Department of Radiodiagnosis, 28862Maulana Azad Medical College and associated Lok Nayak Hospital, Delhi, India.
Department of Medicine, 28862Maulana Azad Medical College and associated Lok Nayak Hospital, Delhi, India.
Acta Radiol. 2023 Jan;64(1):274-281. doi: 10.1177/02841851211063603. Epub 2021 Dec 15.
Central nervous system (CNS) tuberculomas often mimic tumors on conventional imaging, differentiation of which may not be possible without invasive tissue sampling. Diffusion tensor imaging (DTI), owing to its unrivalled property of characterizing molecular diffusion, may help in better lesion characterization and tractography may help understand the pattern of white matter involvement by tuberculomas.
To estimate qualitative and quantitative diffusion tensor changes in brain tuberculomas and to evaluate patterns of white matter involvement using 3D tractography.
Thirty patients with brain tuberculomas were evaluated on a 3-T magnetic resonance scanner. Diffusion tensor images were acquired along 20 non-colinear encoding directions with two b-values (b = 0, b = 1000). Regions of interest (ROIs) were drawn on quantitative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps in the center of the tuberculoma and perilesional area. Similar ROIs were placed in contralateral hemispheres for comparison. Tractography maps were also generated.
Mean FA in the center and perilesional area of tuberculomas were 0.098 ± 0.041 and 0.311 ± 0.135, respectively. ADC values in corresponding regions were 0.920 ± 0.272 ×10 mm/s and 1.157 ± 0.277 ×10 mm/s. These values were significantly different compared to contralateral similar brain parenchyma. Tractography revealed interruption of white fibers in the center with deviation of fibers at the periphery in the majority of tuberculomas with none showing infiltration of white matter described in tumors.
Significant qualitative as well as quantitative DTI changes were seen in tuberculoma and perilesional areas compared to contralateral hemisphere with tractography showing a pattern different from that described in tumors. These findings may help to differentiate tuberculomas from infiltrating tumors.
中枢神经系统（CNS）结核瘤在常规影像学上常类似于肿瘤，若不进行有创性组织采样，可能无法进行区分。弥散张量成像（DTI）由于其无与伦比的分子扩散特征描述能力，可能有助于更好地对病变进行特征描述，而纤维束追踪技术可能有助于了解结核瘤对白质的累及模式。
评估脑结核瘤的弥散张量定性和定量变化，并使用 3D 纤维束追踪技术评估白质受累模式。
对 30 例脑结核瘤患者在 3.0T 磁共振扫描仪上进行评估。采集弥散张量图像，沿 20 个非共线编码方向采集两个 b 值（b=0、b=1000）。在结核瘤中心和瘤周区域的定量分数各向异性（FA）和表观扩散系数（ADC）图上画出感兴趣区（ROI）。在对侧半球上放置类似 ROI 作为对照。也生成了纤维束追踪图。
结核瘤中心和瘤周区域的平均 FA 值分别为 0.098±0.041 和 0.311±0.135。相应区域的 ADC 值分别为 0.920±0.272×10mm/s 和 1.157±0.277×10mm/s。与对侧相似脑实质相比，这些值均有显著差异。纤维束追踪显示，大多数结核瘤中心的白质纤维中断，周边纤维偏斜，没有显示肿瘤中描述的白质浸润。
与对侧半球相比，结核瘤和瘤周区域的弥散张量有明显的定性和定量变化，纤维束追踪显示的模式与肿瘤中描述的不同。这些发现可能有助于区分结核瘤和浸润性肿瘤。
