Cinematic rendering of pancreatic neoplasms: preliminary observations and opportunities

Spontaneous rupture of solid pseudopapillary neoplasm (SPN) of the Pancreas - imaging insights and review of the literature

Solid pseudopapillary neoplasm (SPN) of the pancreas, are rare low-grade malignant pancreatic tumors, most commonly occurring in young women during their second or third decade of life. They can present with vague abdominal symptoms like pain, discomfort, and nausea, or it can be incidentally discovered on imaging studies. There has been limited literature on ruptured SPN, which can be spontaneous or traumatic. In this paper, we present three cases of ruptured SPN, one traumatic and two spontaneous, to add to the scarcity of knowledge regarding this condition and its radiologic features, along with a detailed review of current literature.

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.

Cinematic rendering of solid pseudopapillary tumors: Augmenting diagnostics of an increasingly encountered tumor

Pancreatic solid pseudopapillary tumors (SPTs) are a rare subset of pancreatic neoplasms, accounting for under 2 % of exocrine pancreatic tumors. The incidence of SPTs has shown a significant increase in the past two decades, attributed to heightened cross-sectional imaging utilization. These tumors often present with nonspecific clinical symptoms, making imaging a crucial tool in their detection and diagnosis. Cinematic rendering (CR) is an advanced 3D post-processing technique that generates highly photorealistic realistic images by accurately modeling the interaction of light within the imaged volume. This allows improved visualization of anatomic structures which holds potential to improve diagnostics. In this manuscript we present the first description of CR appearances of SPTs in the reported literature. Through showcasing a range of cases, we highlight the potential of CR in illustrating the diverse imaging characteristics of these unique neoplasms.

Three-dimensional CT cinematic rendering of adrenal masses: Role in tumor analysis and management

The adrenal gland is home to an array of complex physiological and neoplastic disease processes. While dedicated adrenal computed tomography (CT) is the gold standard imaging modality for adrenal lesions, there exists significant overlap among imaging features of adrenal pathology. This can often make radiological diagnosis and subsequent determination of the optimal surgical approach challenging. Cinematic rendering (CR) is a novel CT post-processing technique that utilizes advanced light modeling to generate highly photorealistic anatomic visualization. This generates unique prospects in the evaluation of adrenal masses. As one of the first large tertiary care centers to incorporate CR into routine diagnostic workup, our preliminary experience with using CR has been positive, and we have found CR to be a valuable adjunct during surgical planning. Herein, we highlight the unique utility of CR techniques in the workup of adrenal lesions and provide commentary on the opportunities and obstacles associated with the application of this novel display method in this setting.

Concepts and techniques for revascularization of replaced hepatic arteries in pancreatic head resections

BACKGROUND

The relationship of pancreatic ductal adenocarcinoma (PDAC) to important peripancreatic vasculature dictates resectability. As per the current guidelines, tumors with extensive, unreconstructible venous or arterial involvement are staged as unresectable locally advanced pancreatic cancer (LAPC). The introduction of effective multiagent chemotherapy and development of surgical techniques, have renewed interest in local control of PDAC. High-volume centers have demonstrated safe resection of short-segment encasement of the common hepatic artery. Knowledge of the unique anatomy of the patient's vasculature is important in surgical planning of these complex resections. Hepatic artery anomalies are common and insufficient knowledge can result in iatrogenic vascular injury during surgery.

METHODS AND RESULTS

Here, we discuss different strategies to resect and reconstruct replaced hepatic arteries during pancreatectomy for PDAC to ensure restoration of adequate blood flow to the liver. Strategies include various arterial transpositions, in-situ interposition grafts and the use of extra-anatomic jump grafts.

CONCLUSION

These surgical techniques allow more patients to undergo the only available curative treatment currently available for PDAC. Moreover, these improvements in surgical techniques highlight the shortcoming of current resectability criteria, which rely mainly on local tumor involvement and technical resectability, and disregards tumor biology.

