Computed Tomography Angiography Reconstruction Research Articles

Quantitative analysis of deep learning reconstruction in CT angiography: Enhancing CNR and reducing dose

Background Computed tomography angiography (CTA) provides significant information on image quality in vascular imaging, thus offering high-resolution images despite having the disadvantages of increased radiation doses and contrast agent-related side effects. The deep-learning image reconstruction strategies were used to quantitatively evaluate the enhanced contrast-to-noise ratio (CNR) and the dose reduction effect of subtracted images. Objective This study aimed to elucidate a comprehensive understanding of the quantitative image quality features of the conventional filtered back projection (FBP) and the advanced intelligent clear-IQ engine (AiCE), a deep learning reconstruction technique. The comparison was made in subtracted images with variable concentrations of contrast agents at variable tube currents and voltages, enhancing our knowledge of these two techniques. Methods Data were obtained using a state-of-the-art 320-detector CT scanner. Image reconstruction was performed using FBP and AiCE with various intensities. The image quality evaluation was based on eight iodine concentrations in the phantom setup. The efficiency of AiCE relative to FBP was assessed by computing parameters including the root mean square error (RMSE), dose-dependent CNR, and potential dose reduction. Results The results showed that elevated concentrations of iodine and increased tube currents improved AiCE performance regarding CNR enhancement compared to FBP. AiCE also demonstrated a potential dose reduction ranging from 13.7 to 81.9% compared to FBP, suggesting a significant reduction in radiation exposure while maintaining image quality. Conclusions The employment of deep learning image reconstruction with AiCE presented a significant improvement in CNR and potential dose reduction in CT angiography. This study highlights the potential of AiCE to improve vascular image quality and decrease radiation exposure risk, thereby improving diagnostic precision and patient care in vascular imaging practices.

Detectability of intracranial vessel wall atherosclerosis using black-blood spectral CT: a phantom and clinical study

BackgroundComputed tomography (CT) is the usual modality for diagnosing stroke, but conventional CT angiography reconstructions have limitations.MethodsA phantom with tubes of known diameters and wall thickness was scanned for wall detectability, wall thickness, and contrast-to-noise ratio (CNR) on conventional and spectral black-blood (SBB) images. The clinical study included 34 stroke patients. Diagnostic certainty and conspicuity of normal/abnormal intracranial vessels using SBB were compared to conventional. Sensitivity/specificity/accuracy of SBB and conventional were compared for plaque detectability. CNR of the wall/lumen and quantitative comparison of remodeling index, plaque burden, and eccentricity were obtained for SBB imaging and high-resolution magnetic resonance imaging (hrMRI).ResultsThe phantom study showed improved detectability of tube walls using SBB (108/108, 100% versus conventional 81/108, 75%, p < 0.001). CNRs were 75.9 ± 62.6 (mean ± standard deviation) for wall/lumen and 22.0 ± 17.1 for wall/water using SBB and 26.4 ± 15.3 and 101.6 ± 62.5 using conventional. Clinical study demonstrated (i) improved certainty and conspicuity of the vessels using SBB versus conventional (certainty, median score 3 versus 0; conspicuity, median score 3 versus 1 (p < 0.001)), (ii) improved sensitivity/specificity/accuracy of plaque (≥ 1.0 mm) detectability (0.944/0.981/0.962 versus 0.239/0.743/0.495) (p < 0.001), (iii) higher wall/lumen CNR of SBB of (78.3 ± 50.4/79.3 ± 96.7) versus hrMRI (18.9 ± 8.4/24.1 ± 14.1) (p < 0.001), and (iv) excellent reproducibility of remodeling index, plaque burden, and eccentricity using SBB versus hrMRI (intraclass correlation coefficient 0.85–0.94).ConclusionsSBB can enhance the detectability of intracranial plaques with an accuracy similar to that of hrMRI.Relevance statementThis new spectral black-blood technique for the detection and characterization of intracranial vessel atherosclerotic disease could be a time-saving and cost-effective diagnostic step for clinical stroke patients. It may also facilitate prevention strategies for atherosclerosis.Key points• Blooming artifacts can blur vessel wall morphology on conventional CT angiography.• Spectral black-blood (SBB) images are generated from material decomposition from spectral CT.• SBB images reduce blooming artifacts and noise and accurately detect small plaques.Graphical

Pericoronary adipose tissue density is increased in patients with recent spontaneous coronary dissection

ObjectiveInflammatory activity is one of the potential mechanisms of spontaneous coronary artery dissection (SCAD). Recently, the pericoronary adipose tissue attenuation (PCAT) derived from CT angiography (CTA) has been established as...

Analysis of pulmonary artery variation based on 3D reconstruction of CT angiography.

Objective: The aim of this study is to acquire pulmonary CT (Computed tomography) angiographic data for the purpose of creating a three-dimensional reconstruction. Additionally, we aim to analyze the features and deviations of the branches in both pulmonary lobes. This information is intended to serve as a more comprehensive and detailed reference for medical professionals when conducting preoperative evaluations and devising surgical plans. Method: Between August 2019 and December 2021, 420 patients were selected from the thoracic surgery department at the First Hospital of Jilin University, and underwent pulmonary 64 channel contrast enhanced CT examinations (Philips ICT 256). The images were acquired at a 1.5mm slice thickness, and the DCM files that complied with DICOM (Digital Imaging and Communications in Medicine) standards were analysed for 3D (three dimensional) reconstruction using Mimics 22.0 software. The reconstructed pulmonary artery models were assessed by attending chest surgeons and radiologists with over 10years of clinical experience. The two-dimensional image planes, as well as the coronary and sagittal planes, were utilized to evaluate the arteries. The study analyzed the characteristics and variations of the branches and courses of pulmonary arteries in each lobe of the lungs, with the exception of the subsegmental arterial system. Two chest surgeons and two radiologists with professional titles-all of whom had over a decade of clinical experience-jointly evaluated the 3D models of the pulmonary artery and similarly assessed the characteristics and variations of the branches and courses in each lobe of the lungs. Results: Significant variations were observed in the left superior pulmonary artery across the 420 subjects studied. In the left upper lobe, the blood supply of 4 arteries accounted for 50.5% (n = 212), while the blood supply of 2 arteries in the left lower lobe was the most common, accounting for 79.5% (n = 334). The greatest variation in the right pulmonary artery was observed in the branch supply of the right upper lobe mediastinal artery. In the majority of cases (77.9%), there were two arteries present, which was the most common configuration observed accounting for 64% (n = 269). In the right inferior lobe of the lung, there were typically 2-4 arteries, with 2 arteries being the most common configuration (observed in 79% of cases, n = 332). Conclusion: The three-dimensional reconstruction of pulmonary artery CT angiography enables clear observation of the branches and distribution of the pulmonary artery while also highlighting any variations. This technique holds significant clinical value for preoperative assessments regarding lesions and blood vessels.

Non-invasive characterization of pancoronary inflammation by computed tomography angiography in patients with recent spontaneous coronary dissection

Abstract Background Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic cause of myocardial infarction of unclear aethiology. Histopathological analyses have identified increased coronary inflammation in patients with SCAD [1]. Recently the peri-coronary adipose tissue attenuation (PCAT) derived from standard computed tomography angiography (CTA) has been established as a reproducible method for measuring vascular inflammation which enhances risk stratification in patients with coronary atherosclerosis [2]. Purpose To characterize the pancoronary and vessel-specific inflammation by means of CTA-derived PCAT in patients with recent SCAD compared with individuals without prior SCAD. Methods Patients with confirmed SCAD referred to a tertiary center between 2017 and 2021 who underwent CTA as a routine cardiac evaluation were included in this retrospective study. Subjects were matched 1:1 with individuals with no prior SCAD who underwent CTA within the same timespan, using the same scanner and imaging protocol, with coronary arteries free of obstructive disease and similar clinical characteristics (Table 1). PCAT was analyzed on end-diastolic CTA reconstructions with a semi-automated software using standard methodology (Figure 1A) [3]. Proximal 40 mm of all major coronary vessels &amp;gt;2 mm in diameter as well as the SCAD-related vessel were included. The primary outcome was pancoronary PCAT defined as mean PCAT in the right (RCA), left anterior descending (LAD) and circumflex (LCX) artery. Secondary outcome was vessel-specific PCAT defined as PCAT in RCA and averaged PCAT in LAD and LCX (PCAT LCA). Results The final cohort comprised 35 patients with recent SCAD (median 6.1 mo. [4.0–16.8] since SCAD, 94.3% female) and 35 patients in the non-SCAD group. Pancoronary PCAT was higher in patients with SCAD compared with non-SCAD group (−80.1 [IQR: −74.5, −84.6] vs. −83.4 HU [−78.7, −88.0], P=0.008) suggestive of increased coronary inflammation. Vessel-specific PCAT was higher for the RCA (−80.7 [−70.4, −86.9] vs. −85.3 [−80.4, −90.6] HU, P&amp;lt;0.001) and borderline higher for the LCA (−79.2 [−73.9, −83.2] vs. −83.4 [−78.0, −88.3] HU, P=0.056) in patients with SCAD compared with non-SCAD respectively (Figure 1B). In patients with SCAD, PCAT in previously dissected vessel was not significantly different from averaged PCAT in unaffected vessels (−78.4 [−73.7, −89.0] vs. −80.9 [−74.9, −83.3], P=0.77; Figure 1C). While PCAT numerically decreased with time since SCAD, the association was not statistically significant when patients were stratified into tertiles according to time from SCAD (Figure 1D). Conclusions Patients with recent SCAD have higher pericoronary adipose tissue attenuation compared with non-SCAD patients suggesting increased perivascular inflammatory activity. This association is not restricted to the dissected vessel, nor reflected in routine serum inflammatory analysis and persists over time. Funding Acknowledgement Type of funding sources: None.

