Lombardi Sophie, Tortora Domenico, Picariello Stefania, Sudhakar Sniya, De Vita Enrico, Mankad Kshitij, Varadkar Sophia, Consales Alessandro, Nobili Lino, Cooper Jessica, Tisdall Martin M, D'Arco Felice
Radiodiagnostic Department, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy.
Neuroradiology Unit, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy.
Diagnostics (Basel). 2023 Jul 10;13(14):2331. doi: 10.3390/diagnostics13142331.
Laser ablation for treatment of hypothalamic hamartoma (HH) is a minimally invasive and effective technique used to destroy hamartomatous tissue and disconnect it from the functioning brain. Currently, the gold standard to evaluate the amount of tissue being "burned" is the use of heat maps during the ablation procedure. However, these maps have low spatial resolution and can be misleading in terms of extension of the tissue damage. The aim of this study is to use different MRI sequences immediately after each laser ablation and correlate the extension of signal changes with the volume of malacic changes in a long-term follow-up scan. During the laser ablation procedure, we imaged the hypothalamic region with high-resolution axial diffusion-weighted images (DWI) and T2-weighted images (T2WI) after each ablation. At the end of the procedure, we also added a post-contrast T1-weighted image (T1WI) of the same region. We then correlated the product of the maximum diameters on axial showing signal changes (acute oedema on T2WI, DWI restriction rim, DWI hypointense core and post-contrast T1WI rim) with the product of the maximum diameters on axial T2WI of the malacic changes in the follow-up scan, both as a fraction of the total area of the hamartoma. The area of the hypointense core on DWI acquired immediately after the laser ablation statistically correlated better with the final area of encephalomalacia, while the T2WI, hyperintense oedema, DWI rim and T1WI rim of enhancement tended to overestimate the encephalomalacic damage. In conclusion, the use of intraoperative sequences (in particular DWI) during laser ablation can give surgeons valuable information in real time about the effective heating damage on the hamartomatous tissue, with better spatial resolution in comparison to the thermal maps.
激光消融术治疗下丘脑错构瘤（HH）是一种用于破坏错构瘤组织并使其与功能正常的脑组织分离的微创且有效的技术。目前，评估“灼烧”组织量的金标准是在消融过程中使用热图。然而，这些热图的空间分辨率较低，在组织损伤范围方面可能会产生误导。本研究的目的是在每次激光消融后立即使用不同的磁共振成像（MRI）序列，并将信号变化的范围与长期随访扫描中软化灶变化的体积相关联。在激光消融过程中，每次消融后我们用高分辨率轴向扩散加权成像（DWI）和T2加权成像（T2WI）对下丘脑区域进行成像。在手术结束时，我们还增加了同一区域的增强后T1加权成像（T1WI）。然后，我们将轴向显示信号变化（T2WI上的急性水肿、DWI限制环、DWI低信号核心和增强后T1WI环）的最大直径的乘积与随访扫描中轴向T2WI上软化灶变化的最大直径的乘积相关联，两者均以错构瘤总面积的比例表示。激光消融后立即获取的DWI上低信号核心区域与最终脑软化区域在统计学上具有更好的相关性，而T2WI上的高信号水肿、DWI环和T1WI增强环往往高估了脑软化损伤。总之，在激光消融过程中使用术中序列（特别是DWI）可以为外科医生实时提供有关错构瘤组织有效热损伤的有价值信息，与热图相比具有更好的空间分辨率。
