UTILITY OF APPARENT DIFFUSION COEFFICIENTS WITH DIFFUSIONWEIGHTED MRI IN DIFFERENTIATING BENIGN AND MALIGNANT BONE LESIONS

Abstract

OBJECTIVE:To evaluate the usefulness of diffusion-weightedMRIwith apparent diffusion co-efcients(ADC) cut-off value indifferentiatingbenignandmalignantbonelesions. MATERIALSAND METHODS: 58 patients with suspected bone tumours based on clinical examination and plain radiographs were included in the current study. They were subjected to routine MRI examination with inclusion of diffusion-weighted imaging, followed by histopathology for nal diagnosis.Allthe lesionswere assessed to see the presence of diffusion restriction if any. ADC values (mean, minimum and maximum) were obtained by two observers individually. Interobserver measurement and the ADC values in benign and malignant lesions were calculated. Receiver operating characteristic (ROC) analysis was done to determine optimal cut-off ADC values in distinguishing benign and malignant bone lesions. RESULTS: Of 58 lesions, there were 28 benign lesions and 30malignant lesions. Diffusion restriction was noted in 83.3% ofmalignant lesions whereas 57.1% of benign lesions did not show diffusion restriction. There were higher mean, minimum and maximum ADC values in benign lesions when compared with malignant lesions. With cut-off value of minimumADC as 0.92 x 10-3 mm2/sec to differentiate malignant and benign lesions, the sensitivity of 79% and specicity of 64% was obtained. CONCLUSIONS: DWIis useful in differentiating between benign and malignant lesions with diffusion restriction favoring malignancy. Higher mean, minimumandmaximumADCvalues are seen in benign lesions as compared tomalignant lesions. Even though, there isslight overlap inADCvalues of bothbenignandmalignantlesions,ADCvalueshelpintheirdifferentiation.