Double Aortic Arch as a Rare Condition in a 10-year-old Boy with Recurrent Pneumonia: A Case Report Study

Introduction: A double aortic arch (DAA) is a congenital anomaly of the aortic arch, which is also the most common type of complete vascular ring. This vascular ring can compress the trachea and esophagus, as well as cause respiratory, gastrointestinal, and cardiac symptoms. Case Presentation: In the present case report, a 10-year-old boy with recurrent cough, fever, shortness of breath, chest pain, and a history of recurrent respiratory infections was examined. According to the results of bronchoscopic evaluation, he was found to have a localized tracheomalacia. DAA and dextrocardia condition were also confirmed for this patient by performing a computed tomography angiography of the thorax and the three-dimensional reconstruction of CT angiography. Conclusions: The diagnosis of double aortic arch may be confused with upper respiratory tract infections or foreign body aspiration. Therefore, it was recommended that a particular attention should be paid to the double aortic arch when evaluating cases of stridor in children with unknown causes or recurrent respiratory infections. CT angiography and cardiac MRI were the diagnostic methods of choice for examining vascular rings.

Computed Tomography Angiography and Three-Dimensional Reconstruction of Renal Arteries in Diagnosing the Bleedings After Mini-Percutaneous Nephrolithotomy: A Single-center Experience of 7 Years

ObjectiveThis study aimed to investigate the role of computed tomography angiography (CTA) and three-dimensional (3D) reconstruction of renal arteries in the evaluation of bleeding after mini- percutaneous nephrolithotomy (PCNL). MethodsThirty-one consecutive patients with continuous renal hemorrhage after mini-PCNL were enrolled from January 2015 to January 2022. Demographic and clinical data were retrospectively recorded and analyzed. All patients had received CTA evaluation and subsequently digital subtraction angiography (DSA) embolization to manage renal bleeding. CTA and 3D reconstruction of renal arteries were performed using the 320 multi-detector computed tomography technique and the images were evaluated by experienced radiologists. DSA embolization were performed by an interventional radiologist with more than 10 years of experiences. ResultsCTA and 3D construction of renal arteries showed 28 cases of vascular lesions (28/31, 90.3%), including 15 cases of pseudoaneurysm (15/28, 53.6%), 9 cases of arteriovenous fistula (9/28, 32.1%), and 4 cases of suspicious bleeding spot (4/28, 14.3%). While DSA revealed 31 cases of vascular lesions (100%), including 15 cases of pseudoaneurysm (15/31, 48.4%), 10 cases of arteriovenous fistula (10/31, 32.3%), 6 cases of bleeding spot and (6/31, 19.4%). The serum creatinine level was elevated slightly before mini-PCNL and after DSA embolization (73.1±18.1 vs 92.1±33.6, P <.01). 15 patients (15/31, 48.4%) required blood transfusion, with mean blood transfusion volume of 700 ml ±660 ml (range, 400 ml-1800 ml). The bleeding was controlled without any further severe complications. ConclusionCTA and 3D reconstruction of renal arteries were safe and effective in diagnosing renal arterial bleedings after mini-PCNL, with a sensitivity of 90.3% and a specificity of 100%.

