Laboratory virtual instrument engineering workbench-based semi-automated measurement of cranial asymmetry
Jui-Ming Sun1, Chih-Ta Huang2, Cheng-Ta Hsieh3
1 Section of Neurosurgery, Department of Surgery, Ditmanson Medical Foundation, Chia-Yi Christian Hospital; Department of Biotechnology, Asia University, Taichung City, Taiwan
2 Division of Neurosurgery, Department of Surgery, Sijhih Cathay General Hospital; Department of Medicine, School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
3 Division of Neurosurgery, Department of Surgery, Sijhih Cathay General Hospital; Department of Medicine, School of Medicine, Fu Jen Catholic University, New Taipei City; Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
Division of Neurosurgery, Department of Surgery, Sijhih Cathay General Hospital, No. 2, Lane 59, Jiancheng Road, Xizhi District, New Taipei City 221
Source of Support: None, Conflict of Interest: None
Background: Cranial asymmetry has been associated with the laterality of neurological diseases including chronic subdural hematoma, subdural hygroma, and stroke. Although picture archiving and communication systems (PACS) are commonly used radiologic tools, simple angle or contoured area measurement cannot accurately reflect the actual severity of cranial asymmetry. Therefore, we developed an objective semi-automated image analysis tool based on the Laboratory Virtual Instrument Engineering Workbench (LabVIEW) system and compared its efficacy and variability with those of PACS in measuring cranial asymmetry.
Methods: This image analysis software was developed on the basis of the LabVIEW system. Three sizes of plastic water pipes and computed tomographic images of the brain from three patients were used for experimental and clinical validations, respectively. We compared the percent error of the calculated areas of the pipes as well as coefficient of variation (CV) and cranial index of symmetry (CIS) ratio obtained from LabVIEW and PACS.
Results: Experimental validation showed the overall mean difference of actual size versus estimated size obtained using PACS and LabVIEW-based image analysis to be 7.51% and 4.68%, respectively. This result indicated that LabVIEW-based image analysis provided an estimated area closer to that of the actual size of the phantom, with significantly low inter- and intraobserver variability (P < 0.001). Clinical validation also showed lower variability in the CVs and CIS ratios of areas estimated using LabVIEW-based image analysis, ranging from 0.01% to 0.13% and from 89.2% to 99.1%, respectively.
Conclusion: Our study demonstrated through experimental and clinical validation that LabVIEW-based image analysis is a convenient and effective method for investigating cranial asymmetry. This imaging tool can provide more clues in understanding cranial asymmetry.