A review study on early detection of pancreatic ductal adenocarcinoma using artificial intelligence assisted diagnostic methods

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, chemo-refractory and recalcitrant cancer and increases the number of deaths. With just around 1 in 4 individuals having respectable tumours, PDAC is frequently discovered when it is in an advanced stage. Accordingly, ED of PDAC improves patient survival. Subsequently, this paper reviews the early detection of PDAC, initially, the work presented an overview of PDAC. Subsequently, it reviews the molecular biology of pancreatic cancer and the development of molecular biomarkers are represented. This article illustrates the importance of identifying PDCA, the Immune Microenvironment of Pancreatic Cancer. Consequently, in this review, traditional and non-traditional imaging techniques are elucidated, traditional and non-traditional methods like endoscopic ultrasound, Multidetector CT, CT texture analysis, PET-CT, magnetic resonance imaging, diffusion-weighted imaging, secondary signs of pancreatic cancer, and molecular imaging. The use of artificial intelligence in pancreatic cancer, novel MRI techniques, and the future directions of AI for PDAC detection and prognosis is then described. Additionally, the research problem definition and motivation, current trends and developments, state of art of survey, and objective of the research are demonstrated in the review. Consequently, this review concluded that Artificial Intelligence Assisted Diagnostic Methods with MRI images can be proposed in future to improve the specificity and the sensitivity of the work, and to classify malignant PDAC with greater accuracy.

3D and cinematic rendering of abdominopelvic pathology in the peripartum period

3D with volume rendering and the more recently described technique of cinematic rendering are post-processing techniques that create reconstructions of cross sectional imaging data which enhance image interpretation. This review illustrates the potential applications of volume rendering, 3D, and cinematic rendering in the evaluation of abdominopelvic pathology in the peripartum period. These techniques show promise in improving visualization of pelvic structures, vascular mapping, highlighting textural differences between tissues, and improving understanding of spatial relationships.

Cinematic Rendering: Novel Tool for Improving Pancreatic Cancer Surgical Planning

Pancreatic ductal adenocarcinoma is the third-leading cause of all cancer-related deaths in the US. While 20% of patients have resectable disease at diagnosis, improved control of systemic disease using effective chemotherapeutic regimens allows for aggressive operations involving complex vascular resection and reconstruction. A pancreas protocol computed tomography (PPCT) is the gold standard imaging modality in determining local resectability (degree of tumor-vessel involvement), however, it is limited by the inter-operator variability. While post-processing-3D-rendering helps, it does not allow for real-time dynamic assessment of resectability. A recent development in post-process-rendering called cinematic rendering (CR) overcomes this by utilizing advanced light modeling to generate photorealistic 3D images with enhanced details. Cinematic rendering allows for nuanced visualization of areas of interest. Our preliminary experience, as one of the first centers to incorporate the routine use of CR, has proven very useful in surgical planning. For local determination of resectability, vascular mapping allows for accurate assessment of major arteries and the portovenous system. For the portovenous anatomy it assists in determining the optimal surgical approach (extent of resection, appropriate technique for reconstruction, and need for mesocaval shunting). For arterial anatomy, vessel encasement either represents dissectible involvement via periadventitial dissection or true vessel invasion that is unresectable. CR could potentially provide superior ability than traditional PPCT to discern between the two. Additionally, CR allows for better 3D visualization of arterial anatomic variants which, if not appreciated preoperatively, increases risk of intraoperative ischemia and postoperative complications. Lastly, CR could help avoid unnecessary surgery by enhanced identification of occult metastatic disease that is metastatic disease that is otherwise not appreciated on a standard PPCT.

Clinical application of cinematic rendering in maxillofacial fractures

The purpose of this study was to evaluate the clinical application of cinematically rendered reconstructions of maxillofacial fractures. Ten surgeons and eight radiologists were shown three-dimensional images of 25 different patient cases, generated using both the volume rendering (VR) technique and the cinematic rendering (CR) technique. They were asked to mark the site of the fracture on the three-dimensional images and record the time this activity took. The effectiveness of the reconstructions to communicate with patients was assessed through the opinions of the surgeons and radiologists, as well as 25 patients. Subjective evaluations of the clinical value of the images were performed by the 18 surgeons and radiologists using a 10-item questionnaire. The percentages of correctly identified fractures of the nasal bone (P = 0.034), fracture dislocation (P < 0.001), and free bone fragments (P < 0.001) were significantly higher for CR images when compared to VR images, and identification took an average of 20.81 seconds for CR and 27.48 seconds for VR (P < 0.001). CR images were found to be more beneficial for communication with patients and scored higher for the display of fracture dislocation and free bone fragments than VR images (P < 0.05). CR images were found to have high clinical value in the visualization of maxillofacial fractures.

