Usefulness of sectional images in dural AVF for the interpretation of venous anatomy

Knowledge of the venous anatomy is essential for appropriately treating dural arteriovenous fistulas (AVFs). It is challenging to determine the overall venous structure despite performing selective angiography for dural AVFs with feeder from multiple selected arteries. This is because only a part of the veins can be observed through the shunt in the selected artery. Therefore, after performing selective angiography of all vessels to understand the approximate venous anatomy, the venous anatomy can be easily understood by closely examining the source image of computed tomographic angiography or magnetic resonance angiography. Through this, it is possible to specify the vein that is to be blocked (target embolization), thereby avoiding extensive blocking of the vein and avoiding various complications. In the case of dural AVF with feeder from single selected artery, if the multiplanar reconstruction image of the three-dimensional rotational computed tomography obtained by performing angiography is analyzed thoroughly, a shunted pouch can be identified. If embolization is performed by targeting this area, unnecessary sinus total packing can be avoided.

Three-dimensional CT imaging in extensor tendons using deep learning reconstruction: optimal reconstruction parameters and the influence of dose

The purpose of this study was to assess the optimal reconstruction parameters and the influence of tube current in extensor tendons three-dimensional computed tomography (3D CT) using deep learning reconstruction, using iterative reconstruction as a reference. In the phantom study, a cylindrical phantom with a 3 mm rod simulated an extensor tendon was used. The phantom images were acquired at tube current of 50, 100, 150, 200, and 250 mA. In the clinical study, CT scans of hand tendons were performed on nine hands from eight patients. All images were reconstructed using advanced intelligent clear-IQ engine (AiCE) parameters (body, body sharp, brain CTA, and brain LCD) and adaptive iterative dose reduction three dimensional (AIDR 3D). The objective image quality for tendon detectability was evaluated by calculating the low-contrast object specific contrast-to-noise ratio (CNRLO) in the phantom study and CNR and coefficient of variation (CV) in the clinical study. In the phantom study, CNRLO (at 200 mA) of AiCE parameters (body, body sharp, brain CTA, and brain LCD) and AIDR 3D were 5.2, 5.3, 5.3, 5.8, and 5.0, respectively. In the clinical study, AiCE brain CTA was higher CNR and lower CV values compared to other reconstruction parameters. AiCE without dose reduction may be an effective strategy for further improving the image quality of extensor tendons 3D CT. Our study suggests that the AiCE brain CTA is more suitable for extensor tendons 3D CT compared to other AiCE parameters.

Radiographic comparison of atelocollagen versus deproteinized bovine bone minerals covered with a collagen membrane in alveolar ridge preservation: a retrospective study

BACKGROUND

Atelocollagen (AC) is a low-immunogenic collagen derivative with longer degradation time, which can be a suitable material for alveolar ridge preservation (ARP). However, there are few human studies on AC using for ARP. This research aims to radiographically evaluate the efficacy of AC in comparison to deproteinized bovine bone minerals covered with a collagen membrane (DBBM/CM) in ARP.

METHODS

Medical records in the Implantology Department of the Hospital of Stomatology of Wuhan University were screened for patients who received flapless ARP using either AC or DBBM/CM. A total of 58 patients were included in this retrospective study. 28 patients were treated with AC, while 30 patients were used DBBM/CM. Cone-beam computed tomography (CBCT) scans were taken before extraction and after 6 months of healing. To assess the dimensional change of the extraction sockets, the scanning data were output and transferred to the digital software to measure horizontal bone width change, vertical bone height change and bone volume change in region of interest. To evaluate the bone quality of healed sockets, the bone density of virtual implants was evaluated.

RESULTS

The horizontal bone width changes at all five different levels showed no significant difference between the two groups. The largest horizontal bone width decrement in both groups occurred at the crest of ridge, which decreased 3.71 ± 1.67 mm in AC group and 3.53 ± 1.51 mm in DBBM/CM group (p = 0.68). At the central buccal aspect, the ridge height reduced 0.10 ± 1.30 mm in AC group, while increased 0.77 ± 2.43 mm in DBBM/CM group (p = 0.10). The vertical bone height differences between two groups showed no statistical significance. The percentages of volume absorption in AC group and DBBM/CM group were 12.37%±6.09% and 14.54%±11.21%, respectively. No significant difference in volume absorption was found (p = 0.36). The average bone density around virtual implants in AC group (649.41 ± 184.71 HU) was significantly lower than that in DBBM/CM group (985.23 ± 207.85 HU) (p < 0.001).

CONCLUSIONS

ARP with AC had a similar effect on limiting the dimensional alteration of alveolar ridge, when radiographically compared with DBBM/CM.

Protocol for capturing 3D facial meshes for rhinoseptoplasty planning

OBJECTIVES

To present and execute a protocol for the capture of 3D facial images using photogrammetry through the open access software Blender and its add-on OrtogOnBlender (OOB) and to evaluate the compatibility of the 3D meshes generated with Computed tomography (CT) of the sinuses.

METHODS

Individuals >18 years old, candidates for Rhinoseptoplasty in a tertiary hospital, were submitted to a photographic session to perform the standardized protocol. In the session, divided into 3 phases, sequential photos were taken for processing the photogrammetry in the OOB and producing 3D meshes of the face. The photogrammetry reconstructions were compared with the reference mesh of the soft tissue surface of the Sinus CT scan to assess compatibility between them.

RESULTS

21 patients were included, 67% female. 3 photogrammetry meshes and 1 CT reference mesh were generated, which demonstrated matching compatibility, as most of the mean distances between cloud points were <1.48 mm. Phase 3 of the session with the highest number of photos (54.36 ± 15.05) generated the most satisfactory mesh with the best resolution.

CONCLUSIONS

The proposed protocol is reproducible and feasible in clinical practice, generated satisfactory 3D meshes of the face, being a potential tool for surgical planning and comparison of results. For the implementation of photogrammetry for use in 3D anthropometry, it is necessary to validate this method.

LEVEL OF EVIDENCE: 3

OCEBM Levels of Evidence Working Group.1 "The Oxford 2011 Levels of Evidence". Oxford Centre for Evidence-Based Medicine. http://www.cebm.net/index.aspx?o=5653.

Three-dimensional visualization and evaluation of hilar cholangiocarcinoma resectability and proposal of a new classification

BACKGROUND

As digital medicine has exerted profound influences upon diagnosis and treatment of hepatobiliary diseases, our study aims to investigate the accuracy of three-dimensional visualization and evaluation (3DVE) system in assessing the resectability of hilar cholangiocarcinoma (hCCA), and explores its potential clinical value.

MATERIALS AND METHODS

The discovery cohort, containing 111 patients from April 2013 to December 2019, was retrospectively included to determine resectability according to revised criteria for unresectability of hCCA. 3D visualization models were reconstructed to evaluate resectability parameters including biliary infiltration, vascular involvement, hepatic atrophy and metastasis. Evaluation accuracy were compared between contrast-enhanced CT and 3DVE. Logistic analysis was performed to identify independent risk factors of R0 resection. A new comprehensive 3DVE classification of hCCA based on factors influencing resectability was proposed to investigate its role in predicting R0 resection and prognosis. The main outcomes were also analyzed in cohort validation, including 34 patients from January 2020 to August 2022.

