primary and permanent teeth with tooth position, gender and the presence/absence of this disease.

Methods:

19 teeth were collected from 5 individuals from the same family, 1 non-affected by XLHR and 4 affected by XLHR. Gender, age, tooth position (anterior/posterior) and tooth type (deciduous/permanent) were recorded for each patient. Following collection, teeth were placed in 0.1% thymol solution until µCT scan. Projection images were reconstructed and analysed. A plot profile describing the greyscale distance relationship in µCT images was achieved through a line bisecting each tooth in a region with the presence of enamel and dentin. The enamel and dentin mineralization densities were measured and compared. Univariate ANOVA and post hoc Tukey tests were used for all comparisons.

Results:

Teeth of all affected patients presented dentin with a different mineralization pattern compared with the teeth of healthy patients with dentin defects observed next to the pulp chambers. Highly significant differences were found for gray values between anterior and posterior teeth (p < 0.05), affected and non-affected (p < 0.05), as well as when position and disease status were considered (p < 0.05).

Conclusions:

In conclusion, the mineralization patterns of dentin differed when comparing teeth from patients with and without FHR, mainly next to pulp chambers where areas with porosity and consequently lower mineral density and dentin defects were found.     

牙周骨质丢失与颈动脉钙化相关性的无创性MSCT评价

目的：通过多层螺旋 CT(MSCT)容积成像技术探讨牙周骨质丢失(PBL)与颈动脉钙化的相关性及临床意义。方法回顾性分析270例可疑动脉粥样硬化患者颈部的 MSCT 检查,将原始数据进行薄层重建后进行颅外颈部动脉全程钙化积分的测量,根据平均积分情况将患者分为3组：颈动脉钙化积分<100分者为轻度钙化组;颈动脉钙化积分≥100分者为重度钙化组;颈部动脉无钙化者为对照组。应用 EBW4.5工作站对原始图像进行容积重现(VR)、多平面重建(MPR)、曲面重建(CPR)、最大密度投影(MIP)等多种后处理方法,观察记录各组口内存牙数及牙周骨质丢失情况。结果MSCT 容积成像技术可以在定量测量颈部动脉钙化程度的同时准确显示牙齿数目及牙周骨质丢失情况;颈动脉钙化者牙周骨质丢失牙位数高于对照组,存在统计学差异(P <0.01),且牙周骨质丢失牙位数与颈动脉钙化程度呈正相关。结论牙周骨质丢失与颈动脉钙化密切相关。MSCT 容积成像是定量评估颈动脉硬化与牙周炎严重程度的无创检查方法。     

MR扩散加权成像评估椎体骨量状况的初步研究

目的 探讨椎体MR扩散加权成像(DWI)测量值与双能X线(DXA)、定量GT(QCT)所测骨密度的相关性.方法 152例女性志愿者分别进行以下检查:胸腰椎侧位(T4～L4)X线平片,并采用Genant半定量法对其进行评阅;腰椎(L2～L4)DXA和QCT骨密度测量;腰椎常规行MR矢状面T2 WI、T1 WI和横断面T2 WI扫描;MR常规扫描结束后采用单次激发自旋回波平面回波扩散加权序列(SS-SE-EPI DWI)[扩散敏感因子(b)=500 s/mm2]进行L2～L4椎体横断面DWI扫描,并使用GE-Functool分析软件测量相应椎体表观扩散系数(ADC值).计量资料间的相关性采用Pearson相关分析.结果 随年龄增加,椎体ADC值呈逐步降低趋势.L2～L4椎体平均ADC值(0.241×10-3 mm2/s)与相应椎体平均骨密度DXA(I.038 s/cm2)、QCT(104.2 mg/cm3)具有相关性(r值分别为0.461、0.731,P值均＜0.01).结论 DWI可在常规2腰椎MRI基础上无创性评估椎体骨髓变化状况,进而来评估骨髓的变化对于骨量状况所带来的影响.     

