Initial experience with cinematic rendering for the visualization of extracardiac anatomy in complex congenital heart defects†

Comparison of two 3D reconstruction models for understanding of complicated female pelvic tumors

OBJECTIVE

Three-dimensional (3D) reconstructed models have been shown to improve visualization in complex female pelvic tumors. Cinematic rendering (CR) is a 3D imaging technique for computed tomography (CT) images, which creates more realistic images with the ability to enhance imaging of anatomical features for diagnosis. This study was set up to compare two types of 3D models and to validate the use of 3D anatomical techniques for the diagnosis of complex female pelvic tumors.

METHODS

The preclinical, randomized, two-sequence crossover investigation was performed from December 2022 to January 2023 at First Affiliated Hospital of Chongqing Medical University. Sixteen residents and 10 attending surgeons assessed the cases of 23 patients with two types of 3D model images. The surgeons were randomly assigned to two assessment sequences (CR-3D model group and CT-3D model group). For each case, participants selected one question that probed fundamental questions about the tumor's genesis throughout each assessment period. Following a 4-week washout period, case assessments were transferred to the other image modality.

RESULTS

The main result assessment was the accuracy of the answers. The time to answer the questions and the case assessment questionnaire was added as a secondary outcome. The mean scores in the CR-3D models (19.35 ± 1.87) varied significantly from those in the CT-CR group (16.77 ± 1.8) (P < 0.001), and solving the questions in the CT-3D model sequence (41.96 ± 6.31 s) varied significantly from that in the CR-3D model sequence (52.88 ± 5.95 s) (P < 0.001). Subgroup analysis revealed that there were statistically significant variations in the scores of female reproductive tumors, pelvic tumors other than the reproductive system, and retroperitoneal tumors (P = 0.005). Analysis of the assessment questionnaire showed that more surgeons choose CR 3D reconstruction (8.31 ± 0.76 vs 7.15 ± 1.19, P < 0.001).

CONCLUSIONS

The results suggest that each 3D reconstruction method has its own advantages. Surgeons feel that CR reconstruction models are a useful technique that can improve their comprehension of complex pelvic tumors, while traditional 3D models have an advantage in terms of speed to diagnosis.

Clinical implementation of cinematic rendering

Cinematic rendering is a recently developed photorealistic display technique for standard volumetric data sets. It has broad-reaching applications in cardiovascular, musculoskeletal, abdominopelvic, and thoracic imaging. It has been used for surgical planning and has emerging use in educational settings. We review the logistics of performing this post-processing step and its integration into existing workflow.

Expanded experience with cardiovascular black blood cinematic rendering

Black blood cinematic rendering (BBCR) is a newly described preset for cinematic rendering, which creates photorealistic displays from volumetric data sets with the contrast-enhanced blood pool displayed as dark and transparent. That set of features potentially provides for enhanced visualization of endomyocardial and intraluminal pathology, as well as cardiac devices. The similarity of the images to black-blood magnetic resonance imaging (MRI) may allow for expansion of the evaluation of certain types of pathology into patient populations unable to undergo MRI. In the emergency setting, the rapid acquisition time and reasonable post-processing time make this technique clinically feasible. In this expanded experience, we demonstrate an expanded clinical experience with the BBCR technique, highlighting the applications for intraluminal cardiovascular evaluation, especially focused on current and potential emergency radiology applications.

Multimodality 3D image fusion with live fluoroscopy reduces radiation dose during catheterization of congenital heart defects

Introduction

Imaging fusion technology is promising as it is radiation and contrast sparing. Herein, we compare conventional biplane angiography to multimodality image fusion with live fluoroscopy using two-dimensional (2D)-three-dimensional (3D) registration (MMIF2D-3D) and assess MMIF2D-3D impact on radiation exposure and contrast volume during cardiac catheterization of patients with congenital heart disease (CHD).

Methods

We matched institutional MMIF2D-3D procedures and controls according to patient characteristics (body mass index, age, and gender) and the seven procedure-type subgroups. Then, we matched the number of tests and controls per subgroup using chronological ordering or propensity score matching. Subsequently, we combined the matched subgroups into larger subgroups of similar procedure type, keeping subgroups with at least 10 test and 10 control cases. Air kerma (AK) and dose area product (DAP) were normalized by body weight (BW), product of body weight and fluoroscopy time (BW × FT), or product of body weight and number of frames (BW × FR), and stratified by acquisition plane and irradiation event type (fluoroscopy or acquisition). Three senior interventionists evaluated the relevance of MMIF2D-3D (5-point Likert scale).