RESULTS

3DVE showed an accuracy rate of 91% (95%CI 83.6-95.4%) in preoperatively evaluating hCCA resectability, significantly higher than 81% (95%CI 72.8-87.7%) of that of CT (p = 0.03). By multivariable analysis, hepatic artery involvement in 3DVE was identified an independent risk factor for R1 or R2 resection (OR = 3.5, 95%CI 1.4,8.8, P < 0.01). New 3DVE hCCA classification was valuable in predicting patients' R0 resection rate (p < 0.001) and prognosis (p < 0.0001). The main outcomes were internally validated.

CONCLUSIONS

3DVE exhibited a better efficacy in evaluating hCCA resectability, compared with contrast-enhanced CT. Preoperative 3DVE demonstrated hepatic artery involvement was an independent risk factor for the absence of R0 margin. 3DVE classification of hCCA was valuable in clinical practice.

Concordance and reproducibility in the location of reference points for a volumetric craniofacial analysis: Cross-sectional study

Background

Considering the limitations of visualization that occur even with the use of radiographs, the cone beam computed tomography (CBCT) becomes more attractive to diagnose and propose an assertive treatment plan. This study aimed to evaluate intra and interobserver reproducibility, and concordance of 31 reference points we described considering visualization tools and the three planes of space in a bimaxillary CBCT.

Methods

Three observers located in triplicate the 31 reference points in the CBCT of six healthy patients. Friedman test was used to compare intraobserver paired samples, and interobserver concordance was determined by the intraclass correlation coefficient (ICC) with ranges>0.75 (excellent), between 0.60 and 0.74 (good), between 0.40 and 0.59 (sufficient) and<0.40 (poor). The P value was set at<0.05.

Results

A high ICC (>0.75%) was obtained by comparing the x, y, and z values at the location of landmark points. Excellent ICC>0.75 was for 81.7% and poor<0.40 was 7.5% in the interobserver evaluation. Data showed that 25 points had excellent concordance on the x-plane, 25 on the y-plane, and 26 on the z-plane (0.75%).

Conclusion

Intraobserver concordance analysis indicated that location of anatomical reference points on bimaxillary CBCT is performed with great reproducibility by interpreting their location with a clear description in the three planes of space. Complexity of achieving a good precision degree in the manual marking of reference points caused by convexities of the anatomical structures involved, might explain the variability found. The systematized location of the reference points would contribute to reduce such variability.

An automated landmark method to describe geometric changes in the human mandible during growth

OBJECTIVE

The principal aim of this study was to assess an automatic landmarking approach to human mandibles based on the atlas method. The secondary aim was to identify the areas of greatest variation in the mandibles of middle-aged to older adults.

DESIGN

Our sample consisted of 160 mandibles from computed tomography scans of 80 men and 80 women aged between 40 and 79 years. Eleven anatomical landmarks were placed manually on mandibles. The automated landmarking through point cloud alignment and correspondence (ALPACA) method implemented in 3D Slicer was used to automatically place landmarks to all meshes. Euclidean distances, normalized centroid size, and Procrustes ANOVA were calculated for both methods. A pseudo-landmarks approach was followed using ALPACA to identify areas of changes among our sample.

RESULTS

The ALPACA method showed significant differences in Euclidean distances for all landmarks compared to the manual method. A mean Euclidean distance of 1.7 mm was found for the ALPACA method and 0.99 mm for the manual method. Both methods found that sex, age, and size had a significant effect on mandibular shape. The greatest variations were observed in the condyle, ramus, and symphysis regions.

CONCLUSION

The results obtained using the ALPACA method are acceptable and promising. This approach can automatically place landmarks with an average accuracy of less than 2 mm, which may be sufficient in most anthropometric analyses. In the light of our results, however, odontological application such as occlusal analysis is not recommended.

Preoperative novel magnetic resonance fusion imaging for carotid endarterectomy patients with contrast contraindications: a pilot study

OBJECTIVE

For carotid endarterectomy (CEA) patients with renal dysfunction and allergies to contrast media, we developed a preoperative novel method of non-contrast three-dimensional magnetic resonance fusion imaging (NC-3DMRFI) which could describe well blood vessels, plaques, and bony structures even in surgical position. In this study, we examined the usefulness of this method.

METHODS

We extracted non-contrast magnetic resonance images of bones, blood vessels, and plaques to create a three-dimensional (3D) fusion image. An image acquired in the normal position and another in the surgical position during CEA were used to create a fusion image. We compared the fusion imaging results with the intraoperative findings of six patients with contrast contraindications received CEA.

RESULTS

Preoperative NC-3DMRFI could clearly show the positions of the carotid bifurcation, the distal end of plaque, and the bony structure in five of the six cases. Intraoperative findings and preoperative fusion imaging results were comparable in all cases where fusion images could be created. The fusion imaging in the surgical position during CEA was useful for preoperative examination, and the surgical space could be secured in the case of a high cervical location.

CONCLUSION

This pilot study showed our novel NC-3DMRFI method is useful for preoperative simulation in CEA, especially in patients with renal dysfunction and allergies to contrast media.

Three-dimensional maxillary virtual patient creation by convolutional neural network-based segmentation on cone-beam computed tomography images

OBJECTIVE

To qualitatively and quantitatively assess integrated segmentation of three convolutional neural network (CNN) models for the creation of a maxillary virtual patient (MVP) from cone-beam computed tomography (CBCT) images.

MATERIALS AND METHODS

A dataset of 40 CBCT scans acquired with different scanning parameters was selected. Three previously validated individual CNN models were integrated to achieve a combined segmentation of maxillary complex, maxillary sinuses, and upper dentition. Two experts performed a qualitative assessment, scoring-integrated segmentations from 0 to 10 based on the number of required refinements. Furthermore, experts executed refinements, allowing performance comparison between integrated automated segmentation (AS) and refined segmentation (RS) models. Inter-observer consistency of the refinements and the time needed to create a full-resolution automatic segmentation were calculated.

RESULTS

From the dataset, 85% scored 7-10, and 15% were within 3-6. The average time required for automated segmentation was 1.7 min. Performance metrics indicated an excellent overlap between automatic and refined segmentation with a dice similarity coefficient (DSC) of 99.3%. High inter-observer consistency of refinements was observed, with a 95% Hausdorff distance (HD) of 0.045 mm.

CONCLUSION

The integrated CNN models proved to be fast, accurate, and consistent along with a strong interobserver consistency in creating the MVP.

CLINICAL RELEVANCE

The automated segmentation of these structures simultaneously could act as a valuable tool in clinical orthodontics, implant rehabilitation, and any oral or maxillofacial surgical procedures, where visualization of MVP and its relationship with surrounding structures is a necessity for reaching an accurate diagnosis and patient-specific treatment planning.