The Impact of the COVID-19 Pandemic on Multidisciplinary Clinics: A High-Volume Pancreatic Cancer Center Experience

The unprecedented impact of the Sars-CoV-2 pandemic (COVID-19) has strained the healthcare system worldwide. The impact is even more profound on diseases requiring timely complex multidisciplinary care such as pancreatic cancer. Multidisciplinary care teams have been affected significantly in multiple ways as healthcare teams collectively acclimate to significant space limitations and shortages of personnel and supplies. As a result, many patients are now receiving suboptimal remote imaging for diagnosis, staging, and surgical planning for pancreatic cancer. In addition, the lack of face-to-face interactions between the physician and patient and between multidisciplinary teams has challenged patient safety, research investigations, and house staff education. In this study, we discuss how the COVID-19 pandemic has transformed our high-volume pancreatic multidisciplinary clinic, the unique challenges faced, as well as the potential benefits that have arisen out of this situation. We also reflect on its implications for the future during and beyond the pandemic as we anticipate a hybrid model that includes a component of virtual multidisciplinary clinics as a means to provide accessible world-class healthcare for patients who require complex oncologic management.

Borderline Resectable and Locally Advanced Pancreatic Cancers: A Review of Definitions, Diagnostics, Strategies for Treatment, and Future Directions

ABSTRACT

Locally advanced and borderline resectable pancreatic cancers are being increasingly recognized as a result of significant improvements in imaging modalities. The main tools used in diagnosis of these tumors include endoscopic ultrasound, computed tomography, magnetic resonance imaging, and diagnostic laparoscopy. The definition of what constitutes a locally advanced or borderline resectable tumor is still controversial to this day. Borderline resectable tumors have been treated with neoadjuvant therapy approaches that aim at reducing tumor size, thus improving the chances of an R0 resection. Both chemotherapy and radiotherapy (solo or in combination) have been used in this setting. The main chemotherapy agents that have shown to increase resectability and survival are FOLFORINOX (a combination of folinic acid, fluorouracil, irinotecan, and oxaliplatin) and gemcitabine-nab-paclitaxel. Surgery on these tumors remains a significantly challenging task for pancreatic surgeons. More studies are needed to determine the best agents to be used in the neoadjuvant and adjuvant settings, biologic markers for prognostic and operative predictions, and validation of previously published retrospective results.

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 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.

Periadventitial dissection of the superior mesenteric artery for locally advanced pancreatic cancer: Surgical planning with the "halo sign" and "string sign"

Most patients diagnosed with pancreatic cancer are classified as nonoperative candidates based on the contemporary guidelines of resectability. The advent of more potent control of systemic disease using neoadjuvant chemotherapy has enabled more aggressive operative interventions. In our multidisciplinary practice, patients with Stage III, locally advanced pancreatic cancer and superior mesenteric artery (SMA) encasement are now carefully triaged with high quality, preoperative imaging to determine if they can be considered candidates for operative resection with periadventitial dissection of the SMA. Patients displaying a "halo sign," where the encased SMA remains fully patent and free from arterial invasion, are now candidates for SMA periadventitial dissection. This procedure involves the surgical stripping of the infiltrated neurolymphatic tissue off the SMA leaving behind a bare "skeletonized artery." Alternatively, the "string sign" involving the SMA confers a more likely case of arterial invasion, where a complete oncologic resection cannot be achieved successfully. This method of patient selection in case of SMA involvement abandons the traditional metrics of circumferential degrees of the arterial encasement to guide surgical decisions. Our institutional approach has allowed us to meaningfully expand our operative methods of resection with the potential for improved longitudinal outcomes to pancreatic cancer patients who were deprived historically from the more effective and possibly curative treatment.

Mesoportal bypass, interposition graft, and mesocaval shunt: Surgical strategies to overcome superior mesenteric vein involvement in pancreatic cancer

BACKGROUND

In pancreatic cancer, extensive tumor involvement of the mesenteric venous system poses formidable challenges to operative resection. Such involvement can result from cavernous collateral veins leading to increased intraoperative blood loss or long-segment vascular defects of not only just the superior mesenteric vein but also even jejunal/ileal branches. Strategies to facilitate margin-free resection and safe vascular reconstruction in pancreatic surgery are important, particularly because systemic control of the tumor is improving with multi-agent chemotherapy regimens.

