Simultaneous voxel‐wise analysis of brain and spinal cord morphometry and microstructure within the SPM framework

To validate a simultaneous analysis tool for the brain and cervical cord embedded in the statistical parametric mapping (SPM) framework, we compared trauma‐induced macro‐ and microstructural changes in spinal cord injury (SCI) patients to controls. The findings were compared with results obtained from existing processing tools that assess the brain and spinal cord separately. A probabilistic brain‐spinal cord template (BSC) was generated using a generative semi‐supervised modelling approach. The template was incorporated into the pre‐processing pipeline of voxel‐based morphometry and voxel‐based quantification analyses in SPM. This approach was validated on T1‐weighted scans and multiparameter maps, by assessing trauma‐induced changes in SCI patients relative to controls and comparing the findings with the outcome from existing analytical tools. Consistency of the MRI measures was assessed using intraclass correlation coefficients (ICC). The SPM approach using the BSC template revealed trauma‐induced changes across the sensorimotor system in the cord and brain in SCI patients. These changes were confirmed with established approaches covering brain or cord, separately. The ICC in the brain was high within regions of interest, such as the sensorimotor cortices, corticospinal tracts and thalamus. The simultaneous voxel‐wise analysis of brain and cervical spinal cord was performed in a unique SPM‐based framework incorporating pre‐processing and statistical analysis in the same environment. Validation based on a SCI cohort demonstrated that the new processing approach based on the brain and cord is comparable to available processing tools, while offering the advantage of performing the analysis simultaneously across the neuraxis.     

形变配准算法在宫颈癌后装治疗分次间总剂量评估中的应用

目的:量化分析后装治疗中,使用不同累积剂量计算方法导致的总剂量评估差异。方法:使用混合形变配准算法,对32例已完成后装插植治疗的宫颈癌患者共计进行108次形变配准,并计算每个患者的形变总剂量。根据膀胱和直肠的体积控制情况将32例患者分为体积控制组（18例）和体积未控制组（14例）,计算比较组间累积剂量体积参数（D0.1 cc、D1 cc、D2 cc）和相似度系数（DSC）,并与GEC-ESTRO推荐的分次间剂量累加方法相比较。结果:DSC随形变图像相对体积比值的增大而变差。体积控制组中,GEC-ESTRO推荐方法和形变累积剂量差异（DDIR/DGEC）较小。对于膀胱,体积控制组D2 cc的DDIR/DGEC最大值为1.05,低于未控组1.07;DDIR/DGEC最小值为0.91,高于未控组0.80。提示在使用形变剂量评估过程中,形变剂量值可能比GEC-ESTRO推荐的剂量计算方法偏高5%~7%或偏低9%~20%,偏高和偏低的原因主要为参与形变的体积差异导致剂量网格缩放。而D0.1 cc、D1 cc的DDIR/DGEC更接近1。对于直肠,控制组没有观察到DDIR/DGEC偏高的情况,D2 cc的DDIR/DGEC最大值为0.99,低于未控组1.06;最小值为0.80,低于未控组0.85,但未控制组平均偏高6%。而直肠的D0.1 cc、D1 cc、D2 cc的累积剂量比值都较接近,并且差异不如膀胱显著。结论:在后装治疗中,形变体积可以影响到形变累积剂量的计算结果,合理控制形变轮廓的体积不仅有助于提高形变的准确性,而且形变总剂量评估结果更稳定,建议在后装治疗过程中重视对膀胱和直肠的体积控制。     

Accuracy of guided biopsy of the jawbone in a clinical setting: A retrospective analysis

The aim of this study was to investigate the accuracy of a previously described technique for guided biopsy of osseous pathologies of the jawbone in a clinical setting. The data sets of patients who had undergone guided biopsy procedures were retrospectively examined for accuracy. Digital planning of the biopsies and manufacturing of the tooth-supported drilling template were performed with superimposed cone beam computed tomography and intraoral scans using implant planning software. After a trephine biopsy was taken using the template, the postoperative low-dose cone beam computed tomography was analyzed for accuracy using the planning software with the corresponding (digitally-planned) biopsy cylinder. The mean angular deviation was 4.35 ± 2.5°. The mean depth deviation was ?1.40 ± 1.41 mm. Guided biopsy seems to be an alternative to a conventional approach for minimally invasive and highly accurate jawbone biopsy.     

Transperineal template‐guided mapping biopsy of the prostate

Accurate diagnosis of prostate cancer has eluded clinicians for decades. With our current understanding of prostate cancer, urologists should devise and confidently present the available treatment options – active surveillance/radical treatment/focal therapy to these patients. The diagnostic modalities used for prostate cancer have the dual problem of false negativity and overdiagnosis. Various modifications in the prostate biopsy techniques have increased the accuracy of cancer detection, but we are still far from an ideal diagnostic technique. Transperineal template‐guided mapping biopsy of the prostate is an exhaustive biopsy technique that has been improvised over the past decade, and has shown superior results to other available modalities. We have carried out a PubMed search on the available experiences on this diagnostic modality, and along with our own experiences, we present a brief review on transperineal template‐guided mapping biopsy of the prostate.     

