Abe Takashi, Mizobuchi Yoshifumi, Sako Wataru, Irahara Saho, Otomi Yoichi, Obama Yuki, Nakajima Kohei, Khashbat Delgerdalai, Majigsuren Mungunkhuyag, Kageji Teruyoshi, Nagahiro Shinji, Harada Masafumi
Department of Radiology, Institute of Health Biosciences, The University of Tokushima Graduate School.
Magn Reson Med Sci. 2015;14(4):313-9. doi: 10.2463/mrms.2014-0083. Epub 2015 Jun 23.
In the imaging of intra-axial brain tumors, we sometimes found areas of high signal intensity around the enhanced tumor lesions on arterial spin labeling (ASL) magnetic resonance (MR) imaging. We undertook this study to investigate the relationship between high signal intensity on ASL imaging outside the area of contrast enhancement (CE) and histological diagnosis of intra-axial brain tumors.
We examined images from 28 consecutive patients with intra-axial brain tumors who underwent ASL and CE MR imaging-three with low grade glioma (LGG), 13 with high grade glioma (HGG), six with metastasis, and six with primary central nervous system lymphoma (PCNSL)-and divided imaging findings into an "ASL dominant" group when hyperintensity on ASL was found outside the CE area and a "CE dominant" group when hyperintensity on ASL was not found outside the area of enhancement. We then analyzed the relationship between imaging findings and the histological diagnosis of the tumors.
Four cases were excluded because of poor quality of ASL images, 7 cases were classified as ASL dominant, and 17 cases were classified as CE dominant. The histological diagnoses of ASL dominant cases were LGG in 3 cases, HGG in 3 cases, and PCNSL in one case. Those of CE dominant cases were HGG in 10 cases, metastasis in 5 cases, and PCNSL in 2 cases. All cases with brain metastasis were classified as CE dominant.
The high signal intensity outside the area of contrast enhancement is probably caused by increased perfusion or vascular proliferation, which indicates the presence of glioma or PCNSL and not metastasis. This finding indicates a new utility for ASL images in the diagnosis of brain tumors as a supplement to the conventional measurement of perfusion obtained from ASL images.
在轴内脑肿瘤成像中，我们有时在动脉自旋标记（ASL）磁共振（MR）成像上增强的肿瘤病变周围发现高信号强度区域。我们进行这项研究以探讨对比增强（CE）区域外ASL成像上的高信号强度与轴内脑肿瘤组织学诊断之间的关系。
我们检查了28例连续接受ASL和CE MR成像的轴内脑肿瘤患者的图像，其中3例为低级别胶质瘤（LGG），13例为高级别胶质瘤（HGG），6例为转移瘤，6例为原发性中枢神经系统淋巴瘤（PCNSL）。当在CE区域外发现ASL高信号时，将成像结果分为“ASL优势”组；当在增强区域外未发现ASL高信号时，分为“CE优势”组。然后我们分析了成像结果与肿瘤组织学诊断之间的关系。
由于ASL图像质量差，排除4例，7例分类为ASL优势，17例分类为CE优势。ASL优势病例的组织学诊断为3例LGG，3例HGG，1例PCNSL。CE优势病例的组织学诊断为10例HGG，5例转移瘤，2例PCNSL。所有脑转移瘤病例均分类为CE优势。
对比增强区域外的高信号强度可能是由于灌注增加或血管增生引起的，这表明存在胶质瘤或PCNSL而非转移瘤。这一发现表明ASL图像在脑肿瘤诊断中作为从ASL图像获得的传统灌注测量的补充具有新的用途。
