Search

The aim of this study was to determine the effect of Thiel embalming on the biomechanical properties of nerve tissue, to validate the use of Thiel embalmed bodies as a reliable model system for obtaining biomechanical data to supplement neurodynamic models, for anesthesiological and neurosurgical training and for future preclinical test set-ups involving nerve tissue. Upon the arrival of a body at the anatomy department, a fresh median nerve was harvested, the harvest site was sutured and following the Thiel embalming procedure the Thiel embalmed median nerve of the opposing wrist was harvested. Micro CT was performed to establish the cross-sectional area and biomechanical tensile testing was performed to compare the Young's modulus/elasticity of fresh frozen and Thiel embalmed nerves. Thiel embalming did not cause a significant difference in elasticity when comparing Thiel embalmed and fresh frozen specimens. A correlation was found between the cross-sectional area of Thiel embalmed nerve specimens and their Young's modulus. Thiel embalming does not significantly alter the elasticity of nerve tissue compared to fresh frozen nerve tissue. Similar shapes were observed when comparing the stress/strain curves of both specimen types. This indicates that Thiel embalmed nerve tissue is a viable alternative for using fresh frozen specimens when investigating biomechanical principles/mechanisms. Some specimens showed a reversed trend in Young's modulus that could be related to slight differences in embalming outcome, so caution is advised when Thiel embalmed specimens are used to obtain raw numerical data for direct application in the clinic.

Thiel embalming followed by freezing in the desired position and acquiring CT + MRI scans is expected to be the ideal approach to obtain accurate, enhanced CT data for delineation guideline development. The effect of Thiel embalming and freezing on MRI image quality is not known. This study evaluates the above-described process to obtain enhanced CT datasets, focusing on the integration of MRI data obtained from frozen, Thiel-embalmed specimens.Three Thiel-embalmed specimens were frozen in prone crawl position and MRI scanning protocols were evaluated based on contrast detail and structural conformity between 3D renderings from corresponding structures, segmented on corresponding MRI and CT scans. The measurement error of the dataset registration procedure was also assessed.Scanning protocol T1 VIBE FS enabled swift differentiation of soft tissues based on contrast detail, even allowing a fully detailed segmentation of the brachial plexus. Structural conformity between the reconstructed structures on CT and MRI was excellent, with nerves and blood vessels imported into the CT scan never intersecting with the bones. The mean measurement error for the image registration procedure was consistently in the submillimeter range (range 0.77-0.94 mm).Based on the excellent MRI image quality and the submillimeter error margin, the procedure of scanning frozen Thiel-embalmed specimens in the treatment position to obtain enhanced CT scans is recommended. The procedure can be used to support the postulation of delineation guidelines, or for training deep learning algorithms, considering automated segmentations.

In order to provide an alternative for fresh frozen specimens to map the lymphatic system, the possibility of using Thiel embalmed specimens for this purpose was explored. The thoracic duct was used to investigate if retrograde injection of contrast agent was possible in Thiel embalmed specimens and to verify up to which diameter lymphatic vessels could be reconstructed and rendered in 3D, after CT scanning. 3D renderings were used for digital diameter measurement, to determine the smallest lymphatic diameter that could still be visualized on CT. Finally, the contrast agent concentration was adapted based on the findings during image reconstruction and 3D rendering. All Thiel embalmed specimens proved suitable for retrograde injection of contrast agent into the thoracic duct and all 3D renderings perfectly overlapped with the dissection pictures. The smallest diameter of contrast filled lymphatics that could be reconstructed and rendered in 3D was 0.23 mm. Increasing the concentration of barium sulphate from 10% to 50% reduced the post-processing time needed to render a ‘clean’ 3D structure, following automatic segmentation based on grey values, by 95%. The authors would recommend the use of Thiel embalmed specimens for mapping the lymphatic system, as these specimens do not show the rapid putrefaction that occurs in fresh frozen specimens, thus greatly facilitating experimental planning.

Sacroiliac joint (SIJ) biomechanics have been described in both in vitro and in vivo studies. A standard for joint coordinate systems has been created by the International Society of Biomechanics for most of the joints in the human body. However, a standardized joint coordinate system for sacroiliac joint motion analysis is currently still lacking. This impedes the comparison across studies and hinders communication among scientists and clinicians. As SIJ motion is reported to be quite limited, a proper standardization and reproducibility of this procedure is essential for the interpretation of future biomechanical SIJ studies. This paper proposes a joint coordinate system for the analysis of sacroiliac joint motion, based on the procedure developed by Grood and Suntay, using semi-automated anatomical landmarks on 3D joint surfaces. This coordinate system offers high inter-rater reliability and aspires to a more intuitive representation of biomechanical data, as it is aligned with SIJ articular surfaces. This study aims to encourage further reflection and debate on biomechanical data representation, in order to facilitate interpretation of SIJ biomechanics and improve communication between researchers and clinicians. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Our recently developed prone crawl position (PCP) for radiotherapy of breast cancer patients with lymphatic involvement showed promising preliminary data and it is being optimized for clinical use. An important aspect in this process is making new, position specific delineation guidelines to ensure delineation (for treatment planning) is uniform across different centers. The existing ESTRO and PROCAB guidelines for supine position (SP) were adapted for PCP. Nine volunteers were MRI scanned in both SP and PCP. Lymph node regions were delineated in SP using the existing ESTRO and PROCAB guidelines and were then translated to PCP, based on the observed changes in reference structure position. Nine PCP patient CT scans were used to verify if the new reference structures were consistently identified and easily applicable on different patient CT scans. Based on these data, a team of specialists in anatomy, CT- and MRI radiology and radiation oncology postulated the final guidelines. By taking the ESTRO and PROCAB guidelines for SP into account and by using a relatively big number of datasets, these new PCP specific guidelines incorporate anatomical variability between patients. The guidelines are easily and consistently applicable, even for people with limited previous experience with delineations in PCP.

