Department of Radiology, VU University Medical Center, Amsterdam, the Netherlands.
AJNR Am J Neuroradiol. 2012 Jan;33(1):110-8. doi: 10.3174/ajnr.A2729. Epub 2011 Oct 27.
Retinoblastoma may exhibit variable hyperintensities on DWI, resulting in different values in the ADC maps, depending on their histology and cellularity. However, EP-based DWI has susceptibility artifacts and image distortions, which make DWI of the orbit a challenging technique. The aim of this study was to investigate the feasibility of single-shot turbo spin-echo (HASTE) DWI in the evaluation of children with retinoblastoma and to assess the value of ADC maps in differentiating viable and necrotic tumor tissue.
Two radiologists assessed conventional MR images, DWI, and ADC maps of 17 patients with retinoblastoma (n = 17 eyes). Non-EP DWI was performed by using a HASTE sequence with b-values of 0 and 1000 s/mm(2). ADC values were measured for enhancing and nonenhancing tumor tissue. ADC maps were compared with histopathologic findings regarding tumor differentiation and viability.
On DWI, vital tumor tissue showed hyperintensity with negligible intensity of surrounding vitreous. The difference in mean (range) ADC values between enhancing (1.03 [0.72-1.22] × 10(-3) mm(2) s(-1)) and nonenhancing (1.47 [0.99-1.80] × 10(-3) mm(2) s(-1)) parts of retinoblastoma was statistically significant (P < .0005). Nonenhancing tumor parts showed a significantly lower ADC compared with vitreous (2.67 [2.24-3.20]×10(-3) mm(2) s(-1)) (P < .0005) and subretinal fluid (2.20 [1.76-2.96] × 10(-3) mm(2) s(-1)) (P < .0005). Histopathologically, low ADC values (enhancing tumor part) correlated to viable tumor tissue, whereas intermediate ADC values (nonenhancing tumor parts) correlated to necrotic tumor tissue.
HASTE DWI allowed adequate characterization of retinoblastoma, and ADC is a helpful tool to differentiate viable and necrotic tumor tissue and might be valuable in monitoring the response to eye-preserving therapies.
视网膜母细胞瘤在 DWI 上可能表现出不同的高信号强度，导致 ADC 图上的不同值，这取决于其组织学和细胞构成。然而，基于 EP 的 DWI 存在磁化率伪影和图像扭曲，这使得眼眶 DWI 成为一项具有挑战性的技术。本研究旨在探讨单次激发涡轮自旋回波（HASTE）DWI 在评估患有视网膜母细胞瘤的儿童中的可行性，并评估 ADC 图在区分存活和坏死肿瘤组织方面的价值。
两位放射科医生评估了 17 例患有视网膜母细胞瘤的患者（17 只眼）的常规 MR 图像、DWI 和 ADC 图。非 EP DWI 采用 HASTE 序列，b 值为 0 和 1000 s/mm²。测量增强和非增强肿瘤组织的 ADC 值。将 ADC 图与组织病理学发现进行比较，以评估肿瘤分化和活力。
在 DWI 上，活跃的肿瘤组织表现为高信号，周围玻璃体的信号强度可忽略不计。增强（1.03 [0.72-1.22] × 10(-3) mm² s(-1)) 和非增强（1.47 [0.99-1.80] × 10(-3) mm² s(-1)) 部分视网膜母细胞瘤的平均（范围）ADC 值之间存在显著差异（P<.0005）。非增强肿瘤部分的 ADC 值明显低于玻璃体（2.67 [2.24-3.20]×10(-3) mm² s(-1))（P<.0005）和视网膜下液（2.20 [1.76-2.96] × 10(-3) mm² s(-1))（P<.0005）。组织病理学上，低 ADC 值（增强肿瘤部分）与存活的肿瘤组织相关，而中间 ADC 值（非增强肿瘤部分）与坏死的肿瘤组织相关。
HASTE DWI 可以充分描述视网膜母细胞瘤，ADC 是区分存活和坏死肿瘤组织的有用工具，并且可能在监测眼保存治疗的反应方面具有价值。
