ABSTRACT
PURPOSE: The retroperitoneal nature of the pancreas, marked by minimal intraoperative organ shifts and deformations, makes augmented reality (AR)-based systems highly promising for pancreatic surgery. This study presents preliminary data from a prospective study aiming to develop the first wearable AR assistance system, ARAS, for pancreatic surgery and evaluating its usability, accuracy, and effectiveness in enhancing the perioperative outcomes of patients. METHODS: We developed ARAS as a two-phase system for a wearable AR device to aid surgeons in planning and operation. This system was used to visualize and register patient-specific 3D anatomical models during the surgery. The location and precision of the registered 3D anatomy were evaluated by assessing the arterial pulse and employing Doppler and duplex ultrasonography. The usability, accuracy, and effectiveness of ARAS were assessed using a five-point Likert scale questionnaire. RESULTS: Perioperative outcomes of five patients underwent various pancreatic resections with ARAS are presented. Surgeons rated ARAS as excellent for preoperative planning. All structures were accurately identified without any noteworthy errors. Only tumor identification decreased after the preparation phase, especially in patients who underwent pancreaticoduodenectomy because of the extensive mobilization of peripancreatic structures. No perioperative complications related to ARAS were observed. CONCLUSIONS: ARAS shows promise in enhancing surgical precision during pancreatic procedures. Its efficacy in preoperative planning and intraoperative vascular identification positions it as a valuable tool for pancreatic surgery and a potential educational resource for future surgical residents.
ABSTRACT
Monitoring disease progression is particularly important for determining the optimal treatment strategy in patients with liver disease. Especially for patients with diseases that have a reversible course, there is a lack of suitable tools for monitoring liver function. The development and establishment of such tools is very important, especially in view of the expected increase in such diseases in the future. Image-based liver function parameters, such as the T1 relaxometry-based MELIF score, are ideally suited for this purpose. The determination of this new liver function score is fully automated by software developed with AI technology. In this study, the MELIF score is compared with the widely used ALBI score. The ALBI score was used as a benchmark, as it has been shown to better capture the progression of less severe liver disease than the MELD and ChildâPugh scores. In this study, we retrospectively determined the ALBI and MELIF scores for 150 patients, compared these scores with the corresponding MELD and ChildâPugh scores (Pearson correlation), and examined the ability of these scores to discriminate between good and impaired liver function (AUC: MELIF 0.8; ALBI 0.77) and to distinguish between patients with and without cirrhosis (AUC: MELIF 0.83, ALBI 0.79). The MELIF score performed more favourably than the ALBI score and may also be suitable for monitoring mild disease progression. Thus, the MELIF score is promising for closing the gap in the available early-stage liver disease monitoring tools (i.e., identification of liver disease at a potentially reversible stage before chronic liver disease develops).
Subject(s)
Contrast Media , Liver Diseases , Humans , Retrospective Studies , Liver Diseases/diagnostic imaging , Magnetic Resonance Imaging/methods , Disease ProgressionABSTRACT
Purpose: Image registration is the process of aligning images, and it is a fundamental task in medical image analysis. While many tasks in the field of image analysis, such as image segmentation, are handled almost entirely with deep learning and exceed the accuracy of conventional algorithms, currently available deformable image registration methods are often still conventional. Deep learning methods for medical image registration have recently reached the accuracy of conventional algorithms. However, they are often based on a weakly supervised learning scheme using multilabel image segmentations during training. The creation of such detailed annotations is very time-consuming. Approach: We propose a weakly supervised learning scheme for deformable image registration. By calculating the loss function based on only bounding box labels, we are able to train an image registration network for large displacement deformations without using densely labeled images. We evaluate our model on interpatient three-dimensional abdominal CT and MRI images. Results: The results show an improvement of â¼ 10 % (for CT images) and 20% (for MRI images) in comparison to the unsupervised method. When taking into account the reduced annotation effort, the performance also exceeds the performance of weakly supervised training using detailed image segmentations. Conclusion: We show that the performance of image registration methods can be enhanced with little annotation effort using our proposed method.
ABSTRACT
In the management of patients with chronic liver disease, the assessment of liver function is essential for treatment planning. Gd-EOB-DTPA-enhanced MRI allows for both the acquisition of anatomical information and regional liver function quantification. The objective of this study was to demonstrate and evaluate the diagnostic performance of two fully automatically generated imaging-based liver function scores that take the whole liver into account. T1 images from the native and hepatobiliary phases and the corresponding T1 maps from 195 patients were analyzed. A novel artificial-intelligence-based software prototype performed image segmentation and registration, calculated the reduction rate of the T1 relaxation time for the whole liver (rrT1liver) and used it to calculate a personalized liver function score, then generated a unified score-the MELIF score-by combining the liver function score with a patient-specific factor that included weight, height and liver volume. Both scores correlated strongly with the MELD score, which is used as a reference for global liver function. However, MELIF showed a stronger correlation than the rrT1liver score. This study demonstrated that the fully automated determination of total liver function, regionally resolved, using MR liver imaging is feasible, providing the opportunity to use the MELIF score as a diagnostic marker in future prospective studies.
ABSTRACT
Liver disease and hepatocellular carcinoma (HCC) have become a global health burden. For this reason, the determination of liver function plays a central role in the monitoring of patients with chronic liver disease or HCC. Furthermore, assessment of liver function is important, e.g., before surgery to prevent liver failure after hepatectomy or to monitor the course of treatment. Liver function and disease severity are usually assessed clinically based on clinical symptoms, biopsy, and blood parameters. These are rather static tests that reflect the current state of the liver without considering changes in liver function. With the development of liver-specific contrast agents for MRI, noninvasive dynamic determination of liver function based on signal intensity or using T1 relaxometry has become possible. The advantage of this imaging modality is that it provides additional information about the vascular structure, anatomy, and heterogeneous distribution of liver function. In this review, we summarized and discussed the results published in recent years on this technique. Indeed, recent data show that the T1 reduction rate seems to be the most appropriate value for determining liver function by MRI. Furthermore, attention has been paid to the development of automated tools for image analysis in order to uncover the steps necessary to obtain a complete process flow from image segmentation to image registration to image analysis. In conclusion, the published data show that liver function values obtained from contrast-enhanced MRI images correlate significantly with the global liver function parameters, making it possible to obtain both functional and anatomic information with a single modality.
ABSTRACT
We describe scripting facilities to create medical animations for intervention planning based on medical volume data and derived segmentation information. A data independent scripting language has been developed to separate animation scripts from imaging data. The scripting facilities are adaptive and allow to reuse one script to create animations for many different patients. With expressive animations, we support the individual planning process, the preoperative documentation as well as discussions between medical doctors, for example in a tumor board. We also discuss the enhancement of interactive explorations with animations generated on the fly.