METHODS

We describe a systematic, multidisciplinary assessment for patients with pancreatic cancer that involves the superior mesenteric vein, as well as the preoperative planning of those undergoing operative resection. In addition, detailed descriptions of operative approaches and technical strategies, which evolved with increasing experience at a high-volume center, are presented.

RESULTS

For the preoperative evaluation of tumor-free, vascular locations for potential reconstruction and collateralization, computed tomographic imaging with high-resolution of vascular structures (used with 3-dimensional or cinematic rendering) allows a precise calibration of radiographic data with intraoperative findings. From an operative perspective, we identified 5 potential strategies to consider for resection: collateral preservation, mesoportal bypass (preresection), mesoportal interposition graft (postresection), mesocaval shunt, and various combinations of these strategies. Many of these techniques use interposition grafts, making it essential to assess autologous veins (preferred conduit for reconstruction) or to prepare cryopreserved vascular allografts (an alternative conduit, which must be thawed and should be matched for size and blood type).

CONCLUSION

Herein we share operative strategies to overcome involvement of the superior mesenteric vein in pancreatic cancer. Improvements in preoperative planning and operative technique can address common barriers to resection with curative intent.

Multidisciplinary standards of care and recent progress in pancreatic ductal adenocarcinoma

Despite tremendous gains in the molecular understanding of exocrine pancreatic cancer, the prognosis for this disease remains very poor, largely because of delayed disease detection and limited effectiveness of systemic therapies. Both incidence rates and mortality rates for pancreatic cancer have increased during the past decade, in contrast to most other solid tumor types. Recent improvements in multimodality care have substantially improved overall survival, local control, and metastasis-free survival for patients who have localized tumors that are amenable to surgical resection. The widening gap in prognosis between patients with resectable and unresectable or metastatic disease reinforces the importance of detecting pancreatic cancer sooner to improve outcomes. Furthermore, the developing use of therapies that target tumor-specific molecular vulnerabilities may offer improved disease control for patients with advanced disease. Finally, the substantial morbidity associated with pancreatic cancer, including wasting, fatigue, and pain, remains an under-addressed component of this disease, which powerfully affects quality of life and limits tolerance to aggressive therapies. In this article, the authors review the current multidisciplinary standards of care in pancreatic cancer with a focus on emerging concepts in pancreatic cancer detection, precision therapy, and survivorship.

Pancreatic Cancer Imaging: A New Look at an Old Problem

Computed tomography is the most commonly used imaging modality to detect and stage pancreatic cancer. Previous advances in pancreatic cancer imaging have focused on optimizing image acquisition parameters and reporting standards. However, current state-of-the-art imaging approaches still misdiagnose some potentially curable pancreatic cancers and do not provide prognostic information or inform optimal management strategies beyond stage. Several recent developments in pancreatic cancer imaging, including artificial intelligence and advanced visualization techniques, are rapidly changing the field. The purpose of this article is to review how these recent advances have the potential to revolutionize pancreatic cancer imaging.

Prediagnostic Image Data, Artificial Intelligence, and Pancreatic Cancer: A Tell-Tale Sign to Early Detection

Pancreatic cancer continues to be one of the deadliest malignancies and is the third leading cause of cancer-related mortality in the United States. Based on several models, it is projected to become the second leading cause of cancer-related deaths by 2030. Although the overall survival rate for patients diagnosed with pancreatic cancer is less than 10%, survival rates are increasing in those whose cancers are detected at an early stage, when intervention is possible. There are, however, no reliable biomarkers or imaging technology that can detect early-stage pancreatic cancer or accurately identify precursors that are likely to progress to malignancy. The Alliance of Pancreatic Cancer Consortia, a virtual consortium of researchers, clinicians, and advocacies focused on early diagnosis of pancreatic cancer, was formed in 2016 to provide a platform and resources to discover and validate biomarkers and imaging methods for early detection. The focus of discussion at the most recent alliance meeting was on imaging methods and the use of artificial intelligence for early detection of pancreatic cancer.

Comparison of Cinematic Rendering and Computed Tomography for Speed and Comprehension of Surgical Anatomy

Question

Does the use of cinematic rendering improve the comprehension of the surgical anatomy?

Findings

In this German preclinical randomized crossover study, visualization with cinematic rendering allowed a more correct and faster comprehension of the surgical anatomy compared with conventional computed tomography independent of the level of surgical experience.

