scholarly journals Time-of-flight magnetic resonance angiography imaging of a residual arteriovenous malformation nidus after Onyx embolization for stereotactic radiosurgery planning

2009 ◽  
Vol 26 (5) ◽  
pp. E13 ◽  
Author(s):  
David N. Loy ◽  
Keith M. Rich ◽  
Joseph Simpson ◽  
Ian Dorward ◽  
Lakshmi Santanam ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Mr Angiography ◽  
Spin Echo ◽  
Treatment Plan ◽  
Time Of Flight ◽  
Brain Structures ◽  
Fast Spin Echo ◽  
Embolic Agent ◽  
Slice Thickness ◽  
Arteriovenous Shunting

This report demonstrates that time-of-flight (TOF) MR angiography is a useful adjunct for planning stereotactic radiosurgery (SRS) of large arteriovenous malformations (AVMs) after staged embolization with Onyx. Onyx (ethylene vinyl copolymer), a recently approved liquid embolic agent, has been increasingly used to exclude portions of large AVMs from the parent circulation prior to SRS. Limiting SRS to regions of persistent arteriovenous shunting and excluding regions eliminated by embolization may reduce unnecessary radiation doses to eloquent brain structures. However, SRS dosimetry planning presents unique challenges after Onyx embolization because it creates extensive artifacts on CT scans, and it cannot be delineated from untreated nidus on standard MR sequences. During the radiosurgery procedure, MR images were obtained using a GE Signa 1.5-T unit. Standard axial T2 fast spin echo high-resolution images (TR 3000 msec, TE 108 msec, slice thickness 2.5 mm) were generated for optimal visualization of brain tissue and AVM flow voids. The 3D TOF MR angiography images of the circle of Willis and vertebral arteries were subsequently obtained to visualize AVM regions embolized with Onyx (TR 37 msec, TE 6.9 msec, flip angle 20°). Adjunct TOF MR angiography images demonstrated excellent contrast between nidus embolized with Onyx and regions of persistent arteriovenous shunting within a large AVM prior to SRS. Additional information derived from these sequences resulted in substantial adjustments to the treatment plan and an overall reduction in the treated tissue volume.

Unenhanced calf MR angiography at 3.0 T using electrocardiography-gated partial-fourier fast spin echo imaging with variable flip angle

2010 ◽  
Vol 21 (6) ◽  
pp. 1311-1322 ◽  
Author(s):  
Dan Li ◽  
Jiang Lin ◽  
Fuhua Yan ◽  
Qingyuan Wu ◽  
Weiwei Lv ◽  
...  
Keyword(s):  
Mr Angiography ◽  
Spin Echo ◽  
Flip Angle ◽  
Fast Spin Echo ◽  
Variable Flip Angle ◽  
3.0 T ◽  
Fast Spin

scholarly journals Arterial flow characteristics in the presence of vascular disease and implications for fast spin echo-based noncontrast MR angiography

2011 ◽  
Vol 34 (6) ◽  
pp. 1472-1479 ◽  
Author(s):  
Pippa Storey ◽  
Ruth P. Lim ◽  
Sooah Kim ◽  
David R. Stoffel ◽  
Vivian S. Lee
Keyword(s):  
Vascular Disease ◽  
Mr Angiography ◽  
Spin Echo ◽  
Flow Characteristics ◽  
Arterial Flow ◽  
Fast Spin Echo ◽  
Fast Spin

scholarly journals Tailoring the flow sensitivity of fast spin-echo sequences for noncontrast peripheral MR angiography

2010 ◽  
Vol 64 (4) ◽  
pp. 1098-1108 ◽  
Author(s):  
Pippa Storey ◽  
Iliyana P. Atanasova ◽  
Ruth P. Lim ◽  
Jian Xu ◽  
Daniel Kim ◽  
...  
Keyword(s):  
Mr Angiography ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Flow Sensitivity ◽  
Fast Spin ◽  
Spin Echo Sequences

Peripheral MR Angiography: Separation of Arteries from Veins with Flow-spoiled Gradient Pulses in Electrocardiography-triggered Three-dimensional Half-Fourier Fast Spin-Echo Imaging

Radiology ◽  
2003 ◽  
Vol 227 (3) ◽  
pp. 890-896 ◽  
Author(s):  
Mitsue Miyazaki ◽  
Hiroshi Takai ◽  
Satoshi Sugiura ◽  
Hirofumi Wada ◽  
Rie Kuwahara ◽  
...  
Keyword(s):  
Mr Angiography ◽  
Spin Echo ◽  
Three Dimensional ◽  
Fast Spin Echo ◽  
Fast Spin

L'angiografia a risonanza magnetica nello studio del circolo cerebrale

1992 ◽  
Vol 5 (3) ◽  
pp. 309-330 ◽  
Author(s):  
R. Gasparotti ◽  
G.F. Gualandi ◽  
M. Bonetti ◽  
A. Chiesa ◽  
G. Galli
Keyword(s):  
Mr Angiography ◽  
Spin Echo ◽  
Time Of Flight ◽  
Risonanza Magnetica ◽  
Sulla Base ◽  
Trattamento Endovascolare ◽  
Sono Stati ◽  
Nello Studio

