1 3 Radiol med DOI 10.1007/s11547-016-0654-1 COMPUTED TOMOGRAPHY Pre-surgical assessment of mandibular bone invasion from oral cancer: comparison between different imaging techniques and relevance of radiologist expertise Mario Silva 1 · Eleonora I. Zambrini 2 · Gianfranco Chiari 1 · Ilaria Montermini 1 · Carmelinda Manna 1 · Tito Poli 3 · Davide Lanfranco 3 · Enrico Sesenna 3 · Elena Thai 4 · Nicola Sverzellati 1 Received: 8 April 2016 / Accepted: 23 May 2016 © Italian Society of Medical Radiology 2016 inferior alveolar canal involvement on MRI. Sensitivity of MRI alone (74 %) was higher than CT (52 %). Simulta- neous review of CT and MRI showed the highest specific- ity (91 %), with the increase of diagnostic performance in the subgroup of subjects with positive MRI (AUC = 0.689; p = 0.044). Conclusion Higher expertise allows pre-surgical detection of clinically relevant signs of bone infiltration sensitivity of MRI alone is higher than CT for the detection of bone infil- tration from oral cancer. In MRI positive cases, diagnostic integration with combined review of CT and MRI is sug- gested for optimal diagnostic performance. Keywords Oral cancer · Bone infiltration · Computed tomography · Magnetic resonance imaging · Diagnostic performance · Interobserver agreement Introduction The prevalence of mandibular bone invasion ranges from 12 to 56 % in head and neck tumors [1, 2]. The diagno- sis of mandibular invasion has paramount importance for the pre-operative planning, because the surgical treatment is selected accordingly, with relevant influence on radical treatment as well as quality of life (from periosteal strip- ping to mandibulectomy) [3–6]. Pre-surgical assessment of mandibular invasion is obtained by diagnostic imag- ing. Therefore, the best accuracy of imaging technique or algorithm is needed to tailor surgical approach with opti- mal balance between radical treatment and anatomical conservation. Magnetic resonance imaging (MRI) and computed tomography (CT) are the imaging techniques with the best accuracy for the description of local neoplastic invasion. Abstract Purpose To compare diagnostic performance between computed tomography (CT) and magnetic resonance imag- ing (MRI) for the detection of bone infiltration from oral cancer, and to test interobserver agreement between radi- ologists with different expertises. Materials and methods Pre-surgical CT and MRI were reviewed independently by two radiologists with different expertises in head and neck oncology. A third radiologist reviewed CT and MRI simultaneously. Interobserver agree- ment was calculated by Cohen test. Association between radiological evidence of bone infiltration and histological reference was tested by Fisher’s exact test or Chi-squared test, as appropriate. Receiving operator curve was cal- culated and area under the curve (AUC) was compared between CT, MRI, and both methods together. Results Interobserver agreement was moderate: the trainee under-reported periosteal reaction on CT and inferior alve- olar canal involvement on MRI. Imaging findings associ- ated with histologic evidence of bone infiltration were: periosteal reaction and cortical erosion on CT; bone mar- row involvement, contrast enhancement within bone; and * Mario Silva mario.silva@unipr.it 1 Sezione di Radiologia, Dipartimento di Scienze Chirurgiche, Università degli Studi di Parma, Parma, Italy 2 Sezione di Radiologia, Dipartimento di Diagnostica per Immagini e Medicina di Laboratorio, IRCCS Arcispedale S. Maria Nuova, Reggio Emilia, Italy 3 Unità Operativa di Chirurgia Maxillo Facciale, Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, Università degli Studi di Parma, Parma, Italy 4 Unità Operativa di Anatomia e Istologia Patologica, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy