For several decades, clinicians have predicted intraparenchymal brain pressure or brain tissue compression indirectly based on the degree of distortion of the midline structures (midline shift) and ventricle wall (ventriculomegaly) observed on conventional MRI. However, this method has several limitations. Diffusion tensor imaging (DTI) is a novel MRI technique that can provide information about the microstructural properties of compressed tissue. In this study, the authors evaluated whether DTI can precisely define the degree of tissue compression in patients with chronic subdural hematoma (CSDH).
The study sample consisted of 18 patients (mean age 71 years, 10 men and 8 women) with unilateral CSDH and 12 age-matched volunteers. Diffusion tensor imaging results were acquired before and after the surgical irrigation in the CSDH group. Subdural pressure during the operation was also measured. Fractional anisotropy (FA) values were evaluated at several locations, including the gray matter.
The FA values of the gray matter, especially in the caudate nucleus and putamen, were increased in the patients with CSDH compared with the control group. The change in FA data before and after surgery (ΔFA) correlated with the degree of tissue compression evaluated by measurement of the subdural pressure. Furthermore, the increased FA values in patients with CSDH decreased after surgery.
These findings indicate that FA values of the gray matter, especially in the caudate nucleus and putamen, may be important markers of tissue compression. The assessment of FA values of the gray matter will result in a new, less-invasive diagnostic technique to evaluate the degree of brain compression.
Abbreviations used in this paper:CSDH = chronic subdural hematoma; Δ = change in data before and after surgery; DTI = diffusion tensor imaging; FA = fractional anisotropy; ICP = intracranial pressure; MMSE = Mini-Mental State Examination; MMT = manual muscle test; mRS = modified Rankin Scale; ONS = optic nerve sheath.
Address correspondence to: Eiichi Ishikawa, M.D., Ph.D., Department of Neurosurgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan 305-8575. email: firstname.lastname@example.org.Please include this information when citing this paper: published online June 8, 2012; DOI: 10.3171/2012.4.JNS112305.
OsukaSMatsushitaAYamamotoTSaotomeKIsobeTNagatomoY: Evaluation of ventriculomegaly using diffusion tensor imaging: correlations with chronic hydrocephalus and atrophy. Clinical article. J Neurosurg112:832–8392010
OsukaS, MatsushitaA, YamamotoT, SaotomeK, IsobeT, NagatomoY, : Evaluation of ventriculomegaly using diffusion tensor imaging: correlations with chronic hydrocephalus and atrophy. Clinical article. 112:832–839, 2010)| false
WieshmannUCSymmsMRParkerGJClarkCALemieuxLBarkerGJ: Diffusion tensor imaging demonstrates deviation of fibres in normal appearing white matter adjacent to a brain tumour. J Neurol Neurosurg Psychiatry68:501–5032000
WieshmannUC, SymmsMR, ParkerGJ, ClarkCA, LemieuxL, BarkerGJ, : Diffusion tensor imaging demonstrates deviation of fibres in normal appearing white matter adjacent to a brain tumour. 68:501–503, 2000)| false
YokoyamaKMatsukiMShimanoHSumiokaSIkenagaTHanabusaK: Diffusion tensor imaging in chronic subdural hematoma: correlation between clinical signs and fractional anisotropy in the pyramidal tract. AJNR Am J Neuroradiol29:1159–11632008
YokoyamaK, MatsukiM, ShimanoH, SumiokaS, IkenagaT, HanabusaK, : Diffusion tensor imaging in chronic subdural hematoma: correlation between clinical signs and fractional anisotropy in the pyramidal tract. 29:1159–1163, 2008)| false