Uluğ Aziz M, Truong Thuy N, Filippi Christopher G, Chun Terry, Lee Jimmy K, Yang Charles, Souweidane Mark M, Zimmerman Robert D
Department of Radiology, Weill Medical College of Cornell University, Box 141, 1300 York Avenue, New York, NY 10021, USA.
AJNR Am J Neuroradiol. 2003 Jun-Jul;24(6):1171-6.
Hydrocephalus causes transependymal resorption of spinal fluid that in turn produces periventricular interstitial edema. This study was performed to determine if diffusion imaging can demonstrate this interstitial edema in the periventricular region in patients with obstructive hydrocephalus and if it can be used to assess the treatment response.
Twenty-one patients with obstructive hydrocephalus were evaluated with MR diffusion imaging before and after treatment. The change in ventricular size was measured by using the frontal and occipital horn ratio. The signal intensity abnormalities in periventricular white matter were scored. Average diffusion constants (D(av)) in the periventricular white matter were measured before and after treatment and compared with normal values. Post-treatment resolution of MR imaging abnormalities and changes in ventricular volume were compared with changes in D(av).
D(av) measured from periventricular white matter was increased in hydrocephalic patients compared with age-matched control subjects by a mean of 6.9% (P <.02). After treatment, D(av) decreased by an average of 6.0%: D(av) decreased in 11 patients (53%), it remained essentially unchanged in seven (33%), and it increased in three (14%).
For patients with obstructive hydrocephalus, diffusion is usually increased in the periventricular white matter. Therefore, increased D(av) may be a clinically useful sign of hydrocephalus, and it may prove useful in cases with equivocal clinical or imaging findings. Measurement of D(av) may be valuable in assessing the treatment response in these patients because D(av) usually decreases toward normal levels with successful treatment.
脑积水导致脑脊液经室管膜吸收，进而引起脑室周围间质水肿。本研究旨在确定扩散成像是否能显示梗阻性脑积水患者脑室周围区域的这种间质水肿，以及它是否可用于评估治疗反应。
对21例梗阻性脑积水患者在治疗前后进行磁共振扩散成像评估。通过额角与枕角比值测量脑室大小的变化。对脑室周围白质的信号强度异常进行评分。测量治疗前后脑室周围白质的平均扩散常数（D(av)），并与正常值进行比较。将磁共振成像异常的治疗后消退情况及脑室容积变化与D(av)的变化进行比较。
与年龄匹配的对照组相比，脑积水患者脑室周围白质测量的D(av)平均增加6.9%（P<.02）。治疗后，D(av)平均下降6.0%：11例患者（53%）的D(av)下降，7例（33%）基本保持不变，3例（14%）升高。
对于梗阻性脑积水患者，脑室周围白质的扩散通常增加。因此，D(av)升高可能是脑积水的一个临床有用征象，在临床或影像学表现不明确的病例中可能有用。测量D(av)在评估这些患者的治疗反应方面可能有价值，因为成功治疗后D(av)通常会降至正常水平。