Results

The Overall group consisted of 54 MMIF2D-3D cases. The combined and matched subgroups were pulmonary artery stenting (StentPUL), aorta angioplasty (PlastyAO), pulmonary artery angioplasty (PlastyPUL), or a combination of the latter two (Plasty). The FT of the lateral plane reduced significantly by 69.6% for the Overall MMIF2D-3D population. AKBW and DAPBW decreased, respectively, by 43.9% and 39.3% (Overall group), 49.3% and 54.9% (PlastyAO), and 36.7% and 44.4% for the Plasty subgroup. All the aforementioned reductions were statistically significant except for DAPBW in the Overall and Plasty (sub)groups. The decrease of AKBW and DAPBW in the StentPUL and PlastyPUL subgroups was not statistically significant. The decrease in the median values of the weight-normalized contrast volume (CMCBW) in all five subgroups was not significant. Cardiologists considered MMIF2D-3D very useful with a median score of 4.

Conclusion

In our institution, MMIF2D-3D overall enabled significant AKBW reduction during the catheterization of CHD patients and was mainly driven by reduced FT in the lateral plane. We observed significant AKBW reduction in the Plasty and PlastyAO subgroups and DAPBW reduction in the PlastyAO subgroup. However, the decrease in CMCBW was not significant.

3D CT cinematic rendering of pediatric thoracic vascular anomalies

Thoracic vascular anomalies in the pediatric population are a heterogeneous group of diseases, with varied clinical presentations and imaging findings. High-resolution computed tomography is widely available and has become a standard part of the workup of these patients, often with three dimensional images. Cinematic rendering is a novel 3D visualization technique that utilizes a new, complex global lighting model to create photorealistic images with enhanced anatomic detail. The purpose of this pictorial review is to highlight the advantages of cinematic rendering compared to standard 2D computed tomography and traditional volume-rendered 3D images in the evaluation of thoracic vascular anomalies. Although cinematic rendering remains a new visualization technique under continued study, the improved anatomic detail and photorealistic quality of these images may be advantageous for surgical planning in cases of complex vascular abnormalities. Cinematic rendering may also help improve communication among clinicians, trainees, and patients and their families.

Cinematic rendering of paediatric musculoskeletal pathologies: initial experiences with CT

Cinematic rendering (CR) is a novel post-processing technique similar to volume rendering (VR), which allows for a more photorealistic imaging reconstruction by using a complex light modelling algorithm, incorporating information from multiple light paths and predicted photon scattering patterns. Several recent publications relating to adult imaging have argued that CR gives a better "realism" and "expressiveness" experience over VR techniques. CR has also been shown to improve visualisation of musculoskeletal and vascular anatomy compared with conventional CT viewing, and may help non-radiologists to understand complex patient anatomy. In this review, we provide an overview of how CR could be used in paediatric musculoskeletal imaging, particularly in complex diagnoses, surgical planning, and patient consent processes. We present a direct comparison of VR and CR reconstructions across a range of congenital and acquired musculoskeletal pathologies, highlighting potential advantages and areas for further research.

Three-dimensional perception of cinematic rendering versus conventional volume rendering using CT and CBCT data of the facial skeleton

The aim of this exploratory study is to analyse whether three-dimensional cinematic rendering image reconstructions offer advantages over conventional volume rendering in the visualisation of cone beam computed tomography (CBCT) and computed tomography (CT) images of the facial skeleton. This is of interest, as some information gets lost during the rendering process. This especially applies to structures in the background of the image and some surface information which can be lost. The commonly applied two-dimensional representation of CBCT or CT images in three different axes requires experience for interpretation. Cinematic rendering is a new three-dimensional post processing reconstruction technique, creating photo realistic visualisations, thus possibly enabling an easier interpretation of the images. In this study, ten investigators assessed ten separate patient cases of the orofacial skeleton. For each case, a conventional volume rendering image reconstruction and a cinematic rendering reconstruction of the same area was created. A specially designed questionnaire assessed both objective and subjective criteria of image perception. Objective criteria were assessed by predefined questions on the visual perception of anatomical image characteristics, showing the two reconstruction types of each case randomly to the investigators in two sessions. Subjective criteria were assessed via a visual analogue scale, showing both reconstructions simultaneously in a third session. The results show that cinematic rendering offers advantages especially in the evaluation of depth perception and three-dimensionality. Volume rendering shows advantages in surface sharpness. Cinematic Rendering was subjectively rated higher for almost all reconstructions. The cinematic rendering process however may cause loss of information and blurring of surfaces compared to volume rendering. With respect to the subjective impression, cinematic rendering scored better than volume rendering. The visualisation is perceived as being very close to reality.

