Motion Compensated Unsupervised Deep Learning for 5D MRI

We propose an unsupervised deep learning algorithm for the motion-compensated reconstruction of 5D cardiac MRI data from 3D radial acquisitions. Ungated free-breathing 5D MRI simplifies the scan planning, improves patient comfort, and offers several clinical benefits over breath-held 2D exams, including isotropic spatial resolution and the ability to reslice the data to arbitrary views. However, the current reconstruction algorithms for 5D MRI take very long computational time, and their outcome is greatly dependent on the uniformity of the binning of the acquired data into different physiological phases. The proposed algorithm is a more data-efficient alternative to current motion-resolved reconstructions. This motion-compensated approach models the data in each cardiac/respiratory bin as Fourier samples of the deformed version of a 3D image template. The deformation maps are modeled by a convolutional neural network driven by the physiological phase information. The deformation maps and the template are then jointly estimated from the measured data. The cardiac and respiratory phases are estimated from 1D navigators using an auto-encoder. The proposed algorithm is validated on 5D bSSFP datasets acquired from two subjects.Comment: MICCAI 2023 conference pape

Complications of Recombinant Human BMP-2 for Treating Complex Tibial Plateau Fractures: A Preliminary Report

Bone morphogenic proteins (BMPs) are potent osteoinductive agents. Their use in fracture surgery is still being studied and the clinical indications are evolving. Heterotopic bone after BMP use in spine surgery is a known complication. While some literature describes the ability of BMP to enhance fracture healing, few articles describe complications of BMP. In tibial plateau fractures, after elevating the cartilage en mass, a subchondral void may be created in these fractures. Structural support provided by bone void-filling agents can be augmented with osteoinduction achieved by BMP. We asked whether heterotopic bone formation would occur more frequently with BMP-2 when used in tibial plateau fractures and whether BMP-2 enhanced the ability to maintain surgically restored subchondral bone integrity. Heterotopic bone developed more frequently in patients receiving BMP (10 of 17) than in patients not receiving BMP (one of 23). Four patients receiving BMP and no patients not receiving BMP underwent removal of heterotopic bone. Maintenance of subchondral bone integrity was similar without and with the use of BMP. BMP is a potent osteoinductive agent; however, when used for an off-label indication in periarticular situations, complications such as heterotopic bone are common and increase reoperation rates