Purpose To investigate crawl position with the arm at the treated side alongside the body and at the opposite side above the head for prone treatment in patients requiring breast and regional lymph node irradiation. Methods Patient support devices for crawl position were built for CT simulation and treatment. An asymmetric fork design resulted from an iterative process of prototype construction and testing. The fork's large horn supports the hemi-thorax, shoulder, and elevated arm at the nontreated side and the head. The short, narrow horn supports the arm at the treated side. Between both horns, the treated breast and its regional lymph nodes are exposed. Endpoints were pain, comfort, set-up precision, beam access to the breast and lymph nodes, and plan dose metrics. Pain and comfort were tested by volunteers (n = 9); set-up precision, beam access, and plan dose metrics were tested by means of a patient study (n = 10). The AIO™ (Orfit, Wijnegem, Belgium) prone breastboard (AIO™) was used as a reference regarding comfort and set-up precision. Results Pain at the sternum, the ipsilateral shoulder, upper arm, and neck was lower in crawl position than with bilateral arm elevation on AIO™. Comfort and set-up precision were better on the crawl prototype than on AIO™. In crawl position, beam directions in the coronal and near-sagittal planes have access to the breast or regional lymph nodes without traversing device components. Plan comparison between supine and crawl positions showed better dose homogeneity for the breast and lymph node targets and dose reductions to all organs at risk for crawl position. Conclusions Radiation therapy for breast and regional lymph nodes in crawl position is feasible. Good comfort and set-up precision were demonstrated. Planning results support the hypothesis that breast and regional lymph nodes can be treated in crawl position with less dose to organs at risk and equal or better dose distribution in the target volumes than in supine position. The crawl technique is a candidate methodology for further investigation for patients requiring breast and regional lymph node irradiation.

The goal of this study was to report deep squat hip kinetics in young, athletic adults using a personalized numerical model solution based on inverse dynamics. Thirty-five healthy subjects underwent deep squat motion capture acquisitions and MRI scans of the lower extremities. Musculoskeletal models were personalized using each subject's lower limb anatomy. The average peak hip joint reaction force was 274 percent bodyweight. Average peak hip and knee flexion angles were 107 degrees and 112 degrees respectively. These new findings show that deep squatting kinetics in the younger population differ substantially from the previously reported in vivo data in older subjects.

Study Design. Part 1: A randomized, single-blind study on the effect of contralateral knee extension on sensations produced by the slump test (ST) in asymptomatic subjects. Part 2: A cadaver study simulating the nerve root behavior of part 1. Objective. Part 1: Test if contralateral knee extension consistently reduces normal stretch sensations with the ST. Objective. Part 2: Ascertain in cadavers an explanation for the results. Summary of Background Data. In asymptomatic subjects, contralateral knee extension reduces stretch sensations with the ST. In sciatica patients, contralateral SLR also can temporarily reduce sciatica. We studied this methodically in asymptomatic subjects before considering a clinical population. Methods. Part 1: Sixty-one asymptomatic subjects were tested in control (ST), sham, or intervention (contralateral ST) groups and their sensation response intensity compared. Methods. Part 2: Caudal tension was applied to the L5 nerve root of 3 cadavers and tension behavior of the contralateral neural tissue recorded visually. Results. Part 1: Reduction of stretch sensations occurred in the intervention group but not in control and sham groups (P ≤ 0.001). Results. Part 2: Tension in the contralateral lumbar nerve roots and dura reduced in a manner consistent with the responses in the intervention (contralateral ST) group. Conclusion. Part 1: In asymptomatic subjects, normal thigh stretch sensations with the ST reduced consistently with the contralateral ST, showing that this is normal and may now be compared with patients with sciatica. Conclusion. Part 2: Contralateral reduction in lumbar neural tension with unilateral application of tension-producing movements also occurred in cadavers, supporting the proposed explanatory hypothesis.

Background Visualizing the lymphatic system and recording the spatial relations between the subclavian lymphatic trunk (SLT) and the surrounding anatomical structures will improve radiotherapy treatment planning for breast cancer patients with lymphatic involvement. An experimental approach to retrogradely fill the SLT with contrast agent was explored. Methods Six Thiel embalmed specimens were bilaterally dissected in the cervical and clavicular region to optimize the new experimental approach. A conservative dissection with minimum distortion of spatial relations between different anatomical structures was developed. A pressure reservoir was created inside the venous angle to allow retrograde filling of the SLT under the influence of time and pressure. Results The new methodology proved feasible, showing successful pressure build-up inside the venous reservoir, resulting in filling of the proximal end of the subclavian lymphatic trunk. The pressures needed to significantly fill the subclavian lymphatic trunk proved to be higher than the pressures that the venous walls could withstand. Conclusions Thiel embalmed specimens proved useful for optimizing the experimental approach, but the embalming products could have negatively affected the vessel strength. The authors suggest that their method will be applied on fresh frozen specimens in future studies, to obtain SLT filling up to the axillary lymphatic plexus. Our findings also pointed out that there is still a lot to be learned about the anatomical variability of the SLT and its termination sites. The detailed description of our experimental approach offers valuable information for future lymphatic mapping studies.

