Role of MR spectroscopy and diffusion-weighted imaging in diagnosis of orbital masses

Abstract

PurposeTo assess the value of (MRI), (DWI) and (MRS) in the diagnosis of different orbital masses and differentiation between benign and malignant masses. Patients and methodsSixty patients were enrolled in this study (31 females, 29 males, their ages ranged from 3 month to 75 years with mean age of 35.3 years). Clinical examination, (T1WI&T2WI) MRI and postcontrast T1WI, DWI, and MR Spectroscopy were done in all cases. Histopathological examination was done for 55 patients, and follow-up was done for 5 cases after medical treatment: two cases of pseudotumor and three cases of cellulites. ResultsThe study comprised 60 patients complaining of proptosis, swelling and diminution of vision. Thirty-three (55%) of patients had benign orbital masses and 27 (45%) patients had malignant orbital masses. The mean ADC value of malignant lesions was 0.89 ± 0.20. There was a statistically significant difference (p = ≤.001) between benign and malignant ADC values. The Mean Cho/Cr ratio for benign lesions was 1.19 ± 0.25 which showed statistically high significance (p = ≤.001∗∗) compared to Cho/Cr ratio of malignant lesions which was 2.44 ± 0.30.Diffusion-weighted MRI could differentiate between benign and malignant masses in 75% of cases. However, MRS could overcome this overlap and could differentiate benign from malignant tumors in 96% of scanned patients. ConclusionBoth DWI and MRS imaging are helpful tools in differentiating malignant orbital lesions from benign masses.