Comparison of magnetic resonance imaging and B-mode ultrasound findings in children with retinoblastoma

Abstract

Background: Retinoblastoma is the most frequently occurring primary intraocular neoplasm in the paediatric population and has a good prognosis when treated early. Magnetic resonance imaging (MRI) and B-mode ultrasound are both highly sensitive for identifying features of retinoblastoma.
Aim: To compare the detection of intraocular calcification in retinoblastoma patients between MRI and B-mode ultrasound, describe the demographics, disease laterality and extent at presentation.
Setting: Tertiary hospitals in Johannesburg from October 2020 to August 2022.
Methods: This study retrospectively reviewed records of paediatric patients with confirmed retinoblastoma who had a B-mode ultrasound at presentation performed by an ophthalmologist, and MRI of the brain and orbits.
Results: Thirty-six records were reviewed, with 23 meeting the study inclusion criteria. The male-to-female ratio was 1.09. The mean age at presentation was 21.14 months (median 11.3). Of the 23 patients (46 eyes), 35 eyes had retinoblastoma. Both modalities demonstrated 95% sensitivity in the detection of intraocular calcification. Sixty per cent had International Intraocular Retinoblastoma Classification group E disease, followed by 34% group D, while none presented with group A or B disease.
Conclusion: The detection of intraocular calcification in retinoblastoma patients using B-mode ultrasound and MRI is comparable, demonstrating equal sensitivity in this study; however, the two modalities are complementary rather than interchangeable. Magnetic resonance imaging still has advantages for staging beyond the globe.
Contribution: In resource-constrained settings, the high sensitivity of B-mode ultrasound for detecting calcification allows for early and accurate diagnosis even when advanced technology is scarce.