Thanks to our Italian amici, Alessandro and Puccio for sending me this abstract this morning. This abstract is published in the Vasculab program for their 2011 conference in Italy, October 13-14
http://www.vasculab.it/hemodyn2011/pane ... seases.pdf
auth: Marcello Mancini presauth: Marcello Mancini institutions: Institute of Biostructure and Bioimaging National Council of Research Naples
The Cerebral Circulation Time in the evaluation of neurological diseases
abstract: Background -Recent newly developed ultrasound techniques extend our ability to study the cerebral hemodynamics in patients with neurological disease beyond the conventional blood flow velocity analysis. Different ultrasound methods are currently under investigation that either qualitatively or quantitatively describe brain perfusion.
The most widely used technique is bolus kinetics. After applying a ultrasound contrast agent bolus, time intensity curves of the wash-in and wash-out phase of the bolus passage through the brain are registered by imaging at a set frame rate and analyzing the ultrasound intensity in a given region of interest. Based on the time intensity curves, different parameters can be extracted such as peak intensity, time to peak, mean transit time, and incremental time (Fig1).
These parameters can be displayed in a tissue region of interest defined by the examiner. Studies based on histopathological techniques and on MR imaging demonstrate hypoxia-like brain tissue injury or thrombosis of small veins in patients with Multiple Sclerosis (MS).
Applying dynamic susceptibility contrast Magnetic Resonance Imaging, cerebral mean transit time values were found to be significantly prolonged in MS patients. We present the application of contrast enhanced ultrasound (CEUS) to assess global cerebral circulation time (CCT) in patients with multiple sclerosis (MS). The method is based on the assumption that the time required by an ultrasound contrast agent to pass from the cerebral arteries to the veins should be prolonged in patients with vessel disorders.
Methods: We performed CEUS in 82 patients with MS, and 37 controls. The clinical diagnosis was established by neurological evaluation and neuroimaging findings. Impairment was assessed by the EDSS Scale.
Cerebral Circulation Time was defined as the time difference of ultrasound contrast bolus arrival between the carotid artery and internal jugular vein.
Results The MS patients were comparable to control subjects for age, sex, systolic and diastolic blood pressure and heart rate. The artery arrival time was similar in MS group and controls.
The longest and average Cerebral Circulation Times (CCTL,CCTM) were substantially prolonged in patients with MS compared with controls [CCTL MS patients: median (range) 6.5 sec. (3.3-29.2); controls 5.2 (2.57-7.63; p5.8 sec. (2.6-17.5); controls 4.7 (2.5-7.1); p
Conclusions Compared with the healthy control group, MS patients showed a significant prolongation of CCT. Our results suggest that a microvascular or venous outflow impairment could be associated with MS. The CEUS measurement of CCT may be useful tool to disclose cerebral microcirculatory dysfunction in MS patients.
I takes longer for blood to travel from the carotid, thru the brain and back to the bottom of the jugular in pwMS. Alot longer--20-25% longer. In one person with MS, it took almost 30 seconds (that's just scary.) This is yet another study showing slowed perfusion and mean transit time in pwMS.