The third dimension in perforator mapping-Comparison of Cinematic Rendering and maximum intensity projection in abdominal-based autologous breast reconstruction

BACKGROUND

Cinematic Rendering (CR) is a recently introduced post-processing three-dimensional (3D) visualization imaging tool. The aim of this study was to assess its clinical value in the preoperative planning of deep inferior epigastric artery perforator (DIEP) or muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps, and to compare it with maximum intensity projection (MIP) images. The study presents the first application of CR for perforator mapping prior to autologous breast reconstruction.

METHODS

Two senior surgeons independently analyzed CR and MIP images based on computed tomography angiography (CTA) datasets of 20 patients in terms of vascular pedicle characteristics, the possibility to harvest a DIEP or MS-TRAM flap, and the side of the flap harvest. We calculated inter- and intra-observer agreement in order to examine the accordance of both image techniques.

RESULTS

We observed a good inter- and intra-observer agreement concerning the type of flap and the side of the flap harvest. However, the agreement on the pedicle characteristics varies depending on the considered variable. Both investigators identified a significantly higher number of perforators with MIP compared with CR (observer 1, p<0.0001 and observer 2, p<0.0385).

CONCLUSION

The current study serves as an explorative study, showing first experiences with CR in abdominal-based autologous breast reconstruction. In addition to MIP images, CR might improve the surgeon's understanding of the individual's anatomy. Future studies are required to compare CR with other 3D visualization tools and its possible effects on operative parameters.

3D Printing for Cardiovascular Applications: From End-to-End Processes to Emerging Developments

3D printing as a means of fabrication has seen increasing applications in medicine in the last decade, becoming invaluable for cardiovascular applications. This rapidly developing technology has had a significant impact on cardiovascular research, its clinical translation and education. It has expanded our understanding of the cardiovascular system resulting in better devices, tools and consequently improved patient outcomes. This review discusses the latest developments and future directions of generating medical replicas ('phantoms') for use in the cardiovascular field, detailing the end-to-end process from medical imaging to capture structures of interest, to production and use of 3D printed models. We provide comparisons of available imaging modalities and overview of segmentation and post-processing techniques to process images for printing, detailed exploration of latest 3D printing methods and materials, and a comprehensive, up-to-date review of milestone applications and their impact within the cardiovascular domain across research, clinical use and education. We then provide an in-depth exploration of future technologies and innovations around these methods, capturing opportunities and emerging directions across increasingly realistic representations, bioprinting and tissue engineering, and complementary virtual and mixed reality solutions. The next generation of 3D printing techniques allow patient-specific models that are increasingly realistic, replicating properties, anatomy and function.

Cone-beam computed tomography cinematic rendering: clinical, teaching and research applications

Cone-beam computed tomography (CBCT) is an essential imaging method that increases the accuracy of diagnoses, planning and follow-up of endodontic complex cases. Image postprocessing and subsequent visualization relies on software for three-dimensional navigation, and application of indexation tools to provide clinically useful information according to a set of volumetric data. Image postprocessing has a crucial impact on diagnostic quality and various techniques have been employed on computed tomography (CT) and magnetic resonance imaging (MRI) data sets. These include: multiplanar reformations (MPR), maximum intensity projection (MIP) and volume rendering (VR). A recent advance in 3D data visualization is the new cinematic rendering reconstruction method, a technique that generates photorealistic 3D images from conventional CT and MRI data. This review discusses the importance of CBCT cinematic rendering for clinical decision-making, teaching, and research in Endodontics, and a presents series of cases that illustrate the diagnostic value of 3D cinematic rendering in clinical care.

Cinematic Rendering in Mixed-Reality Holograms: A New 3D Preoperative Planning Tool in Pediatric Heart Surgery