This review intends to rekindle efforts to map the lymphatic system by using a more modern approach, based on medical imaging. The structure, function, and pathologies associated with the lymphatic system are first discussed to highlight the need for more accurately mapping the lymphatic system. Next, the need for an interdisciplinary approach, with a central role for the anatomist, to come up with better maps of the lymphatic system is emphasized. The current approaches on lymphatic system research involving medical imaging will be discussed and suggestions will be made for an all-encompassing effort to thoroughly map the entire lymphatic system. A first-hand account of our integration as anatomists in the radiotherapy department is given as an example of interdisciplinary collaboration. From this account, it will become clear that the interdisciplinary collaboration of anatomists in the clinical disciplines involved in lymphatic system research/treatment still holds great promise in terms of improving clinical regimens that are currently being employed. As such, we hope that our fellow anatomists will join us in an interdisciplinary effort to map the lymphatic system, because this could, in a relatively short timeframe, provide improved treatment options for patients with cancer or lymphatic pathologies all over the world. Anat Rec, 302:1681-1695, 2019. © 2019 American Association for Anatomy.

In vitro evaluation of knee kinematics remains an essential part during pre-clinical testing of new implants and surgical procedures. To assess the kinematics, markers are rigidly attached to the bone segments and tracked using infrared cameras. Subsequently, the position of the markers relative to the bone is determined using computed tomography (CT). Although the accuracy of the aforementioned, CT-based method is not doubted, no real-time information is provided. Therefore, this paper presents a real-time method that uses a registration phase in combination with a pre-operative CT scan to determine the location of the bone relative to the markers. During this registration phase, the bone surface location is identified touching surface points with a tracked pen. The kinematic parameters obtained using this real-time method is compared to the golden standard, CT-based, method. Under optimal conditions, rotational and translational differences around 1mm and 1degree are obtained. This is in the range of the inter- and intra- observer variability in determining the landmarks used for these kinematic calculations. It is therefore concluded that the accuracy of the real-time method allows effectively evaluating the knee kinematics in six degrees of freedom.

Background: Vascular reperfusion of Thiel cadavers can aid surgical and anatomical instruction. This study investigated whether ideal embalming circumstances provide lifelike vascular flow, enabling surgical practice and enhancing anatomical reality. Methods: Pressure-controlled pump-driven administration of blue embalming solution was assessed directly postmortem in a pig model (n = 4). Investigation of subsequent pump-driven vascular injection of red paraffinum perliquidum (PP) included assessment of flow parameters, intracorporeal distribution, anatomical alterations, and feasibility for surgical training. The microscopic distribution of PP was analyzed in pump-embalmed pig and gravity-embalmed human small intestines. Results: Embalming lasted 50-105 min, and maximum arterial pressure was 65 mm Hg. During embalming, the following consecutive alterations were observed: arterial filling, organ coloration, venous perfusion, and further tissue coloration during the next weeks. Most organs were adequately preserved. PP generated low arterial pressures (Conclusions: In a pig model, immediate postmortem pressure-controlled pump embalming generates ideal circumstances for (micro)vascular reperfusion with PP, permitting lifelike anatomy instruction and surgical training.

Biomechanical research and orthopedic training is regularly carried out on human cadavers. Given the post-mortem decay, these cadavers were usually frozen or embalmed. The embalming method according to Dr. Thiel was often praised for the preservation of natural texture. The main aim of this article was to quantitatively analyze the impact of this embalming technique on the biomechanical properties. To that extent, Achilles tendons (calcaneal tendons) of seven cadavers have been tested. For each cadaver, a first tendon was tested following a fresh-frozen conservation, the other following the Thiel embalming process. The results indicated a significant difference in Young's modulus between both groups (P values = 0.046). The secondary aim of this article was to analyze the impact of exposure to room conditions and associated dehydration on the biomechanical properties of cadaver tissue. Therefore, each tendon was tested before and after 2 hr of exposure to room conditions. The resulting dehydration caused a significant increase of the Young's modulus for the thawed fresh-frozen tendons. The properties of the Thiel embalmed tendons were not significantly altered. In conclusion, this research promoted the use of fresh-frozen specimens for biomechanical testing. Effort should, however, be made to minimize dehydration of the tested specimens.

OBJECT The aims of this study were 1) to establish the standard parameters of alignment and total and segmental range of motion (ROM) of the cervical spine in the asymptomatic population, and 2) to identify factors that influence cervical ROM and alignment. METHODS The authors measured 636 standard cervical lateral, flexion, and extension plain radiographs of 212 asymptomatic volunteers. The relationship between cervical alignment and total ROM was assessed with simple linear regression. Multivariate linear regression was used to determine the effect of the influential factors on cervical alignment and total and segmental ROM. RESULTS The mean value for C2–7 cervical alignment was 21.40° ± 12.15°, and the mean value for total ROM was 63.59° ± 15.37°. Sex was a significant factor in cervical alignment, total ROM, and segmental ROM for C2–3 and C5–6 (p < 0.05). Age had a significant negative association with both the total ROM and all of the segmental ROM measurements (p < 0.05). Cervical disc degeneration at the level of interest had a significant negative association with C4–5, C5–6, and C6–7 ROM (p < 0.05). CONCLUSIONS Cervical alignment in female subjects was 2.47° lower than that in male subjects. Total ROM was 3.86° greater in female than in male subjects and decreased 6.46° for each decade of aging. Segmental ROM decreased 1.28° for each decade of aging and 2.26° for each category increase in disc degeneration at the level of interest.