Immobilisation in Australian paediatric medical imaging: A pilot study

AimsThe primary aim of this study is to document the use of paediatric immobilisation techniques in medical imaging. Secondary aims are to investigate differences between current practice of paediatric and non-paediatric facilities and radiographer gender and to investigate immobilisation protocols.MethodsA SurveyMonkey link was distributed through the Australian Society of Medical Imaging and Radiation Therapy (ASMIRT) newsletter. Radiographer members of ASMIRT were invited to participate. Frequency percentage analysis was undertaken; as the 'frequency of immobilisation' response was on a Likert scale and the ages categorical, a Fisher's exact test could determine dependency.ResultsThe use of paediatric immobilisation techniques was determined to be related to age. The most commonly used technique in general X-ray was “other people”; in computed tomography, Velcro, verbal reminders and distraction techniques; and in magnetic resonance imaging, sedation and Velcro. A comparison of immobilisation techniques demonstrated that Velcro use in X-ray was dependent on facility (p = 0.017) with paediatric facilities using it up to 17 years. Immobilisation frequency was dependent in 13–17 years (p = 0.035) with paediatric facilities rarely immobilising and non-paediatric facilities never. No dependencies resulted upon comparing genders. Immobilisation frequency was not dependent between protocols or current practice.ConclusionThe use of paediatric immobilisation technique is related to age with “other people”, sedation, Velcro, verbal reminders and distraction techniques being regularly used. The dependency of Velcro use and immobilisation frequency in 13–17 years is for unknown reasons and further investigation is required. A larger study should be carried out to validate these findings.     

Characterization of coronary atherosclerosis by dual-source computed tomography and HU-based color mapping: a pilot study

To assess HU-based color mapping for characterization of coronary plaque, using intravascular ultrasound virtual histology (IVUS-VH) as a standard of reference. Dual-source computed tomography and IVUS-VH were prospectively performed in 13 patients. In five lesions, HU thresholds of the color-coding software were calibrated to IVUS-VH. In a 15-lesion verification cohort, volumes of vessel, lumen and plaque or percentages of lipid, fibrous and calcified components were obtained through use of pre-set HU cut-offs as well as through purely visual adjustment of color maps. Calibrated HU ranges for fatty or fibrous plaque, lumen and calcification were -10–69, 70–158, 159–436 and 437+. Using these cut-offs, HU-based analysis achieved good agreement of plaque volume with IVUS (47.0 vs. 51.0 mm³). Visual segmentation led to significant overestimation of atheroma (61.6 vs. 51.0 mm³; P = 0.04) Correlation coefficients for volumes of vessel, lumen and plaque were 0.92, 0.87 and 0.83 with HU-based analysis or 0.92, 0.85 and 0.71 with visual evaluation. With both methods, correlation of percentage plaque composition was poor or insignificant. HU-based plaque analysis showed good reproducibility with intra-class correlation coefficients being 0.90 for plaque volume and 0.81, 0.94 or 0.98 for percentages of fatty, fibrous or calcified components. With use of optimized HU thresholds, color mapping allows for accurate and reproducible quantification of coronary plaque. There is no conflict of interest.     

动态CT增强扫描对甲状腺结节诊断价值的初步研究

目的：探讨动态CT增强扫描对甲状腺结节的鉴别诊断价值。方法：选择经病理证实甲状腺结节患者55例进行动态增强扫描,将病灶强化方式分成无强化、不均匀强化和均匀强化3种类型,测量病灶增强前后各时间点的CT值,并根据增强后CT增加值绘制动态曲线。结果：甲状腺癌9例,7例表现为均匀性强化,2例不均匀强化;腺瘤19例,6例呈均匀强化,8例不均匀强化,5例无强化;结节性甲状腺肿27例,9例均匀强化,15例不均匀强化,3例无强化。强化方式在良恶性结节间有显著差异（χ2=6.682,P〈0.05）。多数（7/9）甲状腺癌的动态曲线呈速升缓降型,2例速升速降型,达峰时间为50s;大部分（12/19）腺瘤动态曲线呈速升缓降型,达峰时间约50s,小部分为速升速降型（3/18）或平稳型（4/18）;多数（16/27）结节性甲状腺肿动态曲线呈速升速降型,小部分呈速升缓降型（6/27）或平稳型（5/27）。结论：动态增强扫描就甲状腺结节的强化方式和动态曲线提供更多的信息,对甲状腺结节的鉴别诊断有重要价值。     

A cadaveric model for ligamentum teres function: a pilot study

Purpose

Despite the prevalence and clinical consequences of ligamentum teres pathology, its function is poorly understood. The purpose of this study was to help define the role the ligamentum teres may have in hip joint stabilization and determine whether a ball and string model could be used to describe the function of the ligamentum teres.

