Three-dimensional dynamic time-resolved contrast-enhanced MRA using parallel imaging and a variable ratek-space sampling strategy in intracranial arteriovenous malformations

Object Although conventional catheter angiography is commonly used in the evaluation of intracranial arteriovenous malformations (AVMs), less invasive tools are more suitable for screening or follow-up. Older MR angiography techniques cannot provide high enough temporal and spatial resolution for assessing AVMs. Threetesla time-resolved imaging of contrast kinetics (TRICKS)—a time-resolved, contrast-enhanced 3D MR angiography technique—achieves subsecond time resolution without sacrificing spatial resolution. The purpose of this study was to assess the accuracy of TRICKS at 3 T in the evaluation of AVMs. Methods Between November 2006 and November 2007, 31 patients who were known to have AVMs underwent evaluation in a 3-T unit with the TRICKS technique. The TRICKS images were then evaluated independently by 2 radiologists for nidus detection, early venous filling detection, and Spetzler-Martin classification, and these results were compared with the results of catheter angiography. Results Time-resolved imaging of contrast kinetics achieved 96% sensitivity and 100% specificity both in nidus detection and early venous filling detection. The Spetzler-Martin grades also showed excellent correlation with catheter angiography findings (κ= 0.89). Conclusions Although this is a preliminary study, the authors' results indicate that time-resolved contrast-enhanced 3D MR angiography at 3 T is a good tool to assess AVMs, and has the potential to replace catheter angiography in screening or follow-up examinations of patients with AVMs.

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Time-Resolved Three-Dimensional Contrast-Enhanced Magnetic Resonance Angiography in Patients with Chronic Expanding and Stable Aortic Dissections

Contrast Media & Molecular Imaging ◽

10.1155/2017/5428914 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Michael Trojan ◽

Fabian Rengier ◽

Drosos Kotelis ◽

Matthias Müller-Eschner ◽

Sasan Partovi ◽

...

Keyword(s):

Three Dimensional ◽

False Lumen ◽

Ascending Aorta ◽

Stable Group ◽

Time Resolved ◽

Descending Aorta ◽

Peak Intensity ◽

Contrast Enhanced ◽

Aortic Dissections

Objective. To prospectively evaluate our hypothesis that three-dimensional time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA) is able to detect hemodynamic alterations in patients with chronic expanding aortic dissection compared to stable aortic dissections. Materials and Methods. 20 patients with chronic or residual aortic dissection in the descending aorta and patent false lumen underwent TR-MRA of the aorta at 1.5 T and repeated follow-up imaging (mean follow-up 5.4 years). 7 patients showed chronic aortic expansion and 13 patients had stable aortic diameters. Regions of interest were placed in the nondissected ascending aorta and the false lumen of the descending aorta at the level of the diaphragm (FL-diaphragm level) resulting in respective time-intensity curves. Results. For the FL-diaphragm level, time-to-peak intensity and full width at half maximum were significantly shorter in the expansion group compared to the stable group (p=0.027 and p=0.003), and upward and downward slopes of time-intensity curves were significantly steeper (p=0.015 and p=0.005). The delay of peak intensity in the FL-diaphragm level compared to the nondissected ascending aorta was significantly shorter in the expansion group compared to the stable group (p=0.01). Conclusions. 3D TR-MRA detects significant alterations of hemodynamics within the patent false lumen of chronic expanding aortic dissections compared to stable aortic dissections.

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