Value of conventional MRI and high resolution diffusion weighted imaging in differentiation nasopharynx and skull base osteomyelitis from locoregionally advanced nasopharyngeal carcinoma / 中华放射学杂志

ABSTRACT

Objective:To investigate the value of conventional MRI and high resolution diffusion weighted imaging (DWI) for preoperative discrimination between nasopharyngeal-skull base osteomyelitis (NP-SBO) and locoregionally advanced nasopharyngeal carcinoma (LA-NPC).Methods:From January 2017 to October 2021, 27 patients of NP-SBO and 32 patients of LA-NPC were retrospectively analyzed at the Eye & ENT Hospital of Fudan University. The clinical characteristics and conventional MRI features were collected, and the apparent diffusion coefficient (ADC) values of polygonal (ADC polygonal) and small circle were measured from readout segmentation of long variable echo-trains (RESOLVE) DWI. MRI features included laterality, margin, signal intensity of T 1WI and T 2WI, enhancement degree, component, abscess, deep mucosal white line, bone invasion, lymph nodes involvement and other accompany symphtoms. The independent sample t test, χ 2 test or Fisher exact test were used to compare the features and ADC values of the NP-SBO and LA-NPC groups. The logistic regression was applied to select independent predictors in the distinguishing LA-NPC from NP-SBO. Then, the conventional MRI model, ADC model and conventional MRI in combination with ADC model were built. The area under the receiver operating characteristic curve (AUC) of models were compared using DeLong test. Results:The age, diabetic status, cranial nerve deficits, inner component, abscess, deep mucosal white line, lymph nodes involvement and ADC polygonal were significantly different between NP-SBO and LA-NPC groups ( P<0.05). The logistic regression analysis showed that ADC polygonal (OR=0.972, 95%CI 0.951-0.993, P=0.011) and abscess (OR=0.101, 95%CI 0.013-0.774, P=0.027) were the independent predictors in the discrimination of NP-SBO and LA-NPC. The AUC (95%CI) of conventional MRI model (abscess), ADC model (ADC polygonal) and combination model were 0.634 (0.499-0.756), 0.870 (0.757-0.943), and 0.925(0.829-0.979), respectively. The AUC of combination model was higher than that of conventional MRI model ( Z=4.77, P<0.001), while there was no difference between combination model and ADC model ( Z=1.87, P=0.062). The AUC of conventional MRI model was lower than that of ADC model ( Z=2.84, P=0.005). Conclusion:Conventional MRI in combination with RESOLVE DWI shows good performance in differentiating between NP-SBO and LA-NPC, especially for abscess in combination with ADC polygonal value.