Methods

Eight embalmed cadavers were dissected to remove all soft tissue from around the hip, leaving only the ligamentum teres intact. Available hip abduction, adduction, medial rotation, and lateral rotation range of motion were measured for three repeated trials. The position of the ligamentum teres in relation to the femoral head was recorded at the endpoint position of these movements.

Results

An endpoint position as limited by the ligamentum teres for abduction, medial rotation, and lateral rotation was identified at a mean of 73°(SD 11°), 64°(SD 11°), and 58°(SD 10°), respectively. Hip adduction was limited by bony contact and therefore was not measured. The ligamentum teres wrapped around the femoral head to prevent inferior, posterior, and anterior subluxation with abduction, medial rotation, and lateral rotation, respectively. Repeated measures ANOVA indicated no significant difference in endpoint position based on trial number for the three movements (n.s.).

Conclusion

The ligamentum teres consistently tightened to limit hip abduction, medial rotation, and lateral rotation. These results support a ball and string model for the femoral head and ligamentum teres. This information could be important for those with hip instability and ligamentum teres pathology.     

脑CTA临床应用价值的初步探讨

目的对脑CTA临床应用价值作一初步评估。材料与方法19例脑血管病变、脑膜瘤患者行脑CTA检查。主要扫描技术参数层厚1mm，螺距1，对比剂60％泛影葡胺，给药速度3ml／s，按T＝13×60／F+T120计算延迟时间。图像重建采用最大强度投影(MaxiumIntensityProjection,MIP)。结果脑血管MIP图像图真实地显示血管形态和病变，术前评估肿瘤与邻近血管的关系。结论脑CTA可作为脑血管病变、颅内血供丰富肿瘤的诊断和筛选，制订手术方案，观察治疗效果的较理想手段。     

Dental superimposition: a pilot study for standardising the method

Dental superimposition is becoming more and more important because of the increasing number of illegal immigrants (at least in Italy), with no clinical history, no personal effects or relatives useful for genetic comparison, whose friends and acquaintances can usually only produce photographs. Very few authors have been involved in devising and using this method. The goal of the present study is to establish whether it is possible, and under which conditions, to identify individuals by dental superimposition of teeth visible in an ante-mortem photograph and dental casts of an unidentified body, and to develop a protocol for the spatial orientation analysis of the dentition and qualitative and semi-quantitative analysis of superimpositions. A non-mathematical scoring system has been applied to each superimposition as a first step towards the optimisation of a cheap, quick, semi-quantitative method of identifying individuals when other more used methods are not applicable.     

Trabecular bone structure of the calcaneus: comparison of MR imaging at 3.0 and 1.5 T with micro-CT as the standard of reference