Relapse patterns of two-jaw surgical correction in patients with skeletal Class III malocclusion and different vertical facial types

The aim of this study was to evaluate postoperative relapse after the surgical correction of skeletal Class III deformities of various facial patterns as a guide to surgical planning. A retrospective cohort study of 90 consecutive patients with skeletal Class III malocclusion who underwent bimaxillary surgery was performed. The surgical outcomes and postoperative stability were compared. The primary predictor variable was vertical facial type, which was classified into three groups according to the Frankfort mandibular plane angle (FMA). The primary outcome of angular and linear measurements was obtained using serial cone beam computed tomography scans obtained at time points of preoperative, 1 week after surgery, and orthodontic debonding. No significant difference in skeletal relapse was observed in patients with the different vertical facial types. The mandible displayed a forward and upward relapse in all three groups postoperatively. The patients with a low FMA exhibited a more consistent mandibular relapse pattern than those with a normal or high FMA. These findings suggest that bimaxillary surgery is clinically stable for mandibular prognathism regardless of the vertical facial pattern. However, 1-1.5 mm of overcorrection in the mandible setback should be considered in patients with a low FMA, because of the greater facial depth and consistent forward and upward mandibular relapse pattern.

Comparison of the intraoperative efficacy of the powered rasp and conventional burr in arthroscopic resection of anterior ankle osteophytes

BACKGROUND

The efficacy of the powered rasp, a new reciprocating motion device for arthroscopic resection of osteophytes, has not been verified. The aim of this study was to compare the intraoperative efficacy of the powered rasp in arthroscopic resection of anterior ankle osteophytes to that of the conventional burr.

METHODS

A total of 49 consecutive patients who underwent arthroscopic resection of anterior ankle osteophytes (26 patients with the conventional burr and 23 patients with the powered rasp) were retrospectively reviewed. The preoperative volume of each osteophyte was measured using computerized tomography scan and three-dimensional software. The resection time was measured by review of the individual arthroscopy video, and the estimated resection rate was calculated as the volume of osteophytes/resection time.

RESULTS

The preoperative volume of osteophytes was not different between the two groups (847.8 ± 685.3 mm³ in the conventional burr and 913.3 ± 605.8 mm³ in the powered rasp, p = 0.726). The resection time was 442.4 ± 216.6 s (seconds) in the conventional burr and 386.4 ± 186.3 s in the powered rasp, and the estimated resection rate was 1.8 ± 1.0 mm³/s with the conventional burr and 2.4 ± 1.3 mm³/s with the powered rasp. These measurements were not significantly different between the two groups (p = 0.340 and 0.083, respectively).

CONCLUSION

The intraoperative efficacy of the powered rasp did not show superiority to that of the conventional burr in arthroscopic resection of anterior ankle osteophytes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Vectra 3D Simulation in Lower Eyelid Blepharoplasty: How Accurate is it?

BACKGROUND

Estimating the volume of fat to be resected during lower lid blepharoplasty can be challenging. While the excess fat is clearly visible in the upright position, it retracts into the orbital cavity when the patient is in decubitus. Several tools have been developed to predict the volume required for adequate outcomes and to reduce the risk of complications. Among these, 3D photography, in addition to being noninvasive, radiation-free, portable and relatively inexpensive, can be used to make simulations.

OBJECTIVE

To assess the level of agreement between Vectra H1 camera simulations and the outcome of lower eyelid blepharoplasties with volume removal based on these simulations.

METHODS

Preoperatively, a 3D camera and simulation software (Vectra H1, Canfield Imaging Systems) was used to estimate the fat pad volume to be resected from the lower eyelids in a sample of 35 patients (female n = 34) aged 55 years on average. Following the procedure, the patients were photographed at 1, 3 and 6 months and the outcome was compared to the simulation.

RESULTS

The agreement between the simulated volume and the intraoperative volume was high. While the difference between the postoperative volume and the simulated volume decreased over time, at 6 months the actual volume was still 0.30 mL (right eye) and 0.24 mL (left eye) larger than the simulated volume.

CONCLUSIONS

A systematic and significant difference was found between the simulation volume and the postoperative volume. The low level of agreement observed suggests that the accuracy of the tested software is insufficient for reliable simulations.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

What does preoperative three-dimensional image contribute to complex pancreatic surgery?

The possibility of modelling diagnostic images in three dimensions (3D) in pancreatic surgery is a novelty that provides us multiple advantages. A better visualization of the structures allows us a more accurate planning of the surgical technique and makes it easier the surgery in complex cases. We present the case study of a borderline pancreatic head adenocarcinoma patient to illustrate the advantages of 3D modelling in complex pancreatic surgery. The help of 3D technology allowed us to optimally plan the intervention and facilitate surgical resection. The use of this tool could translate into: shorter operative time, fewer intraoperative complications or an increase in R0 resections. The usability of the program used in our case, agile and intuitive, was an added advantage.

Reliability and accuracy of automatic segmentation of mandibular 3D models on linear measurements

OBJECTIVE

Evaluate if automatic segmentation of mandibular three-dimensional (3D) models is reliable and accurate.

MATERIALS AND METHODS

Eight dry mandibles with eight silica markers were scanned in the i-CAT Classic device (Imaging Sciences International). Automatic segmentation was performed using nine standard preset thresholds in the Dolphin software (Dolphin Imaging & Management Solutions). Three observers individually made twice eight linear measurements on the mandibular 3D models. Another observer made physical measurements, twice as well, on the dry mandibles. Reliability and accuracy were evaluated with intraclass correlation coefficients (ICCs), Dahlberg's formula, Bland-Altman analyses, and changing bias with regression analyses.

RESULTS

Inter-observer and intra-observer ICCs and Dahlberg's error were ≥ 0.75 and ≤ 1.0 mm, respectively, for all measurements. Inter-observer agreement between mandibular 3D models and physical measurements ranged from -0.37 to 0.91 mm.

CONCLUSIONS

Linear measurements made on mandibular 3D models obtained using standard preset thresholds are reliable and accurate. However, additional studies are necessary to confirm this hypothesis for clinical applications.

CLINICAL RELEVANCE

Since the 3D models are useful for diagnostics and surgical planning, it is necessary to determinate whether the linear measurements made on 3D models obtained by automatic segmentation are sufficiently reliable and accurate.

Age estimation based on the acetabulum using global illumination rendering with computed tomography

INTRODUCTION

The acetabulum has been reported as a reliable age estimation marker. However, analyzing its morphological changes can be challenging using computed tomography (CT) imaging. Newly introduced global illumination rendering (GIR) applied to CT can improve the visualization of the fine details and thus the method's performance. This study aimed to analyze age estimation using morphological features of the acetabulum using GIR applied to CT.

