COMPARISON OF CT AND MR-IMAGING IN STAGING OF NECK METASTASES

PURPOSE: To compare the abilities of magnetic resonance (MR) imaging a nd computed tomography (CT) in detection of lymph node metastasis from head and neck squamous cell carcinoma. MATERIALS AND METHODS: MR imag ing and CT were performed with standard protocols in patients with kno wn carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx. H istopathologic examination was performed to validate imaging findings. Between 1991 and 1994, 213 patients undergoing 311 neck dissections w ere accrued at three institutions. RESULTS: For the upper jugular and spinal accessory regions, the areas under the receiver operating chara cteristic curve for combined information on size and internal abnormal ity were 0.80 for CT and 0.75 for MR imaging. Sensitivities, specifici ties, negative predictive values (NPVs), and positive predictive value s (PPVs) were calculated for various size criteria with and without in ternal abnormality information. With use of a 1-cm size or an internal abnormality to indicate a positive node, CT had an NPV of 84% and a P PV of 50%, and MR imaging had an NPV of 79% and a PPV of 52%. CT achie ved an NPV of 90%, correlating with a PPV of 44%, with use of 5-mm siz e as an indicator of a positive node.CONCLUSIONS: CT performed slightl y better than MR imaging for all interpretative criteria. However, a h igh NPV was achieved only when a low size criterion was used and was t herefore associated with a relatively low PPV.