Department of Radiology, Private Umit Hospital, Eskisehir, 26005, Turkey.
Faculty of Medicine, Department of Radiology, Eskisehir Osmangazi University, Eskisehir, 26140, Turkey.
Curr Med Imaging. 2021;17(10):1200-1208. doi: 10.2174/1573405617666210316120314.
Differentiating glioblastoma (GBM) and solitary metastasis is not always possible using conventional magnetic resonance imaging (MRI) techniques. In conventional brain MRI, GBM and brain metastases are lesions with mostly similar imaging findings. In this study, we investigated whether apparent diffusion coefficient (ADC) ratios, ADC gradients, and minimum ADC values in the peritumoral edema tissue can be used to discriminate between these two tumors.
This retrospective study was approved by the local institutional review board with a waiver of written informed consent. Prior to surgical and medical treatment, conventional brain MRI and diffusion-weighted MRI (b = 0 and b = 1000) images were taken from 43 patients (12 GBM and 31 solitary metastasis cases). Quantitative ADC measurements were performed on the peritumoral tissue from the nearest segment to the tumor (ADC1), the middle segment (ADC2), and the most distant segment (ADC3). The ratios of these three values were determined proportionally to calculate the peritumoral ADC ratios. In addition, these three values were subtracted from each other to obtain the peritumoral ADC gradients. Lastly, the minimum peritumoral and tumoral ADC values, and the quantitative ADC values from the normal-appearing ipsilateral white matter, contralateral white matter, and ADC values from cerebrospinal fluid (CSF) were recorded.
For the differentiation of GBM and solitary metastasis, ADC3 / ADC1 was the most powerful parameter with a sensitivity of 91.7% and specificity of 87.1% at the cut-off value of 1.105 (p < 0.001), followed by ADC3 / ADC2 with a cut-off value of 1.025 (p = 0.001), sensitivity of 91.7%, and specificity of 74.2%. The cut-off, sensitivity and specificity of ADC2 / ADC1 were 1.055 (p = 0.002), 83.3%, and 67.7%, respectively. For ADC3 - ADC1, the cut-off value, sensitivity, and specificity were calculated as 150 (p < 0.001), 91.7%, and 83.9%, respectively. ADC3 - ADC2 had a cutoff value of 55 (p = 0.001), sensitivity of 91.7%, and specificity of 77.4, whereas ADC2 - ADC1 had a cut-off value of 75 (p = 0.003), sensitivity of 91.7%, and specificity of 61.3%. Among the remaining parameters, only the ADC3 value successfully differentiated between GBM and metastasis (GBM 1802.50 ± 189.74 vs. metastasis 1634.52 ± 212.65, p = 0.022).
The integration of the evaluation of peritumoral ADC ratio and ADC gradient into conventional MR imaging may provide valuable information for differentiating GBM from solitary metastatic lesions.
使用常规磁共振成像（MRI）技术，有时无法区分胶质母细胞瘤（GBM）和单发转移瘤。在常规脑 MRI 中，GBM 和脑转移瘤的病灶具有相似的影像学表现。本研究旨在探讨瘤周水肿组织的表观扩散系数（ADC）比值、ADC 梯度和最小 ADC 值是否可用于鉴别这两种肿瘤。
本回顾性研究经当地机构审查委员会批准，豁免书面知情同意。在手术和治疗前，对 43 例患者（12 例 GBM 和 31 例单发转移瘤病例）进行常规脑 MRI 和弥散加权 MRI（b = 0 和 b = 1000）检查。对距肿瘤最近的节段（ADC1）、中间节段（ADC2）和最远节段（ADC3）的瘤周组织进行定量 ADC 测量。按比例计算这些三个值的比值，以确定瘤周 ADC 比值。此外，还相互减去这些三个值以获得瘤周 ADC 梯度。最后，记录瘤周和瘤内最小 ADC 值，以及对侧正常白质、同侧正常白质和脑脊液（CSF）的定量 ADC 值。
对于 GBM 和单发转移瘤的鉴别，ADC3 / ADC1 是最有力的参数，截断值为 1.105 时具有 91.7%的敏感性和 87.1%的特异性（p < 0.001），其次是 ADC3 / ADC2，截断值为 1.025（p = 0.001），敏感性为 91.7%，特异性为 74.2%。ADC2 / ADC1 的截断值、敏感性和特异性分别为 1.055（p = 0.002）、83.3%和 67.7%。对于 ADC3 - ADC1，截断值、敏感性和特异性分别计算为 150（p < 0.001）、91.7%和 83.9%。ADC3 - ADC2 的截断值为 55（p = 0.001），敏感性为 91.7%，特异性为 77.4%，而 ADC2 - ADC1 的截断值为 75（p = 0.003），敏感性为 91.7%，特异性为 61.3%。在其余参数中，只有 ADC3 值成功地区分了 GBM 和转移瘤（GBM 1802.50 ± 189.74 与转移瘤 1634.52 ± 212.65，p = 0.022）。
将瘤周 ADC 比值和 ADC 梯度的评估纳入常规 MRI 可能为鉴别 GBM 和单发转移病灶提供有价值的信息。
