Value of diffusion-weighted magnetic resonance imaging (DWI) in differentiating orbital lymphoma from idiopathic orbital inflammatory pseudotumor

Abstract

Background Diffusion-weighted MR imaging can provide physiological information complementing morphological findings from conventional MRI. It detects early tissue changes associated with changes in water content, such as changes in the permeability of cell membranes, cell swelling or cell lysis. Areas of diseased tissue are highlighted with increased signal intensity on diffusion-weighted MR imaging. A decrease in the ADC is expected with increased intracellular tissue caused by either cell swelling or increased cellular density. DWI can be performed without the need for the administration of exogenous contrast medium, so it may of use when contrast administration is contraindicated. It yields quantitative and qualitative information that reflects changes at the cellular level and indicates the integrity of cell membranes. The purpose of this study was mainly to assess the diagnostic value of DWI for the discrimination of orbital lymphoma from idiopathic orbital inflammatory pseudotumor. Results Of our 53 cases presented with proptosis or visual disturbances, 32 cases (60.4%) had found to be present with idiopathic orbital inflammatory pseudotumor and 21 cases (39.6%) had orbital lymphoma. On conventional MR imaging, ill-defined tumor margin and orbital preseptal space involvement had a significant association with orbital lymphoma, whereas intense post-contrast enhancement of lesion and radiologic evidence of sinusitis were associated with orbital inflammatory pseudotumor. The mean ADC value of orbital lymphoma was significantly lower than those of benign inflammatory pseudotumor, yielding 100% sensitivity, 99% specificity, and 90.5% accuracy for differentiating both entities. Conclusions Diffusion-weighted MR imaging (DWI) is valuable in discriminating orbital inflammatory pseudotumor from malignant orbital lymphoma that help patients to initial management.

P-ANCA Vasculitis Presenting with Orbital Infiltration

“…Multiple prior investigations have found that lower ADC values are consistent with malignancy, whereas higher values are consistent with inflammatory process. 10,11 ADC values in our case were consistent with inflammatory process. In addition, relatively elevated perfusion was seen in the orbital mass indicating that this lesion has increased vascular supply compared with the normal orbit, which is consistent with inflammatory and neoplastic lesions.…”

“…ADC values can help differentiate malignancy from inflammatory processes, although significant overlap still exists. 11 Because inflammation in and around the eye may be the presenting symptom, initiating a proper workup facilitates diagnosis, which may help reduce the increased mortality associated with AAV.…”

Orbital rhabdomyosarcoma in a 19-year-old male patient: A case report and literature review

“…Idiopathic orbital inflammation (IOI) often called pseudotumor, which is the third most common orbital disease, typically cause an increase in oculomotor muscle size [11] . On MRI, IOI shows an infiltrative mass, less often a focal mass, with contrast enhancement and lacks restricted diffusion with mean ADC value of 1.15 (± 0.37) × 10 −3 mm 2 /s [11 , 12] . In contrast, RMS with strongly restricted diffusion – like this case- is usually close to extraocular muscles without enlargement of the muscle belly.…”