Statistical Morphology and Fragment Mapping of Complex Proximal Humeral Fractures.

Background and Objectives: Proximal humerus fractures (PHFs) are common in the elderly, but the treatment results are often poor. A clear understanding of fracture morphology and distribution of cortical bone loss is important for improved surgical decision making, operative considerations, and new implant designs. The aim of this study was to develop a 3D segmentation fracture mapping technique to create a statistical description of the spatial pattern and cortical bone loss of complex PHFs. Materials and Methods: Fifty clinical computed tomography (CT) scans of complex PHFs and their contralateral intact shoulders were collected. In-house software was developed for semi-automated segmentation and fracture line detection and was combined with manual fracture reduction to the contralateral template in a commercial software. A statistical mean model of these cases was built and used to describe probability maps of the fracture lines and cortical fragments. Results: The fracture lines predominantly passed through the surgical neck and between the tuberosities and tendon insertions. The superior aspects of the tuberosities were constant fragments where comminution was less likely. Some fracture lines passed through the bicipital sulcus, but predominantly at its edges and curving around the tuberosities proximally and distally. Conclusions: A comprehensive and systematic approach was developed for processing clinical CT images of complex fractures into fracture morphology and fragment probability maps and applied on PHFs. This information creates an important basis for better understanding of fracture morphology that could be utilized in future studies for surgical training and implant design.

Technical considerations and tips for using the Tegus remote proctoring system in elective and emergency cases and in webinars.

Smart angiography suites (SAS) refer to the incorporation of audio-video technology and internet connectivity into the angiography suite to enable bidirectional communication for teleproctoring. Remote streaming support (RESS) is intended to increase patient safety by supporting interventionalists with limited experience or who are practicing in geographically remote areas. The aim of this review is to describe real-life experience of the Tegus system and to share practical tips concerning its use and setup. We describe the platform itself, settings and integration in our angiography suite. We provide technical tips intended to help new and potential users to achieve an optimal experience for both neurointerventionalists and proctors. We describe both elective cases that we have performed with teleproctoring and emergencies. Lastly, we describe a different room setup and software solutions used in live workshops. Use of teleproctoring enabled involvement of proctors in cases where an already experienced interventionalist needed support in the decision-making process concerning the sizing and deployment of devices with which he was familiar only on a basic level. Excellent video feed quality and instant communication enabled optimal preparation and in vivo implantation of those devices without the need for physical proctors' presence. In emergency cases the system allowed a senior physician to offer support during cases where optimal device sizing is critical. Our usage concept of the rig permitted monitoring of thrombectomy cases by junior physicians. During webinars a remote streaming platform enabled us to conduct workshops that simulated an "on-site" experience as closely as possible during the COVID-19 pandemic.

Mechanical Thrombectomy in Acute Terminal Internal Carotid Artery Occlusions Using a Large Manually Expandable Stentretriever (Tiger XL Device): Multicenter Initial Experience.

BACKGROUND: The recently introduced Tigertriever XL Device for treatment of cerebral vessel occlusions combines manual adjustability and maximum length in one device. In this study, we report our initial experience with the Tigertriever XL in terminal ICA occlusions. METHODS: Retrospective multicenter analysis of acute terminal ICA occlusions treated by mechanical thrombectomy using the Tigertriever XL Device. RESULTS: 23 patients were treated using the Tigetriever XL due to an acute occlusion of the terminal ICA. The overall successful reperfusion rate after a median of two maneuvers using the Tigertriever XL Device was 78.3% (mTICI 2b-3). In 43.5% (10/23) additional smaller devices were applied to treat remaining occlusions in downstream territories, which resulted in a final successful reperfusion rate of 95.7%. Device related complications did not occur. Two symptomatic intracerebral hemorrhages (sICH) were observed. CONCLUSIONS: The Tigertriever XL Device might be a helpful tool in the treatment of ICA terminus occlusions with large clot burden resulting in high reperfusion rates. This is mainly related to the manual adjustability of the device combined with the maximum length.

Dose reduction in perfusion CT in stroke patients by lowering scan frequency does not affect automatically calculated infarct core volumes.

BACKGROUND AND PURPOSE: CT Perfusion technique (CTP) is a quantitative, easily performed, accepted and reliable method for detection of ischemic brain changes. Based on calculated parameters, the size of ischemic penumbra and irreversibly damaged infarct core can be determined which helps guide treatment decisions. However, due to the dynamic nature of the CTP study, it is dose intensive. This study determines the consequences of retrospectively reducing the number of scans in the dynamic acquisition by half on the volume of the automatically calculated infarct core (non-viable tissue) and penumbra (tissue at risk) volumes. Our hypothesis was that equivalent volumetric information could be obtained at a substantial dose savings. MATERIALS AND METHODS: Fifty one consecutive patients with occlusion of M1 and/or M2 segment of the middle cerebral artery and ischemic stroke proven by follow-up MRI were included. CTP scans were first analyzed in a standard fashion and automatically generated volumes measured in milliliters were recorded in a database. A second analysis was conducted after removing every second data acquisition from the sequential CTP scans. Automatic volume measurements were repeated, recorded and compared to the initial values obtained using the full dataset. RESULTS: The two CTP protocols were statistically equivalent pertaining to automatic infarct core volume calculation but a case-by-case analysis revealed substantial overestimation in some cases. CONCLUSION: Reduction of radiation exposure in CTP without objective loss of accuracy of automatically calculated infarct core volume is feasible but might lead to clinically relevant infarct core overestimation in individual cases.

Hematocrit and Serum Hemoglobin Do Not Influence Values in Computed Tomography Perfusion of Patients With Acute Ischemic Stroke.

OBJECTIVE: There is a correlation between both serum hemoglobin (HGB) and hematocrit (HCT) and attenuation values of vessels in noncontrast-enhanced computed tomography (NECT), which could influence calculated perfusion maps in CT perfusion. METHODS: We retrospectively included 45 patients, who presented with acute new neurological symptoms and underwent NECT and CT perfusion (128-row multi detector scanner, coverage: 6.9 cm craniocaudally; 80 kV; 200 mAs; temporal resolution: 2 seconds using 40 mL Ultravist 370 at a flow rate of 5 mL/s) on admission and a follow-up MRI within 1 week of admission. RESULTS: Hematocrit, HGB, and attenuation values did not differ between patients with stroke and controls. A statistically significant correlation was found between HCT and HGB and attenuation values in the internal carotid artery or middle cerebral artery on NECT (P < 0.05). No statistically significant correlation was observed between HCT and HGB and perfusion maps. CONCLUSIONS: Hematocrit and HGB do not influence calculated perfusion maps. There is no need for HCT/HGB-adjusted cerebral blood volume thresholds in stroke patients.

Radiographic diagnosis and differentiation of an aggressive angiomyxoma in a male patient.

Aggressive angiomyxoma is a rare soft-tissue tumor which usually occurs in female patients of reproductive age. Its occurrence in men is even more unusual and as illustrated in this case the difference between pathology suggested by a physical examination and its actual extent can be quite striking. We present a case report of an 81-year-old man with the typical MRI appearances of a pelvic aggressive angiomyxoma, describe imaging and histopathologic features of this rarely seen locally infiltrative neoplasm and also discuss therapeutic options for patients with an aggressive angiomyxoma.