3D CT Reconstruction Research Articles

This video demonstrates, step by step, a right thoracoscopic S9+10 segmentectomy through a subxiphoid approach combining both interlobar fissure and inferior pulmonary ligament approaches, on the basis of 3D-CT reconstruction and fluorescence imaging

This video demonstrates, step by step, a right thoracoscopic S9+10 segmentectomy through a subxiphoid approach combining both interlobar fissure and inferior pulmonary ligament approaches, on the basis of 3D-CT reconstruction and fluorescence imaging

Fracture patterns in midshaft clavicle fractures

Current classifications of midshaft clavicle fractures are based on radiography. The aim of the study was to evaluate the fracture pattern of clavicle fractures using 3-dimensional computed tomography (3D CT). A retrospective analysis was performed on CT scans of 65 acute clavicle fractures. Using quantitative 3D CT reconstruction techniques, the fracture of the clavicle was virtually reduced. Based on these reconstructions, a group-based fracture heat map and small fragment heat map, and the location of the most common fracture line were determined. Also, the direction and amount of displacement were evaluated. Three fracture patterns could be distinguished. The primary fracture line in type 1 is going from posteromedial to anterolateral and located between 50% and 68% of the clavicle's length. In type 2, a transverse fracture line is located around 55%, and in type 3, a superolateral to inferomedial line is located between 47% and 56%. Wedged fracture fragments can be seen in types 1 and 2 and are mainly situated inferiorly. The displacement is similar in all types, but the main direction of displacement is specific for the different types (posterior, anterior, inferior). We can conclude that several fracture patterns can be seen in clavicle fractures. Most fractures are located laterally at the midshaft of the clavicle. Wedged segments are mainly located inferiorly, and at the posterior part of the clavicle, no comminution is ever seen. The direction of displacement depends on the fracture pattern.

A New Algorithm for Classifying Acetabular Fracture Patterns on Three-dimensional Computed Tomography Reconstructions Markedly Improves Residents' Ability to Correctly Classify Fractures.

CT and three-dimensional (3D) CT reconstructions have been shown to improve the understanding of acetabular fractures. With the increased availability of 3D pelvic CT reconstructions, our goal for this study was to develop an algorithm to aid residents in the classification of acetabular fractures. We hypothesized that the use of a stepwise algorithm will markedly enhance the trainees' ability to correctly identify acetabular fracture patterns. This was a multicenter study that included 33 residents. Residents reviewed 15 sets of 3D reconstructions of the 10 acetabular fracture patterns. Residents completed the first round, and the results were collected electronically. Three weeks later, they were asked to classify the fractures a second time with the use of the algorithm. The number of correct responses from the two sessions was analyzed to determine if the algorithm improved residents' ability to correctly classify fracture patterns. Thirty-three residents classified 15 fractures which yielded 495 unique responses. Residents correctly classified 52.5% (260/495) of fractures without the algorithm, which significantly increased to 77.5% (384/495) (P = 0.001) with the algorithm. When stratified by year in residency, all residents were able to correctly classify markedly more fractures with the algorithm. Overall, we believe this method is a reproducible diagnostic tool that will assist residents in classifying acetabular fractures. We were able to demonstrate that with the use of this algorithm, residents' ability to correctly classify acetabular fractures is markedly enhanced, regardless of year in training. This algorithm will be a useful adjunct to assist and advance trainees' education and understanding of a complex topic.

Osteosynthesis of Common Acetabular Fractures Operated on Through a Single Posterior (Kocher-Langenbeck) Approach with or without Trochanteric Flip Osteotomy. A Case Series.

