The Usefulness of the Ivy Sign on Fluid-Attenuated Intensity Recovery Images in Improved Brain Hemodynamic Changes after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis in Adult Patients with Moyamoya Disease

Objective

MR perfusion and single photon emission computerized tomography (SPECT) are well known imaging studies to evaluate hemodynamic change between prior to and following superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in moyamoya disease. But their side effects and invasiveness make discomfort to patients. We evaluated the ivy sign on MR fluid attenuated inversion recovery (FLAIR) images in adult patients with moyamoya disease and compared it with result of SPECT and MR perfusion images.

Methods

We enrolled twelve patients (thirteen cases) who were diagnosed with moyamoya disease and underwent STA-MCA anastomosis at our medical institution during a period ranging from September of 2010 to December of 2012. The presence of the ivy sign on MR FLAIR images was classified as Negative (0), Minimal (1), and Positive (2). Regions were classified into four territories: the anterior cerebral artery (ACA), the anterior MCA, the posterior MCA and the posterior cerebral artery.

Results

Ivy signs on preoperative and postoperative MR FLAIR were improved (8 and 4 in the ACA regions, 13 and 4 in the anterior MCA regions and 19 and 9 in the posterior MCA regions). Like this result, the cerebrovascular reserve (CVR) on SPECT was significantly increased in the sum of CVR in same regions after STA-MCA anastomosis.

Conclusion

After STA-MCA anastomosis, ivy signs were decreased in the cerebral hemisphere. As compared with conventional diagnostic modalities such as SPECT and MR perfusion images, the ivy sign on MR FLAIR is considered as a useful indicator in detecting brain hemodynamic changes between preoperatively and postoperatively in adult moyamoya patients.     

Subclinical albuminuria is linked to gray matter atrophy in type 2 diabetes mellitus

Objective

Microalbuminuria (MA), a marker of renal microvascular disease, is associated with brain atrophy and neurovascular changes in older adults with type 2 diabetes mellitus (DM). We evaluated the relationship between urine albumin-to-creatinine ratio (UACR) and regional brain volumes to determine whether subclinical albuminuria may indicate early structural brain changes in type 2 DM.

Materials/Methods

We studied UACR and brain volumes in 85 type 2 DM patients (64.8 ± 8.3 years) and 40 age-matched controls using 3D magnetization prepared rapid acquisition with gradient echo (MP-RAGE) MRI (magnetic resonance imaging) at 3 Tesla. The relationship between UACR and brain volumes was analyzed using the least square models.

Results

In DM patients, UACR ≥ 5 mg/g, UACR ≥ 10 mg/g and clinically significant MA (UACR ≥ 17 mg/g [males] and 25 mg/g [females]) were associated with lower gray matter (GM) volume in the frontal lobe (r²_adj = 0.2–0.4, P = 0.01–0.05) and UACR ≥ 5 mg/g was also related to global GM atrophy (r²_adj = 0.1, P = 0.04), independent of DM duration, glucose levels, HbA_1c and hypertension. For UACR ≥ 5 mg/g, a lower global GM volume was related to worse executive function (P = 0.04) in the DM group. No associations were found for UACR (< 5 mg/g) and controls.

Conclusions

Subclinical albuminuria (UACR ≥ 5 mg/g) is associated with lower GM volume that has clinical impact on cognitive function in older diabetic patients, and these relationships are independent of DM control and hypertension. Therefore, UACR levels may serve as an additional marker of DM-related brain structural changes.     

FLAIR与T_2W序列对颅脑占位病变诊断的对比研究

目的：对比研究FLAIR序列与T2加权序列在颅脑占位病变中的诊断敏感性，方法：对64例颅脑占位病变患者行快速FLAIR及T2加权序列MR扫描，比较FLAIR序列及T2加权序列显示脑占位病变的差异。结果：（1）64例脑占位病变中，FLAIR显示病灶124个，T2加权像显示109个，FLAIR与T2加权像在显示病灶数目上无统计学差异（P＞0．05）；（2）12例脑转移瘤患者，FLAIR共显示病灶72个，T2加权像权显示57个，FLAIR较T2加权像显示病灶数目敏感（P＜0．05）；（3）109个病灶的边界，水肿及内部结构在FLAIR均较T2加权像显示清晰（P＜0．01）。结论：FLAIR像在检出转移性肿瘤的病灶数目及显示脑占位病变的病灶边界、范围及内部结构均优于T2加权像，可作为常规颅脑检查的补充序列。     

FLAIR颅内椎动脉高信号在延髓梗塞诊断中的价值

目的:探讨低场强磁共振液体衰减反转恢复(fluid-attenuated inversion recovery,FLAIR)序列与其他序列搭配在延髓梗塞应用的临床价值,提高延髓梗塞的诊断水平。方法:搜集具有延髓梗塞及其后组颅神经损害为主要临床症状的MRI资料14例。采用西门子Concerto型0.2T磁共振,常规GRE-T1WI、T2WI、FLAIR和TOF-MRA检查,观察椎动脉闭塞的MRI征像。结果:8例(57.1%)FLAIR显示颅内椎动脉高信号,其中颅内椎动脉和基底动脉高信号3例。10例TOF-MRIA显示椎动脉严重狭窄或闭塞中有8例和FLAIR显示颅内椎动脉高信号一致。5例(35.7%)颅内椎动脉夹层,FLAIR均显示颅内椎动脉高信号。结论:FLAIR颅内椎动脉高信号并不意味着已经发生延髓梗塞,但有延髓梗塞的风险。FLAIR颅内椎动脉高信号是延髓梗塞的早期征像。     

老年胼胝体压部FLAIR序列异常高信号发生机制的探讨

目的在磁共振液体衰减翻转恢复（FLAIR）序列图像，胼胝体压部出现高信号通常被认为是病理变化。本研究的目的是分析这种病理改变在老年患者中的发生率及其可能的病理机制，并综述该MR表现的鉴别诊断。方法回顾性复习132例疑诊神经系统疾病的患者（男56例，女76例，年龄9～90岁，平均59岁）的FLAIR序列图像。分别观察胼胝体压部、深部脑白质改变、梗死及脑萎缩的情况。结果在132例患者中，33例（平均年龄59岁）患者的FLAIR像上胼胝体压部可见异常高信号改变，这种异常改变与年龄、脑白质的异常、脑萎缩及认知障碍的表现显著相关。结论FLAIR像上胼胝体压部高信号在老年患者中是常见的表现，多见于有认知障碍的老年患者。其病理变化通常被称之为“脑白质疏松症”。了解该异常表现发生的机制及该表现的鉴别诊断可避免不必要的有创诊断和治疗。