Time Resolved 3D MRA. Applications for Interventional Neuroradiology

Clinical Course and Management of Vein of Galen Varix of the Neonate: A Case Report and Literature Review

A 28-year-old pregnant woman underwent an emergency caesarian section after 39 weeks of gestation because of decreased fetal movement and baseline fetal heart rate variability. The neonate was diagnosed with neonatal asphyxia and presented with right cardiac failure due to pulmonary hypertension. The neonate presented convulsion, and plane computed tomography (CT) showed dilation of the vein of Galen and sinuses on day 3. Magnetic resonance imaging and CT with contrast were performed after cardiac failure subsided, and there was no evidence of arteriovenous shunt and normalization of the vein of Galen. The patient was diagnosed with vein of Galen varix (VGV). In the previous literature, only 3 cases of VGV have been reported. VGV is considered to be caused by right cardiac failure without the presence of an arteriovenous shunt and requires treatment only for cardiac failure and its cause. Therefore, it is important to differentiate VGV from vein of Galen aneurysmal malformation.

Feasibility of Noninvasive Diagnosis and Treatment Planning in a Case Series with Carotid-Cavernous Fistula using High-Resolution Time-Resolved MR-Angiography with Stochastic Trajectories (TWIST) and Extended Parallel Acquisition Technique (ePAT 6) at 3 T

PURPOSE

The evaluation of carotid-cavernous fistulas (CCFs) and the intracranial vasculature has been predominantly carried out using conventional digital subtraction angiography (DSA). Recent developments in time-resolved magnetic resonance angiography (MRA) provide the opportunity to assess both multiple arterial and venous phases with high temporal and spatial resolution. Here, we investigated the feasibility of this technique to functionally assess CCF prior to intervention.

METHODS

Six consecutive patients with clinical symptoms of a CCF were scheduled for clinically indicated MRA and underwent a protocol that comprised conventional imaging sequences and high resolution time-resolved MRA with interleaved stochastic trajectories (TWIST). The location of the fistulous communication, the flow pattern, and venous drainage were determined by time-resolved MRA and compared with DSA which was available in five out of six patients.

RESULTS

Typical morphological findings (including enlargement of the superior ophthalmic vein, exophthalmos) were found in all cases in both conventional MRI and time-resolved MRA source data. The temporal resolution of time-resolved MRA enabled a good separation of the early filling of the cavernous sinus during the arterial phase. Direct fistulous communication was assessed in three patients with good correlation to DSA, whereas indirect CCF could not definitely be visualized. The time-resolved MRA provided information about the flow pattern and the venous drainage of the fistula in all patients, which is essential for therapy planning.

CONCLUSION

Time-resolved MRA provides important morphological and functional information in patients with CCF. Although DSA remains the gold standard for diagnosis and exact classification of fistulas, time-resolved MRA can provide the relevant hemodynamic information to plan interventional treatment as a one-step procedure with a focused diagnostic workup.

Role of matrix metalloproteinases (MMPs) and MMP inhibitors on intracranial aneurysms: a review article

Cerebrovascular disease is one of the leading causes of death in the world, and about one-fourth of cerebrovasculardeaths are due to ruptured cerebral aneurysms (CA). Hence it is important to find a way to reduce aneurysmformation and its subsequent morbidity and mortality. Proteolytic activity capable of lysing gelatin hasbeen shown to be increased in aneurysm tissue and expression of plasmin, membrane-type matrix metalloproteinase-1(MT1-MMP), and matrix metalloproteinase-2 (MMP-2) in aneurysmal wall is more than what we observein normal cerebral arteries. MMP inhibitors such as doxycycline and statins may prohibit aneurysm formationand growth. MMPs are important in tissue remodeling associated with various physiological and pathologicalprocesses such as morphogenesis, angiogenesis, apoptosis and tissue repair. In this article we review therole of MMPs and MMP inhibitors in formation of aneurysm.