The Kocher-Langenbeck approach is recommended in the majority of common posterior acetabular injuries. Trochanteric osteotomy can be used to extend the exposure of the Kocher-Langenbeck approach superiorly and anteriorly. We evaluated the functional outcome of common acetabular fractures operated on through the Kocher-Langenbeck approach with or without trochanteric flip osteotomy. This prospective study enrolled 42 patients with posterior wall, posterior column, transverse, posterior wall with posterior column, transverse with posterior wall and both column acetabular fractures. The Kocher-Langenbeck approach was used in 35 patients and trochanteric flip osteotomy was done in 7 patients. The radiological outcome was evaluated by Matta's criteria and the functional outcome was evaluated using modified Merle d'Aubigné and Postel criteria. D'Aubigne Postel scores at the final follow-up were excellent in 12 patients, good in 18, fair in 8 and poor in 4. Thirty-seven patients had congruent reduction (anatomical in 29, imperfect in 8) and 5 patients had non-congruent reduction on radiographs as per Matta's criteria. Radiographic congruity (88.09%, 37 out of 42 cases) correlated fairly well with the functional outcome (excellent or good functional outcome in 71.4%, 30 out of 42 cases). The complications included traumatic nerve palsy (3 cases), iatrogenic nerve palsy (2 cases), deep venous thrombosis (2 cases), wound infection (3 cases), non-congruent reduction (5 cases), 8 cases of osteoarthritis of hip, 2 cases of avascular necrosis of femoral head and 3 cases of heterotrophic ossification. 1. Surgical treatment of common acetabular fractures with major posterior involvement can be attempted via a single posterior approach (Kocher-Langen-beck with or without trochanteric flip osteo-tomy) and leads to good-to-excellent results in a majority of the cases. 2. It is superior to conservative management, which has been found to be accompanied by a much higher rate of complications. 3. A thorough study of the pre-opera-tive radiographs, Judet's views and 3D-reconstructed CT images helps in classifying the fracture and thereby assigning or not assigning it for the posterior approach.

The Value of CT Three-Dimensional Reconstruction in Nursing and Diagnosis of Senile Hip Fracture.

Aim To study the diagnostic effect of hip fracture in the elderly. In this paper, a total of 100 elderly patients with hip fracture from January 2020 to May 2021 were selected for X-ray and CT examination after admission. The operation was taken as the final criteria for determining hip fracture type, and the diagnosis of hip fracture by CT three-dimensional reconstruction was analyzed and studied. The results showed that the diagnostic rate of CT 3D reconstruction for various types of hip fracture in the elderly was higher than that of CT plain scan and X-ray (P < 0.05). For the diagnosis of intra-articular small bone fragments, the rate of missed diagnosis was 2% (2/100) with CT 3D reconstruction, 10% (10/100) with conventional CT scan, and 20% (20/100) with X-ray. The rate of misdiagnosis was 5.0% (5/100) with CT 3D reconstruction. Routine CT scan was 15% (15/100), X-ray was 30% (30/100), and CT 3D reconstruction was significantly lower than other examinations (P < 0.05). Conclusion CT 3D reconstruction has high accuracy in the diagnosis of various types of hip fractures in the elderly.

The Value of CT 3D Reconstruction in the Classification and Nursing Effect Evaluation of Ankle Fracture.

Aim To study the application value of ankle fracture classification and diagnosis. In this paper, the clinical data of 100 cases of ankle fracture patients admitted from May 2020 to May 2021 were analyzed by CT 3D reconstruction. All patients received surgical treatment and underwent spiral CT 3D reconstruction and X-ray examination before surgery. The results showed that 20 cases (20.00%) of the 100 cases were PER, 24 cases (24%) of the 100 cases were PAB, 31 cases (31%) of the 100 cases were SER, and 25 cases (25%) of the 100 cases were SAB, respectively. Conclusion The diagnostic accuracy of CT 3D reconstruction for different types of ankle fracture is higher than that of X-ray, and the differences are statistically significant (P < 0.05). CT 3D reconstruction is applied in the early diagnosis of ankle fracture, which can accurately detect the classification of patients. It has important clinical application value and can be used as the first choice for the early classification diagnosis of ankle fracture.

Angular and linear measurements of adult flexible flatfoot via weight-bearing CT scans and 3D bone reconstruction tools

