Follow-up Cone Beam Computed Tomography Research Articles

An in vitro comparative evaluation of efficiency of three rotary nickel-titanium file systems in terms of remaining dentin thickness using cone-beam computed tomography.

The objective of the present research was to assess and compare the residual dentin thickness after biomechanical preparation of teeth using three distinct rotary nickel-titanium (Ni-Ti) file systems. In the current experimental study, a total of 45 single-rooted teeth were selected for the analysis. The cementoenamel junction of each tooth was decoronated using a diamond disc. The teeth were randomly allocated to three groups, with each group representing a different rotary file system: Group 1: Hero GOLD (Micro Mega), Group 2: One Curve (Micro Mega), and Group 3: HyFlex electro-discharge machining (EDM) (Coltene-Whaledent, Altstatten, Switzerland). To evaluate the initial condition of the teeth, cone-beam computed tomography (CBCT) scans were conducted before the biomechanical preparation. The teeth were positioned on a modeling wax sheet, and the CBCT scans provided baseline measurements. The biomechanical preparation of the root canals followed the manufacturer's recommended guidelines for each file system. After the completion of the canal preparation, follow-up CBCT scans were conducted. The postprocedure CBCT scans were then compared with the initial scans to assess any changes in the residual thickness of dentin in the teeth. Post hoc Tukey analysis of variance tests was utilized to examine differences between the groups. A statistically significant result was defined as P = 0.05 or less for every test. The comparison of preinstrumentation and postinstrumentation CBCT images showed that the HyFlex EDM group removed less dentin clinically compared to the other two groups, i.e., Hero GOLD and One Curve. No significant statistical difference was found between Hero GOLD versus One Curve, One Curve versus HyFlex EDM, and Hero GOLD versus HyFlex EDM. Based on the results of this study, the HyFlex EDM file system exhibited superior cutting efficiency at various levels. Nonetheless, additional investigations are required to comprehensively assess the influence of Ni-Ti rotary file systems on the remaining dentin thickness.

Uncertainty estimation and evaluation of deformation image registration based convolutional neural networks

Objective. Fast and accurate deformable image registration (DIR), including DIR uncertainty estimation, is essential for safe and reliable clinical deployment. While recent deep learning models have shown promise in predicting DIR with its uncertainty, challenges persist in proper uncertainty evaluation and hyperparameter optimization for these methods. This work aims to develop and evaluate a model that can perform fast DIR and predict its uncertainty in seconds. Approach. This study introduces a novel probabilistic multi-resolution image registration model utilizing convolutional neural networks to estimate a multivariate normal distributed dense displacement field (DDF) in a multimodal image registration problem. To assess the quality of the DDF distribution predicted by the model, we propose a new metric based on the Kullback–Leibler divergence. The performance of our approach was evaluated against three other DIR algorithms (VoxelMorph, Monte Carlo dropout, and Monte Carlo B-spline) capable of predicting uncertainty. The evaluation of the models included not only the quality of the deformation but also the reliability of the estimated uncertainty. Our application investigated the registration of a treatment planning computed tomography (CT) to follow-up cone beam CT for daily adaptive radiotherapy. Main results. The hyperparameter tuning of the models showed a trade-off between the estimated uncertainty’s reliability and the deformation’s accuracy. In the optimal trade-off, our model excelled in contour propagation and uncertainty estimation (p <0.05) compared to existing uncertainty estimation models. We obtained an average dice similarity coefficient of 0.89 and a KL-divergence of 0.15. Significance. By addressing challenges in DIR uncertainty estimation and evaluation, our work showed that both the DIR and its uncertainty can be reliably predicted, paving the way for safe deployment in a clinical environment.

Estimation of Loss of Crestal Bone Around Dental Implants in Various Tissue Biotypes Using CBCT.