L'Angiografia a Risonanza Magnetica (ARM) è stata utilizzata per lo studio del circolo cerebrale a completamento della convenzionale indagine RM spin-echo (RM-SE) in 20 pazienti portatori di malformazioni artero-venose (MAV) cerebrali (17 sovratentoriali e 3 sottotentoriali). Per un'efficace dimostrazione sia delle afferenze arteriose che del drenaggio venoso sono stati contemporaneamente impiegati diversi tipi di sequenze ad «pacchetto» 2D e 3D (Time-of-Flight MR Angiography). Nei 5 casi con emorrragia intraparenchimale spontanea è stata utilizzata l'Angio-RM a contrasto d'ampiezza (Magnitude MR Angiography). I reperti sono stati confrontati con quelli dell'angiografia e della RM spin-echo. L'angio-RM è risultata essenziale ai fini di una diagnosi non invasiva di malformazione artero-venosa cerebrale in 3 pazienti (15%) con MAV di piccole dimensioni (diametro max di 15 mm), non riconoscibili nelle immagini spin-echo, ed in 4 casi dubbi (20%) in cui la RM-SE poneva solo un sospetto sulla base di rilievi indiretti. In tutti i casi di emorragia cerebrale da rottura spontanea di MAV l'Angio-RM ha permesso il riconoscimento del nidus angiomatoso residuo, mascherato dal segnale del sangue nelle immagini spin-echo, trovando successiva conferma nell'angiografia. L'Angio-RM si è inoltre dimostrata superiore alia RM spin-echo nella caratterizzazione anatomica delle MAV, riconoscendo un maggior numero di vasi afferenti e precisando meglio il tipo di drenaggio venoso. Confrontata con l'angiografia, l'Angio-RM in 3 casi è risultata insufficiente per la dimostrazione di vasi afferenti di calibro sottile, quali le arterie corioidee e le arterie cerebellari superiori, mentre in altri 3 casi ha mancato la visualizzazione di scarichi venosi profondi non dilatati. Nonostante l'angiografia rimanga l'unica indagine radiologica in grado di fornire una completa caratterizzazione sia morfologica che emodinamica delle MAV cerebrali, indispensabile ai fini di una terapia chirurgica o di un trattamento endovascolare, in base ai risultati del presente studio l'angio-RM può essere considerata come indagine fondamentale nella fase di inquadramento diagnostico, complementare alia RM tradizionale.

Intracranial black-blood MR angiography with high-resolution 3D fast spin echo

1998 ◽  
Vol 40 (2) ◽  
pp. 298-310 ◽  
Author(s):  
Andrew L. Alexander ◽  
Henry R. Buswell ◽  
Yi Sun ◽  
Brian E. Chapman ◽  
Jay S. Tsuruda ◽  
...  
Keyword(s):  
High Resolution ◽  
Mr Angiography ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Black Blood ◽  
Fast Spin

Abstract 2766: Hemodynamic Changes Following Direct EC-IC Bypass In Moyamoya Disease Patients Measured Using Combined Arterial Spin Labeling And Dynamic Susceptibility Contrast MR Imaging

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Greg Zaharchuk ◽  
Ryan L Spilker ◽  
Gary K Steinberg
Keyword(s):  
Spin Echo ◽  
Fast Spin Echo ◽  
Slice Thickness ◽  
Dynamic Susceptibility ◽  
Quantitative Methodology ◽  
Dynamic Susceptibility Contrast ◽  
Hemodynamic Changes ◽  
Anterior Circulation ◽  
Mr Perfusion Imaging ◽  
Direct Bypass

Background: The goal of direct bypass in Moyamoya patients is to reduce the risk of future strokes, presumably by improving cerebral hemodynamics. Combined ASL and DSC MR perfusion imaging (CAD-perfusion) is a new quantitative methodology to measure perfusion parameters ( 1 ). Methods: We applied this method to 20 newly-diagnosed, symptomatic Moyamoya patients (11 bilateral, 9 unilateral). Imaging was acquired at 3T (GE MR 750, Waukesha, WI) before and approximately 6 months following direct STA-MCA anastomosis. ASL was performed using 3D fast-spin-echo background-suppressed pseudocontinuous ASL with the following parameters (TR/TE/label time/post-label delay 5500/2.5/1500/2000 ms; spatial resolution 3 × 3 × 4 mm; imaging time 4:37). DSC was performed using gradient-echo EPI with the following parameters (TR/TE 1800/40 ms; 1.9 × 1.9 × 5 mm; 0.1 mmol/kg Multihance contrast). Images were co-registered, placed into template space, and resliced to 10 mm axial slice thickness corresponding to the ASPECTS slices using SPM8. CAD-perfusion images (CAD-CBF and CAD-CBV) were created using standard methods ( 1 ). Analysis was by hemisphere (n=20 posterior, n=31 bypassed anterior, and n=9 non-bypassed anterior regions). Hemodynamic measurements were made in mixed cortical ROI’s. The Wilcoxon rank-sum test was used to assess significance at the p<0.05 level. Results: 6 months following bypass, Tmax in the bypassed anterior circulation decreased significantly (from 3.6±1.2 to 3.0±0.9 sec, p=0.019) but did not change in either the non-bypassed anterior circulation or posterior circulation. CAD-CBF did not increase in any of the three regions; in particular, no increase was seen in the anterior bypassed regions (from 34.8±8.5 to 36.8±8.1 ml/100 g/min, p>0.05). This is consistent with prior reports suggesting that baseline CBF does not change following bypass ( 2 ). Interestingly, CAD-CBV was significantly increased in all regions following bypass; this change was largest in the non-bypassed anterior circulation (from 4.5±1.0 to 6.1±2.3%, p=0.035). Conclusion: Hemodynamic changes following bypass are complex and involve both hemispheres. CAD-perfusion MRI allows the ability to follow these parameters in a quantitative way.

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