Acquired adult flatfoot is a frequent deformity which implies multiple, complex and combined 3D modifications of the foot skeletal structure. The difficult thorough evaluation of the degree of severity pre-op and the corresponding assessment post-op can now be overcome by cone-beam (CBCT) technology, which can provide access to the 3D skeletal structure in weight-bearing. This study aims to report flatfoot deformities originally in 3D and in weight-bearing, with measurements taken using two different bone segmentation techniques. 21 such patients, with indication for surgical corrections, underwent CBCT (Carestream, US) while standing on one leg. From these scans, 3D models of each bone of the foot were reconstructed by using two different state-of-the-art segmentation tools: a semi-automatic (Mimics Innovation Suite, Materialise, Belgium), and an automatic (Bonelogic Ortho Foot and Ankle, Disior, Finland). From both reconstructed models, Principal Component Analysis was used to define anatomical reference frames, and original foot and ankle angles and other parameters were calculated mostly based on the longitudinal axis of the bones, in anatomical plane projections and in 3D. Both bone model reconstructions revealed a considerable valgus of the calcareous, plantarflexion and internal rotation of the talus, and typical Meary’s angles in the lateral and transverse plane projections. The mean difference from these angles between semi-automatic and automatic segmentations was larger than 3.5 degrees for only 3 of the 32 measurements, and a large number of these differences were not statistically significant. CBCT and the present techniques for bone shape reconstruction finally provide a novel and valuable 3D assessment of complex foot deformities in weight-bearing, eliminating previous limitations associated to unloaded feet and bidimensional measures. Corresponding measurements on the bone models from the two segmentation tools compared well. Other more representative measurements can be defined in the future using CBCT and these techniques.

Volume and Distribution of Periprosthetic Bone Cysts in the Distal Tibia and Talus before Early Revision of Total Ankle Arthroplasty

Periprosthetic osteolysis is a common complication following total ankle arthroplasty (TAA). However, understanding of osteolysis volume and distribution is still evolving, undermining efforts to reduce the incidence of osteolysis via bone remodeling. We obtained data on the characteristics of osteolysis developing within the distal tibia and talus after TAA. Three-dimensional computed tomography (3D-CT) reconstructions of 12 patients who underwent HINTEGRA TAA were performed. We identified 27 volumes of interest (VOIs) in the tibia and talus and used statistical methods to identify the characteristics of osteolysis in the VOIs. The osteolysis volume was significantly larger in the talus than in the tibia (162.1 ± 13.6 and 54.9 ± 6.1 mm3, respectively, p = 0.00). The extent of osteolysis within the peri-prosthetic region was greater than within other regions (p &lt; 0.05). Particularly, in the talus, the region around the talar pegs exhibited 24.2 ± 4.5% more osteolysis than any other talar region (p = 0.00). Our results may suggest that extensive osteolysis within the peri-prosthetic region reflects changes in stress flow and distribution, which vary according to the design and placement of the fixation components. This is the first study to report 3D osteolysis patterns after TAA. Careful planning of TAA design improvements may reduce the incidence of osteolysis. Our results will facilitate the further development of TAA systems.

Comparison of femoral tunnel and early curative effect analysis between arthroscopic three approach and traditional anteromedial portal for reconstruction of anterior cruciate ligament

To study the three-approach and traditional anterior medial technique to establish the femoral tunnel of position, length, and coronal angle and the early efficacy of anterior cruciate ligament reconstruction. Through retrospective research, from December 2018 to June 2019, a total of 36 patients diagnosed with simple anterior cruciate ligament tear and undergoing surgery were collected. All patients had a clear history of knee sprains and were divided into two groups. A group of 16 patients, including 11 males and 5 females, with an average age of (30.13±6.54) years and an injury time of 7 to 60 (30.19±15.78) days, three-approach technique was used to drill the femoral tunnel to reconstruct the anterior cruciate ligament. Another group of 20patients, including 15 males and 5 females, with an average age of (30.80±8.60) years, and an injury time of 7 to 60 (27.35±15.50) days, the traditional anterior medial approach was used to drill the femoral tunnel to reconstruct anterior cruciate ligament. CT 3D reconstruction technique was used to evaluate the femoral tunnel and the knee joint function was evaluated by Lysholm score of the knee joint. All patients achieved primary healing after the surgical incision. No femoral tunnel fracture, vascular and nerve damage, difficulty in graft passage during the operation, and venous thrombosis occurred. All 36 patients were followed up on an outpatient basis, with a follow up period of 9 to 15 (12.00±2.83) months. Three-dimensional CT reconstruction was used to evaluate the femoral tunnel of the patients. The position of the femoral tunnel was described using the quartile method as the three-approach group:the lower (27.83±1.97) % of the femoral condyle and the posterior (25.57±3.20) %;the traditional approach group:the lower (28.38±3.21) % of the femoral condyle and the posterior (26.23±3.20) %. Bone tunnel length, three-approach group:(35.20±5.52) mm in total length, (23.20±2.07) mm in thick bone tunnel;traditional approach group:(34.60±4.26) mm in total length, (22.56±2.50) mm in thick bone tunnel. Coronal plane angle, three-approach group:(47.93±5.98) °;traditional approach group:(41.78±6.62) °. Knee joint Lysholm score, three-approach group:48.67±4.18 before surgery;97.00±2.48 at last follow up;traditional approach group:49.75±5.33 before surgery, 97.30±2.68 at last follow up, there were significant differences before and after surgery, no significant statistical difference between two groups. The positions of the femoral tunnel drilled by the two methods were within the range of the anatomic stop of the anterior cruciate ligament, and there was no statistical difference. Compared with the traditional anterior medial approach, the coronal plane angle of the femoral tunnel drilled by the three-approach approach is relatively large, and there were no statistical differences in the length of the tunnel, the early postoperative effect of the two surgical methods, and the operation time. But the three approach has a wider and clearer vision. In addition, the knee flexion angle required for drilling the femoral tunnel during surgery is significantly smaller than that of traditional approach technology, which reduces the difficulty of surgery.

