Perfusion and diffusion magnetic resonance imaging in human cerebral venous thrombosis

Background Diagnosis of cerebral venous thrombosis (CVT) is usually achieve d by digital subtraction angiography or magnetic resonance angiography, whi le structural brain tissue damage can be assessed by computed tomography or magnetic resonance imaging (MRI). Using perfusion and diffusion weighted i maging (PWI, DWI) we aimed in this study to identify pathophysiological pat terns corresponding to only functional and hence reversible tissue involvem ent. Methods PWI, DWI, and conventional MRI were performed in six CVT patie nts acutely and after 16-26 days when their clinical condition had improved . All patients were treated with partial thromboplastin time-effective intr avenous heparin. After intravenous administration of a paramagnetic contras t agent, bolus track PWI allows pixel based determination of mean transit t ime (MTT) and cerebral blood volume (CBV). DWI was performed with two diffe rent b values (0, 1000 s/mm(2)) for calculation of apparent diffusion coeff icient (ADC) maps. Results in five of six cases increased MTT values were o bserved initially, whereas the CBV was normal, indicating a reduction of ce rebral blood flow. ADC values were normal. On follow up after clinical reco very MTT prolongations had resolved. Areas with prolonged MTT did not evolv e into structural lesions. Conclusion In patients with CVT, prolongations o f MTT in the absence of changes in CBV and ADC seem to indicate reversible involvement of brain tissue, a situation corresponding to the ischaemic pen umbra.