A pilot study on preoperative vascular anatomy and clinical application in rectal cancer resection

To assess the utility of preoperatively evaluating the vascular anatomy using multisection spiral computed tomography angiography (CTA) and image fusion technology in the treatment of obese patients undergoing laparoscopic radical resection for rectal cancer. This randomised prospective study included 56 patients who underwent laparoscopic surgery for rectal cancer. Patients were randomly divided into two groups: the fusion imaging group (preoperative CTA and image fusion reconstruction [n=28]) and the control group (not performed CTA and image fusion reconstruction before the operation [n=28]). Duration of surgery was defined as the primary endpoint, and the volume of bleeding, the number of lymph node dissections, conversion to laparotomy, time to recovery of postoperative flatus, length of hospitalisation as well as perioperative complications were defined as secondary endpoints. Compared with the control group, the duration of surgery in the image fusion group was shorter, bleeding volume was reduced, and the number of lymph node dissections was greater (p<0.05); however, there was no significant differences between the two groups regarding time to postoperative flatus recovery, conversion to laparotomy, length of hospitalisation, and perioperative complications (p>0.05). Preoperative assessment of the vascular anatomy was an effective method and avoided some invisible risks during surgery, and resulted in a better therapeutic effect.

A dissection … of the Dacron?

A dissection … of the Dacron?

Automatic vs manual coronary CT angiography reconstruction for whole-heart coverage CT scanner: a comparison study in general patient population.

Due to the limited temporal resolution and cardiac motion, coronary computed tomography angiography (CCTA) exam is one of the most challenging CT protocols which may require operating radiologist to apply additional phase adjustment or motion correction for image reconstruction. To evaluate image quality between automatic and manual CCTA reconstruction in a 0.25 second rotation time, 16 cm coverage, single-beat, CT scanner with automated phase selection and AI-assisted motion correction. CCTA exams of 535 consecutive patients were included. All exams were first reconstructed with an automatically selected phase. If there was an unacceptable motion artifact, a manual reconstruction process was performed by radiologists. Additionally, automatic image series which consist of auto-phase selection and a follow-up motion correction were reconstructed. For these two manual and automatic image series, a four-point Likert scale rating system was used to evaluate image quality of the coronary artery segment by two experienced radiologists, according to the 18-segment model. Fifty-one patients (9.5%) did not have satisfactory image quality after auto-phase selection. In these patients, the heart rate during scanning was higher (78.3±18.4 bpm) than in the remaining 484 patients (68.9±13.1 bpm). Overall, 734 out of the 918 vessel segments were identified for quality evaluation among 51 patients. Automatic and manual image series were rated as having average Likert scores of 3.48±0.62 and 3.32±0.67 (P < 0.001), respectively. Using a 0.25 second rotation speed, 16 cm z-coverage, CT scanner installed with an AI-assisted motion correction algorithm, the automatic image reconstruction with scanner equipped auto-phase-selection and motion correction algorithm outperforms manually controlled image reconstruction by radiologists. This suggests that the traditional CCTA exam reconstruction workflow could be altered allowing less radiologist involvement and becoming more efficient.

Floating EVAS!

A 79 year old patient, unfit for open surgery, treated for a pararenal aortic aneurysm with the endovascular aneurysm sealing system (EVAS) with three chimneys in both renal arteries and the superior mesenteric artery, was lost to follow up and presented six years later with a type Ia endoleak and sac enlargement to 9 cm. (A) Computed tomography angiography reconstruction of the migrated left EVAS stent (red arrow). (B) The patient was successfully treated with a custom made thoraco-abdominal stent graft with three inner branches, an aorto-uni-iliac endoprosthesis on the right, plug on the left and femorofemoral crossover bypass.Image 1

Intraoperative CT-angiography reconstruction of the vertebral artery utilizing neuronavigation and intraoperative i.v. contrast application for dorsal upper cervical axial and subaxial cervical spine instrumentation

Intraoperative CT-angiography reconstruction of the vertebral artery utilizing neuronavigation and intraoperative i.v. contrast application for dorsal upper cervical axial and subaxial cervical spine instrumentation

Generative adversarial networks improve interior computed tomography angiography reconstruction

