Gamma knife surgery for arteriovenous malformations in the brain: integration of time-resolved contrast-enhanced magnetic resonance angiography into dosimetry planning

2007 ◽  
Vol 107 (4) ◽  
pp. 854-859 ◽  
Author(s):  
Christian A. Taschner ◽  
Vianney Le Thuc ◽  
Nicolas Reyns ◽  
Juergen Gieseke ◽  
Jean-Yves Gauvrit ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Mr Angiography ◽  
Data Sets ◽  
Time Resolved ◽  
Contrast Enhanced ◽  
Hybrid Data ◽  
Brain Avms ◽  
The Brain

Object The aim of this study was to develop an algorithm for the integration of time-resolved contrast-enhanced magnetic resonance (MR) angiography into dosimetry planning for Gamma Knife surgery (GKS) of arteriovenous malformations (AVMs) in the brain. Methods Twelve patients harboring brain AVMs referred for GKS underwent intraarterial digital subtraction (DS) angiography and time-resolved MR angiography while wearing an externally applied cranial stereotactic frame. Time-resolved MR angiography was performed on a 1.5-tesla MR unit (Achieva, Philips Medical Systems) using contrast-enhanced 3D fast field echo sequencing with stochastic central k-space ordering. Postprocessing with interactive data language (Research Systems, Inc.) produced hybrid data sets containing dynamic angiographic information and the MR markers necessary for stereotactic transformation. Image files were sent to the Leksell GammaPlan system (Elekta) for dosimetry planning. Results Stereotactic transformation of the hybrid data sets containing the time-resolved MR angiography information with automatic detection of the MR markers was possible in all 12 cases. The stereotactic coordinates of vascular structures predefined from time-resolved MR angiography matched with DS angiography data in all cases. In 10 patients dosimetry planning could be performed based on time-resolved MR angiography data. In two patients, time-resolved MR angiography data alone were considered insufficient. The target volumes showed a notable shift of centers between modalities. Conclusions Integration of time-resolved MR angiography data into the Leksell GammaPlan system for patients with brain AVMs is feasible. The proposed algorithm seems concise and sufficiently robust for clinical application. The quality of the time-resolved MR angiography sequencing needs further improvement.

scholarly journals Contrast-Enhanced Magnetic Resonance Angiography Using a Novel Elastin-Specific Molecular Probe in an Experimental Animal Model

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Carolin Reimann ◽  
Julia Brangsch ◽  
Jan Ole Kaufmann ◽  
Lisa C. Adams ◽  
David C. Onthank ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Quality ◽  
Magnetic Resonance Angiography ◽  
Contrast Agent ◽  
Mr Angiography ◽  
Molecular Probe ◽  
Time Resolved ◽  
Clinical Dose ◽  
Contrast Enhanced ◽  
First Pass

Objectives. The aim of this study was to test the potential of a new elastin-specific molecular agent for the performance of contrast-enhanced first-pass and 3D magnetic resonance angiography (MRA), compared to a clinically used extravascular contrast agent (gadobutrol) and based on clinical MR sequences. Materials and Methods. Eight C57BL/6J mice (BL6, male, aged 10 weeks) underwent a contrast-enhanced first-pass and 3D MR angiography (MRA) of the aorta and its main branches. All examinations were on a clinical 3 Tesla MR system (Siemens Healthcare, Erlangen, Germany). The clinical dose of 0.1 mmol/kg was administered in both probes. First, a time-resolved MRA (TWIST) was acquired during the first-pass to assess the arrival and washout of the contrast agent bolus. Subsequently, a high-resolution 3D MRA sequence (3D T1 FLASH) was acquired. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for all sequences. Results. The elastin-specific MR probe and the extravascular imaging agent (gadobutrol) enable high-quality MR angiograms in all animals. During the first-pass, the probes demonstrated a comparable peak enhancement (300.6 ± 32.9 vs. 288.5 ± 33.1, p>0.05). Following the bolus phase, both agents showed a comparable intravascular enhancement (SNR: 106.7 ± 11 vs. 102.3 ± 5.3; CNR 64.5 ± 7.4 vs. 61.1 ± 7.2, p>0.05). Both agents resulted in a high image quality with no statistical difference (p>0.05). Conclusion. The novel elastin-specific molecular probe enables the performance of first-pass and late 3D MR angiography with an intravascular contrast enhancement and image quality comparable to a clinically used extravascular contrast agent.

Assessment of arteriovenous malformations with 3-Tesla time-resolved, contrast-enhanced, three-dimensional magnetic resonance angiography

2009 ◽  
Vol 110 (3) ◽  
pp. 492-499 ◽  
Author(s):  
Kanako Kunishima ◽  
Harushi Mori ◽  
Daisuke Itoh ◽  
Shigeki Aoki ◽  
Hiroyuki Kabasawa ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Arteriovenous Malformations ◽  
Mr Angiography ◽  
Catheter Angiography ◽  
Good Tool ◽  
Time Resolved ◽  
Contrast Enhanced ◽  
Venous Filling ◽  
Time Resolved Imaging

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.

Time-resolved, contrast-enhanced 3D MR angiography in the subclavian steal effect

VASA ◽  
2010 ◽  
Vol 39 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Schubert
Keyword(s):  
Mr Angiography ◽  
Time Resolved ◽  
Time To Peak ◽  
Vertebral Arteries ◽  
Subclavian Steal ◽  
Cerebrovascular Events ◽  
Graphic Analysis ◽  
Contrast Enhanced ◽  
Hemodynamic Information ◽  
Supraaortic Vessels

The subclavian steal effect indicates atherosclerotic disease of the supraaortic vessels but rarely causes cerebrovascular events in itself. Noninvasive imaging providing detailed anatomic as well as hemodynamic information would therefore be desirable. From a group of 25 consecutive patients referred for MR angiography, four with absent or highly attenuated signal in one of the vertebral arteries on 3D multislab time-of-flight MR angiography were selected to undergo 3D time-resolved contrast-enhanced MR angiography. The time-resolved 3D contrast series (source images and MIPs) were evaluated visually and by graphic analysis of time-intensity curves derived from the respective V1 and V3 segments of both vertebral arteries on the source images. In two cases with high-grade proximal left subclavian stenosis, time-resolved 3D ce-MRA was able to visualise retrograde contrast filling of the left VA. There was a marked delay in time-to-peak between the left and right V1 segments in one case and a shallower slope of enhancement in another. In the other two cases, there was complete or collateralised segmental occlusion of the VAs.

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