To evaluate the loss of crestal bone height around dental implants placed in various tissue biotypes. 20 patients with single edentulous sites were allocated randomly, with 10 samples in each into Group I (implants were placed in thick tissue biotype) and Group II (implants were placed in thin tissue biotype). Baseline cone-beam computed tomography (CBCT) was performed after implant placement in both groups, and follow-up CBCT was taken at the time of cementation prior to occlusal loading to assess the crestal bone loss around the mesial and distal side of implants in both groups. A significant loss of crestal bone at both the distal and mesial sides of the implants at the time of cementation was observed in both groups but Group II showed more crestal bone loss as compared to Group I. Mean crestal bone loss was more in Group II (thin tissue biotype) in comparison to Group I (thick tissue biotype). The thick biotype causes less crestal bone changes than the thin biotype, which evokes more loss of crestal bone during the period of peri-implant healing.

Autologous concentrated growth factor mediated accelerated bone healing in root-end microsurgery: A multicenter randomized clinical trial

IntroductionConcentrated growth factor (CGF) is a new-generation autologous platelet concentrate that promotes tissue regeneration and has anti-inflammatory properties. This randomized multicenter trial aimed to evaluate the effects of CGF on bone healing in combination with root-end microsurgery. MethodsHealthy adult patients indicated for root-end microsurgery were randomly assigned to either the CGF or control (no CGF implantation) groups. CGF was implanted into the bone cavity after root-end filling with mineral trioxide aggregate. Clinical and periapical radiographic evaluations were conducted at 1, 3, 6, and 12 months postoperatively, with follow-up cone-beam computed tomography (CBCT) at 6 months. The lesion volume reduction rate was calculated based on data from the preoperative and follow-up CBCT images. ResultsA total of 24 patients were enrolled. The treatment success rate was 91.7% and 83.3% on 12-month periapical radiography and 6-month CBCT, respectively, without a significant difference between the two groups. The lesion volume reduction rate in the CGF group (75.6%) was significantly higher than that in the control (61.0%) group. ConclusionsAutologous CGF in conjunction with root-end microsurgery accelerated lesion reduction as observed on CBCT. Administering autologous blood products to stimulate healing in addition to removing the source of infection appears to be a promising treatment option for root-end microsurgery.

Does the Protrusion of Corticobasal Implants in the Maxillary Sinuses Affect Sinus Health? A Retrospective Study.

The aim of this retrospective study is to investigate the effect of corticobasal implant penetration in the nasal and maxillary sinuses on sinus health and implant survival rate in cases of severely atrophid ridges. This retrospective study was conducted on thirty patients with 172 implants who underwent corticobasal implant treatment between 2014 and 2018. Implants were divided into two groups according to the penetration depths (Group A, <4 mm; Group B, 4 mm). Inclusion criteria for the study included: (A) patients with severe maxillary ridge resorption with an immediately loaded corticobasal implant-supported prosthesis that showed implant protrusion inside the maxillary sinus on cone-beam computed tomography (CBCT); and (B) patients with a preoperative and postoperative follow-up CBCT scan using the same standard technique and machine. (C) Patients without any history of sinusitis before implant insertion patients who fulfilled the inclusion criteria were recalled for follow-up. The presence of sinus complications was clinically assessed according to the clinical practice guidelines for adult sinusitis of the American Academy of Otolaryngology-Head and Neck Surgery and Radiologically using CBCT. Moreover, patient satisfaction was evaluated using yes-or-no questions. The result was statistically analyzed using Fisher's Exact test. Despite the differences in implant penetration depths, no clinical signs of sinusitis were evident in any patient. One patient presented with transient epistaxis after the surgery, and 2 patients with nine implants revealed nonsignificant thickening of the sinus membrane radiologically (p = 0.055). All implants showed optimum bone-implant contact with a 100% survival rate. A significant relationship was reported between the thickness of the membrane and the patient's gender, hypertension, and smoking habits. (p = 0.001*, p = 0.002*, and p = 0.034*, respectively). Penetration of corticobasal implants in the maxillary sinus did not compromise the health of the maxillary sinus or implant survival rate. Limited posterior maxillary bony support and maxillary sinus pneumatization present challenges in implant dentistry and increase the possibility of implant protrusion inside the maxillary and nasal cavities. Hence, studying the effect of this protrusion on the maxillary sinuses' health and implant survival is highly significant.

Three dimensional condylar positional and morphological changes following mandibular reconstruction based on CBCT analysis: a prospective study

ObjectiveThis study aimed to evaluate the condylar positional changes following mandibular reconstruction with preservation of the condylar head using Cone-Beam Computed Tomography (CBCT). Also, to assess joint space changes and the overall volumetric space compared to the preoperative status.MethodologyThis prospective study included 30 patients (60 joints) subjected to unilateral mandibular resection and reconstruction with preservation of the condylar head. The Helkimo index and preoperative (T1), two weeks postoperative (T2), and follow-up CBCTs (T3) after at least six months were gathered and processed to evaluate the condylar position and TMJ joint space using Anatomage Invivo 6. A student’s t-test and repeated-measures ANOVA statistics were used. A P value of less than 0.05 was considered statistically significant.ResultsThirty patients (14 males, 16 females) with a mean age of 40.01 ± 12.7 years (a range of 18.1–62.9 years) were included. On the tumor side, there were significant variances in the vertical and mediolateral condylar positions between the three-time points (T1, T2, T3). Immediately after the operation, the condyles were significantly displaced in a downward direction at T2, which became larger after the last follow-up period (T3) (p = 0.007). The condylar positions at the anteroposterior direction were relatively stable without significant differences between the three times points (p = 0.915). On the non-tumor side, the condylar positions were relatively stable in the mediolateral and anteroposterior positions.In the tumor side, all of the TMJ spaces were significantly increased in size following the mandibular reconstructions (T2 and T3). However, on the non-tumor side, the anterior, posterior, and medial joint spaces were significantly changed postoperatively.ConclusionAfter mandibular reconstruction with condylar preservation, the condylar position and volumetric measurement immediately changed noticeably and continued to be a permanent change over time compared to relatively stable condyles on the non-tumor side. According to Helkimo index, patients become adapted to the postoperative changes without significant differences between the two sides.

Increased rate of pseudarthrosis in the anterior intersegmental gap after mandibular reconstruction with fibula free flaps: a volumetric analysis.

Pseudarthrosis after mandibular reconstruction leads to chronic overload of the osteosynthesis and impedes dental rehabilitation. This study evaluates the impact of gap site on osseous union in mandible reconstruction using a new volumetric analysis method with repeated cone-beam computed tomography (CBCT). The degree of bone regeneration was evaluated in 16 patients after mandible reconstruction with a fibula free flap and patient-specific reconstruction plates. Percentual bone volume and width changes in intersegmental gaps were retrospectively analyzed using a baseline CBCT in comparison to a follow-up CBCT. Patients' characteristics, plate-related complications, and gap sites (anterior/posterior) were analyzed. Detailed assessments of both gap sites (buccal/lingual/superior/inferior) were additionally performed. Intersegmental gap width (p = 0.002) and site (p < 0.001) significantly influence bone volume change over two consecutive CBCTs. An initial larger gap width resulted in a lower bone volume change. In addition, anterior gaps showed significantly less bone volume changes. Initial gap width was larger at posterior segmental gaps (2.97 vs 1.65 mm, p = 0.017). A methodology framework has been developed that allows to quantify pseuarthrosis in reconstructed mandibles using CBCT imaging. The study identifies the anterior segmental gap as a further risk factor for pseudarthrosis in reconstructions with CAD/CAM reconstruction plates. Future research should evaluate whether this outcome is related to the biomechanics induced at this site.

3D driven hard tissue augmentation based on reverse planning Reconstruction of an advanced, horizonto-vertical alveolar ridge defect: A case report

This case report presents a novel, 3D-driven reverse planning for surgical rehabilitation of an advanced alveolar ridge defect. Utilizing a completely digital workflow, alveolar ridge augmentation could virtually be simulated thus simplifying the surgical procedure. In this case report the digitally planned treatment of a severe horizontovertical alveolar ridge defect is presented. Preoperative cone-beam computed tomography (CBCT) scan was segmented using a semi-automatic segmentation technique in an open-source medical image processing software (3D Slicer) to develop virtual 3D models of dental and alveolar structures. Intraoral scan, bite registration was also acquired to generate a digital wax-up. Consequently, prosthetically ideal implant positions could be planned in 3D. Based on future implant positions, adequate amount of hard tissue augmentation could be planned virtually. Individualized form of the barrier membrane could be determined, allowing the additive manufacturing of a membrane cutting template for shaping the barrier membrane during surgery. The combination of a non-resorbable barrier membrane, tenting screws, and composite graft (50% xenograft, 50% autogenous bone) was utilized. A follow-up CBCT scan was taken after 9 months to determine volumetric and 3D morphological changes. After 9 months, a hard tissue gain of 0.81 cm 3 could be observed. During the 6-9 month healing period membrane exposition did not occur. Virtual planning and subsequent surgical simulation on 3D models is a novel method in “prosthetically driven” augmentation potentially reducing the duration of surgery and postoperative complications. However, further studies are necessary to drive any more conclusions.

No Significant Bone Resorption after Open Treatment of Mandibular Condylar Head Fractures in the Medium-Term.

Open treatment of condylar head fractures (CHF) is considered controversial. In this retrospective cohort study our primary objective was therefore to assess bone resorption and remodeling as well as patients function after open treatment of CHF in a medium-term follow-up (15.1 ± 2.2 months). We included 18 patients with 25 CHF who underwent open reduction and internal fixation, between 2016 and 2021, in our analysis. The clinical data and cone-beam computed tomography (CBCT) datasets were analyzed. The condylar processes were segmented in the postoperative (T1) and follow-up (T2) CBCT scans. Volumetric and linear bone changes were the primary outcome variables, measured by using a sophisticated 3D-algorithm. The mean condylar head volume decreased non-significantly from 3022.01 ± 825.77 mm3 (T1) to 2878.8 ± 735.60 mm3 (T2; p = 0.52). Morphological alterations indicated remodeling and resorption. The pre-operative maximal interincisal opening (MIO) was 19.75 ± 3.07 mm and significantly improved to 40.47 ± 1.7 mm during follow-up (p = 0.0005). Low rates of postoperative complications were observed. Open reduction of CHF leads to good clinical outcomes and low rates of medium-term complications. This study underlines the feasibility and importance of open treatment of CHF and may help to spread its acceptance as the preferred treatment option.

Use of transcortical miniscrews for alveolar ridge preservation following tooth extraction: A pilot study.

The purpose of this split-mouth pilot study was to investigate the effects of a transcortical miniscrew placed over the buccal plate of an extraction socket for alveolar ridge preservation in humans. One week after the extraction of bilateral maxillary premolars, cone-beam computed tomography (CBCT) and intraoral digital imaging were performed (T0). A transcortical miniscrew was placed over the buccal plate of the extraction socket on one side (experiment), and the extraction socket on the contralateral side was left untreated (control). Follow-up CBCT and intraoral digital imaging were performed at 8months immediately after miniscrew removal (T8). Changes in the width of the alveolar bone and ridge were measure by superimposing T0 and T8 of CBCTs and intraoral digital scans. Six participants completed the study protocol. Overall, the experimental side with the miniscrew demonstrated less bone loss and less alveolar ridge reduction than the control side. Bone loss on the experimental side (0.7±0.2mm) was significantly less than that on the control side (1.3±0.7mm) at the apical level of the socket on axial CBCT imaging (Wilcoxon signed rank test, p=.031). The experimental side (-18±8%) exhibited less reduction in the alveolar ridge width than the control side (-21±12%) at the crestal level on coronal superimposition of the intraoral digital scans. Transcortical miniscrew placement over the buccal plate of the extraction socket resulted in less resorption of the alveolar ridge and bone 8months after tooth extraction. NCT03205800: Temporary Anchorage Devices for Ridge Preservation (TAD).