The present study aimed to establish a baseline for detailed 3D brachial plexus reconstruction from magnetic resonance imaging (MRI). Concretely, the goal was to determine the individual brachial plexus anatomy with maximum detail and accuracy achievable, as yet irrespective of whether the methods used could be economically and practically applied in the clinical setting.Six embalmed cadavers were randomly taken for MRI imaging of the brachial plexus. Detailed two-dimensional (2D) segmentation for all brachial plexus parts was done. The 2D brachial plexus segmentations were 3D reconstructed using Mimics(®) software. Then, these 3D reconstructions were anatomically validated by dissection of the cadavers. After finalising the cadaver experiments, brachial plexus MRIs were obtained in three healthy male volunteers and the same reconstruction procedure as in vitro was followed.A procedure was developed for brachial plexus 3D reconstruction based on MRI without the use of any contrast agent. Anatomical validation of six cadaver brachial plexus reconstructions showed high correspondence with the dissected brachial plexuses. Anatomical variations of the main branches were equally present in the 3D reconstructions generated. However, there were also some differences that related to the difference between the surface anatomy of the nerve and the internal nerve structure. In vivo, it was possible to reconstruct the complete brachial plexus in such a manner that normal-appearing BPs were derived in a reproducible way.This study showed that the described procedure results in accurate and reproducible brachial plexus 3D reconstructions.

Background Multi-level cervical degeneration of the spine is a common clinical pathology that is often repaired by anterior cervical discectomy and fusion (ACDF). The aim of this study was to investigate the kinematics of the cervical spine after hybrid surgery compared with 2-level ACDF. Material/Methods Five freshly frozen, unembalmed whole human cadavers were used including 3 males and 2 females with a mean age of 51±8 years. After evaluating the intact spine for range of motion (ROM), sagittal alignment and instantaneous center of rotation (ICR), each cadaver underwent 4 consecutive surgeries: 2-level artificial disc replacement (ADR) from C4 to C6 (ADR surgery); 2-level ACDF from C4 to C6 (ACDF surgery); hybrid C4–5 ACDF and C5–6 ADR (ACDF+ADR surgery); and hybrid C4–5 ADR and C5–6 ACDF (ADR+ACDF surgery). The ROM and ICR of adjacent intact segments (C3–4; C6–7), and whole sagittal alignment were revaluated. Results Two-level ACDF resulted in increased ROM at C3–4 and C6–7 compared with intact spine. ROM was significantly different to intact spine using ACDF surgery at C3–C4 and C6–C7 and ROM was increased with ACDF+ADR surgery at C6–C7 (all P

Although many authors stated that a user-centred design approach in medical device development has added values, the most common research approach within healthcare is evidence-based medicine, which tend to focus on functional data rather than patient wellbeing and comfort. End user comfort is well addressed in literature for commercial products such as seats and hand tools but no data was found for medical devices. A commercial patient support device for breast radiotherapy was analysed and a relation was found between discomfort and uncompensated internal body forces. Derived from CT-images, simplified patient free-body diagrams were analysed and pain and comfort evaluated. Subsequently, a new patient position was established and prototypes were developed. Patient comfort- and prototype optimization was done through iterative prototyping. With this approach, we were able to compensate all internal body forces and establish a force neutral patient free-body diagram. This resulted in comfortable patient positioning and favourable medical results.

Purpose To determine the mechanisms and extents of popliteus impingements before and after TKA and to investigate the influence of implant sizing. The hypotheses were that (1) popliteus impingements after TKA may occur at both the tibia and the femur, and (2) even with an apparently well-sized prosthesis, popliteal tracking during knee flexion is modified compared to the preoperative situation. Methods The location of the popliteus in three cadaver knees was measured using computed tomography, before and after implantation of plastic TKA replicas, by injecting the tendon with radiopaque liquid. The pre- and post-operative positions of the popliteus were compared from full extension to deep flexion using normosized, oversized, and undersized implants (one size increments). Results At the tibia, TKA caused the popliteus to translate posteriorly, mostly in full extension: 4.1 ± 2 mm for normosized implants, and 15.8 ± 3 mm with oversized implants, but no translations were observed when using undersized implants. At the femur, TKA caused the popliteus to translate laterally at deeper flexion angles, peaking between 80° and 120°: 2 ± 0.4 mm for normosized implants and 2.6 ± 0.5 mm with oversized implants. Three-dimensional analysis revealed prosthetic overhang at the posterosuperior corner of normosized and oversized femoral components (respectively, up to 2.9 mm and 6.6 mm). Conclusions A well-sized tibial component modifies popliteal tracking, while an undersized tibial component maintains more physiologic patterns. Oversizing shifts the popliteus considerably throughout the full arc of motion. This study suggests that both femoro- and tibio-popliteus impingements could play a role in residual pain and stiffness after TKA. Electronic supplementary material The online version of this article (doi:10.1007/s00167-016-4330-8) contains supplementary material, which is available to authorized users.

To investigate the effect of osteoporosis and intervertebral disc degeneration on the endplate cartilage injury in rats.A total of 48 female Sprague Dawley rats (3 months) were randomly divided into Groups A, B, C and D with 12 rats in each group. Osteoporosis and intervertebral disc degeneration composite model, simple degeneration model and simple osteoporosis model were prepared in Groups A, B and C respectively. After modeling, four rats of each group at 12th, 18th and 24th week were sacrificed. Intervertebral height of cervical vertebra C6/C7 was measured. Micro-CT was used to image the endplate of cephalic and caudal cartilage at C6/C7 intervertebral disc. Abraded area rate of C6 caudal and C7 cephalic cartilage endplate was calculated, and then C6/C7 intervertebral disc was routinely embedded and sectioned, stained with safranin O to observe histological changes microscopically.At 12, 18 and 24 weeks, intervertebral disc height of C6/C7 were (0.58±0.09) mm, (0.53±0.04) mm and (0.04±0.06) mm in Group A rats, (0.55±0.05) mm, (0.52±0.07) mm and (0.07±0.05) mm in Group B rats. At 24th week, intervertebral disc height of Group A rats was significantly lower than that of Group B rats (P0.05); intervertebral disc height of Groups A and B rats at each time point were significantly lower than that of Groups C and D (P0.05). There was no significantly statistical difference of intervertebral disc height between Groups C and D (P0.05). At 12 and 18 weeks, the abraded rate of C6 caudal and C7 cephalic cartilage endplate in Group A rats were significantly higher than that in Groups B, C and D rats (P0.05); the abraded rate in Group B was significantly higher than that in Groups C and D (P0.05). Microscopic observation of CT showed that ventral defects in C6 caudal or C7 cephalic cartilage endplate in Groups A and B appeared after 12 weeks of modeling; obvious cracks were found in front of the C6 and C7 vertebral body, and cartilage defect shown the trend of "repairing" at 18 and 24 weeks after modeling.Intervertebral disc degeneration and osteoporosis can cause damage to the cartilage endplate. Co-existence of these two factors can induce more serious damage to the endplate, which has possitive correlation with intervertebral disc degeneration. Osteoporosis plays a certain role in intervertebral disc degeneration process, and accelerates the degeneration of intervertebral disc in a specific time window.

Purpose: (1) To assess validity and reproducibility of mucosal thickness (MT) registration by means of an ultrasonic device and (2) to determine MT stability of connective tissue grafts (CTG) when applied at the buccal aspect of single implants demonstrating alveolar process deficiency. Materials and Methods: For the validity assessment, 4 human cadaver edentulous maxillae were used to determine MT at 100 different sites. Soft tissue thickness as recorded with the ultrasonic device was compared to MT as registered with Micro-CT, taking the latter as gold standard. For the reproducibility assessment, 50 duplicate ultrasonic registrations were used. For the clinical part, 10 non-smoking patients with a single implant were included. All demonstrated alveolar process deficiency and had been provided with a provisional screw-retained crown at the time of inclusion. Following an intra-sulcular incision at the buccal aspect, a CTG was inserted to thicken soft tissues. MT was assessed at t0 (before CTG), t1 (immediately after CTG), t2 (suture removal), t3 (permanent crown installation) and t4 (9 months after CTG). Results: There was a strong correlation between ultrasonic and Micro-CT measurements (r=0.89, p

Purpose To develop contouring guidelines for the brachial plexus (BP) using anatomically validated cadaver datasets. Magnetic resonance imaging (MRI) and computed tomography (CT) were used to obtain detailed visualizations of the BP region, with the goal of achieving maximal inclusion of the actual BP in a small contoured volume while also accommodating for anatomic variations. Methods and Materials CT and MRI were obtained for 8 cadavers positioned for intensity modulated radiation therapy. 3-dimensional reconstructions of soft tissue (from MRI) and bone (from CT) were combined to create 8 separate enhanced CT project files. Dissection of the corresponding cadavers anatomically validated the reconstructions created. Seven enhanced CT project files were then automatically fitted, separately in different regions, to obtain a single dataset of superimposed BP regions that incorporated anatomic variations. From this dataset, improved BP contouring guidelines were developed. These guidelines were then applied to the 7 original CT project files and also to 1 additional file, left out from the superimposing procedure. The percentage of BP inclusion was compared with the published guidelines. Results The anatomic validation procedure showed a high level of conformity for the BP regions examined between the 3-dimensional reconstructions generated and the dissected counterparts. Accurate and detailed BP contouring guidelines were developed, which provided corresponding guidance for each level in a clinical dataset. An average margin of 4.7 mm around the anatomically validated BP contour is sufficient to accommodate for anatomic variations. Using the new guidelines, 100% inclusion of the BP was achieved, compared with a mean inclusion of 37.75% when published guidelines were applied. Conclusion Improved guidelines for BP delineation were developed using combined MRI and CT imaging with validation by anatomic dissection.

To determine the mechanisms and extents of popliteus impingements before and after TKA and to investigate the influence of implant sizing. The hypotheses were that (1) popliteus impingements after TKA may occur at both the tibia and the femur, and (2) even with an apparently well-sized prosthesis, popliteal tracking during knee flexion is modified compared to the preoperative situation. The location of the popliteus in three cadaver knees was measured using computed tomography, before and after implantation of plastic TKA replicas, by injecting the tendon with radiopaque liquid. The pre- and post-operative positions of the popliteus were compared from full extension to deep flexion using normosized, oversized, and undersized implants (one size increments). At the tibia, TKA caused the popliteus to translate posteriorly, mostly in full extension: 4.1 +/- 2 mm for normosized implants, and 15.8 +/- 3 mm with oversized implants, but no translations were observed when using undersized implants. At the femur, TKA caused the popliteus to translate laterally at deeper flexion angles, peaking between 80A degrees and 120A degrees: 2 +/- 0.4 mm for normosized implants and 2.6 +/- 0.5 mm with oversized implants. Three-dimensional analysis revealed prosthetic overhang at the posterosuperior corner of normosized and oversized femoral components (respectively, up to 2.9 mm and 6.6 mm). A well-sized tibial component modifies popliteal tracking, while an undersized tibial component maintains more physiologic patterns. Oversizing shifts the popliteus considerably throughout the full arc of motion. This study suggests that both femoro- and tibio-popliteus impingements could play a role in residual pain and stiffness after TKA.

The purpose of this study is twofold: first, to visualize both the tibial and femoral bony insertion surfaces and second, to describe the anterior cruciate ligament (ACL) geometrically, using novel 3D CT imaging. In addition, new concepts of best-fit cylinder and central axis are introduced and evaluated. Eight unpaired knees of embalmed cadavers were used in this study. Following the dissection process, the ACL was injected with a contrast medium for CT imaging. The obtained CT images in extension, 45A degrees, 90A degrees and full flexion were segmented and rendered in 3D allowing morphological and morphometric analysis of the ACL. Anatomical footprint centres, femoral and tibial footprint surface area, best-fit ACL-cylinder intersection area, best-fit ACL-cylinder/footprint coverage ratio, best-fit ACL-cylinder central axis projections at the tibial and femoral footprint in the four positions were used to describe the anatomy of the ACL, based on the Bernard, Hertel and Amis grid. Based on these parameters, with the best-fit cylinder representing the bulk of the ACL, a changing fibre-recruitment pattern was seen with a moving position of the central axis from posterior to anterior on the femoral and tibial footprint, going from extension to flexion. Furthermore, the numerical data show an increase in tibial footprint coverage by the best-fit cylinder through the ACL when the knee is progressively flexed, whereas an inverse relationship was seen on the femoral side. This study is the first to describe the detailed anatomy of the human ACL with respect to its course and footprints using a 3D approach. It confirms the large difference and inter-patient variability between the tibial and femoral footprint area with the former being significantly smaller. The best-fit cylinder concept illustrates the recruitment pattern of the native ACL where in extension the postero-lateral fibres are recruited and in flexion rather the antero-medial bundle, which can be valuable information in reconstructive purposes. The best-fit cylinder and central axis concept offers additional insights into the optimal tunnel placement at the tibial and femoral footprint in order to cover the largest portion of the native ACL soft tissue, aiming for optimal ACL reconstruction.

Purpose The evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers. Methods Chest CT’s of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized. Results Good correlations were found between IQs and the measured physical-technical image quality: noise (ρ = −1.00), contrast-to-noise (ρ = 1.00) and contrast-detail (ρ = 0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively. Conclusions The automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs.

We investigated the healing process on excisional wounds infected with Staphylococcus aureus in rats, treated with 50 mu L of ethyl acetate III from Vernonia scorpioides (Lam.) Pers., Asteraceae, rifamycin diethylamide B 25 mg, or saline. The lesions were measured daily and after seven days were surgically removed and histologically processed. The results indicate a favorable action of the EAIII, demonstrated by the increased wound contraction, smaller area of necrotic tissue, good development of granulation tissue, extensive extracellular matrix deposition and epithelial regeneration. This sub-fraction was phytochemically investigated in parallel studies, revealing the presence of sesquiterpene lactones (glaucolides and hirsutinolides) such as diacethylpiptocarphol and related hirsutinolides, flavonoids and cinnamic acid derivatives and also a new polyacetylene, which have been previously published. Results support the effectiveness of V. scorpioides antimicrobial activity in infected wound healing in rats.

To determine the correlation between the clinical and physical image quality of chest images by using cadavers embalmed with the Thiel technique and a contrast-detail phantom.The use of human cadavers fulfilled the requirements of the institutional ethics committee. Clinical image quality was assessed by using three human cadavers embalmed with the Thiel technique, which results in excellent preservation of the flexibility and plasticity of organs and tissues. As a result, lungs can be inflated during image acquisition to simulate the pulmonary anatomy seen on a chest radiograph. Both contrast-detail phantom images and chest images of the Thiel-embalmed bodies were acquired with an amorphous silicon flat-panel detector. Tube voltage (70, 81, 90, 100, 113, 125 kVp), copper filtration (0.1, 0.2, 0.3 mm Cu), and exposure settings (200, 280, 400, 560, 800 speed class) were altered to simulate different quality levels. Four experienced radiologists assessed the image quality by using a visual grading analysis (VGA) technique based on European Quality Criteria for Chest Radiology. The phantom images were scored manually and automatically with use of dedicated software, both resulting in an inverse image quality figure (IQF). Spearman rank correlations between inverse IQFs and VGA scores were calculated.A statistically significant correlation (r = 0.80, P.01) was observed between the VGA scores and the manually obtained inverse IQFs. Comparison of the VGA scores and the automated evaluated phantom images showed an even better correlation (r = 0.92, P.001).The results support the value of contrast-detail phantom analysis for evaluating clinical image quality in chest radiography.