METHODS

We collected 200 postmortem CT scans. A segmentation of the acetabular joint was initially done. Then, three-dimensional (3D) reconstruction of the images was performed using GIR. These images were saved and then analyzed by two operators based on the three morphological criteria described in the Rougé-Maillart method. Reproducibility was assessed by intraclass correlation (ICC). Age estimation was assessed by multiple linear regression.

RESULTS

The sample was composed of 155 males and 45 females, with a mean age of 50 ± 18.3 years old. We observed high agreement in both the inter-observer and intra-observer reproducibility for the three variables (ICC of 75.6 to 90.8% and 89.3 to 95.8%, respectively) and the total score (ICC of 93.5% and 95%, respectively). The three variables, as well as the total score, were significantly correlated with age groups. The total score showed a prediction rate higher than 85% for ages under 40 and over 70 years old. We identified three models with two validated models with an adjusted R² of 85.6% and 84.8%, respectively; a standard error of 0.688 and 0.706, respectively; and a good correlation of all variables and no inter-correlation. The first validated model included the three morphological criteria scores, and the second model was based on the total score.

CONCLUSION

GIR applied to CT provides photorealistic images that can be useful for forensic imaging intended for age estimation based on morphological methods.

Impact of high-density mapping on outcome of the second ablation for atrial fibrillation

PURPOSE

Identification of a conduction gap between the left atrium and pulmonary vein (LA-PV gap) and the circuit of atrial tachycardia after pulmonary vein isolation (PVI) is an important process during the second ablation for atrial fibrillation (AF). The high-density mapping system RHYTHMIA® is useful for identification of an LA-PV gap and the circuit of atrial tachycardia. Therefore, this study was performed to investigate the effect of RHYTHMIA® in terms of the outcome of the second ablation for AF.

METHODS

One hundred patients underwent a second ablation for AF in our institute from April 2015 to December 2018. We retrospectively evaluated 49 patients using RHYTHMIA® (group 1) and 51 patients using the conventional method with additional anatomical guide by CARTO® system.

RESULTS

In group 1, we performed redo PVI for 41 patients with 49 LA-PV countable gaps and ablation for other atrial arrhythmias in 7 patients. In group 2, we performed redo PVI in 40 patients with 33 LA-PV countable gaps and ablation for other atrial arrhythmias in 9 patients. Three and two unstable arrhythmias in each group were not ablated. The final recurrence of atrial arrhythmia was significantly lower in group 1 than 2 (8/49 (16%) vs. 17/51 (33%), respectively; P = 0.017). Atrial arrhythmias other than AF after the second ablation occurred in only one patient in group 1 but seven patients in group 2.

CONCLUSION

Using high-density mapping for the second ablation of AF was found to be superior to the conventional ablation method in terms of the suppression of atrial events in this study. This technique warrants further investigation.

Production and clinical evaluation of breast lesion skin markers for automated three-dimensional ultrasonography of the breast: a pilot study

Objectives

Automated ultrasound of the breast has the advantage to have the whole breast scanned by technicians. Consequently, feedback to the radiologist about concurrent focal abnormalities (e.g., palpable lesions) is lost. To enable marking of patient- or physician-reported focal abnormalities, we aimed to develop skin markers that can be used without disturbing the interpretability of the image.

Methods

Disk-shaped markers were casted out of silicone. In this IRB-approved prospective study, 16 patients were included with a mean age of 57 (39–85). In all patients, the same volume was imaged twice using an automated breast ultrasound system, once with and once without a marker in place. Nine radiologists from two medical centers filled scoring forms regarding image quality, image interpretation, and confidence in providing a diagnosis based on the images.

Results

Marker adhesion was sufficient for automated scanning. Observer scores showed a significant shift in scores from excellent to good regarding diagnostic yield/image quality (χ², 15.99, p < 0.01), and image noise (χ², 21.20, p < 0.01) due to marker presence. In 93% of cases, the median score of observers “agree” with the statement that marker-induced noise did not influence image interpretability. Marker presence did not interfere with confidence in diagnosis (χ², 6.00, p = 0.20).

Conclusion

Inexpensive, easy producible skin markers can be used for accurate lesion marking in automated ultrasound examinations of the breast while image interpretability is preserved. Any marker-induced noise and decreased image quality did not affect confidence in providing a diagnosis.

Key Points

• The use of a skin marker enables the reporting radiologist to identify a location which a patient is concerned about.

• The developed skin marker can be used for accurate breast lesion marking in ultrasound examinations.

Successful surgical strategy for ventral thoracic spinal perimedullary spinal arteriovenous fistulas: Case report

Background:

Spinal arteriovenous fistulas (AVFs) are vascular lesions that often pose significant surgical challenges. This is particularly true for those located close to the anterior spinal artery. Here, we analyzed the surgical options for treating an anterior perimedullary AVF (pAVFs).

Case Description:

A 66-year-old male with the right lower extremity weakness was diagnosed with a spinal dural AVF at the L1 level. It was initially treated with open surgery followed by CyberKnife radiosurgery at another institution. Five years later, he presented with a persistent pAVF fistula now involving the T11 level; the major feeder originated on the left at the T7–T8 level (e.g., involving a left-sided “duplicated” anterior spinal artery). Utilizing a three-dimensional (3D) computer tomography (CT) guided approach; he underwent a left-sided posterolateral T10–T12 laminectomy, sufficient to allow for 30–40° of anterior spinal cord rotation. This was performed under neurophysiological monitoring without any significant changes. Surgery included indocyanine green video angiography, temporary feeder clipping, and complete occlusion of the AVF, followed by complete clipping/resection as confirmed on postoperative magnetic resonance imaging.

Conclusion:

Utilizing a 3D CT image, a ventral pulmonary arteriovenous malformation was excised utilizing a left-sided posterolateral approach allowing for 30–40° of cord rotation.

Construction of digital three-dimensional reconstruction model of rabbit vascular network

In order to study the construction of digital three-dimensional model of rabbit vascular network and provide a powerful basis for the model construction and image processing of human vascular network, in this study, rabbit abdominal and pelvic vessels are perfused with latex-bismuth oxide contrast agent. After that, the internal fibrous structure of the abdominal and pelvic vascular network in rabbits is studied by micro-computed tomography (Micro-CT). Angiography and post-processing software are performed. Firstly, six female rabbits are selected as the study subjects and are anesthetized by intraperitoneal injection of 12% chloral hydrate. After complete anesthesia, laparotomy is performed on the rabbits. The abdominal wall of the rabbit is cut longitudinally to expose the pelvic and abdominal cavity completely. The posterior peritoneum is found and opened. The catheter is inserted into the abdominal aorta and renal artery to complete the abdominal aorta and arterial intubation. Latex, bismuth oxide and potassium hydroxide are mixed in a ratio of 1:1:1 to form latex-bismuth oxide mixed solution as a mixed contrast agent for blood vessel perfusion. After the rabbit is perfused with mixed contrast medium, four organs, including bladder, uterus, small intestine and kidney, are selected as the research organs to construct the three-dimensional model of vascular network in this study. Finally, the above organs are scanned in vitro by micro-CT technology, and the original images of each organ are processed. Then, Mimics 17.0 software is used to build a digital three-dimensional model of the abdominal and pelvic vascular network in rabbits, obtain the information parameters of each network, and analyze the classification and diameter of blood vessels. The results show that the classification of bladder vascular network can only be divided into two levels, uterine vascular network can be divided into three levels, and small intestine and kidney vascular network can be divided into four levels. Therefore, the combination of micro-CT scanning and contrast agent can successfully construct a digital three-dimensional model of rabbit vascular network, which provides a new idea and method for the study of human abdominal and pelvic organs and physiological characteristics.