Evaluation of cone beam computed tomography referral profile: Retrospective study in a Turkish paediatric subpopulation.

Increasing use of cone beam computed tomography (CBCT) for dentomaxillofacial diagnosis raises concerns about radiation dose which is known to be higher compared to conventional dental imaging methods. This retrospective study investigated the CBCT referrals in a Turkish paediatric subpopulation in terms of referring department, field of view (FOV),and findings. A total of 8,880 CBCT images were reviewed retrospectively and images of paediatric patients (?14 years old) were selected. In paediatric patients; data related to patient age and gender, referring department, FOV, region of interest for localised applications, and reason for CBCT referral were recorded. FOVs of CBCT scans were classified as face, jaws (maxilla and mandible), maxilla, mandible, and tooth. CBCT indications were categorised based upon an adaptation of the European DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) multicenter and multidisciplinary project recommendations as impacted teeth, trauma, orofacial clefts, dental anomalies, bone pathology, syndromes, and other. Patients undergoing consecutive CBCT examinations for follow-up were also recorded. In order to record the incidental findings noticed in the CBCT evaluation, the radiological report prepared by the radiologist was used. The results were analysed statistically with a significance level set at p<0.05. Four hundred forty-nine of the 8880 CBCT scans were taken from paediatric patients under the age of 14, representing approximately 5% of all scans. Most of the referrals were from Department of Paediatric Dentistry (36.3%), followed by Department of Orthodontics (25.6%). The most frequently imaged region was the maxilla (33.4%), followed by the face (20.5%). The most common region of interest for localised applications was the maxillary canine/incisor region (85.55%). The most common indication was impacted teeth (41.4%) followed by bone pathology (31%) and dental anomalies (29.6%); 11.6% of the patients underwent follow-up CBCT examinations especially for orofacial clefts and syndromes. This retrospective study investigating CBCT indications in a Turkish paediatric subpopulation and comparing existing applications with DIMITRA project recommendations can guide dental professionals in referring paediatric patients for CBCT.

Percutaneous Transhepatic and Translumbar Sclerotherapy of a Thoracic Duct Cyst: A Case Report

AbstractA 58-year-old male presented with chronic abdominal pain lasting 5 years and a 15 × 6-cm multicystic thoracic duct cyst with three compartments, located in the right retrocrural and retrocardiac regions from T5/T6 to T12/L1. A transhepatic route was selected to sclerose the middle and lower compartments. Subsequent contrast injection showed minimal contrast passage into the upper compartment through a narrow neck, but the guidewire could not pass into this compartment. The contrast-filled upper compartment was punctured with a 22-g Chiba needle using a translumbar approach under cone-beam computed tomography (CT) guidance and ethanol sclerotherapy was performed. Six-month follow-up CT revealed decreased thoracic duct cyst size (5×3 cm) and no pain. This case illustrates successful percutaneous transhepatic and translumbar sclerotherapy for retrocardiac and retrocrural thoracic duct cysts, which are very difficult to remove surgically.

The Use of Biphasic Calcium Phosphate Substitute (BCP) in Mandibular Defects in Dogs: Use of CBCT to Evaluate Bone Healing.

This study aimed to assess the use of cone beam computed tomography (CBCT) to follow-up bone healing of mandibular bone defects in dogs, filled with a combination of autologous blood and millimetric BCP granules. CBCT was performed ≥4 weeks postoperatively. CBCT gray-scale values were measured from multiplanar reconstructions of the defects and compared to that of normal contralateral mandibular bone and to pure BCP/blood composite time 0 (T0) value. Other parameters, determined by affecting grades according to specific criteria included: bone ridge margin restoration; biomaterial homogeneity; bone-biomaterial interface. Results: 8 dogs with 14 defects were included. Median age was 7.2 years (1-15 years). Follow-up CBCT was performed 1 to 7.5 months postoperatively (mean 3.3 months). Defect CBCT gray-scale values at follow-up were significantly greater than T0 (p < 0.05). Ratios of maximum and minimum densities of the defects to contralateral mandibular bone followed a linear correlation with time (p < 0.05). The bone ridge margin was adequately restored in all the defects and significantly correlated with time (p = 0.03). Biomaterial homogeneity was fair to good in 11 defects and significantly correlated with the bone ridge margin parameter (p = 0.05) and time (p = 0.006). There was no significant correlation with the bone-material interface. The latter was satisfactory in 12 defects and significantly correlated with time (p = 0.01) but not with the other parameters. The biomaterial was more homogeneous in smaller defects and with increasing time. CBCT allowed effective assessment of bone healing via the measurement of CBCT gray-scale values and assessment of multiple radiological variables.

