Int J CARS DOI 10.1007/s11548-013-0816-8 ORIGINAL ARTICLE Percutaneous lung biopsy: comparison between an augmented reality CT navigation system and standard CT-guided technique R. F. Grasso · E. Faiella · G. Luppi · E. Schena · F. Giurazza · R. Del Vescovo · F. D’Agostino · R. L. Cazzato · B. Beomonte Zobel Received: 14 October 2012 / Accepted: 16 January 2013 © CARS 2013 Abstract Purpose Percutaneous lung biopsies (PLBs) performed for the evaluation of pulmonary masses require image guid- ance to avoid critical structures. A new CT navigation sys- tem (SIRIO, “Sistema robotizzato assistito per il puntamento intraoperatorio”) for PLBs was validated. Methods The local Institutional Review Board approved this retrospective study. Image-guided PLBs in 197 patients were performed with a CT navigation system (SIRIO). The pro- cedures were reviewed based on the number of CT scans, patients’ radiation exposure and procedural time recorded. Comparison was performed with a group of 72 patients undergoing standard CT-guided PLBs. Sensitivity, specificity and overall diagnostic accuracy were assessed in both groups. Results SIRIO-guided PLBs showed a significant reduction in procedure time, number of required CT scans and the radi- ation dose administered to patients ( p < 0.001). In terms of diagnostic accuracy, SIRIO proved to be more accurate for small-sized lesions (<20mm) than standard CT-guidance. Conclusion SIRIO proved to be a reliable and effective tool when performing CT-guided PLBs and was especially useful for sampling small (<20 mm) lesions. Keywords Optical tracking · CT scan · Lung biopsy · Virtual navigation guidance R. F. Grasso · E. Faiella · G. Luppi · F. Giurazza · R. Del Vescovo · F. D’Agostino · R. L. Cazzato (B ) · B. Beomonte Zobel Department of Radiology, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy e-mail: r.cazzato@unicampus.it E. Schena Department of Biomedical Engineering, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 200, 00128 Rome, Italy Introduction Percutaneous lung biopsy (PLB) using computed tomog- raphy (CT) or CT-fluoroscopy as a guiding system is a well-established technique to diagnose pulmonary lesions of unknown origin [1]. However, there are some concerns regarding both tech- niques. CT-guidance is limited by the high amount of radia- tion dose administered to patients and by the lack of real-time visualization. On the other hand, CT-fluoroscopy allows a real-time visualization even though it provides a high amount of radiation both to patients and to operators [1]. The recently introduced C-arm cone beam CT (CBCT) has increased the spatial resolution owing to its real-time fluoroscopic and 3D capabilities, even though concerns are still present due to the significant radiation burden to patients and operators [1]. Accordingly, new research perspectives are moving toward tracking systems allowing spatial navigation in real time with a burden of radiation that is low for patients and null for operators. These systems allow electromagnetic, optical or hybrid tracking of devices used during the surgical or inter- ventional procedure and their real-time visualization in a model obtained from a data set of previously acquired CT or MRI images. Therefore, the physicians’ ability to pin- point lesions is augmented and the operators’ learning curve is shortened [2]. Nowadays, several electromagnetic [3–6] optical [7, 8] or hybrid [9, 10] navigation systems have been tested in sev- eral different fields of medicine. Most of these studies were carried out on phantoms [3–9], animal models [3, 8], cadav- ers [6, 8, 10] and rarely in vivo [4, 6, 7]. In fact, studies car- ried out in vivo are few and most of them were conducted on small and heterogeneous cohorts of patients [4, 6, 7, 11]. To our knowledge, only few papers investigated the perfor- mance of navigation systems in the specific field of PLBs 123