Comparison of 3.0- and 1.5-T Three-dimensional Time-of-Flight MR Angiography in Moyamoya Disease: Preliminary Experience

Background: To evaluate the value of time-of-flight MR angiography (TOF MRA) for the assessment of extracranial-intracranial (EC-IC) bypass in Moyamoya disease in comparison with computed tomography angiography (CTA). Patients and methods: A consecutive series of 23 patients with Moyamoya disease were analyzed retrospectively. Twenty three patients underwent 25 procedures of extracranial-intracranial bypass. Cranial CTA was performed within one week after the surgery to assess bypass patency. Then TOF MRA was scanned within 24 h after CTA on a 3T MRI system. Using 5-point scales (0 = poor to 4 = excellent), two radiologists rated the image quality and vessel integrity of bypass for three segments (extracranial, trepanation, intracranial). Results: Image quality was high in both CTA and TOF MRA (mean quality score 3.84 ± 0.37 and 3.8 ± 0.41), without statistical difference (p = 0.66). Mean scores of TOF MRA with respect to bypass visualization were higher than CTA in the intracranial segment (p = 0.026). No significant difference of bypass visualization regarding the extracranial and trepanation segments was found between TOF MRA and CTA (p = 0.66 and p = 0.34, respectively). For the trepanation segment, TOF MRA showed pseudo lesions in 2 of all 25 cases. Conclusions: 3T TOF MRA, a non-contrast technique not exposing the patients to radiation, proved to be at least equal to CTA for the assessment of EC-IC bypass, and even superior to CTA with respect to the intracranial segment. In addition, readers should be aware of a potential overestimation showing focal pseudo lesions of the bypass at the trepanation segment in TOF MRA.

Download Full-text

Influence of imaging parameters, flow velocity, and pulsatile flow on three-dimensional time-of-flight MR angiography: experimental studies

European Journal of Radiology ◽

10.1016/s0720-048x(96)01152-7 ◽

1997 ◽

Vol 26 (1) ◽

pp. 83-91 ◽

Cited By ~ 16

Author(s):

Takao Kodama ◽

Katsushi Watanabe

Keyword(s):

Flow Velocity ◽

Pulsatile Flow ◽

Mr Angiography ