Is CT still useful in the study protocol of retinoblastoma?

摘要

BACKGROUND AND PURPOSE: Intralesional calcium deposition is considered a key element for differentiating\udretinoblastoma from simulating lesions. Our aim was to assess whether MR imaging\udassociated with ophthalmologic investigations (ophthalmoscopy and ultrasonography) could replace CT\udin the detection of diagnostic intralesional calcifications in retinoblastoma.\udMATERIALS AND METHODS: Ophthalmoscopic findings, MR images, CT scans, and histologic examination\udof 28 retinoblastomas from 23 consecutive children (11 males, 12 females; age range at\udadmission, 1–35 months; mean age, 11 months; median age, 9 months) were retrospectively evaluated.\udUltrasonography was performed in 18 patients with 21 retinoblastomas. MR imaging included\udT2-weighted spin-echo and gradient-echo images, fluid-attenuated inversion recovery images, and\udT1-weighted spin-echo images with and without contrast enhancement. Clinical data were integrated\udwith MR imaging data to evaluate the utility of both approaches to discover calcifications; particularly,\uda correlation between intralesional signal-intensity void spots on MR imaging and hyperattenuating\udareas on CT scans was performed.\udRESULTS: Ophthalmoscopy detected calcifications in 12 of 28 eyes (42.85%). Ultrasonography detected\udcalcifications in 20 of 21 eyes (95.23%). CT showed hyperattenuating intralesional areas\udconsistent with calcifications in 27 of 28 eyes (96.42%). MR imaging showed intralesional signalintensity\udvoid spots in 25 of 28 eyes (89.28%). All spots detected with MR imaging matched the\udpresence of calcifications on CT scans. Gradient-echo T2*-weighted and fast spin-echo T2-weighted\udimages showed the highest degree of correlation with CT. When we put together ophthalmoscopy,\udultrasonography, and MR imaging data, no calcifications detected on CT were missed, and the\uddifferential diagnosis was thorough.\udCONCLUSIONS: A combination of clinical data and MR images may remove potentially harmful ionizing\udradiation from the study protocol of retinoblastoma.