Siegal T, Rubinstein R, Tzuk-Shina T, Gomori J M
Neuro-Oncology Clinic, Hadassah Hebrew University Hospital, Jerusalem, Israel.
J Neurosurg. 1997 Jan;86(1):22-7. doi: 10.3171/jns.1997.86.1.0022.
It was recently demonstrated that imaging of brain tumors by relative cerebral blood volume (CBV) maps reconstructed from dynamic magnetic resonance (MR) data provide similar diagnostic information compared to positron emission tomography (PET) or 201Tl single-photon emission computerized tomography (201Tl-SPECT) scans. The authors used relative CBV mapping for routine follow-up evaluation of patients with brain tumors and compared its sensitivity to diagnostic MR imaging, 201Tl-SPECT and clinical assessment. Fifty-nine patients were prospectively followed using 191 concomitant studies of dual section relative CBV maps, MR imaging, 201Tl-SPECT, and neurological evaluations. Studies were repeated every 2 to 3 months (median three evaluations/patient). The relative CBV maps were graded as relative CBV 0 to 4, where Grades 3 and 4 are indicative of proliferating tumors (four = rapid leak). There were 44 high-grade and 15 low-grade tumors followed during treatment. During the follow-up period a change in relative CBV grade was observed in 56% of the patients, revealing an increasing grade in 72% of them. The rapid leak phenomenon was detected in 35% of all studies and in 81% of those with a worsening relative CBV grade. Tumor progression was detected earlier by relative CBV maps as follows: earlier than MR imaging in 32% of the studies (earlier by a median of 4.5 months; p < 0.01); earlier than 201Tl-SPECT in 63% (median 4.5 months; p < 0.01), and earlier than clinical assessment in 55% (median 6 months; p < 0.01). In 82% of studies with positive MR imaging but negative 201Tl-SPECT, the lesions were smaller than 1.5 cm. The relative CBV maps clearly delineated the appearance of rapid leak in these lesions. Routine use of relative CBV maps that can be implemented on any high-field MR unit and added to the regular MR evaluation provides useful functional information in patients with brain tumors. When used as an adjunct follow-up evaluation it proved more sensitive than the other modalities for early prediction of tumor growth. It is very sensitive to small regional changes, unlike functional imaging such as PET or SPECT scans. Based on previous experience with 76 regional CBV studies, the authors conclude that regional CBV mapping correlates with active tumor and it may separate enhancing scar and radiation injury from infiltrative tumor. A new effect named the rapid leak phenomenon was also observed; this phenomenon, as identified on the regional CBV maps, correlates with high malignancy.
最近有研究表明，通过动态磁共振（MR）数据重建的相对脑血容量（CBV）图对脑肿瘤进行成像，与正电子发射断层扫描（PET）或201铊单光子发射计算机断层扫描（201Tl-SPECT）相比，能提供相似的诊断信息。作者使用相对CBV图对脑肿瘤患者进行常规随访评估，并将其敏感性与诊断性MR成像、201Tl-SPECT及临床评估进行比较。对59例患者进行前瞻性随访，共进行了191项双层面相对CBV图、MR成像、201Tl-SPECT及神经学评估的同步研究。每2至3个月重复进行研究（每位患者平均评估3次）。相对CBV图分为0至4级，其中3级和4级提示肿瘤增殖（4级表示快速渗漏）。治疗期间共随访44例高级别肿瘤和15例低级别肿瘤。随访期间，56%的患者相对CBV分级发生变化，其中72%的患者分级升高。在所有研究中，35%检测到快速渗漏现象，在相对CBV分级恶化的研究中，这一比例为81%。相对CBV图能更早检测到肿瘤进展，情况如下：比MR成像早32%的研究（中位数早4.5个月；p<0.01）；比201Tl-SPECT早63%（中位数4.5个月；p<0.01）；比临床评估早55%（中位数6个月；p<0.01）。在MR成像阳性但201Tl-SPECT阴性的研究中，82%的病变小于1.5 cm。相对CBV图清晰显示了这些病变中的快速渗漏表现。可在任何高场MR设备上实施并添加到常规MR评估中的相对CBV图的常规使用，能为脑肿瘤患者提供有用的功能信息。作为辅助随访评估时，它在早期预测肿瘤生长方面比其他方式更敏感。与PET或SPECT扫描等功能成像不同，它对小区域变化非常敏感。基于之前76项局部CBV研究的经验，作者得出结论，局部CBV图与活跃肿瘤相关，它可能将强化瘢痕和放射性损伤与浸润性肿瘤区分开来。还观察到一种名为快速渗漏现象的新效应；在局部CBV图上识别出的这种现象与高恶性相关。