Cinematic rendering (CR) is based on a new algorithm that creates a photo-realistic three-dimensional (3D) picture from cross-sectional images. Previous studies have shown its positive impact on preoperative planning. To date, CR presentation has only been possible on 2D screens which limited natural 3D perception. To depict CR-hearts spatially, we used mixed-reality technology and mapped corresponding hearts as holograms in 3D space. Our aim was to assess the benefits of CR-holograms in the preoperative planning of cardiac surgery. Including 3D prints allowed a direct comparison of two spatially resolved display methods. Twenty-six patients were recruited between February and September 2019. CT or MRI was used to visualize the patient's heart preoperatively. The surgeon was shown the anatomy in cross-sections on a 2D screen, followed by spatial representations as a 3D print and as a high-resolution hologram. The holographic representation was carried out using mixed-reality glasses (HoloLens®). To create the 3D prints, corresponding structures were segmented to create STL files which were printed out of resin. In 22 questions, divided in 5 categories (3D-imaging effect, representation of pathology, structure resolution, cost/benefit ratio, influence on surgery), the surgeons compared each spatial representation with the 2D method, using a five-level Likert scale. The surgical preparation time was assessed by comparing retrospectively matched patient pairs, using a paired t-test. CR-holograms surpassed 2D-monitor imaging in all categories. CR-holograms were superior to 3D prints in all categories (mean Likert scale 4.4 ± 1.0 vs. 3.7 ± 1.3, P < 0.05). Compared to 3D prints it especially improved the depth perception (4.7 ± 0.7 vs. 3.7 ± 1.2) and the representation of the pathology (4.4 ± 0.9 vs. 3.6 ± 1.2). 3D imaging reduced the intraoperative preparation time (n = 24, 59 ± 23 min vs. 73 ± 43 min, P < 0.05). In conclusion, the combination of an extremely photo-realistic presentation via cinematic rendering and the spatial presentation in 3D space via mixed-reality technology allows a previously unattained level of comprehension of anatomy and pathology in preoperative planning.

Cinematic Rendering in Anatomy: A Crossover Study Comparing a Novel 3D Reconstruction Technique to Conventional Computed Tomography

Integration of medical imaging into preclinical anatomy courses is already underway in many medical schools. However, interpretation of two-dimensional grayscale images is difficult and conventional volume rendering techniques provide only images of limited quality. In this regard, a more photorealistic visualization provided by Cinematic Rendering (CR) may be more suitable for anatomical education. A randomized, two-period crossover study was conducted from July to December 2018, at the University Hospital of Erlangen, Germany to compare CR and conventional computed tomography (CT) imaging for speed and comprehension of anatomy. Sixteen students were randomized into two assessment sequences. During each assessment period, participants had to answer 15 anatomy-related questions that were divided into three categories: parenchymal, musculoskeletal, and vascular anatomy. After a washout period of 14 days, assessments were crossed over to the respective second reconstruction technique. The mean interperiod differences for the time to answer differed significantly between the CR-CT sequence (-204.21 ± 156.0 seconds) and the CT-CR sequence (243.33 ± 113.83 seconds; P < 0.001). Overall time reduction by CR was 65.56%. Cinematic Rendering visualization of musculoskeletal and vascular anatomy was higher rated compared to CT visualization (P < 0.001 and P = 0.003), whereas CT visualization of parenchymal anatomy received a higher scoring than CR visualization (P < 0.001). No carryover effects were observed. A questionnaire revealed that students consider CR to be beneficial for medical education. These results suggest that CR has a potential to enhance knowledge acquisition and transfer from medical imaging data in medical education.

The 'Cauliflower Heart': a case report of congenital bi-atrial aneurysms causing non-controllable arrhythmia

Background

Congenital aneurysms of the atrium are very rare malformations. Known complications are therapy-resistant arrhythmias. Different treatments such as medical therapy, electrophysiological ablation, and surgery have been proposed. However, there are no guidelines on treatment.

Case summary

We describe the case of a neonate with bi-atrial aneurysms causing atrial arrhythmia. Arrhythmia was first observed in the 28th week of gestation. Maternal digoxin treatment did not show any effect. After birth, bi-atrial aneurysms were diagnosed and determined as the probable cause of the atrial tachycardia and later of atrial flutter. Antiarrhythmic drug treatment was initiated. However, only frequency control could be achieved. At the age of 7 months, the patient underwent surgical resection. Since surgery, sinus rhythm is present.

Conclusion

Atrial aneurysms are rare malformations, known complications are atrial arrhythmia. If medical treatment fails, surgery correction appears to be indicated going along with low operative risk and a high probability of successful termination of arrhythmia.

Updates in Vascular Computed Tomography

Computed tomography angiography (CTA) has become a mainstay for the imaging of vascular diseases, because of high accuracy, availability, and rapid turnaround time. High-quality CTA images can now be routinely obtained with high isotropic spatial resolution and temporal resolution. Advances in CTA have focused on improving the image quality, increasing the acquisition speed, eliminating artifacts, and reducing the doses of radiation and iodinated contrast media. Dual-energy computed tomography provides material composition capabilities that can be used for characterizing lesions, optimizing contrast, decreasing artifact, and reducing radiation dose. Deep learning techniques can be used for classification, segmentation, quantification, and image enhancement.