In interior computed tomography (CT), the x-ray beam is collimated to a limited field-of-view (FOV) (e.g. the volume of the heart) to decrease exposure to adjacent organs, but the resulting image has a severe truncation artifact when reconstructed with traditional filtered back-projection (FBP) type algorithms. In some examinations, such as cardiac or dentomaxillofacial imaging, interior CT could be used to achieve further dose reductions. In this work, we describe a deep learning (DL) method to obtain artifact-free images from interior CT angiography. Our method employs the Pix2Pix generative adversarial network (GAN) in a two-stage process: (1) An extended sinogram is computed from a truncated sinogram with one GAN model, and (2) the FBP reconstruction obtained from that extended sinogram is used as an input to another GAN model that improves the quality of the interior reconstruction. Our double GAN (DGAN) model was trained with 10 000 truncated sinograms simulated from real computed tomography angiography slice images. Truncated sinograms (input) were used with original slice images (target) in training to yield an improved reconstruction (output). DGAN performance was compared with the adaptive de-truncation method, total variation regularization, and two reference DL methods: FBPConvNet, and U-Net-based sinogram extension (ES-UNet). Our DGAN method and ES-UNet yielded the best root-mean-squared error (RMSE) (0.03 ± 0.01), and structural similarity index (SSIM) (0.92 ± 0.02) values, and reference DL methods also yielded good results. Furthermore, we performed an extended FOV analysis by increasing the reconstruction area by 10% and 20%. In both cases, the DGAN approach yielded best results at RMSE (0.03 ± 0.01 and 0.04 ± 0.01 for the 10% and 20% cases, respectively), peak signal-to-noise ratio (PSNR) (30.5 ± 2.6 dB and 28.6 ± 2.6 dB), and SSIM (0.90 ± 0.02 and 0.87 ± 0.02). In conclusion, our method was able to not only reconstruct the interior region with improved image quality, but also extend the reconstructed FOV by 20%.

Management of Acute Uncomplicated Stanford B Aortic Dissection in The Era of Endovascular Repair: A Case Report

Introduction: Uncomplicated type B aortic dissections have been traditionally treated with medication therapy. While it may provide good short-term results, longterm prognosis may be less favorable. With improvements in endovascular repair and the potential risk of disease progression, thoracic endovascular aortic repair (TEVAR) has been considered inpatients with uncomplicated type B aortic dissection. We present the case of 78-year-old gentleman who presented with acute uncomplicated type B aortic dissection managed by endovascular repair Case illustration: A 78 year-old hypertensive patient admitted to the hospital with persistent chest discomfort and cough for 2 weeks. The CT aortic angiogram showed type B dissection. Based on the recent guidelines, TEVAR should be considered in patients with uncomplicated type B aortic dissection, thus we prepared the patient for TEVAR procedure. First we established multidisciplinary vascular team for the pre-procedural preparation of the patient. We perform careful measurement through detailed CT angiography reconstruction from carotid to femoral arteries. We found proximal diameter was 30-35mm, distal diameter was 23mm and landing zone right after left brachial ostium, suitable for stent graft Valiant Captivia 36-32x150mm. The CT also showed that both femoral artery were normal, we decided to use right femoral artery as the access. We proceed to the procedure 2 days later, under general anaesthesia, digital subtraction angiography revealed dissection of descending aorta, and selected device was inserted. Subsequent contrast injection revealed total occlusion of the false lumen. Patient was transferred to ICU for postprocedural care, and extubated the day after. The hospital stay was uneventful, and one-month follow up CT shows no endoleak. Conclusion : Management of uncomplicated Stanford B dissections is very challenging. TEVAR has emerged as an alternative to surgery with lower morbidity and mortality rates that might offer good long-term results.

In Reply: Identification of the Distal Dural Ring and Definition of Paraclinoid Aneurysms According to Bony Landmarks on 3-Dimensional Computed Tomography Angiography: A Cadaveric and Radiological Study.

