Evaluation of Virtual Reality for Detection of Lung Nodules on Computed Tomography.

Virtual reality (VR) systems can offer benefits of improved ergonomics, but their resolution may currently be limited for the detection of small features. For detection of lung nodules, we compared the performance of VR versus standard picture archiving and communication system (PACS) monitor. Four radiologists and 1 novice radiologist reviewed axial computed tomography (CTs) of the thorax using standard PACS monitors (SM) and a VR system (HTC Vive, HTC). In this study, 3 radiologists evaluated axial lung-window CT images of a Lungman phantom. One radiologist and the novice radiologist reviewed axial lung-window patient CT thoracic images (32 patients). This HIPAA-compliant study was approved by the institutional review board. Detection of 227 lung nodules on patient CTs did not result in different sensitivity with SM compared with VR. Detection of 23 simulated Lungman phantom lung nodules on CT with SM resulted in statistically greater sensitivity (78.3%) than with VR (52.2%, P = .041) for 1 of 3 radiologists. The trend was similar but not significant for the other radiologists. There was no significant difference in the time spent by readers reviewing CT images with VR versus SM. These findings indicate that performance of a commercially available VR system for detection of lung nodules may be similar to traditional radiology monitors for assessment of small lung nodules on CTs of the thorax for most radiologists. These results, along with the potential of improving ergonomics for radiologists, are promising for the future development of VR in diagnostic radiology.

The Corticospinal Reserve Capacity: Reorganization of Motor Area and Excitability As a Novel Pathophysiological Concept in Cervical Myelopathy.

BACKGROUND: In degenerative cervical myelopathy (DCM), the dynamics of disease progression and the outcome after surgical decompression vary interindividually and do not necessarily correlate with radiological findings. OBJECTIVE: To improve diagnostic power in DCM by better characterization of the underlying pathophysiology using navigated transcranial magnetic stimulation (nTMS). METHODS: Eighteen patients with DCM due to cervical spinal canal stenosis were examined preoperatively with nTMS. On the basis of the initial Japanese Orthopedic Association (JOA) Score, 2 patient groups were established (JOA ≤12/>12). We determined the resting motor threshold, recruitment curve, cortical silent period, and motor area. Accordingly, 8 healthy subjects were examined. RESULTS: Although the resting motor threshold was comparable in both groups (P = .578), the corticospinal excitability estimated by the recruitment curve was reduced in patients (P = .022). In patients with only mild symptoms (JOA > 12), a compensatory higher activation of non-primary motor areas was detected (P < .005). In contrast, patients with severe impairment (JOA ≤ 12) showed a higher cortical inhibition (P < .05) and reduced cortical motor area (P < .05) revealing a functional restriction on the cortical level. CONCLUSION: Based on these results, we propose a new concept for functional compensation for DCM on the cortical and spinal level, ie corticospinal reserve capacity. nTMS is a useful tool to noninvasively characterize the pattern of functional impairment and compensatory reorganization in patients suffering from DCM. The change in nTMS parameters might serve as a valuable prognostic factor in these patients in the future.