Comparison of HASTE versus EPI-Based DWI for Retinoblastoma and Correlation with Prognostic Histopathologic Parameters.

Background And Purpose: Non-EPI-based DWI has shown better performance in head and neck pathologies owing to lesser susceptibility artifacts compared with EPI-DWI. However, only sporadic studies have investigated the feasibility of non-EPI-based DWI in retinoblastoma (RB). We qualitatively and quantitively compared EPI-DWI and HASTE-DWI in RB and correlated the tumor ADC values obtained from these 2 techniques with histopathologic markers.

Materials And Methods: Twenty-one treatment-naive patients with RB underwent 1.5T orbital MR imaging. EPI-DWI and HASTE-DWI were acquired at 3 b-values (0, 500, and 1000 s/mm). All patients subsequently underwent surgical enucleation. For qualitative image assessment, scoring of overall image quality, artifacts, tumor sharpness, and tumor conspicuity was done by using a 5-point Likert scale. Quantitative assessment included calculations of SNR, contrast-to-noise ratio (CNR), geometric distortion, and ADC. Qualitative scores were compared by using the Wilcoxon signed-rank test, and quantitative parameters were analyzed with a test.

Results: All 21 patients had unilateral RB; 15 were male and 6 were female with a median age of 36 months (range, 9-72 months). On histopathology, patients had either poorly differentiated ( 13/21) or moderately differentiated ( = 8/21) RB. Other poor prognostic markers evaluated were optic nerve invasion ( = 10/21), choroidal invasion ( = 12/21), and anterior eye segment enhancement on MRI ( = 6/21). HASTE-DWI demonstrated higher image quality scores than EPI-DWI (< .01), except for tumor conspicuity score, which was higher for EPI-DWI (< .001). HASTE-DWI showed lower SNR, CNR, and geometric distortion than EPI-DWI (< .001). The average acquisition times of EPI-DWI and HASTE-DWI were ∼1 and 14 minutes, respectively. The mean tumor ADC value on EPI-DWI was 0.62 ± 0.14 × 10 mm/s and on HASTE-DWI was 0.83 ± 0.17 × 10 mm/s. A significant correlation between EPI-DWI and HASTE-DWI ADC values ( = 0.8; = .01) was found. Lower ADC values were found in tumors with poor prognostic markers, but none reached a statistically significant difference.

Conclusions: HASTE-DWI shows improved overall image quality; however, it lacks in terms of tumor conspicuity, SNR, CNR, and longer acquisition time compared with EPI-DWI. ADC values derived from HASTE-DWI show no advantage over EPI-DWI in correlation with histopathologic prognostic markers.