Intraoral and extraoral approach for surgical treatment of Eagle's syndrome: a retrospective study.

Eagle's syndrome is not uncommon in clinical work. Because of its atypical symptoms, it is easy to be misdiagnosed as other diseases, further leading to misdiagnosis and mistreatment. At present, there is no expert consensus or treatment guidelines for the disease. We evaluated the clinical characteristics and postoperative efficacy of 103 patients with Eagle's syndrome based on their clinical symptoms, radiological studies, and physical examination. Through the multicenter clinical study of Tongji Medical College and Dalian Medical University, we found some characteristics of Eagle's syndrome in operation and imaging. In total, 103 patients with Eagle's syndrome (treated from January 2010 to January 2020) were retrospectively enrolled. The postoperative curative effect was analyzed by three surgical methods: styloid process resection through the external cervical approach (styloid process could not be touched through the mouth or could be touched under the jaw or when the CT scan showed that the inclination angle was not large), tonsillectomy + styloidectomy, and preservation of the tonsil for styloidectomy (the styloid process bone could be touched directly during intraoral palpation or in whom the distal part of the styloid process could not be directly touched, but the CT scan showed that the bone inclined toward the oropharynx and its distal part was relatively close to the oropharynx cavity; whether tonsillectomy was performed depended on whether the patient's tonsil was too large to affect the surgical incision). According to the Quality of Well-Being Scale (QWB), we calculated the W value of the scale before operation and 30 days, 3 months, 6 months and 12 months after operation, and compared the W value of each group. The average length of the styloid process was 33 mm (range 25-61 mm). The patients were followed up for 12-36 months (average 15 months). Of the 103 patients, 21 underwent styloid process resection through the external cervical approach, 49 underwent tonsillectomy and styloidectomy, and 33 underwent styloidectomy with preservation of the tonsil. The treatment cured 48 (46%) cases, was effective in 35 (34%) and was ineffective in 20 (20%). The R language 3.6.3 software was used to perform the nonparametric rank sum test, differences in characteristics between groups were analyzed using the Kruskal-Wallis test with Dunn post hoc tests ( R package FSA) for categorical variables, and there was no significant difference between the three types of operations (H = 0.491, P = 0.782). QWB showed that the quality of life after operation was improved compared with that before operation. Operation is an effective method for treating Eagle's syndrome. There were no significant differences between the effects of the intraoral and external cervical approaches. Imaging examination-especially CT scanning and 3D reconstruction of the styloid process-is very helpful for diagnosis, but not an absolute criterion for the selection of surgery protocol.

A simplified model for determining the cutting plane during thoracoscopic anatomical partial lobectomy of the right lower lobe.

