Multi-detector row computed tomography (MDCT) and magnetic resonance imaging (MRI) in the evaluation of the mandibular invasion by squamous cell carcinomas (SCC) of the oral cavity. Correlation with pathological data

Abstract

Background: To retrospectively compare the diagnostic accuracy of magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) in the assessment of the mandibular invasion by squamous cell carcinoma (SCC) having histopathological exams as standard of reference.

Materials and methods: Institutional review board approval with a waiver of informed patient consent was obtained. Of the 147 patients selected from our database who underwent surgical excision of a tumour arising into the oral cavity, thirty-six patients (26 men, 10 women; mean age, 56 years; range, 30-75 years) with hystologically proven SCC who performed both a preoperative MRI and MDCT, composed our final study population.Images were qualitatively analyzed in consensus by two expert radiologist in head and neck imaging. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were assessed for both MRI and MDCT.Differences in sensitivity, specificity, positive and negative predictive values were calculated at a statistical significance of p < .05.

Results: The sensitivity, the specificity and the accuracy of MRI and MDCT in the detection of the mandibular involvement were respectively 93%, 82%, 86% and 79%, 82%, 81%, while the positive predictive value (PPV) and negative predictive value (NPV) were respectively 76%, 95% and 73%, 86%. There wasn't any statistically significant difference in overall diagnostic accuracy between MRI and MDCT in the evaluation of mandibular tumour invasion (p > .05).

Conclusion: MRI showed to have a higher sensitivity compare to MDCT in the assessment of mandibular involvement from SCC arising in the oral cavity although none statistically significant differences were noted.

Figure 1

MRI SE T1 coronal plane (a), SE T1 coronal plane without (b) and after gadolinium (c). MRI shows a left floor of the mouth tumour that invading the mandible with cortical erosion and medullary bone involvement (arrows). CT in coronal plane (d) shows cortical invasion (arrow). Gross speciment (e) and histologycal data (f) confirm the cortical and medullary bone invasion (pathological stage pT4).

Figure 2

MRI SE T1 axial planes before (a) and after gadolinium infusion (b); SE T1 coronal planes before (c) and after gadolinium infusion (d). MRI shows alveolar ridge carcinoma (arrows) with an infiltration of the cortical and medullary bone (circles). CT in axial planes (e-f) shows an infiltration of the cortex (arrows). Histologycal data (g-h) shows the only cortical bone infiltration.

Figure 3

MRI SE T1 axial (a) and coronal planes before (b) and after gadolinium infusion (c). MRI shows a left floor of the mouth tumour with an infiltration of medullary bone, that demonstrates hypointense signal in T1 and enhancement after gadolinium infusion in the edentulous site (arrows). CT in axial (d-e) planes shows normal mandibular cortex. On the histologycal data the mandible was infiltrated (pathological stage T4).

Figure 4

MRI SE T1 coronal planes before (a) and after gadolinium infusion (b); SE T1 axial plane after gadolinium infusion (c). MRI shows a right floor of the mouth tumour with a suspected infiltration of medullary bone in the edentulous site (arrows). CT in coronal (d) sagittal (e) and axial (f) planes shows a suspected infiltration of the cortex (arrows). The histological result indicated that the mandible was free from neoplastic invasion (pathological stage T3).