Reproducibility of digital indirect bonding technique using three-dimensional (3D) models and 3D-printed transfer trays

OBJECTIVE

To evaluate the reproducibility of digital tray transfer fit on digital indirect bonding by analyzing the differences in bracket positions.

MATERIALS AND METHODS

Digital indirect bonding was performed by positioning brackets on digital models superimposed by tomography using Ortho Analyzer (3Shape) software. Thirty-three orthodontists performed indirect bonding on prototyped models of the same malocclusion using prototyped transfer trays for two types of brackets (MiniSprint Roth and BioQuick self-ligating). The models with brackets were scanned using an intraoral scanner (Trios, 3Shape). Superimpositions were made between the digital models obtained after indirect bonding and those from the original virtual setup. To analyze the differences in bracket positions, three planes were examined for each bracket: vertical, horizontal, and angulation. Three orthodontists repeated indirect bonding after 15 days, and Bland-Altman plots and intraclass correlation coefficients were used to evaluate inter- and intraevaluator reproducibility and reliability, respectively. Repeated-measures analysis of variance (ANOVA) was used to analyze the differences between bracket positions, and multivariate ANOVA was used to evaluate the influence of orthodontists' experience on the results.

RESULTS

Differences between bracket positions were not statistically significant, except mesial-distal discrepancies in the BioQuick group (P = .016). However, differences were not clinically significant (horizontal varied from 0.04 to 0.13 mm; angulation, 0.45° to 2.03°). There was no significant influence of orthodontist experience and years of clinical practice on bracket positions (P = .314 and P = .158). The reproducibility among orthodontists was confirmed.

CONCLUSIONS

The reproducibility of digital indirect bonding was confirmed in terms of bracket positions using three-dimensional printed transfer trays.

Comparisons and Combined Application of Two-Dimensional and Three-Dimensional Real-time Shear Wave Elastography in Diagnosis of Thyroid Nodules

Purpose Two-dimensional and three-dimensional real-time shear wave elastography (2D+3D SWE) represents a new technology for the quantification of tissue elasticity. This study investigated whether they could be performed to differentiate between benign and malignant thyroid nodules.

Methods Conventional B-mode ultrasound, 2D and 3D SWE were performed in 96 patients with 97 thyroid nodules with pathology results.

Results All the elastography values of 2D&3D SWE in malignant thyroid nodules were higher than those in benign nodules. These two elastography methods alone could not improve diagnostic value comparing to B-mode ultrasound significantly. However, B-mode US + 2D SWE (TI-RADS ≥ 4c or S-Emean ≥ 23.75 kPa, suspicious), B-mode US + 3D SWE (TI-RADS ≥ 4c or 3D-T-Emean ≥ 20.75 kPa, suspicious), B-mode US + 2D + 3D SWE (TI-RADS ≥ 4c or S-Emean ≥ 23.75 kPa or 3D-T-Emean ≥ 20.75 kPa, suspicious) had higher sensitivity and accuracy values than those of 3 methods alone but lower specificity values. Among them, B-mode ultrasound + 2D SWE had the highest sensitivity, NPV, accuracy and Youden's index (0.881, 0.788, 0.804 and 0.57).

Conclusions 2D SWE or 3D SWE alone could not improve the diagnostic value of differentiating malignant from benign thyroid nodules comparing to conventional B-mode ultrasound. But combination methods could improve the diagnostic value, especially B-mode US + 2D SWE.

Stereoscopic Images from Computed Tomography Angiograms

OBJECTIVE

To present an adaptation of the anaglyph photography technique to be used with radiological images from computed tomography angiograms, enabling stereoscopic visualization of a patient's individual abnormal vascular anatomy for teaching, case discussion, or surgical planning purposes.

METHODS

Traditional anaglyph procedures with actual objects yield 2 independent photographs, simulating the image perceived by each eye. Production of anaglyphs from angiograms involve 3 basic procedures: volume rendering, image capture, and image fusion. Volume renderings were reconstructed using a free, open-source DICOM (Digital Imaging and Communications in Medicine) reader. Subsequently, the virtual object was positioned to mimic the operator's angle of view, and different perspectives of the reconstructed volume could be obtained through exclusively horizontal rotation. The 2 images were then fused after their color composition was modified so that each eye would perceive only 1 image when using anaglyph glasses.

RESULTS

Forty-three angiograms were reviewed for the purpose of this study and a total of 6 examinations were selected for illustration of the technique. Stereoscopic display was possible for all of them and in the 3 types of support tested: computer monitor, tablet, and smartphone screens.

CONCLUSIONS

Anaglyph display of computed tomography angiograms is an effective and low-cost alternative for the stereoscopic visualization of a patient's individual intracranial vascular anatomy.

Volume-rendered computed tomography images of the surgical field for endolymphatic sac surgery

PURPOSE

Identification of the endolymphatic sac has failed occasionally. Postoperative complications have also rarely been reported. Given a safer and more reliable surgery, preoperative anatomical assessments are valuable, however, the vestibular aqueduct has seldom been seen with multi-planar reconstruction (MPR) computed tomography (CT) images yet. Our study aimed to determine the significance and utility of volume-rendered (VR) CT images of the surgical field for identifying the vestibular aqueduct, compared with MPR CT images.

SUBJECTS AND METHODS

14 patients with Meniere's disease who underwent endolymphatic sac surgery between 2008 and 2011. Location and size of the vestibular aqueduct were assessed using VR and MPR CT images, independently.

RESULTS

Accuracy of identifying the location differed significantly between VR and MPR CT images (rate of total correct evaluations: 100% by VR CT images vs 75% by MPR CT images, p = 0.02). Size was correctly identified in cases with a small endolymphatic sac using VR CT images (rate of total correct evaluations for size of the vestibular aqueduct: 100% by VR CT vs 57% by MPR CT, p = 0.046). VR CT images also demonstrated clearly the relationship between the endolymphatic sac and high jugular bulb. In two cases, the endolymphatic sac was identified by VR images, not by MPR images.

CONCLUSION

Accurate information about the location and size of vestibular aqueduct can allow sac surgeons to identify a tiny endolymphatic sac more easily and certainly, and also aids surgical trainees to learn sac surgery safely.

Automated 3D segmentation and diameter measurement of the thoracic aorta on non-contrast enhanced CT

Objectives

To develop and evaluate a fully automatic method to measure diameters of the ascending and descending aorta on non-ECG-gated, non-contrast computed tomography (CT) scans.