Mandibular involvement in SAPHO syndrome: a retrospective study

BackgroundMandible osteomyelitis can occur in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, a rare chronic inflammatory disease; however, few studies have explored its characteristics and management.MethodsWe reviewed the medical records of consecutive SAPHO patients with mandible involvement diagnosed in Peking Union Medical College Hospital from September 2014 to July 2019. Demographic, clinical, laboratory, and imaging data were collected at baseline. Prescription data and follow-up magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT) images were collected from the hospital information system. An electronic questionnaire was distributed to all patients to obtain their latest symptoms.ResultsA total of 26 SAPHO patients with mandibular involvement were involved, all of whom responded to the questionnaire (38.5% male; median age, 28 years; median follow-up duration, 2.1 years). Ten patients (38.5%) had undergone an oral procedure 1 month before the onset of mandibular symptoms. All 14 of the patients who underwent a surgical intervention relapsed within a median duration of 2 months (range 0.25–4.0 months), and 24 patients (92.3%) achieved improvement with conservative treatment. Following bisphosphonate treatment, remission of bone marrow oedema and osteolysis was observed on MRI and CBCT, and 5 patients receiving bisphosphonates with follow-up CBCT after remission did not relapse in 5.4 months (mean 6.0, range 3.2–9.9 months).ConclusionMandibular involvement of SAPHO syndrome predominantly occurs in young women. Dental procedures are a possible risk factor. Conservative treatment, especially intravenous bisphosphonates, can lead to oral improvement.

Short-term and long-term effects of rapid maxillary expansion on the nasal soft and hard tissue.

To evaluate nasal soft and hard tissue changes immediately post-rapid maxillary expansion (RME) and to assess the stability of these changes using cone beam computed tomography (CBCT). A total of 35 treatment group (TG) patients (18 girls, 17 boys; 9.39 ± 1.4) had a pre-RME CBCT and a post-RME CBCT approximately 66 days after expansion, and 25 patients had a follow-up CBCT 2.84 years later. A total of 28 control group (CG; no RME) patients (16 girls, 12 boys; 8.81 ± 1.6) had an initial CBCT and a CBCT an average of 2.25 years later. Soft and hard tissue nasal landmarks were measured in transverse, sagittal, and coronal planes of space on CBCT scans. Differences within the same group were evaluated by paired t-tests or Wilcoxon signed-rank tests. Long-term comparisons between TG and CG were evaluated by independent-sample t-tests or Wilcoxon rank-sum tests. Immediately post-RME, there were statistically significant mean increases of 1.6 mm of alar base width, 1.77 mm of pyriform height, and 3.57 mm of pyriform width (P < .05). CG showed the significant increases over 2.25 years (P < .001). Compared with CG, the long-term evaluation of TG demonstrated only pyriform height and pyriform width showed a statistically significant difference (P < .01). Although RME produced some significant increase on the nasal soft tissue immediately after expansion, it regressed to the mean of normal growth and development over time. However, long-term evaluation of TG compared with CG showed only pyriform height and pyriform width to be affected by RME.