To the Editor: We greatly appreciate this interest in our work, and sincerely thank the authors for their comments.1 Surgical exploration is clearly the only way to determine the true relationship between an aneurysm and the distal dural ring (DDR). We thus could only statistically validate the DDR plane method using surgery. This provided statistical limits for our group of 27 patients without selection bias. Because this surgical group consisted only of intradural or transitional aneurysms because our practice does not treat asymptomatic extradural aneurysms surgically, we therefore could not demonstrate the applicability of the DDR plane method for extradural aneurysms using surgical exploration. Because of this limitation, we could only evaluate the DDR plane method using the T2-weighted magnetic resonance imaging-magentic resonance angiography fusion technique for extradural cases but could not use these patients for statistical validation. We agree that it is not realistic to have a diagnostic method with 100% accuracy, and certainly our small sample size is insufficient for high-powered statistical results with a narrow CI. To achieve a 95% CI with a 10% margin of error, we would need to evaluate more than 40 patients with transitional aneurysms within a population of 200 surgically treated paraclinoid aneurysms. Such a large number of cases is unrealistic even within a multicenter study. Anatomic studies and our cadaveric dissections confirmed that the DDR is attached to the optic strut (OS) superior border anteriorly.2-4 In previous radiological studies, it was found that using the OS as a reference point can be inaccurate for localizing paraclinoid aneurysms in medial or posterior locations.5 These findings can be explained by the fact that the DDR slopes downward in the medial and posterior directions and is not parallel to the planum sphenoidale.3 For this reason, we believe that our circumferential 3-dimensional DDR model is more accurate. As we all know, the geometric determination of a plane requires 3 noncollinear points. Thus, any points that are coplanar with the DDR could be used. For example, 3 points could be selected from the readily identifiable OS superior border. The problem is that the manipulations that could be made using the 3-dimensional computed tomography angiography reconstruction software at our institution (Vitrea version 6.7, Vital Images Inc, Minnetonka, Minnesota) were limited to the drawing of lines for defining a plane. We were unable to find a way to create a plane with this software that was defined by 3 points. As a result, we used 4 coplanar points around the DDR to define the imaginary plane. An important aspect for our selection of which points to use is that the opticocarotid elevation, the superior border of the OS, and the intersection between internal carotid artery (ICA) and anterior clinoid process (ACP) are located in 1 continuous line representing DDR bony attachments anterolaterally (Scerback et al,4 Figure 2); thus, any of these points can be selected to create the DDR plane. We selected 4 distant points to define the plane. These were the following: the anterior clinoid point in which the ICA intersects with the inferior border of the ACP (the intersection point is on the inferomedial border of the ACP; however, this may not be sufficiently clear on all images because of the 2-dimensional view); the lateral point of the OS superior border adjunct to the ACP attachment; the medial point of the optico-carotid elevation near the tubercullum sellae; the posterior point of the posterior clinoid process base. If some of these bony landmarks are blocked from view by the ICA, or more likely by a giant aneurysm, bone-subtraction computed tomography angiography can aid with imaging these points. The semitransparent view option for imaging vascular structures enables visualization of the DDR bony landmarks. The semitransparent viewing mode is also very useful for visualizing the parts of transitional aneurysms that are hidden by bony structures. In conclusion, we greatly appreciate the interest in this work and sincerely hope that readers will find our DDR plane method approach useful. Disclosures The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.

Rapid vessel segmentation and reconstruction of head and neck angiograms using 3D convolutional neural network

The computed tomography angiography (CTA) postprocessing manually recognized by technologists is extremely labor intensive and error prone. We propose an artificial intelligence reconstruction system supported by an optimized physiological anatomical-based 3D convolutional neural network that can automatically achieve CTA reconstruction in healthcare services. This system is trained and tested with 18,766 head and neck CTA scans from 5 tertiary hospitals in China collected between June 2017 and November 2018. The overall reconstruction accuracy of the independent testing dataset is 0.931. It is clinically applicable due to its consistency with manually processed images, which achieves a qualification rate of 92.1%. This system reduces the time consumed from 14.22 ± 3.64 min to 4.94 ± 0.36 min, the number of clicks from 115.87 ± 25.9 to 4 and the labor force from 3 to 1 technologist after five months application. Thus, the system facilitates clinical workflows and provides an opportunity for clinical technologists to improve humanistic patient care.

Utility of CT Angiography for the Prediction of Coronary Artery Compression in Patients Undergoing Transcatheter Pulmonary Valve Replacement.