Material and methods

The method combines multi-atlas registration to obtain seed points, aorta centerline extraction, and an optimal surface segmentation approach to extract the aorta surface around the centerline. From the extracted 3D aorta segmentation, the diameter of the ascending and descending aorta was calculated at cross-sectional slices perpendicular to the extracted centerline, at the level of the pulmonary artery bifurcation, and at 1-cm intervals up to 3 cm above and below this level. Agreement with manual annotations was evaluated by dice similarity coefficient (DSC) for segmentation overlap, mean surface distance (MSD), and intra-class correlation (ICC) of diameters on 100 CT scans from a lung cancer screening trial. Repeatability of the diameter measurements was evaluated on 617 baseline-one year follow-up CT scan pairs.

Results

The agreement between manual and automatic segmentations was good with 0.95 ± 0.01 DSC and 0.56 ± 0.08 mm MSD. ICC between the diameters derived from manual and from automatic segmentations was 0.97, with the per-level ICC ranging from 0.87 to 0.94. An ICC of 0.98 for all measurements and per-level ICC ranging from 0.91 to 0.96 were obtained for repeatability.

Conclusion

This fully automatic method can assess diameters in the thoracic aorta reliably even in non-ECG-gated, non-contrast CT scans. This could be a promising tool to assess aorta dilatation in screening and in clinical practice.

Key Points

• Fully automatic method to assess thoracic aorta diameters.

• High agreement between fully automatic method and manual segmentations.

• Method is suitable for non-ECG-gated CT and can therefore be used in screening.

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5931-z) contains supplementary material, which is available to authorized users.

In vivo 3-dimensional Kinematics of Cubitus Valgus after Non-united Lateral Humeral Condyle Fracture

Background

Nonunion of lateral humeral condyle fracture causes cubitus valgus deformity. Although corrective osteotomy or osteosynthesis can be considered, there are controversies regarding its treatment. To evaluate elbow joint biomechanics in non-united lateral humeral condyle fractures, we analyzed the motion of elbow joint and pseudo-joint via in vivo three-dimensional (3D) kinematics, using 3D images obtained by computed tomography (CT) scan.

Methods

Eight non-united lateral humeral condyle fractures with cubitus valgus and 8 normal elbows were evaluated in this study. CT scan was performed at 3 different elbow positions (full flexion, 90° flexion and full extension). With bone surface model, 3D elbow motion was reconstructed. We calculated the axis of rotation in both the normal and non-united joints, as well as the rotational movement of the ulno-humeral joint and pseudo-joint of non-united lateral condyle in 3D space from full extension to full flexion.

Results

Ulno-humeral joint moved to the varus on the coronal plane during flexion, 25.45° in the non-united cubitus valgus group and -2.03° in normal group, with statistically significant difference. Moreover, it moved to rotate externally on the axial plane -26.75° in the non-united cubitus valgus group and -3.09° in the normal group, with statistical significance. Movement of the pseudo-joint of fragment of lateral condyle showed irregular pattern.

Conclusions

The non-united cubitus valgus group moved to the varus with external rotation during elbow flexion. The pseudo-joint showed a diverse and irregular motion. In vivo 3D motion analysis for the non-united cubitus valgus could be helpful to evaluate its kinematics.

Clinical diagnostic utility of contrast-enhanced three-dimensional fluid-attenuated inversion recovery for selection of brain biopsy sites in neurosarcoidosis: A case report

Neurosarcoidosis is difficult to diagnose, because definite diagnosis requires detailed histology of the central nervous system. Three-dimensional contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) is more useful for detecting leptomeningeal lesions compared with 3D CE-T1 weighted imaging. However, the clinical diagnostic utility of 3D CE-FLAIR for neurosarcoidosis is unclear. We describe a case of a 46-year-old Japanese woman who was admitted to our department due to chronic headache with fever and diplopia. Using 3D CE-FLAIR, we performed brain biopsy from right cerebellar lesion. The histological examination revealed typical non-caseating granulomas, indicating neurosarcoidosis. Our findings suggest that 3D CE-FLAIR may detect leptomeningeal lesions that are candidates for biopsy in chronic meningitis undetermined etiology.

Usefulness of three-dimensional image navigation system for evaluation of hepatic artery before living donor liver transplantation: a case report

BACKGROUND

The evaluation of the hepatic vascular anatomy in living liver donors is increasingly being performed by three-dimensional (3D) computed tomography (CT) angiography. However, details of hepatic artery anatomy obtained by 3D CT angiography are not always superior to those obtained by angiography. Here, we report a case in which the 3D image navigation system helped to detect segment II, III, and IV arteries (A2, A3, and A4, respectively) that individually originated from the proper hepatic artery (PHA); this could not be detected by 3D CT angiography.

CASE PRESENTATION

A 46-year-old man with end-stage primary biliary cirrhosis was admitted to our hospital for evaluation as a candidate for living donor liver transplantation. The patient's younger sister, aged 43 years, was the only living donor candidate. The predicted left liver graft volume with the middle hepatic vein was found to be 403 mL using the region-growing method with 3D CT software. This volume was sufficiently large for the recipient because the standard liver volume of the recipient was 1095 mL. 3D CT angiography was performed twice but could not reveal the anatomical structure of the left and middle hepatic arteries. However, simulation using the region-growing method demonstrated individual branching off of A2, A3, and A4 from the PHA; conventional angiography demonstrated the same results. Each branch was approximately 1 mm in diameter, which was too small for secure anastomosis. Therefore, we selected the right liver graft for simplicity. The postoperative course of the donor and recipient was uneventful, and they were discharged on postoperative days 10 and 46, respectively.

CONCLUSIONS

In conclusion, reconstruction of the hepatic vasculature using the 3D software by region-growing method might be a useful adjunct for surgical planning in the evaluation of the hepatic arteries in living liver donors.

Evaluation of the oropharynx in class I and II skeletal patterns by CBCT

PURPOSE

This study aimed to evaluate the dimensions of the oropharynx and its shape in the minimum cross-sectional area, in individuals with Class I and Class II skeletal patterns, using three-dimensional CBCT images.

METHODS

Forty-two cone-beam computed tomography images of grown individuals were evaluated. The images were divided according to the patient's skeletal patterns. The dimensions of the oropharyngeal airway space were determined using the Dolphin Imaging software.

RESULTS

The volume and the minimum cross-sectional area were greater in patients with a Class I skeletal pattern, with a median difference of 5379 mm³ and 86.8 mm², respectively. The anteroposterior and lateral diameters in the minimum cross-sectional area were also higher in Class I individuals (2.3 and 6.0 mm, respectively), but the ratio between them was not different.

CONCLUSIONS

The volume and the minimum cross-sectional area of the oropharynx, as well as the anteroposterior and lateral diameters, are lower in individuals with a class II skeletal pattern than in individuals with a class I skeletal pattern. There was no difference in the shape of the oropharynx in healthy individuals with different skeletal patterns.

Rapid 3D mandibular superimposition for growing patients

OBJECTIVE

To evaluate the precision and reproducibility of a protocol to perform rapid voxel-based superimposition of the mandible in growing patients using CBCT.

MATERIALS AND METHODS

The sample comprised two cone-beam computed tomography scans taken at least 1 year apart from each of 24 growing patients. Voxel-based superimposition was performed by two examiners independently. The internal part of the symphysis extending to the first molar was used as the reference. The superimposition process took approximately 5 minutes. Once the mandibles were superimposed, surface models were created and root mean square (RMS) changes were obtained by means of iterative closest point. To evaluate precision, differences in three areas were measured between time point 1 (T1) and time point 2 (T2) superimposed. To evaluate reproducibility between different examiners, the distances between T2 superimposed by each operator were measured in five different areas. Descriptive statistics were used to evaluate the precision of the superimposition and the interexaminer reproducibility measurements for each case were reported individually.

RESULTS

The superimposition mean error between T1 and T2 for the right and left sides of the mandible and chin were 0.23 mm, 0.25 mm, and 0.33 mm, respectively. Interexaminer reproducibility error was ≤0.3 mm in 20 of 24 cases for measurements near the registration area. In the ramus area, two cases had errors >1 mm (1 mm-1.3 mm).

CONCLUSION

The rapid superimposition was precise for assessing dentoalveolar changes and structures close to the registration area. However, evaluation of the condyles and ramus area had limitations and needs improvement.

Age-related morphological regression of myelinated fibers and capillary architecture of distal peripheral nerves in rats

BACKGROUND

Regression of myelinated peripheral nerve fibers in the lower extremities contributes to sarcopenia and balance dysfunction in normal aging. This subclinical regression of myelinated fibers (MFs) is heavily influenced by alterations in microvasculature, though the mechanism underlying these age-related degenerative phenomena remains unclear. The aim of the present study was to examine age-related regressions in myelinated distal peripheral nerve fibers as well as capillary architecture in rats using both morphological and histochemical methods.

RESULTS

MFs were categorized into tertiles of 'large', 'medium', and 'small' sizes based on the distribution of MF diameters. A two-way ANOVA was used to assess effects of fiber size (large/medium/small) and group (young/elderly) on myelin thickness, axon diameter, myelin perimeter, axon perimeter, and G-ratio (axon diameter/fiber diameter). Significant main effects were observed for both MF size and group with respect to all dimensions except for G-ratio. Values for fiber diameter (P < 0.01), myelin thickness (P < 0.01), axon diameter (P < 0.01), myelin perimeter (P < 0.01), and axon perimeter (P < 0.01) were significantly lower than those in the young group. Additionally, mean capillary diameter and number of microvascular branch points were significantly lower in the elderly group than in the young group.

CONCLUSIONS

The present study demonstrated that spontaneous age-related regression predominantly occurs for all fiber sizes in the distal peripheral nerves and the capillary architecture. The results of the present study further suggest that both the distal MFs and capillaries in the peripheral nerve may simultaneously regress with aging.

Three-Dimensional Angiographic Evaluation of Middle Cerebral Artery Trunk Aneurysms: Demonstration of the Close Relationship Between the Early Frontal Cortical Branches and Lateral Lenticulostriate Arteries

BACKGROUND

For the treatment planning of a patient with a middle cerebral artery (MCA) trunk aneurysm, understanding the anatomic relationship among the aneurysm, branching vessels, and lenticulostriate arteries (LSAs) is important. We aimed to demonstrate the branching-vessel anatomy related to an MCA trunk aneurysm using 3-dimensional (3D) angiography.

METHODS

We retrospectively reviewed 3D angiographic findings of 64 cases of MCA trunk aneurysms using a 3D workstation with various postprocessing conditions. We classified the aneurysms into 4 groups (early frontal cortical branch [EFCB], early temporal cortical branch [ETCB], LSA, and nonbranching aneurysms) and analyzed the relationship between the branching vessels and the LSAs.

RESULTS

There were 30 EFCB aneurysms, 25 ETCB aneurysms, 7 LSA aneurysms, and 2 nonbranching aneurysms. Twenty-six (86.7%) of the 30 EFCB aneurysms shared common origins and were associated with the LSAs, but none of the 25 ETCB aneurysms were. Three of 24 patients who received clipping for an EFCB aneurysm experienced a postoperative infarction in the LSA territory. In these 3 patients, the LSA originated from the EFCB and was closely related with the aneurysm.

CONCLUSIONS

We have identified a clinically important anatomic relationship between the MCA trunk aneurysm and branching vessels, including the LSAs. EFCB aneurysms show a close relationship with the LSAs. Pretreatment identification of the origin of the LSAs is important to obviate any perforator injury in EFCB aneurysms.

Risk factor analysis of bone resorption following secondary alveolar bone grafting using three-dimensional computed tomography

BACKGROUND/AIM

The purpose of this study is to analyze the risk factors for bone resorption following secondary bone grafting in the alveolar cleft, using three-dimensional (3D) computed tomography (CT) based on surgical simulation software (SimPlant OMS, Materialise Dental, Leuven, Belgium).

METHODS

We reviewed the secondary alveolar bone grafts performed by a single surgeon between January 2005 and January 2014. A total of 40 patients with unilateral alveolar cleft were included in this study. The grafted alveolar bone was measured using surgical simulation software. In order to validate the measurement, each data set was measured by three different analysts and the inter- and intraobserver variabilities were calculated. A total of eight risk factors for grafted bone survival, including patient age, sex, body mass index (BMI), palatal fistula, amount of grafted bone, dental appliance, canine or incisor eruption, and preoperative upper respiratory tract infection, were evaluated using the linear mixed model and Mann-Whitney test.

RESULTS

The average alveolar defect size was 4.98 cc and the average graft survival was 67.5%. The inter- and intraobserver variabilities of simulation software were 0.758 and 0.915, respectively. Among the risk factors, only dental appliance (p = 0.02) and canine eruption (p = 0.041) were significantly correlated with graft survival. Other risk factors, including the amount of grafted bone, did not show a significant relationship with graft survival.

CONCLUSION

Measurement of an alveolar bone defect using a simulation program based on 3D CT is reliable and reproducible. Secondary bone grafting survival was significantly correlated with canine eruption and dental appliance in the alveolar cleft.

Effect of therapeutic insoles on the medial longitudinal arch in patients with flatfoot deformity: a three-dimensional loading computed tomography study

BACKGROUND

Insoles are frequently used in orthotic therapy as the standard conservative treatment for symptomatic flatfoot deformity to rebuild the arch and stabilize the foot. However, the effectiveness of therapeutic insoles remains unclear. In this study, we assessed the effectiveness of therapeutic insoles for flatfoot deformity using subject-based three-dimensional (3D) computed tomography (CT) models by evaluating the load responses of the bones in the medial longitudinal arch in vivo in 3D.