BackgroundFew studies have examined the use of two-dimensional computed tomography (2D CT) and three-dimensional (3D) reconstruction images to determine the intersegmental plane (ISP) for pulmonary segmentectomy, but a systematic approach and nomenclature are currently lacking. This current study used 3D reconstruction of CT imaging to analyze variations in the right lower lobe’s pulmonary ISP and created a simplified model to determine the optimum cutting plane (CP) for clinical application for operative planning and use during thoracoscopic anatomical partial lobectomy (APL).MethodsBetween January 2018 and October 2019, 325 patients with pulmonary lesions were identified who underwent thin-slice CT scans of the chest. The ISPs were identified by analyzing the 2D CT scans and 3D reconstruction images and the anatomical characteristics segmental boundary. The CP for the thoracoscopic procedure was then determined within the safe surgical margins, and a simplified CP model was created.ResultsThe boundary between adjacent lung segment A and segment B was be expressed as “ISP: Sa-Sb”. The ISP was divided into venous ISP (VISP), arterial ISP (AISP), and bronchial ISP (BISP). The proposed model of the CP can be expressed as follows: CP (f) = (V/A/B) ISP (x) + (V/A/B) sub ISP (y) + (V/A/B) sub-sub ISP (z).ConclusionsThis report is a first attempt to provide a nomenclature for identifying the ISP, and create a simplified model for determining the CP for thoracoscopic partial lobectomy.

Characteristics and classification of medial malleolar fractures.

The morphology of medial malleolar fracture is highly variable and difficult to characterize without 3D reconstruction. There is also no universally accepeted classification system. Thus, we aimed to characterize fracture patterns of the medial malleolus and propose a classification scheme based on 3D CT reconstruction. We retrospectively reviewed 537 consecutive cases of ankle fractures involving the medial malleolus treated in our institution. 3D fracture maps were produced by superimposing all the fracture lines onto a standard template. We sliced fracture fragments and the standard template based on selected sagittal and coronal planes to create 2D fracture maps, where angles α and β were measured. Angles α and β were defined as the acute angles formed by the fracture line and the horizontal line on the selected planes. A total of 121 ankle fractures were included. We revealed several important fracture features, such as a high correlation between posterior collicular fractures and posteromedial fragments. Moreover, we generalized the fracture geometry into three recurrent patterns on the coronal view of 3D maps (transverse, vertical, and irregular) and five recurrent patterns on the lateral view (transverse, oblique, vertical, Y-shaped, and irregular). According to the fracture geometry on the coronal and lateral view of 3D maps, we subsequently categorized medial malleolar fractures into six types based on the recurrent patterns: anterior collicular fracture (27 type I, 22.3%), posterior collicular fracture (12 type II, 9.9%), concurrent fracture of anterior and posterior colliculus (16 type III, 13.2%), and supra-intercollicular groove fracture (66 type IV, 54.5%). Therewere three variants of type IV fractures: transverse (type IVa), vertical (type IVb), and comminuted fracture (type IVc). The angles α and β varied accordingly. Our findings yield insight into the characteristics and recurrent patterns of medial malleolar fractures. The proposed classification system is helpful in understanding injury mechanisms and guiding diagnosis, as well as surgical strategies. Cite this article: Bone Joint J2021;103-B(5):931-938.

Clinical and radiographic results of eccentric glenoid reaming in anatomical total shoulder arthroplasty using 3D planning and PSI

BackgroundTreatment of deformed type B glenoids with anatomical total shoulder arthroplasty (TSA) can be challenging when using standard imaging and instrumentation. 3D planning and PSI-guided (patient-specific instrumentation) eccentric reaming may substantially aid in both the glenoid correction and implantation of anatomical components in difficult cases. We hypothesized that the implementation of preoperative planning and a PSI-guided anatomical component protocol would result in accurate correction of the glenoid deformity and precise glenoid implant positioning. MethodsTwenty-two consecutive patients with primary glenohumeral osteoarthritis, intact rotator cuff and modified-Walch type B glenoids were treated with anatomical total shoulder arthroplasty. Preoperative 3D planning and PSI were used to guide eccentric reaming and correct glenoid deformity. Postoperative clinical and radiographic outcomes were assessed in all patients with a minimum follow-up of 2 years (mean of 26 months). Postoperative corrections of glenoid version and inclination were measured and the variation between preoperative planning and postoperative implant position was evaluated on CT 3D reconstructions. Similarly, both humeral subluxation in the axial scapular plane and glenoid joint line medialization were compared between preoperative and postoperative computed tomographic imaging. ResultsThe mean age was 57 years (range, 54-68). Significant improvements in pain and functional outcome measurements were seen in all 22 subjects. Mean native glenoid version and inclination were −15° ± 5° and 3° ± 5°, respectively. Postoperatively, version was corrected to −7° ± 6° and inclination to 1° ± 2°. Cortical central peg perforation was noted in 1 case and cement perforation in 3 cases. The mean deviation from the preoperative plan was 3° ± 3° for version and 2° ± 2° for inclination. Humeral head subluxation improved from 68% ± 6% to 37% ± 6% and re-centering on the glenoid implant was achieved in all cases. The mean executed medialization of the glenoid joint line was 6 ± 3 mm and proved accurate to within 1 ± 1 mm of the planned medialization. A strong linear correlation was found between the degree of correction of retroversion and the amount of medialization (R = 0.82; P< .001). Conclusion3D preoperative planning and PSI guided correction of deformed modified-type B glenoids resulted in accurate postoperative correction of the glenoid deformity, correct glenoid component implantation with low deviation from the planned position and excellent short-term functional and radiographic results. Level of Evidence: Level IV; Case Series; Treatment Study.