We aimed to evaluate the utility of computed tomography angiography (CTA) for coronary compression (CC) prediction in patients with congenital heart disease undergoing balloon-expandable transcatheter pulmonary valve replacement (TPVR). Coronary compression is a serious complication of TPVR, but the value of preprocedural CTAs to assess CC risk is largely unexplored. In all, 586 patients underwent TPVR between January 2009 and July 2018. Adults with a pre-TPVR CTA and children with a CTA performed less than one year prior to TPVR were included. Patients with poor CTA image quality or with aborted cases due to reasons other than CC were excluded. Sixty-six patients were finally included. Cardiac anatomy was assessed via multiplanar reconstruction of CTAs. Coronary compression occurred in 9 (14%) of the 66 patients who underwent TPVR. Most CC cases (seven of nine) occurred in patients with conduits. Proximity of the right ventricular outflow tract (RVOT) landing zone to the coronary arteries and to the chest wall was a significant risk factor for compression (P < .001 and P = .019, respectively). Compression risk increased significantly if patients had an RVOT to coronary artery distance of ≤3 mm (P < .001) and an RVOT to chest wall distance of ≤8 mm (P = .026). Anomalous course of coronary arteries was another significant univariate risk factor (P = .003). Right ventricular outflow tract landing zone distance of ≤3 mm to a coronary artery, landing zone distance of ≤8 mm to the chest wall, and anomalous coronary arteries are associated with increased CC risk. Electrocardiogram gating may not be necessary if coronary arteries are opacified on CTAs. Larger studies are needed to explore and confirm these coronary artery compression risk factors.

Clinical Value of Multi-Slice Spiral CT Angiography, Colon Imaging, and Image Fusion in the Preoperative Evaluation of Laparoscopic Complete Mesocolic Excision for Right Colon Cancer: a Prospective Randomized Trial

PurposeTo evaluate the clinical value of CT angiography (CTA), CT colonography (CTC), and image fusion in the preoperative evaluation of laparoscopic complete mesocolic excision (CME) for right colon cancer. MethodsIn this randomized prospective study, 80 patients undergoing laparoscopic CME for right colon cancer were randomly divided into two groups: image fusion [the original images were reconstructed using CTA and CTC, then fused into three-dimensional images of the blood vessels and intestines (n = 40)] and control (without CTA and CTC reconstruction before surgery). All patients underwent plain and enhanced abdominal CT before surgery. ResultsIn the image fusion group, the gastrocolic trunk of Henle was present in 33 cases, and its branches originated from the colon vein, right gastroepiploic vein, and superior anterior pancreaticoduodenal vein. Among these patients, 5 exhibited the right gastroepiploic vein and superior anterior pancreaticoduodenal vein; 21 exhibited a gastrointestinal trunk consisting of 2 or 3 branches of the right gastroepiploic vein, right colon vein, and middle colon vein; and 7 exhibited 3 or 4 gastro-pancreatic and colon trunks consisting of the right colon vein, middle colon vein, right gastroepiploic vein, and superior anterior pancreaticoduodenal vein. The correspondence with the anatomy actually observed during surgery was 100%. Compared with the conventional CT group, the duration of the operation in the image fusion group was shorter, with reduced intraoperative bleeding, and more lymph node dissection. There were no significant differences in the incidence of complications and length of hospital stay between the two groups (p > 0.05). ConclusionsFor laparoscopic CME for right colon cancer, CTA, CTC, and image fusion were effective preoperative evaluation methods, which avoided some unseen dangers in the operation process and led to better therapeutic outcomes.

Retrospective Cohort Study on Vessel Deformation During Fenestrated or Branched Endovascular Aortic Repair; Traditional CTA Roadmaps Provide Insufficient and Inadequate Guidance During Target Vessel Cannulation