Objetivo La prueba neurodinamica del nervio mediano (PNES1, prueba neurodinamica 1 de la extremidad superior, o ULNT1 en ingles) se utiliza con frecuencia para evaluar la mecanica y la fisiologia del plexo braquial y del nervio mediano. El presente estudio investiga las PNES1 positivas en una poblacion sana con arco axilar de Langer (AAL) y analiza si el AAL afecta al arco de movimiento durante la extension de codo (AM-EC) durante la PNES1. Material y metodos De los 640 voluntarios examinados, finalmente se incluyeron 26 lados con AAL. La realizacion de un cuestionario clinico adicional revelo “sintomas menores” en algunos sujetos. Estos sintomas menores no se consideraron un trastorno porque no suponian un obstaculo para la realizacion de las actividades diarias y los sujetos no solicitaron atencion medica. Este estudio investiga si la PNES1 puede producir o reproducir sintomas menores o respuestas anormales en sujetos con AAL. Se comparo el AM-EC del lado izquierdo y derecho de los sujetos. Por otra parte, se comparo el angulo de sustraccion, que es el efecto de colocar la columna cervical en flexion lateral contralateral, entre los lados con AAL y los controles. Resultados Los lados con arco axilar de Langer mostraron un aumento significativo en la aparicion de sintomas menores y PNES1 positivas, pero no se observo efecto alguno en el AM-EC. Conclusiones Estos hallazgos indican que el AAL puede afectar de forma transitoria al haz neurovascular axilar. La falta de efectos sobre los AM-EC puede ser consecuencia del origen vascular de los sintomas menores o de una respuesta del nervio cubital/cordon medial a la PNES1.

Objective The neurodynamic test of the median nerve (ULNT1) is frequently used to assess the mechanics and physiology of the brachial plexus and median nerve. The present study looks for a positive ULNT1 in a healthy population with Langer's axillary arch (LAA) and analyzes whether LAA affects the elbow extension range of motion (EE-ROM) of the ULNT1. Method Of 640 volunteers screened, 26 LAA sides were finally included. Additional history taking revealed “minor symptoms” in some subjects. Minor symptoms do not qualify as a disorder because there is no interference with daily activities and no medical advice is sought. This study investigates whether the ULNT1 can (re)produce minor symptoms or abnormal responses in subjects with LAA. The EE-ROM was compared between the subjects' left and right side, and the subtraction angle—which is the effect of placing the cervical spine in contralateral lateral flexion—was compared between LAA sides and controls. Results Langer's axillary arch sides showed a significant increase in the occurrence of minor symptoms and positive ULNT1, but no influence was observed on the EE-ROM. Conclusions These findings suggest that LAA may be capable of transiently provoking the axillary neurovascular bundle. The unaffected EE-ROM may be the consequence of a vascular origin of the minor symptoms or the consequence of an ulnar nerve/medial cord response to the ULNT1.

Purpose: The present study aimed to measure the effect of a morphometric atlas selection strategy on the accuracy of multi-atlas-based BP autosegmentation using the commercially available software package ADMIRE (R) and to determine the optimal number of selected atlases to use. Autosegmentation accuracy was measured by comparing all generated automatic BP segmentations with anatomically validated gold standard segmentations that were developed using cadavers. Materials and methods: Twelve cadaver computed tomography (CT) atlases were included in the study. One atlas was selected as a patient in ADMIRE (R), and multi-atlas-based BP autosegmentation was first performed with a group of morphometrically preselected atlases. In this group, the atlases were selected on the basis of similarity in the shoulder protraction position with the patient. The number of selected atlases used started at two and increased up to eight. Subsequently, a group of randomly chosen, non-selected atlases were taken. In this second group, every possible combination of 2 to 8 random atlases was used for multi-atlas-based BP autosegmentation. For both groups, the average Dice similarity coefficient (DSC), Jaccard index (JI) and Inclusion index (INI) were calculated, measuring the similarity of the generated automatic BP segmentations and the gold standard segmentation. Similarity indices of both groups were compared using an independent sample t-test, and the optimal number of selected atlases was investigated using an equivalence trial. Results: For each number of atlases, average similarity indices of the morphometrically selected atlas group were significantly higher than the random group (p

Background: The first aim of this study was to evaluate the correlation between clinical and physical-technical image quality applied to different strengths of iterative reconstruction in chest CT images using Thiel cadaver acquisitions and Catphan images. The second aim was to determine the potential dose reduction of iterative reconstruction compared to conventional filtered back projection based on different clinical and physical-technical image quality parameters. Methods: Clinical image quality was assessed using three Thiel embalmed human cadavers. A Catphan phantom was used to assess physical-technical image quality parameters such as noise, contrast-detail and contrast-to-noise ratio (CNR). Both Catphan and chest Thiel CT images were acquired on a multislice CT scanner at 120 kVp and 0.9 pitch. Six different refmAs settings were applied (12, 30, 60, 90, 120 and 150refmAs) and each scan was reconstructed using filtered back projection (FBP) and iterative reconstruction (SAFIRE) algorithms (1,3 and 5 strengths) using a sharp kernel, resulting in 24 image series. Four radiologists assessed the clinical image quality, using a visual grading analysis (VGA) technique based on the European Quality Criteria for Chest CT. Results: Correlation coefficients between clinical and physical-technical image quality varied from 0.88 to 0.92, depending on the selected physical-technical parameter. Depending on the strength of SAFIRE, the potential dose reduction based on noise, CNR and the inverse image quality figure (IQF(inv)) varied from 14.0 to 67.8 %, 16.0 to 71.5 % and 22.7 to 50.6 % respectively. Potential dose reduction based on clinical image quality varied from 27 to 37.4 %, depending on the strength of SAFIRE. Conclusion: Our results demonstrate that noise assessments in a uniform phantom overestimate the potential dose reduction for the SAFIRE IR algorithm. Since the IQF(inv) based dose reduction is quite consistent with the clinical based dose reduction, an optimised contrast-detail phantom could improve the use of contrast-detail analysis for image quality assessment in chest CT imaging. In conclusion, one should be cautious to evaluate the performance of CT equipment taking into account only physical-technical parameters as noise and CNR, as this might give an incomplete representation of the actual clinical image quality performance.

