Assessment of resectability of pancreatic cancer using novel immersive high-performance virtual reality rendering of abdominal computed tomography and magnetic resonance imaging.

PURPOSE: Virtual reality (VR) allows for an immersive and interactive analysis of imaging data such as computed tomography (CT) and magnetic resonance imaging (MRI). The aim of this study is to assess the comprehensibility of VR anatomy and its value in assessing resectability of pancreatic ductal adenocarcinoma (PDAC). METHODS: This study assesses exposure to VR anatomy and evaluates the potential role of VR in assessing resectability of PDAC. Firstly, volumetric abdominal CT and MRI data were displayed in an immersive VR environment. Volunteering physicians were asked to identify anatomical landmarks in VR. In the second stage, experienced clinicians were asked to identify vascular involvement in a total of 12 CT and MRI scans displaying PDAC (2 resectable, 2 borderline resectable, and 2 locally advanced tumours per modality). Results were compared to 2D standard PACS viewing. RESULTS: In VR visualisation of CT and MRI, the abdominal anatomical landmarks were recognised by all participants except the pancreas (30/34) in VR CT and the splenic (31/34) and common hepatic artery (18/34) in VR MRI, respectively. In VR CT, resectable, borderline resectable, and locally advanced PDAC were correctly identified in 22/24, 20/24 and 19/24 scans, respectively. Whereas, in VR MRI, resectable, borderline resectable, and locally advanced PDAC were correctly identified in 19/24, 19/24 and 21/24 scans, respectively. Interobserver agreement as measured by Fleiss κ was 0.7 for CT and 0.4 for MRI, respectively (p < 0.001). Scans were significantly assessed more accurately in VR CT than standard 2D PACS CT, with a median of 5.5 (IQR 4.75-6) and a median of 3 (IQR 2-3) correctly assessed out of 6 scans (p < 0.001). CONCLUSION: VR enhanced visualisation of abdominal CT and MRI scan data provides intuitive handling and understanding of anatomy and might allow for more accurate staging of PDAC and could thus become a valuable adjunct in PDAC resectability assessment in the future.

Reversible skeletal disease and high fluoride serum levels in hematologic patients receiving voriconazole.

We here investigate the occurrence of fluoride intake-associated alterations in patients with hematologic disease on triazol antifungal medication. Clinical, laboratory, and radiology data of overall 43 patients with hematologic malignancies taking voriconazole (n = 20), posaconazole (n = 8), and itraconazole (n = 4), and a hematologic patient control group (n = 11) are described. Bone pain and radiologic evidence of periostitis were exclusively observed in patients receiving long-term voriconazole. Cessation of treatment led to clinical improvement in all cases. In line with clinical evidence, fluoride serum concentration was elevated in patients receiving voriconazole (median, 156.5 µg/L; interquartile range, 96.8 µg/L; normal < 30 µg/L) but not in the other treatment groups (P < .001 for all comparisons vs voriconazole). We conclude that serum fluoride levels were elevated on average 5-fold above normal levels in hematologic patients receiving voriconazole. Clinically relevant skeletal disease was associated with renal insufficiency and above 10-fold elevated fluoride levels, and was reversible on termination of voriconazole treatment.

Neural activation associated with corrective saccades during tasks with fixation, pursuit and saccades.

Corrective saccades are small eye movements that redirect gaze whenever the actual eye position differs from the desired eye position. In contrast to various forms of saccades including pro-saccades, recentering-saccades or memory guided saccades, corrective saccades have been widely neglected so far. The fMRI correlates of corrective saccades were studied that spontaneously occurred during fixation, pursuit or saccadic tasks. Eyetracking was performed during the fMRI data acquisition with a fiber-optic device. Using a combined block and event-related design, we isolated the cortical activations associated with visually guided fixation, pursuit or saccadic tasks and compared these to the activation associated with the occurrence of corrective saccades. Neuronal activations in anterior inferior cingulate, bilateral middle and inferior frontal gyri, bilateral insula and cerebellum are most likely specifically associated with corrective saccades. Additionally, overlapping activations with the established pro-saccade and, to a lesser extent, pursuit network were present. The presented results imply that corrective saccades represent a potential systematic confound in eye-movement studies, in particular because the frequency of spontaneously occurring corrective saccades significantly differed between fixation, pursuit and pro-saccades.