Accuracy assessment of cone beam computed tomography-derived laboratory-based surgical templates on partially edentulous patients

Objectives: The aim of the present prospective clinical study was to evaluate the match between the positions and axes of the virtually planned and the placed implants using laboratory‐based surgical guides generated from cone beam computed tomography (CBCT). Materials and methods: A total of 132 implants were placed with the aid of 3D‐based transfer templates in 52 consecutive partially edentulous patients between April 2008 and March 2010. After individual adaptation of the scan templates and CBCT scanning, the acquired data for virtual implant planning and simulation were processed using the med3D software program. After finalizing the virtual placement of the implants the radiographic templates were converted into operative guides containing titanium sleeves for cavity preparation. Preoperative planning was merged with postoperative CBCT data to identify linear and angular deviations between virtually planned and placed implants. Results: Compared with the planned implants the installed implants showed linear deviations in the median at the neck and apex of 0.27 mm (range 0.01–0.97 mm), and of 0.46 mm (range 0.03–1.38 mm), respectively. The angle deviation was 1.84° in median, with a range of 0.07–6.26°. The extent of deviation depends on the size of the tooth gap and the distribution of the remaining teeth. Conclusion: The results of this study suggested that laboratory‐fabricated surgical guides using CBCT data may be reliable in implant placement under prosthodontic considerations in partial edentulism. To cite this article:
Behneke A, Burwinkel M, Knierim K, Behneke N. Accuracy assessment of cone beam computed tomography‐derived laboratory‐based surgical templates on partially edentulous patients.
Clin. Oral Impl. Res. 23 , 2012; 137–143.
doi: 10.1111/j.1600‐0501.2011.02176.x     

Evaluation of the accuracy of computer-assisted techniques in the interstitial brachytherapy of the deep regions of the head and neck

PurposeWe sought to investigate the feasibility and accuracy of computer-assisted techniques in the interstitial brachytherapy of the deep regions of the head and neck.Materials and MethodsA computer-assisted brachytherapy workflow was applied to 10 patients with tumors in the deep regions of the head and neck. Based on the brachytherapy treatment preplan, we constructed a digital stereotactic model to accurately transfer the virtual plan into the navigation system, and subsequently printed the individual templates. The navigation system and the individual template were combined together to visualize and guide brachytherapy needle implantation. Preoperative and intraoperative image data were reconstructed and registered to measure and analyze the needle deviation.ResultsA total of 58 needles were successfully inserted in 10 patients with the guidance of computer-assisted techniques and a mean deviation of 5.2 mm. The inserting trajectories and depths of the needles were as follows: from the parotid and masseter regions to the infratemporal fossa or skull base, the range was 15.7–74.6 mm; from the submandibular and retromandibular regions to the infratemporal fossa or skull base, the range was 15.6–70.6 mm; from the infraorbital region to the pterygomandibular region, the range was 63.7–69.7 mm; and from the periorbital region to the intraorbital region, the range was 47.6–61.8 mm. The dose distribution met the treatment requirement well.ConclusionsThe computer-assisted interstitial brachytherapy workflow was proven to be feasible and accurate for the deep regions of the head and neck.     

Reconstruction after skin cancer excision through a dermal induction template: our experience

Dermal substitutes offer alternative approaches for wounds of all thicknesses where sufficient donation sites are not available for self‐grafts. Several dermal substitutes are described in literature. This study included 20 patients treated with a dermal induction template after the removal of malignant skin cancers situated in various parts of the body. The participants were especially aged patients with multiple skin cancers, and complex clinical conditions, often affected by pathologies such as cardiopathy, diabetes mellitus, and hypercholesterolaemia, and receiving pharmacological multi‐therapies, particularly antiplatelets and anticoagulants. In many of these patients, the general complex clinical picture provided significant contraindication for complex reconstructive surgery because of the high risk involved. All patients achieved complete healing about 8 weeks after the first surgery. By using a dermal induction template, it was possible to cover substantial loss of substances without the need of autologous tissue, with smoother and less apparent scar, minor occurrence of hypertrophic and retracted scars, better flexibility of healed skin and therefore a better result from an aesthetic point of view.     

Synthesis of Co–Fe 1D Nanocone Array Electrodes Using Aluminum Oxide Template

Porous anodic alumina oxide (AAO) obtained via two-step anodization is a material commonly used as a template for fabricating 1D nanostructures. In this work, copper and cobalt-iron 1D nanocones were obtained by an electrodeposition method using AAO templates. The templates were produced using two-step anodization in H₂C₂O₄. The Co–Fe nanostructures are characterized by homogeneous pore distribution. The electrocatalytic activity of the produced nanomaterials was determined in 1 M NaOH using the linear sweep voltammetry (LSV) and chronopotentiometry (CP) methods. These materials can be used as catalysts in the water-splitting reaction. The sample’s active surface area was calculated and compared with bulk materials.