Evaluation of ventriculomegaly using diffusion tensor imaging: correlations with chronic hydrocephalus and atrophy.
OBJECTIVE
Ventriculomegaly is a common imaging finding in many types of conditions. It is difficult to determine whether it is related to true hydrocephalus or to an atrophic process by using only imaging procedures such as MR imaging after traumatic injury, stroke, or infectious disease. Diffusion tensor (DT) imaging can distinguish the compression characteristics of white matter, indicating that increased diffusion anisotropy may be related to white matter compression. In this preliminary study, the authors compared the DT imaging findings of ventriculomegaly with those of chronic hydrocephalus or atrophy to clarify the potential of diffusion anisotropy in the identification of hydrocephalus.


METHODS
Ten patients with chronic hydrocephalus, 8 patients with atrophy (defined by conventional devices and surgical outcome), and 14 healthy volunteers underwent DT imaging. Images were acquired before and after shunting or once in cases without shunting. The fractional anisotropy (FA) values at many points around the lateral ventricle were evaluated.


RESULTS
The FA patterns around the lateral ventricle in the chronic hydrocephalus and atrophy groups were different. Especially in the caudate nucleus, FA was increased in the chronic hydrocephalus group compared with the atrophy group. Furthermore, the FA values returned to normal levels after shunt placement.


CONCLUSIONS
Assessment of the FA value of the caudate nucleus may be an important, less invasive method for distinguishing true hydrocephalus from ventriculomegaly. Further research in a large number of patients is needed to verify the diagnostic ability of this method.
Osuka
Satoru
S
Department of Neurosurgery, University of Tsukuba, Tsukuba, Japan.
Matsushita
Akira
A
Yamamoto
Tetsuya
T
Saotome
Kousaku
K
Isobe
Tomonori
T
Nagatomo
Yasushi
Y
Masumoto
Tomohiko
T
Komatsu
Yoji
Y
Ishikawa
Eiichi
E
Matsumura
Akira
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy; D001927:Brain Diseases / Q000473:pathology*; D002421:Caudate Nucleus / Q000473:pathology*; D002557:Cerebrospinal Fluid Shunts; D002908:Chronic Disease; D003937:Diagnosis, Differential; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000473:pathology* / Q000601:surgery; D020547:Lateral Ventricles / Q000473:pathology*; D008297:Male; D008875:Middle Aged