Three dimensional CT reconstruction: a comparison between 2D, 3D CT and original anatomical structures

Subxiphoid video-assisted thoracoscopic surgery (VATS) is considered a safe and feasible operation for anterior mediastinal mass resection. However, diaphragmatic injury, presented as tearing or puncturing, may occur during subxiphoid VATS despite of low incidence. This study aims to explore risk factors for diaphragmatic injury in subxiphoid VATS, as well as strategies to reduce occurrence of the injury. We retrospectively reviewed clinical records of 44 consecutive adult patients who underwent subxiphoid VATS. These patients were divided into two groups: diaphragmatic injury group and non-injury group. Perioperative outcomes and anatomic features derived from 3D CT reconstructions were compared between the two groups. Significant differences were observed in operation time (223.25 ± 92.57 vs. 136.28 ± 53.05, P = 0.006), xiphoid length (6.47 ± 0.85 vs. 4.79 ± 1.04, P = 0.001) and length of the xiphoid below the attachment point on the diaphragm (24.86 ± 12.02 vs. 14.61 ± 9.25, P = 0.029). Odds ratio for the length of the xiphoid below the attachment point on the diaphragm was 1.09 (1.001-1.186), P = 0.048 by binary logistic regression analysis. We identified the length of the xiphoid below the attachment point on the diaphragm as an independent risk factor for diaphragm injury during subxiphoid VATS. Prior to subxiphoid VATS, a 3D chest CT reconstruction is recommended to assess the patients' anatomic variations within the xiphoid process. For patients with longer xiphoid process, a higher incision at the middle and upper part of the xiphoid process, and partial xiphoid process resection or xiphoidectomy is preferred.

Purpose: To measure the normal size of the styloid process using 3D (three-dimensional) reconstruction CT. Materials and Methods: We retrospectively analyzed 3D reconstruction images obtained after coronal and axial CT scanning of the temporal bone or neck of 115 patients. The length and shape of both sides of the styloid process, the location of its tip, and calcification of the stylohyoid ligament were retrospectively analysed. Results: The mean length of the styloid process was 26.6 (7.9)mm on the right side, and 26.4(8.3)mm on the left, a statistically insignificant difference (p=0.694). Its mean length was 26.2 (8.5)mm in men and 26.7 (7.2)mm in women, a statically in significant difference (p=0.733). As for variation with age, mean length tended to increase until the third decade, but not beyond. Segmental type (104/230, 45.2%) and fragmental type (73/230, 31.7%) were more commonly seen in shape of styloid process, and tapering tip of styloid process (156/230, 67.9%) is more commonly seen than clubbing tip of it (74/230, 32.1%). The process was angulated in six cases (2.6%); its tip was more frequently located between the internal and external carotid artery (211 cases, 91.7%) than more medially (19 cases, 8.3%). In the former location, the length of the process was 26.2( 7.2)mm, and in the latter, 37.0(6.0)mm. The difference was statistically significant (p=0.000). Calcification had occurred in 33 cases (14.3%). Conclusion: The length of a normal styloid process was 18-32 mm. There were no statistically significant differences between its two sides, or between the sexes. Length tended to increase until the third decade, but not beyond. Predominantly the tip was located between the internal and external carotid artery, though the process was longer when its tip was located medially.

Objective A lot of problems have been encountered in percutaneous nephrolithotomy in treatment of staghorn calculi, 3D CT reconstruction technique could construct the real staghorn calculi and kidney 3D image, which help us in the operations to make sure the best percutaneous renal channel, and improve the success rate of puncture by B-ultrasound localization. Methods Twenty-five patients with staghorn calculi who underwent urinary CT scan and 3D reconstruction were enrolled into CT reconstruction group. Through 3D rotation display, we designed the shortest distance channel, which directed to renal pelvis, with the most widely and convenient operating angle. Thirty patients only underwent urinary CT scan, and designed the operating channel with multiplanar CT film, who were enrolled into CT group. All of them underwent 16 F channel PCNL procedures in lateral semisupine lithotomy position, treated by nephroscope Holmium laser lithotripsy. While we discussed 2 typical cases of staghorn calculi cases. Results There were statistical significances in blood loss [(108±24) ml vs (156±45) ml], operative time [(109±20) min vs (121±23) min], stone-free rate (91.21% vs 85.73%), blood transfusion (0 vs 6.67%), and massive hemorrhage post-operative cured by selective embolism of renal artery(0 vs 6.67%) between the two groups. Besides, there were no differences in the nephrostomy tube remaining time [(6.5±1.9) d vs (7.7±1.7) d] and hospital stay duration [(13.0±1.8) d vs (14.5±3.0) d]. Conclusions 3D CT reconstruction technique could construct the real staghorn calculi and kidney 3D image, which provided a more accurate percutaneous renal channel, it's safe and effective for PCNL. Key words: CT reconstruction; Renal; Percutaneous nephrolithotomy

Does 3D CT reconstruction help the surgeon to preoperatively assess calcaneal fractures?