METHODS

We studied eight individuals (16 feet) with mild flatfoot deformity. CT scans were performed on both feet under non-loaded and full-body-loaded conditions, first with accessory insoles and then with therapeutic insoles under the same conditions. Three-dimensional CT models were constructed for the tibia and the tarsal and metatarsal bones of the medial longitudinal arch (i.e., first metatarsal bone, cuneiforms, navicular, talus, and calcaneus). The rotational angles between the tarsal bones were calculated under loading with accessory insoles or therapeutic insoles and compared.

FINDINGS

Compared with the accessory insoles, the therapeutic insoles significantly suppressed the eversion of the talocalcaneal joint.

INTERPRETATION

This is the first study to precisely verify the usefulness of therapeutic insoles (arch support and inner wedges) in vivo.

The Morphological Changes in the Capillary Architecture of the Tibial Nerve Associated with Spontaneous Aging and Aerobic Exercise Intervention during Aging in Rats

[Purpose] Peripheral nerve degradation associated with aging is linked to failure of interactions in capillary metabolism. The aim of this study was to morphologically investigate the age-related changes in the capillary architecture of the tibial nerve in spontaneous aging and with aerobic exercise intervention in rats. [Subjects] Male Sprague-Dawley rats (n=15) were used in the present study. [Methods] The rats were divided into control (Cont, n=5), elderly (Elder, n=5), and elderly with aerobic exercise (Elder+Ex, n=5) groups. Aerobic training of low intensity was performed for 10 weeks using a treadmill starting at 96 weeks of age by the Elder+Ex group. The capillary diameter, cross-sectional area and number of microvascular ramifications in the tibial nerve were compared among the Cont (20-week-old), Elder (106-week-old) and Elder+Ex groups using three-dimensional images gained from confocal laser scanning microscopy. [Results] The capillary diameter, cross-sectional area and number of microvascular ramifications in the Elder group were significantly smaller than those observed in the Cont and Elder+Ex groups. [Conclusion] These findings suggest that the capillaries in the peripheral nerve degrade with spontaneous aging and that aerobic exercise of low intensity promotes angiogenesis, and protects the capillary from oxidative stress.

An in vivo study of hindfoot 3D kinetics in stage II posterior tibial tendon dysfunction (PTTD) flatfoot based on weight-bearing CT scan

OBJECTIVE

The objective of this study was to evaluate the rotation and translation of each joint in the hindfoot and compare the load response in healthy feet with that in stage II posterior tibial tendon dysfunction (PTTD) flatfoot by analysing the reconstructive three-dimensional (3D) computed tomography (CT) image data during simulated weight-bearing.

METHODS

CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot were taken first in a non-weight-bearing condition, followed by a simulated full-body weight-bearing condition. The images of the hindfoot bones were reconstructed into 3D models. The 'twice registration' method in three planes was used to calculate the position of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint.

RESULTS

From non- to full-body-weight-bearing condition, the difference in the talus position relative to the calcaneus in the talocalcaneal joint was 0.6° more dorsiflexed (p = 0.032), 1.4° more everted (p = 0.026), 0.9 mm more anterior (p = 0.031) and 1.0 mm more proximal (p = 0.004) in stage II PTTD flatfoot compared with that in a healthy foot. The navicular position difference relative to the talus in the talonavicular joint was 3° more everted (p = 0.012), 1.3 mm more lateral (p = 0.024), 0.8 mm more anterior (p = 0.037) and 2.1 mm more proximal (p = 0.017). The cuboid position difference relative to the calcaneus in the calcaneocuboid joint did not change significantly in rotation and translation (all p ≥ 0.08).

CONCLUSION

Referring to a previous study regarding both the cadaveric foot and the live foot, joint instability occurred in the hindfoot in simulated weight-bearing condition in patients with stage II PTTD flatfoot. The method used in this study might be applied to clinical analysis of the aetiology and evolution of PTTD flatfoot, and may inform biomechanical analyses of the effects of foot surgery in the future. Cite this article: Bone Joint Res 2013;2:255-63.

Simplified zero ischemia in robot assisted partial nephrectomy: initial yonsei experience

Purpose

To evaluate the safety and feasibility of a simplified zero ischemia technique using kidney donor computed tomographic (CT) angiography and conventional laparoscopic bulldog clamps.

Materials and Methods

We conducted a review of seven robot-assisted partial nephrectomies (RAPNs) performed by a single surgeon from January 2012 to May 2012. Using a simplified protocol of 3-dimentional reconstruction, tertiary arterial branches supplying the tumor were selectively clamped prior to resection. We used conventional laparoscopic bulldog clamps instead of microsurgical vessel clamps. The patients' demographic information, perioperative outcomes, pathologic outcomes and pre- and postoperative renal functions up to 3 months follow-up were analyzed.

Results

RAPN were successfully performed for seven complex renal hilar tumors. There were no significant differences in the total operation time, estimated blood loss or postoperative outcomes compared with published literature on standard RAPN. Negative surgical margins were reported in all cases.

Conclusions

We presented a simplified-zero ischemia technique using kidney Donor CT angiography and conventional laparoscopic bulldog clamps. We have also demonstrated its safety and feasibility in patients with complex renal hilar tumors. This modified technique can be easily adopted by most surgeons who are currently performing RAPN.

The Usefulness of Reconstructed 3D Images in Surgical Planning for Cochlear Implantation in a Malformed Ear with an Abnormal Course of the Facial Nerve

Objectives

It is not unusual for a cochlear implantation (CI) candidate to have some type of ear malformation, in particular an abnormal course of the facial nerve (FN). In this study, we attempted to reconstruct a three-dimensional (3D) image of temporal bone structures with malformation using computed tomography (CT) imaging and examined its usefulness in the surgical planning of CI in a malformed ear.

Methods

We prepared 3D images for 6 separate CI cases before surgery. First, we manually colored preoperative CT images using Photoshop CS Extended. We then converted the colored CT images to 3D images using Delta Viewer, free-ware for Macintosh. Before surgery, we discussed any problems anticipated based on the 3D images and plans for surgery with those who would be performing the CI.

Results

Case 1: The subject was a 3-year-old boy with malformed ossicles, semicircular canal (SC) hypoplasia, internal auditory canal stenosis, and an abnormal course of the FN. 3D image indicated that the stapes were absent, and the FN was more anteriorly displaced, so that it was difficult to perform cochleostomy. The surgical findings were similar to those depicted on the 3D image, so we could insert an electrode based on the preoperative image simulation without complications. Case 2: The subject was a 7-year-old boy with malformed stapes, atresia of the round window, cochlear and SC aplasia, and an abnormal course of the FN with bifurcation. CI was performed with no problems, in the same manner as in Case 1.

Conclusion

We were able to successfully depict the structures of the inner ear, ossicles, and FN as 3D images, which are very easy to understand visually and intuitively. These 3D images of the malformed ear are useful in preoperative image simulation and in surgical planning for those performing a CI procedure.