Kim E Y, Kim S S
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Acta Radiol. 2005 Apr;46(2):187-92. doi: 10.1080/02841850510022714.
To describe the MR findings of primary central nervous system T-cell lymphoma (T-PCNSL) in immunocompetent patients.
Seven patients with pathologically proven T-PCNSL were included in our study. The number, location, shape, enhancement pattern, and signal intensity of the tumors were determined. Diffusion-weighted images (DWI) and perfusion-weighted images (PWI) were obtained in four and two patients, respectively. Apparent diffusion coefficients (ADCs) were generated, and regions of interest were defined in each lesion.
Four patients with T-PCNSL had a single mass, while the others had multiple lesions (four, three, and two lesions, respectively). All seven cases of T-PCNSL had a supratentorial location: 12 in the subcortical area and 1 in the thalamus. No leptomeningeal involvement was noted. All tumors showed iso- to low T1 and iso- to slightly high T2 signal intensity to the adjacent gray matter. Rim enhancement was seen in 5 of the 7 patients (71.4%), while heterogeneous and homogeneous enhancement was seen in each of two. On DWI and ADC maps, the enhancing lesions showed slight hyperintensity in three patients (mean ADC ratio, 0.92 +/- 0.06) and iso-intensity in the other (ADC ratio, 1.02 +/- 0.05). Cystic areas consistent with necrosis were noted in three patients. High-signal intensity area in the cortex was noted on T1-weighted images in three patients, suggesting hemorrhage. In two patients, the same signal intensity area was noted within the mass. The two masses on the relative cerebral blood volume (rCBV) map demonstrated either similar or slightly higher signal intensity than that of the contralateral white matter. The rCBV ratios of these two masses were 1.27 +/- 0.16 and 1.35 +/- 0.2, respectively.
T-PCNSLs show a predilection for a subcortical location, a relatively high incidence of cortical or intratumoral hemorrhage, rim enhancement, or cystic-areas consistent with necrosis on magnetic resonance imaging. The lower rCBV ratio of the tumor might be helpful in differentiating T-PCNSL from other brain tumors such as high-grade glioma.
描述免疫功能正常患者原发性中枢神经系统T细胞淋巴瘤（T-PCNSL）的磁共振成像（MR）表现。
本研究纳入7例经病理证实的T-PCNSL患者。确定肿瘤的数量、位置、形态、强化方式及信号强度。分别对4例和2例患者进行了扩散加权成像（DWI）和灌注加权成像（PWI）检查。生成表观扩散系数（ADC），并在每个病灶中定义感兴趣区。
4例T-PCNSL患者为单发肿块，其余患者有多个病灶（分别为4个、3个和2个病灶）。7例T-PCNSL均位于幕上：12个位于皮质下区域，1个位于丘脑。未发现软脑膜受累。所有肿瘤在T1加权像上相对于相邻灰质呈等信号至低信号，在T2加权像上呈等信号至稍高信号。7例患者中有5例（71.4%）表现为环形强化，2例分别表现为不均匀强化和均匀强化。在DWI和ADC图上，强化病灶在3例患者中呈轻度高信号（平均ADC比值为0.92±0.06），在另1例患者中呈等信号（ADC比值为1.02±0.05）。3例患者发现与坏死相符的囊性区域。3例患者在T1加权像上皮质出现高信号区，提示出血。2例患者在肿块内发现相同信号强度区域。2个肿块在相对脑血容量（rCBV）图上显示与对侧白质信号强度相似或略高。这2个肿块的rCBV比值分别为1.27±0.16和1.35±0.2。
T-PCNSL在磁共振成像上表现为倾向于皮质下位置，皮质或肿瘤内出血、环形强化或与坏死相符的囊性区域的发生率相对较高。肿瘤较低的rCBV比值可能有助于将T-PCNSL与其他脑肿瘤如高级别胶质瘤相鉴别。