Background For many years, researchers have attempted to describe shoulder motions by using different mathematical methods. The aim of this study was to describe a procedure to quantify clavicular motion. Methods The procedure proposed for the kinematic analysis consists of 4 main processes: 3 transcortical pins in the clavicle, motion capture, obtaining 3-dimensional bone models, and data processing. Results Clavicular motion by abduction (30° to 150°) and flexion (55° to 165°) were characterized by an increment of retraction of 27° to 33°, elevation of 25° to 28°, and posterior rotation of 14° to 15°, respectively. In circumduction, clavicular movement described an ellipse, which was reflected by retraction and elevation. Kinematic analysis shows that the articular surfaces move by simultaneously rolling and sliding on the convex surface of the sternum for the 3 movements of abduction, flexion, and circumduction. Conclusion The use of 3 body landmarks in the clavicle and the direct measurement of bone allowed description of the osteokinematic and arthrokinematic movement of the clavicle.

Biomechanical research and orthopedic training is regularly carried out on human cadavers. Given the post-mortem decay, these cadavers were usually frozen or embalmed. The embalming method according to Dr. Thiel was often praised for the preservation of natural texture. The main aim of this article was to quantitatively analyze the impact of this embalming technique on the biomechanical properties. To that extent, Achilles tendons (calcaneal tendons) of seven cadavers have been tested. For each cadaver, a first tendon was tested following a fresh-frozen conservation, the other following the Thiel embalming process. The results indicated a significant difference in Young's modulus between both groups (P values = 0.046). The secondary aim of this article was to analyze the impact of exposure to room conditions and associated dehydration on the biomechanical properties of cadaver tissue. Therefore, each tendon was tested before and after 2 hr of exposure to room conditions. The resulting dehydration caused a significant increase of the Young's modulus for the thawed fresh-frozen tendons. The properties of the Thiel embalmed tendons were not significantly altered. In conclusion, this research promoted the use of fresh-frozen specimens for biomechanical testing. Effort should, however, be made to minimize dehydration of the tested specimens.

Metal artifacts may negatively affect radiologic assessment in the oral cavity. The aim of this study was to evaluate different metal artifact reduction techniques for metal artifacts induced by dental hardware in CT scans of the oral cavity. Clinical image quality was assessed using a Thiel-embalmed cadaver. A Catphan phantom and a polymethylmethacrylate (PMMA) phantom were used to evaluate physical-technical image quality parameters such as artifact area, artifact index (AI), and contrast detail (IQFinv). Metal cylinders were inserted in each phantom to create metal artifacts. CT images of both phantoms and the Thiel-embalmed cadaver were acquired on a multislice CT scanner using 80, 100, 120, and 140 kVp; model-based iterative reconstruction (Veo); and synthesized monochromatic keV images with and without metal artifact reduction software (MARs). Four radiologists assessed the clinical image quality, using an image criteria score (ICS). Significant influence of increasing kVp and the use of Veo was found on clinical image quality (p = 0.007 and p = 0.014, respectively). Application of MARs resulted in a smaller artifact area (p

Purpose The purpose of this study was to determine the effects of atlas selection based on different morphometric parameters, on the accuracy of automatic brachial plexus (BP) segmentation for radiation therapy planning. The segmentation accuracy was measured by comparing all of the generated automatic segmentations with anatomically validated gold standard atlases developed using cadavers. Methods and Materials Twelve cadaver computed tomography (CT) atlases (3 males, 9 females; mean age: 73 years) were included in the study. One atlas was selected to serve as a patient, and the other 11 atlases were registered separately onto this "patient" using deformable image registration. This procedure was repeated for every atlas as a patient. Next, the Dice and Jaccard similarity indices and inclusion index were calculated for every registered BP with the original gold standard BP. In parallel, differences in several morphometric parameters that may influence the BP segmentation accuracy were measured for the different atlases. Specific brachial plexus-related CT-visible bony points were used to define the morphometric parameters. Subsequently, correlations between the similarity indices and morphometric parameters were calculated. Results A clear negative correlation between difference in protraction-retraction distance and the similarity indices was observed (mean Pearson correlation coefficient = −0.546). All of the other investigated Pearson correlation coefficients were weak. Conclusions Differences in the shoulder protraction-retraction position between the atlas and the patient during planning CT influence the BP autosegmentation accuracy. A greater difference in the protraction-retraction distance between the atlas and the patient reduces the accuracy of the BP automatic segmentation result.