The aim of this study is to determine normal glenopolar angle (GPA) values on bone specimens of the scapula and compare them with various radiological views and CT examination. GPA values were measured on 100 mature, dry, non-paired scapulae, 20 pairs of dry scapulae, 50 AP radiographs of the shoulder, 50 Neer I views, 50 AP chest radiographs and 20 3D CT reconstructions of the scapula. Measurements made on bone specimens of the scapula showed an average GPA value of 42.3°; the mean absolute side-to-side difference was on average 1.6°. The average GPA measured on 50 AP shoulder radiographs was 35.9°, on Neer I views 40.6° and AP chest radiographs 37.1°, with the mean absolute side-to-side difference on average 4.9°; on 3D CT the average GPA was 43.0° and the mean absolute side-to-side difference on average 1.4°. GPA values depend on the method of measurement used. Measurements made on 3D CT reconstructions and Neer I views showed almost the same values as those measured on bone specimens. The values measured on AP shoulder views and AP chest radiographs were statistically significantly lower. Side-to-side variability (right and left) measured on 3D CT reconstructions was insignificant, and the obtained values corresponded to the values from bone specimens. Therefore, the best method to measure the GPA is a 3D CT reconstruction and an exact Neer I projection.

X-ray cone beam CT (CBCT) is widely used in many fields such as clinic diagnosis, public safety inspection, and nondestructive testing. In recent years, radiation risk gets growing concern by the public. As a result, X-ray cone-beam CT (CBCT) imaging of low dose is becoming more and more helpful in many fields especially clinic diagnosis and public safety inspection. To get better reconstruction results, a typical idea is to add useful and meaningful constraints in reconstruction procedure. The evaluation criterion of reconstruction could be a general target function concerning both physical models and specific constraints. As computer hard-ware evolves greatly, optimization-based iterative algorithms to minimizing these functions have been proposed and proved helpful for low-dose case. However, these methods are usually time consuming. Nowadays, deep learning method has been utilized in image processing. In CT fields, it has been shown that reconstruction algorithms based on convolutional neural network (CNN) is effective in solving problems with low-dose or sparse-view case. In our work, we proposed a novel CNN structure which is designed for transferring cone-beam projection to fan-beam projection of each cross section attenuation map of an object with noise reduction. After the 3D problem is turned to be a 2D one, we simply use the system matrix to reconstruct the object. Because of its slice-wise character, the method can effectively simplify the 3D reconstruction problem.

Cerebral air embolism may be caused by iatrogenic or post-traumatic introduction of air into arterial or venous systems. It is usually revealed by computerized tomography. In this paper, we report a case with thorax trauma and loss of consciousness, in whom cerebral massive air embolism was detected and its distribution was demonstrated by using 3D spiral CT reconstruction. To our knowledge, this is the first case in whom 3D spiral CT reconstruction was used for demonstration of cerebral arterial air embolism.

IntroductionPulmonary segmentectomy, when combined with hilar and mediastinal lymphadenectomy, is currently considered the gold standard treatment for early-stage lung tumors (NSCLC) smaller than 2 cm in diameter. The preoperative planning for segmentectomies usually includes a contrast-enhanced CT with 2D reconstructions (axial, coronary, and sagittal). Recent technological advances allow 3D (volume rendering) reconstructions of preoperative CT scans, intended to improve the surgeon’s understanding of the segmental anatomy.The study aims to investigate the added value of 3D reconstruction in enhancing the surgeon’s understanding of anatomical structures, thus facilitating surgical planning and improving oncological outcomes.Methods and analysisThis is a prospective, randomized, controlled study.Patients will be randomized into two groups:1. Group 2D: the preoperative workup for these patients will consist of a contrast-enhanced chest CT with two-dimensional (2D) reconstructions (axial, coronary, and sagittal);2. Group 3D: the preoperative workup for these patients will consist of a contrast-enhanced chest CT with two-dimensional (2D) reconstructions (axial, coronary, and sagittal) and a 3D reconstruction (volume rendering) of the same chest CT employing dedicated software.The primary endpoints will be negative margin (R0) resection rate, resection margin (staple line-to-tumor distance), and thoracotomy conversions.We will use Fisher’s exact test for binary outcomes and Mann–Whitney U test for continuous outcomes. For subgroup analyses, we will use regression. Multivariable analyses will be based on logistic regression for binary outcomes and linear regression for continuous outcomes.Ethics and disseminationThe protocol and the model informed consent forms have been reviewed and approved by the ethics committee (N.: 1–2023) concerning scientific content and compliance with applicable research and human subject regulations.A Subcommittee on Publications was established to review all publications and report its recommendations to the steering committee. The anonymized participant-level dataset and statistical code for generating the results will not be publicly available.Trial registrationThe protocol was registered at ClinicalTrials.gov (ID: NCT05716815; Prospective rAndomized sTudy efficaCy tHree-dimensional rEconstructions Segmentectomy - Full-Text View - ClinicalTrials.gov). Jan 19, 2023.

