Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging in Deep Cerebral Venous Thrombosis

Abstract

Background-Diffusion-weighted (DWI) and perfusion-weighted (PI) MRI are highly sensitive techniques for early diagnosis of arterial infarction, but little data on venous cerebral ischemia are available. We describe a case in which DWI, PI, and fast T2-weighted sequences were performed in the acute phase of deep cerebral venous thrombosis (CVT). Case Description-An 11-year-old girl with Crohn's disease developed deep CVT in which extensive edema was shown in the deep gray matter on T2-weighted sequence images. Isotropic echo-planar DWI demonstrated a local augmentation of the apparent diffusion coefficient ( 1.1 to 1.6ϫ10 Ϫ3 mm 2 /s), consistent with vasogenic edema. In dynamic contrast-enhanced PI, the regional cerebral blood volume was increased and the passage time of the contrast bolus was markedly prolonged. Clinically, the patient recovered totally after intravenous full-dose heparinization. T2 abnormalities, apparent diffusion coefficient values (0.8 to 0.92ϫ10 Ϫ3 mm 2 /s), and brain perfusion alterations resolved without damage to brain tissue. Conclusions-Unlike arterial infarction, DWI demonstrated vasogenic edema in a patient with deep CVT, which proved to be reversible in follow-up magnetic resonance imaging. PI showed areas with extensive venous congestion, but perfusion deficits were missing. Therefore, we believe that DWI and PI may play a role in detecting venous congestion in CVT and in prospective differentiation of vasogenic edema and venous infarction.

Compromise of Brain Tissue Caused by Cortical Venous Reflux of Intracranial Dural Arteriovenous Fistulas

“…10 Alternatively, previous experimental studies showed that retrograde venous pressure might counteract capillary perfusion pressure to decrease cerebral blood flow, and thus cause arterial ischemia resulting in cellular or cytotoxic edema. 12,21 Previous experimental and clinical diffusion-weight imaging studies of cerebral venous thrombosis have shown that ADC value was decreased, 12,22,23 normal, 23 increased, 24 or heterogeneous. 25,26 The ADC values decreased by 56% at 30 minutes after experimental cerebral venous thrombosis, and secondary increases in ADC subsequently developed in a rat model.…”

Diagnosis and Management of Cerebral Venous Thrombosis

“…This may include DWI abnormalities consistent with acute infarction, but the degree of DWI findings may be reduced in venous infarction compared with arterial infarction ( Figure 7). 124 An altered enhancement pattern suggestive of collateral flow or of venous congestion may be seen. There are some characteristic patterns of brain parenchymal changes that distinguish CVT from other entities.…”

“…Normally, the early veins begin to opacify at 4 to 5 seconds after injection of contrast material into the carotid artery, and the complete cerebral venous system is opacified in 7 to 8 seconds. 74,91,124,152 If cerebral veins or dural sinuses are not visualized in the normal sequences of cerebral angiography, the possibility of acute thrombosis is suspected. This finding accounts for the observed delayed cerebral perfusion seen with perfusionweighted MRI with prolonged transit time.…”

The Cerebral Perfusion of Circulation Disturbances. Part Ii (Ct- And Mri Semiotics, Patterns of Pathological Changes). Review

“…Достоверно дифференциро-вать вазогенный отёк от цитотоксического можно с помощью МР-режимов DWI и ADC (apparent diffusion coefficient -истинный коэффициент диффузии) картирования. Вазогенный отёк ха-рактеризуется гипо-или изоинтенсивными оча-гами на DWI [41] и повышением интенсивности сигнала при ADC-картировании [42]. Проявле-ния вазогенного отёка раньше, чем цитотокси-ческого, причисляют к особенностям венозного инфаркта [1,41].…”