Teleproctoring for Neurovascular Procedures: Demonstration of Concept Using Optical See-Through Head-Mounted Display, Interactive Mixed Reality, and Virtual Space Sharing-A Critical Need Highlighted by the COVID-19 Pandemic.

BACKGROUND AND PURPOSE: Physician training and onsite proctoring are critical for safely introducing new biomedical devices, a process that has been disrupted by the pandemic. A teleproctoring concept using optical see-through head-mounted displays with a proctor's ability to see and, more important, virtually interact in the operator's visual field is presented. MATERIALS AND METHODS: Test conditions were created for simulated proctoring using a bifurcation aneurysm flow model for WEB device deployment. The operator in the angiography suite wore a Magic Leap-1 optical see-through head-mounted display to livestream his or her FOV to a proctor's computer in an adjacent building. A Web-based application (Spatial) was used for the proctor to virtually interact in the operator's visual space. Tested elements included the quality of the livestream, communication, and the proctor's ability to interact in the operator's environment using mixed reality. A hotspot and a Wi-Fi-based network were tested. RESULTS: The operator successfully livestreamed the angiography room environment and his FOV of the monitor to the remotely located proctor. The proctor communicated and guided the operator through the procedure over the optical see-through head-mounted displays, a process that was repeated several times. The proctor used mixed reality and virtual space sharing to successfully project images, annotations, and data in the operator's FOV for highlighting any device or procedural aspects. The livestream latency was 0.71 (SD, 0.03) seconds for Wi-Fi and 0.86 (SD, 0.3) seconds for the hotspot (P = .02). The livestream quality was subjectively better over the Wi-Fi. CONCLUSIONS: New technologies using head-mounted displays and virtual space sharing could offer solutions applicable to remote proctoring in the neurointerventional space.

Spinal cord compression by tophaceous gout with fluorodeoxyglucose-positron-emission tomographic/MR fusion imaging.

A 36-year-old woman presented with lower extremity paralysis. Her past medical history included gout. Conventional radiography and MR imaging revealed bone erosion and soft tissue lesions of the thoracic spine. Fluorodeoxyglucose-positron-emission tomographic (FDG-PET) images revealed hypermetabolic lesions of the thoracic spine. A CT-guided biopsy was diagnostic for inflammatory tophaceous gout. This case describes the CT, MR, and FDG-PET imaging characteristics of acute inflammatory gout. FDG-PET imaging characteristics of this disorder have not been previously described.

Aggressive fibromatosis of the neck in a patient with Gardner's syndrome.

We report a patient with Gardner's syndrome who, in addition to a total colectomy, had multiple excisions of desmoid tumors in both thighs. He presented with left-sided neck swelling and pain. MRI was highly suggestive of desmoid tumors in multiple neck muscles. To our knowledge this is the first description of diffuse fibromatosis of the neck in association with Gardner's syndrome.

Persistence of gadolinium in CSF: a diagnostic pitfall in patients with end-stage renal disease.

Two dialysis-dependent patients with end-stage renal disease underwent brain and spine MR imaging a few days after having undergone gadolinium-enhanced imaging studies. Increased signal intensity in the subarachnoid space on T1-weighted and fluid-attenuated inversion recovery images was noted. Excretion of gadolinium into the CSF was proven in one case by mass spectrometry. Dialysis-dependent patients with end-stage renal disease and neurologic abnormalities often undergo contrast-enhanced MR imaging. Recognition that these patients may show increased signal intensity in the subarachnoid space because of gadolinium excretion into CSF may prevent diagnostic errors.

Malignant abdominal tumors in children.

The medical records of 53 patients between the ages of 1 and 18 years, with malignant abdominal tumors seen between 1987 and 1993 were reviewed. Wilms' tumor was the most common tumor constituting 28.3% of all cases. The others included Non- Hodgkin's lymphomas (20.8%), neuroblastomas (11.3%), rhabdomyosarcomas, germ cell tumors 9.4% each and a miscellaneous group. Majority of patients (60.3%) were under 5 years of age. The male to female ratio was 1:1. Among 15 patients with Wilms' tumor, majority (46.7%) had stage III tumors at presentation and all but one patient, were referred to our Hospital more than a month following initiation of their symptoms. In contrast, 5 out of 7 patients with Stage I and II tumors were seen within the first month of their symptoms. The commonly utilized techniques to aid diagnosis were ultrasonography and computerized tomography scan and the common treatment modality was a combination of surgery and chemotherapy. For Wilms' tumor, the mean follow-up was 1 year and nine months, the survival rate was 93.3% and there were no recurrences. With early diagnosis and multimodality treatment, the survival rates for childhood malignancies can be greatly improved.