3D planning and patient-specific surgical guides in forearm osteotomy in children: Radiographic accuracy and clinical morbidity

IntroductionThree-dimensional (3D) planning and patient-specific surgical guides are increasingly used in the treatment of skeletal deformities. The present study hypothesis was that they are reliable in forearm osteotomy in children, with low morbidity. Material and methodsTwenty-there children with one or several osteotomies to correct forearm deformities were retrospectively included: 9 (20 osteotomies) with surgical guide (G+), and 14 (28 osteotomies) without (G-). Etiologies comprised 8 cases of Madelung disease (3G+, 5G−) and 15 of post-traumatic malunion (6G+, 9G−). Mean age at surgery was 14.8±1.9 years. The patient-specific 3D-printed polyamide guides were produced from 3D virtual models based on 3D CT reconstruction. Mean follow-up was 22.1±13.6 months. ResultsMean correction error was 5.3°±4.1 and 4.2°±4.1 in the frontal and sagittal planes respectively in G+ (p=0.6). Surgery time was significantly shorter in G+, by a mean 42min (p=0.02). Mean total radiation dose (preoperative CT+intraoperative fluoroscopy) was significantly higher in G+ (p<0.0001). Complications rates were similar between groups. Improvement in PRWE score was significantly greater in G+. ConclusionThe present preliminary results were encouraging. 3D planning and patient-specific surgical guides can be used in the treatment of forearm deformity in children. Level of evidenceIII; retrospective cohort study.

Second sacral sacralalar\u2010iliac (S2AI) screw placement in adult degenerative scoliosis (ADS) patients: an imaging study

BackgroundThe imaging characteristics of sacral sacralalar-iliac (S2AI) screw trajectory in adult degenerative scoliosis (ADS) patients will be determined.MethodsS2AI screw trajectories were mapped on three-dimensional computed tomography (3DCT) reconstructions of 40 ADS patients. The starting point, placement plane, screw template, and a circle centered at the lowest point of the ilium inner cortex were set on these images. A tangent line from the starting point to the outer diameter of the circle was selected as the axis of the screw trajectory. The related parameters in different populations were analyzed and compared.ResultsThe trajectory length of S2AI screws in ADS patients was 12.00 ± 0.99 cm, the lateral angle was 41.24 ± 3.92°, the caudal angle was 27.73 ± 6.45°, the distance from the axis of the screw trajectory to the iliosciatic notch was 1.05 ± 0.81 cm, the distance from the axis of the screw trajectory to the upper edge of the acetabulum was 1.85 ± 0.33 cm, and the iliac width was 2.12 ± 1.65 cm. Compared with females, the lateral angle of male ADS patients was decreased, but the trajectory length was increased (P < 0.05). Compared to patients without ADS in previous studies, the lateral angle of male patients was larger, the lateral angle of female patients was increased, and the caudal angle was decreased (P < 0.05).ConclusionsThere is an ideal trajectory of S2AI screws in ADS patients. A different direction should be noticed in the placement of S2AI screws, especially in female patients.