Three-dimensional qualitative and quantitative analyses of the effect of periradicular lesions on the outcome of regenerative endodontic procedures: A prospective clinical study

Qualitative and quantitative evaluation of the outcomes of regenerative endodontic procedure (REP) on human immature necrotic teeth with apical periodontitis using cone-beam computed tomography (CBCT) MATERIALS AND METHODS: Immature permanent teeth (n = 50) with necrotic pulp and periradicular pathosis were treated with a cell-homing concept-based REP. Following the procedure, a limited field-of-view CBCT scan was obtained. At each recall session (6, 12, 18 months), clinical tests were performed, and a digital periapical radiograph was taken. When significant radiographic changes were evident in the follow-up, a final CBCT scan was taken for qualitative and quantitative assessment. These initial and follow-up CBCT scans were assessed for quantification of changes in root length, pulp space diameter and periradicular lesion size. The data were statistically analysed using t test, one-way ANOVA, post hoc test and paired t test (P = 0.05). Of the teeth, 94.6% were clinically successful based on the lack or regression of signs and symptoms after 48 months follow-up. REP resulted in a statistically significant increase in root length, decrease in pulp space diameter and periradicular radiolucency (P < 0.05). CBCT images illustrated various patterns of root maturation including an increased thickening of the canal walls and continued root maturation (37.1%), continued root development with the apical foramen remaining open (57.1%), severe calcification (obliteration) of the canal space (2.9%) and hard tissue barrier formation in the canal space between the coronal plug and the root apex (2.9%). This study highlighted that the expected outcome of radiographic root development was less predictable when immature permanent teeth with periradicular pathosis were treated with REP. The size and extent (expansion/destruction of the cortical plate) of periradicular lesions and abscesses influence the outcome of REP. These factors must be taken into consideration during treatment planning.

Endovascular treatment of wide-necked aneurysms of the visceral and renal arteries using the double microcatheter technique via a single access route

We aimed to evaluate the utility of and complications associated with the double microcatheter technique for the treatment of wide-necked visceral and renal artery aneurysms (VRAAs). Nine patients (mean age, 58 years; age range, 42-69 years; 4 men, 5 women) with wide-necked VRAAs who underwent treatment with the double microcatheter technique from January 2016 to July 2018 were included in the study. For all patients, anatomical features were confirmed using cone-beam computed tomography (CT) with rotational angiography. The aneurysmal location, size, volume, neck-to-dome ratio, number of coils used, and coil packing density were investigated. Technical success, complications (coil migration and organ ischemia), changes in the complete blood count or serum creatine level, and recurrence were also evaluated. Three renal artery aneurysms and 6 splenic artery aneurysms were treated by the double microcatheter technique. The mean size of the aneurysms was 26.09±4.76 mm, mean volume was 6.19±3.69 cm3, and mean neck-to-dome ratio was 1.53±0.24. The number of coils used ranged from 7 to 16. The mean packing density was 11.32%±3.72%. Technical success was achieved in all 9 patients. Renal ischemia occurred in two patients with renal artery aneurysm, one of whom showed minimal scar formation on follow-up CT after infarction. No coil migrations or disease recurrences were observed. The double microcatheter technique for the treatment of wide-necked VRAAs appears to be relatively safe and useful. However, complex renal artery aneurysm should be carefully managed in order to prevent infarction.

On the use of single‐isocenter VMAT plans for SBRT treatment of synchronous multiple lung lesions: Plan quality, treatment efficiency, and early clinical outcomes

Cone‐beam computed tomography (CT)‐guided volumetric‐modulated arc therapy (VMAT) plans for stereotactic body radiotherapy (SBRT) treatment of synchronous multiple lung lesions with a flattening filter‐free (FFF) beam is a safe and highly effective treatment option for oligometastases lung cancer patients. Fourteen patients with metastatic non–small‐cell lung cancer (NSCLC) lesions (two to five) received a single‐isocenter VMAT SBRT treatment in our clinic. Four‐dimensional (4D) CT‐based treatment plans were generated using advanced AcurosXB‐based dose calculation algorithm using heterogeneity corrections with a single isocenter placed between/among the lesions. Compared to 10X‐FFF and traditional flattened 6X (6X‐FF) beams, 6X‐FFF beam produced highly conformal radiosurgical dose distribution to each target volume, reduced dose to adjacent organs at risk (OAR), and significantly reduced the lung SBRT fraction duration to < 3.5 min/fraction for 54/50 Gy treatments in 3/5 fractions — significantly improving patient convenience and clinic workflow. Early follow‐up CT imaging (mean, 9 months) results show high local control rates (100%) with no acute lung or rib toxicity. Longer clinical follow up in a larger patient cohort is ongoing to further validate the outcomes of this treatment approach.