PURPOSE: To investigate in vitro the calcaneal trabecular bone structure in elderly human donors with high spatial resolution magnetic resonance (MR) imaging at 3.0 T and 1.5 T, to quantitatively compare MR measures of bone microarchitecture with those from micro-computed tomography (CT), and to compare the performance of 3.0-T MR imaging with that of 1.5-T MR imaging in differentiating donors with spinal fractures from those without spinal fractures. MATERIALS AND METHODS: The study was performed in line with institutional and legislative requirements; all donors had dedicated their body for educational and research purposes prior to death. Sagittal MR images of 49 human calcaneus cadaveric specimens were obtained (mean age of donors, 79.5 years +/- 11 [standard deviation]; 26 male donors, 23 female donors). After the spatial coregistering of images acquired at 3.0-T and 1.5-T MR imaging, the signal-to-noise-ratios and structural parameters obtained at each magnetic field strength were compared in corresponding sections. Micro-CT was performed on calcaneus cores obtained from corresponding regions in 40 cadaveric specimens. Vertebral deformities of the thoracic and lumbar spine were radiographically classified by using the spinal fracture index. Diagnostic performance of the structural parameters in differentiating donors with vertebral fractures from those without was assessed by using receiver operator characteristic (ROC) analysis, including area under the ROC curve (A(z)). RESULTS: Correlations between structural parameters at 3.0-T MR imaging and those at micro-CT were significantly higher (P < .05) than correlations between structural parameters at 1.5-T MR imaging and those at micro-CT (trabecular thickness, r = 0.76 at 3.0 T vs r = 0.57 at 1.5 T). Trabecular dimensions were amplified at 3.0 T because of increasing susceptibility artifacts. Also, higher ROC values were found for structural parameters at 3.0 T than at 1.5 T, but differences were not significant (trabecular thickness, A(z) = 0.75 at 3.0 T vs A(z) = 0.66 at 1.5 T, P > .05). CONCLUSION: MR imaging at 3.0 T provided a better measure of the trabecular bone structure than did MR imaging at 1.5 T. There was a trend for better differentiation of donors with from those without osteoporotic vertebral fractures at 3.0 T than at 1.5 T.     

The potential of micro-CT for dating post-cranial bone fractures: a macroscopic,radiographic, and microtomography study of fractures of known post-traumatic ages

International Journal of Legal Medicine - The estimation of the post-traumatic survival time (PTST) in case of bone injuries remains a tricky issue in the forensic field, especially when dealing...     

Comparison of bone mineral density in the jaws of patients with and without chronic periodontitis

Objectives

Although several studies have addressed the relationship between systemic bone mineral status and the severity of periodontitis, there is little knowledge of the relationship between periodontal disease and locally detected bone mineral density. The aim of this study was to compare the mandibular bone mineral density of patients with chronic periodontitis with that of periodontally healthy subjects.

Methods

48 systemically healthy subjects were included in the study and underwent a periodontal examination to determine their status. 24 subjects were periodontally healthy and the other 24 had moderate or severe chronic periodontitis. The mandibular bone mineral density of the subjects was determined by dual energy X-ray absorptiometry. The region of interest on the body of the mandible was independently determined on the dual energy absorptiometry radiographs, and a computer calculated the bone mineral density of these regions.

Results

The mandibular bone mineral density of the subjects with periodontitis was significantly lower than that of the periodontally healthy subjects (p < 0.01). There were significant negative correlations between the mandibular bone mineral density values and parameters related to the amount of periodontal destruction.

Conclusions

Low bone mineral density in the jaw may be associated with chronic periodontitis.     

Drug and light delivery strategies for photodynamic antimicrobial chemotherapy (PACT) of pulmonary pathogens: a pilot study

Pulmonary disease is the main cause of morbidity and mortality in cystic fibrosis (CF) suffers, with multidrug-resistant Pseudomonas aeruginosa and Burkholderia cepacia complex as problematic pathogens in terms of recurrent and unremitting infections. Novel treatment of pulmonary infection is required to improve the prognosis and quality of life for chronically infected patients. Photodynamic antimicrobial chemotherapy (PACT) is a treatment combining exposure to a light reactive drug, with light of a wavelength specific for activation of the drug, in order to induce cell death of bacteria. Previous studies have demonstrated the susceptibility of CF pathogens to PACT in vitro. However, for the treatment to be of clinical use, light and photosensitizer must be able to be delivered successfully to the target tissue. This preliminary study assessed the potential for delivery of 635 nm light and methylene blue to the lung using an ex vivo and in vitro lung model. Using a fibre-optic light delivery device coupled to a helium-neon laser, up to 11% of the total light dose penetrated through full thickness pulmonary parenchymal tissue, which indicates potential for multiple lobe irradiation in vivo. The mass median aerodynamic diameter (MMAD) of particles generated via methylene blue solution nebulisation was 4.40 μm, which is suitable for targeting the site of infection within the CF lung. The results of this study demonstrate the ability of light and methylene blue to be delivered to the site of infection in the CF lung. PACT remains a viable option for selective killing of CF lung pathogens.     