Meaning

Cinematic rendering is a tool that may assist general surgeons with preoperative preparation and intraoperative guidance through an improved interpretation of computed tomography imaging data.

Importance

Three-dimensional (3-D) volume rendering has been shown to improve visualization in general surgery. Cinematic rendering (CR), a novel 3-D visualization technology for postprocessing of computed tomographaphy (CT) images, provides photorealistic images with the potential to improve visualization of anatomic details.

Objective

To determine the value of CR for the comprehension of the surgical anatomy.

Design, Setting, and Participants

This preclinical, randomized, 2-sequence crossover study was conducted from February to November 1, 2018, at University Hospital of Erlangen, Germany. The 40 patient cases were evaluated by 18 resident and attending surgeons using a prepared set of CT and CR images. The patient cases were randomized to 2 assessment sequences (CR-CT and CT-CR). During each assessment period, participants answered 1 question per case that addressed crucial issues of anatomic understanding, preoperative planning, and intraoperative strategies. After a washout period of 2 weeks, case evaluations were crossed over to the respective second image modality.

Main Outcomes and Measures

The primary outcome measure was the correctness of answers. Secondary outcome was the time needed to answer.

Results

The mean (SD) interperiod differences for the percentage of correct answers in the CR-CT sequence (8.5% [7.0%]) differed significantly from those in the CT-CR sequence (−13.1% [6.3%]) (P < .001). The mean (SD) interperiod differences for the time spent to answer the questions in the CR-CT sequence (−18.3 [76.9] seconds) also differed significantly from those in the CT-CR sequence (52.4 [88.5] seconds) (P < .001). Subgroup analysis revealed that residents as well as attending physicians benefitted from CR visualization. Analysis of the case assessment questionnaire showed that CR added significant value to the comprehension of the surgical anatomy (overall mean [SD] score, 4.53 [0.75]). No carryover or period effects were observed.

Conclusions and Relevance

The visualization with CR allowed a more correct and faster comprehension of the surgical anatomy compared with conventional CT imaging, independent of level of surgeon experience. Therefore, CR may assist general surgeons with preoperative preparation and intraoperative guidance.

Initial experience with 3D CT cinematic rendering of acute pancreatitis and associated complications

Inflammation of the pancreas can present with a wide range of imaging findings from mild enlargement of the gland and surrounding infiltrative fat stranding through extensive glandular necrosis. Complications of pancreatitis are varied and include infected fluid collections, pseudocysts, and vascular findings such as pseudoaneurysms and thromboses. Cross-sectional imaging with computed tomography (CT) is one of the mainstays of evaluating patients with pancreatitis. New methods that allow novel visualization volumetric CT data may improve diagnostic yield for the detection of findings that provide prognostic information in pancreatitis patients or can drive new avenues of research such as machine learning. Cinematic rendering (CR) is a photorealistic visualization method for volumetric imaging data that are being investigated for a variety of potential applications including the life-like display of complex anatomy and visual characterization of mass lesions. In this review, we describe the CR appearance of different types of pancreatitis and complications of pancreatitis. We also note possible future directions for research into the utility of CR for pancreatitis.

Pitfalls in the MDCT of pancreatic cancer: strategies for minimizing errors

Multidetector computed tomography (MDCT) is a widely used cross-sectional imaging modality for initial evaluation of patients with suspected pancreatic ductal adenocarcinoma (PDAC). However, diagnosis of PDAC can be challenging due to numerous pitfalls associated with image acquisition and interpretation, including technical factors, imaging features, and cognitive errors. Accurate diagnosis requires familiarity with these pitfalls, as these can be minimized using systematic strategies. Suboptimal acquisition protocols and other technical errors such as motion artifacts and incomplete anatomical coverage increase the risk of misdiagnosis. Interpretation of images can be challenging due to intrinsic tumor features (including small and isoenhancing masses, exophytic masses, subtle pancreatic duct irregularities, and diffuse tumor infiltration), presence of coexisting pathology (including chronic pancreatitis and intraductal papillary mucinous neoplasm), mimickers of PDAC (including focal fatty infiltration and focal pancreatitis), distracting findings, and satisfaction of search. Awareness of pitfalls associated with the diagnosis of PDAC along with the strategies to avoid them will help radiologists to minimize technical and interpretation errors. Cognizance and mitigation of these errors can lead to earlier PDAC diagnosis and ultimately improve patient prognosis.