Introduction: Optimal visualization of target vessels in three-dimensions (3D) plays a key role in complex endovascular procedures, such as fenestrated and branched endovascular aortic repair (EVAR). A popular imaging technique to enhance target vessel visualization is image fusion. Image fusion combines real-time fluoroscopy with static preprocedural anatomical images, typically computed tomography angiography (CTA) to create an arterial roadmap. However, the introduction of stiff endovascular devices cause the arteries to stretch, leading to a mismatch between the actual position of the (origin of the) artery and its representation on the image fusion roadmap. This retrospective study assesses vessel deformation of the aorta and its side branches due to the introduction of a stiff endovascular devices, during fenestrated and branched EVAR. Furthermore, the influence of vascular tortuosity on the extent of vessel deformation was analysed. Methods: Patients that underwent fenestrated or branched EVAR between January 2015 and January 2018 were retrospectively included in this study. Two imaging datasets were collected from each patient: 1) the preoperative CTA and 2) the intraoperative contrast-enhanced cone beam computed tomography (ce-CBCT), acquired after the insertion of the stiff guidewire and stent delivery device (Zenith® custom made, Cook, Bloomington IN, USA) . Manual registration of both datasets was performed, using the bony landmarks of the vertebrae. Subsequently, the ostium of the celiac artery (CA), superior mesenteric artery (SMA), left renal artery (LRA) and right renal artery (RRA) were marked in both the CTA and ce-CBCT reconstructions. The ostium displacement of the four target vessels was reported as a 3D vector as well as a 2D vector in the coronal plane (RRA and LRA) or sagittal plane (CA and SMA). The tortuosity index of the iliac and the abdominal aortic segment were calculated. The effect of the tortuosity index on the extent of vessel deformation was assessed using linear regression. Results: In total 77 target vessels from 20 patients were included in this study. The 3D mean displacement vector of the ostium of the CA, SMA, RRA and LRA were respectively 8.7±3.8mm, 7.4±2.7mm, 7.9±2.7mm and 7.6±4.4mm. The 2D mean displacement vector for the SMA and CA in the sagittal viewing plane was 4.9±2.9mm and 6.5±3.0mm respectively. The 2D mean displacement vector of the RRA and LRA in the coronal viewing plane was 7.0±2.8mm 6.2±4.3mm respectively. An example of the 2D displacement of the RRA in the coronal plane is shown in Figure 1. In total, 74% of the target vessels had a 2D vector displacement of more than 50% of the diameter of the vessel. The mean tortuosity index of the abdominal aortic segment and the iliac segment was 1.10 and 1.34 respectively. Linear regression showed no association between the extend of vessel displacement and the tortuosity index of the abdominal aortic segment (p=0.37), nor the iliac segment (p=0.11). Conclusion: There is significant vessel displacement of the ostium of the target vessels, during fenestrated and branched EVARs caused by the introduction of stiff endovascular devices. Consequently, preoperative CTA roadmaps are inadequate to guide target vessel cannulation during fenestrated or branched EVAR. Disclosure: Nothing to disclose

Application effects of CT angiography and three-dimensional reconstruction technique in repairing scar around the mouth and chin with expanded forehead axial flap

Objective: To explore application effects of CT angiography (CTA) and three-dimensional reconstruction technique in repairing scar around the mouth and chin with expanded forehead axial flap. Methods: From June 2013 to October 2017, 9 patients with hyperplastic scar around the mouth and chin after deep burns on face were admitted to our unit. The sizes of scars of patients ranged from 8 cm×7 cm to 13 cm×8 cm. One cylindrical skin soft-tissue dilator with nominal volume of 400 to 500 mL was implanted in forehead area of each patient. Five to six months after the dilator was implanted, scar around the mouth and chin was resected, and the dilator was removed. The secondary wound after scar resection was repaired by expanded forehead axial flap with bilateral superficial temporal vessel pedicles. Three of the nine patients received microstomia diorthosis at the same time. Before the operation, CTA and three-dimensional reconstruction were applied to obtain three-dimensional images of superficial temporal arteries and the branches in the donor site, which could identify the travel, adjacent location, and vascular anastomosis of the above-mentioned vessels to guide flap design. The sizes of flaps of patients ranged from 25 cm×9 cm to 30 cm×8 cm. Two to three weeks after the operation, flap pedicles were cut off, restored, and trimmed. The donor site was sutured directly. Ten to twelve days after the flap repair operation, the flap site received depilation treatment with semiconductor freezing point laser once a month for 4 to 6 times. Results: Flaps of all patients survived well, with no blood circulation disorder. The flaps of three patients were slightly bulky, while they were with natural appearance after flap thinning operation in 3 months post flap repair operation. During follow-up of 6 months to 2 years after the operation, color, texture, and thickness of the flaps were close to normal skin around scars. The appearance of perioral and mental region, and opening function of mouth improved significantly, with no recurrence of scar. Frontotemporal incision was hidden, hair on head grew normally, and reconstructed hairline was natural. Conclusions: Scar around the mouth and chin repaired with expanded forehead axial flap were with good appearance and function in operation area and good shape in donor site. CTA and three-dimensional reconstruction technique can provide clear three-dimensional images of superficial temporal arteries and the branches in expanded forehead axial flaps, which can provide reliable basis for preoperative designing of flap, reduce operative risk, and improve survival rate of flap, thus having clinical application value.