Hypnosedation for endocavitary uterovaginal applications: A pilot study

PurposeImplantations for uterovaginal brachytherapy are usually performed under general or spinal anesthesia, which are not without risk. As it is a rather short procedure and since postoperative pain is minimal, hypnosedation was proposed to selected patients requiring endocavitary applications as part of their routine treatment.Methods and MaterialsConsecutive patients requiring intracavitary uterovaginal brachytherapy from January to October 2019 were included if they accepted the procedure. A premedication was systematically administered. Hypnosedation was based on an Ericksonian technique. The procedure was immediately interrupted if the patient requested it, in cases of extreme anxiety or pain. Procedure was in that case rescheduled with a “classical” anesthesia technique.ResultsA total of 20 patients were included. Four patients had to be converted toward a general anesthesia: one because of a fibroma on the probe's way and three young patients with a very anteverted/retroverted uterus that was painful at every mobilization. Mean and maximum pain scores during implant were 2.9/10 and 5.1/10, respectively. The most painful maneuver was cervical dilation for 45% of the patients, followed by mold insertion in 40% of cases. About 85% of the patients declared that hypnosis helped them relax; 90% of the patients would recommend the technique. No procedure-related complication occurred.ConclusionWith a 70% success rate (correct implant with mean pain and anxiety scores < 5), one can conclude that uterovaginal brachytherapy implantation under hypnosedation is feasible and received a high satisfaction rate from the patients. This technique may reduce overall treatment time in a context of difficult access to the OR and to anesthesiologists, while reducing anesthetic drugs resort and postoperative nausea.     

A new tilt on pelvic radiographs: a pilot study

Aim  The aim of this study was to evaluate pelvic tilt on commonly performed measurements on radiography in primary protrusio acetabuli and developmental dysplasia of the hip. Materials and methods  A dry assembled pelvis and spine skeleton was positioned in an isocentric skull unit and films exposed with increasing degrees of angulation of pelvic tilt. The films were then read by two independent readers for seven different measurements used to evaluate the hips and acetabular: acetabular line to ilioischial line, teardrop appearance, intercristal/intertuberous ratio, co-ordinates of femoral head, centre edge angle, acetabular depth/width ratio and acetabular angle. Results  There was so much variation in the protrusio results that no formal recommendation of any standard radiographic test can be given. Only the inter tuberous distance is not effected by pelvic tilt. The acetabular angles for developmental dysplasia of the hip showed the most potential with pelvic tilt below 15°. Conclusion  As pelvic tilt increases, measurements used in protusio become unreliable, and computed tomography/magnetic resonance imaging are probably going to be more accurate as one can directly visualise pelvic intrusion. We recommend a lateral view to assess the degree of pelvic tilt in patients with protrusion to ensure these measurements are valid.     

A simplified and inexpensive method for the preparation of fresh or fixed bone samples for forensic histological examination

ABSTRACT

The histological analysis of bone for forensic application requires thin sections to be prepared from extracted bone of suitable quality for visualization through conventional light microscopy and (if required) the measurement of microstructural features, such as osteons. While a number of protocols for the preparation of thin sections exist, they are often time consuming and complex, or require expensive and non-portable equipment. A revised protocol is presented for obtaining high quality thin sections for light microscopy and histological analyses, tested in fresh, fixed, and dry archaeological cortical bone. It does not require extensive experience, or expensive materials or equipment, and can be further adapted for use with manual tools if necessary.     

A method for the automatic characterization of bone architecture in 3D mice microtomographic images

We developed an automatic method to characterize mice bone architecture from three-dimensional (3D) microtomographic images. The distal metaphyses of the femur of mice were imaged using 3D synchrotron radiation microtomography at the European Synchrotron Radiation Facility (ID19) with a voxel size of 6.65 μm. Within each reconstructed volume, a region of interest was defined and trabecular and cortical bones were automatically separated. Then, 3D morphologic and topologic model-independent parameters quantifying the 3D bone architecture were computed in both regions. The technique was applied to study the response of the C57BL/6J@Ico strain of mice submitted to a model of bone loss by hind limb unloading produced by tail-suspension.