The Effect of Disease Type on Changes in Total Lung Volume after Lung Transplantation Measured by Three-Dimensional (3D) CT Reconstruction

<h3>Purpose</h3> It is accepted that a donor's predicted total lung capacity (pTLC) can be 75-125% of the recipient's pTLC in lung transplantation; however, ‘optimal graft size' is not clearly defined, especially in restricted lung disease (RD) patients. These disagreements exist as it is difficult to accurately measure lung size before and after transplantation and it is also difficult to predict and evaluate the extent of re-expansion of the restricted thoracic cavity after transplantation. This study examined changes in lung volume after lung transplantation using a 3D lung volume measurement from CT scans before and after surgery under the assumption that the patient's thoracic cavity would return to the size of the patient without underlying lung disease after surgery. <h3>Methods</h3> A total of 113 patients, who underwent lung transplantation between September 2012 and April 2019 in our institute, and met the inclusion criteria were enrolled in the study. This included 88 patients who were diagnosed with RD and 25 patients who were diagnosed with non-RD. Patients were further divided into oversized and undersized groups according to the donor and recipient pTLC ratio, and a total of 4 groups were studied. Preoperative and postoperative lung volume on CT scans were measured using the synapse 3D program (Fuji film, Japan). <h3>Results</h3> RD patients showed a significant increase in total lung volume (TLV) after surgery, while non-RD patients showed a decrease in TLV. These changes showed the greatest increase in the RD group within 1 year and continuously increased up to 5 years. In the non-RD group, TLV decreased within 3 months of surgery. These changes were not related to graft size. <h3>Conclusion</h3> In lung transplant patients, the thoracic cavity re-expanded in RD patients and reduced in the non-RD patients, returning to healthy values without lung disease status in terms of TLV.

The technical feasibility and preliminary results of minimally invasive endoscopic-TLIF based on electromagnetic navigation: a case series

BackgroundUniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved.MethodsThis retrospective study explored the effects of electromagnetic navigation on improving Endo-TLIF with percutaneous pedicle screw fixation. Clinical information from 42 patients who had received Endo-TLIF with percutaneous pedicle screw fixation from May 2019 to November 2020 was analyzed retrospectively. The procedures were assisted under electromagnetic navigation. The rate of adjustment for guide wires, frequency of X-ray exposure, operative time, accuracy of pedicle screw location, and clinical outcomes were recorded.ResultsThe mean follow-up for 42 patients was 11.9 ± 3.1 months. The mean age of the patients was 56.1 ± 9.26 years, with a female/male ratio of 25:17. According to postoperative CT scans and 3D reconstructions, the excellent and good rate of pedicle screws was 96.4%. The rate of adjustment for guide wires under the assistance of electromagnetic navigation was 1.78%, and the frequency of X-ray exposure was 8.27 ± 1.83. The operative time was 167.25 ± 28.16 min, including the duration of guide wire insertion (14.63 ± 5.45 min) and duration of decompression and cage placement (75.43 ± 13.97 min). The duration of hospitalization after operation was 2.59 ± 1.16 days. The preoperative VAS score was 7.51 ± 1.91, and the preoperative ODI was 82.42 ± 8.7%. At the last follow-up, the VAS score was 2.09 ± 0.59, and the ODI was 11.09 ± 3.2%. There were statistically significant improvements in the VAS score and ODI in all patients at the follow-up (p < 0.05).ConclusionsElectromagnetic navigation can provide accurate positioning and guidance in real time, which improves the surgical efficiency of percutaneous pedicle screw placement and endoscopic decompression in Endo-TLIF with reduced radiation exposures.

The Role of 3D Reconstruction of the Skull in Patients with Suspected Shunt Malfunction

Background: Mechanical shunt malfunction may lead to significant morbidity and mortality. Shunt series assessments help evaluate shunt integrity; however, they are of limited value in the area of the skull due to skull curvature, thickness, and air sinuses. We describe the role of 3D bone reconstruction CT (3DCT) in demonstrating the shunt integrity over the skull, comparing this technique to skull X-rays (SXR). Methods: Data were collected retrospectively for shunted patients with concurrent SXR and 3DCT and for patients presenting with shunt failures at the region of the skull, including clinical course and radiological findings. We compared the SXR and 3DCT findings. The 3DCT was reconstructed from standard diagnostic CT protocols performed during evaluation of suspected shunt malfunction and not thin-slice CT protocols. Results: Forty-eight patients with 57 shunts underwent SXR and 3DCT. Interobserver agreement was high for most variables. Both SXR and 3DCT had a high sensitivity, specificity, and accuracy identifying tubing disconnections (between 0.83 and 1). Full valve type and setting were significantly more accurate based on SXR versus 3DCT (>90 vs. <20%), and valve integrity was significantly more readily verified on 3DCT versus SXR (100 vs. 52%). Conclusions: 3DCT and SXR complement each other in diagnosing mechanical shunt malfunctions over the skull. The main limitation of 3DCT is identification of valve type and settings, which are clearer on SXR, while the main limitation of SXR is a less ability to evaluate valve integrity. 3DCT also enables an intuitive 3D understanding of the shunt tubing over the skull.