Cone-beam computed tomography of the head in standing equids

BackgroundComputed tomography in standing horses has revolutionized diagnostic imaging. The O-arm®, a cone beam computed tomography (CBCT) scanner with a gantry opening of 96.5 cm is routinely used for image-guided spine and neurosurgery in humans. The aim of this study is to describe the set-up and first experiences using the O-arm® to achieve CBCT imaging of the head in standing horses.CT imaging of the predefined region of interest (ROI) was tested on 2 cadaveric heads, concentrating on centering issues within the gantry, as well as determining the number of scans needed per ROI. All horses presented with head-related diseases and subjected to a CBCT examination between February 2015 and November 2016 for CBCT were included. Per scan, a limited field of view, i.e. a cylindrical volume of 21 cm in diameter and 16 cm in height was acquired within 13 s. Depending on the dimensions of the ROI, the minimum number of scans could range from one to six, if the entire equine head is to be examined in an adult horse.ResultsSixty-eight horses were included, five of which had a follow-up CBCT exam, and two of which were presented twice for two different indications (75 clinical cases). A total number of 449 acquired three-dimensional (3D) scans were recorded for these 75 cases. Two-hundred and forty-two 3D scans (54%) were considered as diagnostic quality. The imaging procedure was generally well tolerated by the sedated, standing equid, and diagnostic studies were performed in 73 out of 75 cases (97.3%). Motion artefacts and inadequate centering of the ROI were the most common reasons for non-diagnostic quality images and repeat scans of the same ROI.ConclusionsCBCT is a valuable imaging modality for the equine head. Advantages of the O-arm® compared to a conventional multi-slice helical CT for imaging of the head in standing equids include the rapid image acquisition, the gantry’s mobility in all dimensions, and the free movability of the entire imaging unit. Disadvantages include the considerable sensitivity to motion artefact, increased scatter, low soft tissue contrast and the limited dimensions of the field of view.

Three-dimensional evaluation of the maxillary effects of two orthopaedic protocols for the treatment of Class III malocclusion: A prospective study.

To compare the three-dimensional maxillary dentoskeletal effects of a modified alternate rapid maxillary expansion and constriction facemask protocol (Alt-RAMEC/FM) with the traditional rapid maxillary expansion facemask protocol (RME/FM) performed in deciduous or early mixed dentition Class III patients. Orthodontic Clinic of the Section of Dentistry of the Department of Surgery and Translational Medicine of the University of Florence. Thirty-four Class III patients were enrolled and allocated by alternating assignment to either Alt-RAMEC/FM or RME/FM therapy. Prior to treatment, all patients were evaluated, and a cone beam computed tomography (CBCT) scan was acquired. After completion of the orthopaedic therapy (average interval 1.2years), a follow-up CBCT scan was obtained. Anatomic landmark identification on the CBCTs and subsequent quantification of the changes were performed. The primary outcome variable was the anteroposterior displacement of the anterior nasal spine (ANS AP). The treatment groups were compared with independent samples t tests. The patients in the two treatment groups showed a similar degree of compliance. No statistically significant differences were recorded for any variable when comparing the Alt-RAMEC/FM and RME/FM groups. In particular, the between-group difference for ANS AP was 0.0mm (95%CI: -0.6;0.7, P=0.933). Both Alt-RAMEC/FM and RME/FM produced favourable orthopaedic changes in Class III growing patients. Neither protocol was superior to the other in terms of maxillary protraction effectiveness.