Objective: To discuss the CT findings after inferior vena cava(IVC) filter placement, and their value in evaluating the status of IVC filters after placement and related complications. Methods: Pertinent data of 31 cases with IVC filter placement who underwent abdominal CT plain scan, contrast-enhanced scan and 3D reconstruction from January 2011 to May 2016 was collected for this study. The location, morphology and complications of IVC filters were evaluated on CT images. Results: (1) CT and 3D reconstruction images can clearly display the IVC filter and determine its type. Among the 31 cases, 12 cases of Ease type (including the retrievable Opt type) showed six-diamond shape, and 6 struts converging at the upper and lower apex of the filter formed the symmetric double baskets, with a retrieval hook in the bottom of OptEase filter; 7 cases of Vena Tech showed a cone shape formed by 6~8radial prongs, with vertical stabilizing struts around; 6 cases of Gunther Tulip presented as inverted tulip shape, with a hook at the top and 4 struts below; 4 cases of Simon Nitinol presented as overlapping umbrellas , with 8 partially overlapping loops forming the top umbrella , and 6 diverging legs forming the lower umbrella ; 2 cases of temporary retrivable filter Tempofilter II showed long-arm umbrella shape, with 8 struts forming the cone-shaped basket, connected with long retrieval handle located in the course from internal jugular vein to inferior vena cava. (2) In 28 cases the filters were located in the infrarenal IVC, which was the conventional position, while 3 cases were in the suprarenal IVC, all of which formed suprarenal IVC thrombus before filter placement. (3) 10 cases showed obvious thrombus in the filters and above IVC, 1 of which also showed IVC stenosis, while no thrombus was found in the remaining 21 cases. (4) None of the 31 cases showed rupture of the main body or struts of IVC filters. 1filter migrated to the hepatic IVC and penetrated to liver parenchyma; the other 30 cases were classified into four grades according to IVC filter strut interactions with IVC wall. There were 7 cases classified as Grade 0, 13 cases as Grade 1, 3 cases as Grade 2, and 7 cases as Grade 3 (3 cases penetrating to the aortic wall and lumbar vertebrae, 1 case to the right psoas major and ileum, and 1 each to the aortic wall, anterior lumbar, and right diaphragmatic crura). The filters were significantly tilted in 7 cases, with the angle between the central longitudinal axis of the filter and the IVC being more than 15°, which showed the best result with coronal and sagittal reconstruction. Conclusion: CT can clearly show the shapes, location and complications of IVC filters, which can provide a good way for retrieval of filters and treatment of complications. Key words: Inferior vena cava filter; Tomography, X-ray computed; 3D reconstruction; Complications

Augmented reality in hepatobiliary-pancreatic surgery: a technology at your fingertips

The value of CT angiography and three-dimensional (3D) reconstructions was investigated in the postoperative care after surgical repair of aortic coarctation and compared with conventional angiography. Twenty-five patients referred because of suspicion of stenosis in the area of former coarctation were prospectively studied with CT angiography and catheter angiography. We determined the morphometric and morphologic findings such as aortic diameter, stenosis, aneurysm, intimal flaps, circumscribed pouch, or arteriosclerotic plaques with 3D reconstructions, using maximum-intensity-projection (MIP) technique and catheter angiography. The results of both techniques were compared. The ratio of the narrowest diameters of the former coarctation and the descending aorta was correlated with the systolic pullback blood pressure gradient in all patients. The former coarctation was normal in 11 patients, (44%), group A; narrowed in 12 children (48%), group B; and dilated in two children (8%), group C. An intimal flap and a circumscribed pouch were delineated in four subjects. MIP reconstructions and catheter angiography revealed identical results regarding the classification into groups A, B, C; intimal flaps; and circumscribed pouches. Statistical analysis revealed good correlation between the narrowest aortic diameters measured on MIP reconstructions and catheter angiography, whereas no correlation between the systolic pullback blood pressure gradient and the diameter ratio of the former coarctation and the descending aorta was found. CT angiography and 3D reconstructions using MIP represent a reliable noninvasive technique to replace diagnostic catheter angiography in the postoperative care of patients with coarctation and provide the clinician with valuable information concerning further invasive procedures.