3D CT cinematic rendering of the spleen: Potential role in problem solving

Cinematic rendering (CR) is a new 3D visualization methodology for volumetric diagnostic imaging including computed tomography (CT) datasets composed of isotropic voxels. CR produces photorealistic images with enhanced detail relative to other 3D visualization methods and realistic shadowing. In this review, we provide a number of examples of splenic pathology visualized with CR including conditions affecting the splenic vasculature, neoplasms, and accessory spleens. These examples are compared to 2D CT and traditional 3D CT techniques and the potential advantages of CR are highlighted. CR displays textural changes in the splenic parenchyma to particular advantage, and a portion of this review will be devoted to examples of how textural features can help distinguish intrapancreatic accessory spleens from neuroendocrine tumors.

CT cinematic rendering for pelvic primary tumor photorealistic visualization

Pelvic tumors can be both complicated and challenging, and computed tomography (CT) has played an important role in the diagnosis and treatment planning of these conditions. Cinematic rendering (CR) is a new method of 3D imaging using CT volumetric data. Unlike traditional 3D methods, CR uses the global illumination model to produce high-definition surface details and shadow effects to generate photorealistic images. In this pictorial review, a series of primary pelvic tumor cases are presented to demonstrate the potential value of CR relative to conventional volume rendering (VR). This technique holds great potential in disease diagnosis, preoperative planning, medical education and patient communication.

CT of ovarian cancer: 3D cinematic rendering for preoperative evaluation

Background

Ovarian cancer is the second most common gynecologic malignancy. As the primary imaging modality, computed tomography (CT) can provide staging information for preoperative planning and determination of surgical resectability. As a new three-dimensional postprocessing tool for CT images, cinematic rendering (CR) has the potential to depict anatomic details accurately.

Case presentation

(Case 1) A 44-year-old married woman was diagnosed with recurrent ovarian cancer. CT images indicated the recurrent nodules and masses in the pelvic cavity and the upper middle abdominal peritoneum. The CR image showed that the multiple metastatic lesions and lymph nodes could not be completely removed by reoperation. The patient agreed to receive continued chemotherapy. (Case 2) A 51-year-old woman was admitted to our hospital due to abdominal distension and defecation that had increased for 6 months, with aggravation over the past 3 days. CT examination found cystic and solid masses in the bilateral ovarian area. The CR image demonstrated that the ovarian mass violated the posterior wall of the bladder and the anterior rectal wall. The preoperational imaging evaluation ensured the safety of the operation.

Conclusion

CR could improve the visualization of ovarian cancer masses, metastatic lymph nodes, and peritoneal metastases. CR has a good clinical value and will be more helpful in the preoperational evaluation of ovarian cancer.

Deep learning with cinematic rendering: fine-tuning deep neural networks using photorealistic medical images

Deep learning has emerged as a powerful artificial intelligence tool to interpret medical images for a growing variety of applications. However, the paucity of medical imaging data with high-quality annotations that is necessary for training such methods ultimately limits their performance. Medical data is challenging to acquire due to privacy issues, shortage of experts available for annotation, limited representation of rare conditions and cost. This problem has previously been addressed by using synthetically generated data. However, networks trained on synthetic data often fail to generalize to real data. Cinematic rendering simulates the propagation and interaction of light passing through tissue models reconstructed from CT data, enabling the generation of photorealistic images. In this paper, we present one of the first applications of cinematic rendering in deep learning, in which we propose to fine-tune synthetic data-driven networks using cinematically rendered CT data for the task of monocular depth estimation in endoscopy. Our experiments demonstrate that: (a) convolutional neural networks (CNNs) trained on synthetic data and fine-tuned on photorealistic cinematically rendered data adapt better to real medical images and demonstrate more robust performance when compared to networks with no fine-tuning, (b) these fine-tuned networks require less training data to converge to an optimal solution, and (c) fine-tuning with data from a variety of photorealistic rendering conditions of the same scene prevents the network from learning patient-specific information and aids in generalizability of the model. Our empirical evaluation demonstrates that networks fine-tuned with cinematically rendered data predict depth with 56.87% less error for rendered endoscopy images and 27.49% less error for real porcine colon endoscopy images.