Monika Probst1, Vivien Richter2, Jochen Weitz3, Jan Stefan Kirschke4, Carl Ganter5, Matthias Troeltzsch6, Mathias Nittka7, Carl-Peter Cornelius6, Claus Zimmer4, Florian Andreas Probst6. 1. Department of Diagnostic and Interventional Neuroradiology (Head: Prof. C. Zimmer), Klinikum rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675, Munich, Germany. Electronic address: monika.probst@tum.de. 2. Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Eberhard Karls University Tuebingen, Hoppe-Seyler-Straße 3, 72076, Tuebingen, Germany. 3. Department of Oral and Maxillofacial Surgery, Klinikum rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675, Munich, Germany. 4. Department of Diagnostic and Interventional Neuroradiology (Head: Prof. C. Zimmer), Klinikum rechts der Isar, Technical University Munich, Ismaninger Straße 22, 81675, Munich, Germany. 5. Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Ismaninger Straße 22, 81675, Munich, Technical University Munich, Germany. 6. Department of Oral and Maxillofacial Surgery, Ludwig Maximilians University of Munich, Lindwurmstraße 2a, 80337, Munich, Germany. 7. Siemens AG, Healthcare Sector, Allee am Roethelheimpark 2, 91052, Erlangen, Germany.
Abstract
PURPOSE: Magnetic resonance imaging (MRI) is an excellent imaging modality for displaying peripheral nerves. Since the knowledge about MRI of the inferior alveolar nerve (IAN) is limited, this pilot study aims to identify the prospects and limitations of MRI of the IAN, with special consideration of metal artifacts. MATERIALS AND METHODS: Initially, in vitro MRI of a dental implant was performed to establish an optimized protocol for metal artifact reduction using WARP sequences (a software package provided by Siemens Healthcare, Erlangen, Germany) including view angle tilting (VAT) and slice-encoding metal artifact correction (SEMAC) techniques. MRI with this optimized protocol was performed in three volunteers and four patients presenting with postoperative IAN impairment. Measuring the evaluable area and the artifact size was performed to assess the benefit of the specific artifact reduction sequences. RESULTS: In vitro imaging of a dental implant demonstrated that WARP sequences with VAT and SEMAC techniques led to a volume reduction of the artifact of up to 69.1%. Observations in both volunteers and patients with neurosensory IAN impairment showed a distinct artifact reduction with the MRI protocol adapted to metallic materials. Additionally VAT and SEMAC techniques improved the imaging due to further artifact reduction. As a main drawback of the VAT technique, the image quality was compromised by a blurring effect. Still, on 3-T MRI the resolution was high enough to reveal even fine structures. Imaging of the IAN was successful in all cases despite metallic material in the region of interest, and structural IAN changes could be detected in correlation with clinical symptoms. CONCLUSION: In contrast to conventional radiography and computed tomography, MRI can directly depict the IAN and provide reliable information on its position and exact course within the mandible. MRI offers an objective assessment of IAN injuries, supporting the decision-making process regarding surgical exploration and microneural repair. With the advent of specialized MRI techniques such as VAT and SEMAC, reduction of metal artifacts is considerably improved.
PURPOSE: Magnetic resonance imaging (MRI) is an excellent imaging modality for displaying peripheral nerves. Since the knowledge about MRI of the inferior alveolar nerve (IAN) is limited, this pilot study aims to identify the prospects and limitations of MRI of the IAN, with special consideration of metal artifacts. MATERIALS AND METHODS: Initially, in vitro MRI of a dental implant was performed to establish an optimized protocol for metal artifact reduction using WARP sequences (a software package provided by Siemens Healthcare, Erlangen, Germany) including view angle tilting (VAT) and slice-encoding metal artifact correction (SEMAC) techniques. MRI with this optimized protocol was performed in three volunteers and four patients presenting with postoperative IAN impairment. Measuring the evaluable area and the artifact size was performed to assess the benefit of the specific artifact reduction sequences. RESULTS: In vitro imaging of a dental implant demonstrated that WARP sequences with VAT and SEMAC techniques led to a volume reduction of the artifact of up to 69.1%. Observations in both volunteers and patients with neurosensory IAN impairment showed a distinct artifact reduction with the MRI protocol adapted to metallic materials. Additionally VAT and SEMAC techniques improved the imaging due to further artifact reduction. As a main drawback of the VAT technique, the image quality was compromised by a blurring effect. Still, on 3-T MRI the resolution was high enough to reveal even fine structures. Imaging of the IAN was successful in all cases despite metallic material in the region of interest, and structural IAN changes could be detected in correlation with clinical symptoms. CONCLUSION: In contrast to conventional radiography and computed tomography, MRI can directly depict the IAN and provide reliable information on its position and exact course within the mandible. MRI offers an objective assessment of IAN injuries, supporting the decision-making process regarding surgical exploration and microneural repair. With the advent of specialized MRI techniques such as VAT and SEMAC, reduction of metal artifacts is considerably improved.
Authors: Katrine Mølgaard Johannsen; João Marcus de Carvalho E Silva Fuglsig; Brian Hansen; Ann Wenzel; Rubens Spin-Neto Journal: Oral Radiol Date: 2022-09-30 Impact factor: 1.882
Authors: Egon Burian; Nico Sollmann; Lucas M Ritschl; Benjamin Palla; Lisa Maier; Claus Zimmer; Florian Probst; Andreas Fichter; Michael Miloro; Monika Probst Journal: Sci Rep Date: 2020-07-14 Impact factor: 4.379
Authors: H Michael Gach; Stacie L Mackey; Sana Rehman; Mo Kadbi; Jacqueline E Zoberi; Jose Garcia-Ramirez; Perry W Grigsby Journal: J Contemp Brachytherapy Date: 2017-10-30
Authors: Adib Al-Haj Husain; Daphne Schönegg; Silvio Valdec; Bernd Stadlinger; Thomas Gander; Harald Essig; Marco Piccirelli; Sebastian Winklhofer Journal: J Imaging Date: 2022-03-17