Small bowel obstruction (SBO) is a common cause of emergency presentations for abdominal pain and can be complicated by mesenteric ischemia. Computed tomography is currently central to diagnosis and management planning. Currently accepted signs identify secondary effects of the root physiological insult, which is vascular obstruction. We hypothesized that with advancements in CT technology and reconstruction algorithms, we can now more closely interrogate the mesenteric vasculature for obstruction and more accurately predict the need for surgical intervention. We retrospectively audited the charts of all patients presenting with a clinical diagnosis of SBO at a single institution in a 12-month period. Two blinded consultant radiologists were then asked to analyze 3D MIP reconstruction CT scans for vascular obstruction in addition to any currently accepted signs of ischemia. Comparison between vascular cutoff and accepted current signs in the need for surgical intervention and the presence of any signs of ischemia in theater were recorded. Vascular cutoff had a comparable, with a trend towards superiority, sensitivity and specificity and inter-observer agreement to currently accepted signs of ischemia. The absence of a cut off sign has an excellent negative predictive value for ischemia with only 2 (3.7%) patients demonstrating ischemia at surgery where the vascular cutoff sign was not seen to be present. Interrogating vascular obstruction using 3D MIP reconstructions in small bowel obstruction may be a more sensitive and specific sign for prediction of surgical intervention, possibly occurring earlier in the obstruction pathway.

A comprehensive method for studying pore structure and seepage characteristics of coal mass based on 3D CT reconstruction and NMR

BackgroundThe TRIANGLE operation benefits patients with pancreatic cancer; however, the Heidelberg triangle, where the operation occurs, contains vessels that can impact safety, especially in laparoscopic pancreaticoduodenectomy (LPD) with the TRIANGLE operation. This study aimed to identify Heidelberg triangle vessel types and their implications in pancreaticoduodenectomy (PD).MethodsRetrospective collection of radiographic data was performed from January 2017 to April 2023. Three-dimensional (3D) CT reconstructions were performed on patients. Vascular types in the Heidelberg triangle were classified based on named vessels crossing its interior. The impact of these types on surgical outcomes and complications in PD with the TRIANGLE operation was assessed.ResultsPreoperative CT reconstruction was conducted on 184 pancreatic surgery patients. The findings revealed 99 patients (53.8%) with the type I Heidelberg triangle, lacking named vessels crossing the interior. Type II (n = 85, 46.2%), with named vessels crossing the interior, was identified. Among reconstructed patients who underwent PD with the TRIANGLE operation (n = 103), they were categorized as type I (n = 57) or type II (n = 46). The results showed that LPD patients with type II had significantly higher median intraoperative blood loss (300 mL vs. 200 mL, P = 0.030) and mean examined lymph nodes (17.2 ± 7.6 vs. 13.4 ± 5.2, P = 0.019) compared to those with type I. No significant differences were found in operative time or postoperative complications.ConclusionThe presence of named vessels crossing the interior of the Heidelberg triangle was associated with increased intraoperative bleeding during LPD combined with the TRIANGLE operation. Therefore, targeted preoperative planning is required before the operation, thus improving the safety of the TRIANGLE operation in minimally invasive surgery.

Despite the advancement of the deep neural network, the 3D CT reconstruction from its correspondence 2D X-ray is still a challenging task in computer vision. To tackle this issue here, we proposed a new class-conditioned network, namely CCX-rayNet, which is proficient in recapturing the shapes and textures with prior semantic information in the resulting CT volume. Firstly, we propose a Deep Feature Transform (DFT) module to modulate the 2D feature maps of semantic segmentation spatially by generating the affine transformation parameters. Secondly, by bridging 2D and 3D features (Depth-Aware Connection), we heighten the feature representation of the X-ray image. Particularly, we approximate a 3D attention mask to be employed on the enlarged 3D feature map, where the contextual association is emphasized. Furthermore, in the biplanar view model, we incorporate the Adaptive Feature Fusion (AFF) module to relieve the registration problem that occurs with unrestrained input data by using the similarity matrix. As far as we are aware, this is the first study to utilize prior semantic knowledge in the 3D CT reconstruction. Both qualitative and quantitative analyses manifest that our proposed CCX-rayNet outperforms the baseline method.