Application of three-dimensional image reconstruction technology based on high-resolution CT in pyeloplasty.

BackgroundThree-dimensional (3D) image reconstruction technology is widely used in surgical operations for its intuitive visualization. Pyeloplasty requiresprecise cutting and suturing. The reconstruction technology can accurately determine the location and scope of the stenosis at the junction of the renal pelvis and ureter and the relationship with the surrounding vasculature. The purpose of this article is to retrospective evaluate the application value of image reconstruction technology in pyeloplasty based on high-resolution 3D CT images.MethodsA total of 20 patients with renal pelvic ureteral junction obstruction admitted to our hospital from August 2019 to August 2020 were selected. In this group, left pyeloplasty was performed in 8 patients and right pyeloplasty in 12 patients. In terms of conditions, there was 1 case with secondary pyeloplasty, 6 cases of patients with kidney stones, 2 cases with renal ectopic blood vessels, 1 case with renal prolapse, 1 case with horseshoe kidney, and 1 case with ureteral polyps. There were 12 males and 8 females, with an average age of 34.65±10.67 years and an average body mass index (BMI) of 22.48±3.03 kg/m2. In all patients, 3D CT reconstruction technology was used to guide the formulation of robot-assisted laparoscopic pyeloplasty plans; verify the consistency between the actual operation and the preoperative planning; and observe the operation time, blood loss, postoperative exhaust time, indwelling drainage tube time, and follow-up for comorbidities.ResultsThe operation was successful in all 20 patients. The actual operation was 100% consistent with the preoperative planning, the operative time was 160.80±63.26 min, the intraoperative blood loss was 47±30.45 mL, the postoperative exhaust time was 1.15±0.37 days, the drainage tube indwelling time was 4.35±1.50 days, and the average follow-up time was 7.95±3.41 months. There were no complications.ConclusionsThree-dimensional image reconstruction technology based on high-resolution CT has high clinical application value in the treatment of ureteropelvic junction obstruction (UPJO), which simplifies the operation process and shortens the operation time, and is a valuable tool for auxiliary surgeons in devising the operation plan.

The Nottingham radiation protocol for O-arm navigation in paediatric deformity patients: a feasibility study

O-arm assisted pedicle screw placement has been proven to be more accurate than free-hand technique. Radiation exposure remains the primary drawback. We determined thefeasibility and safety of a reduced radiation protocol in paediatric patients undergoing scoliosis correction. A reduced radiation protocol for a medtronic O-arm navigational system was devised. 3D CT reconstructions of an anthropomorphic pelvic phantom indicated adequate image quality after reduction to 14% of current manufacturer default factors. A feasibility study to test the image quality was undertaken on four patients, one with syndromic and three with idiopathic scoliosis each receiving progressively reducing radiation exposure of 60%, 50%, 40% and 14% of what would have been delivered using the manufacturer default protocol. This represented 32% of the mayo clinic protocol. It was achieved by reducing the x-ray tube current to 10mA while keeping the tube potential at 90kVp. A low dose O-arm protocol was able to generate adequate image quality while delivering as little as 14% (for lumbar region reconstructions) of the recommended protocol radiation dose. The total radiation dose delivered with this protocol was approximately 0.8 milliSieverts for a single spin. This effective dose represents < 1/3 of average UK and < 1/6 average US annual radiation exposure. There were no neurological or implant-related complications. Our low dose O-arm radiation protocol significantly reduces the radiation exposure compared to the manufacturer recommended Mayo clinic protocol providing operational image quality to allow accurate screw placement in spinal deformity.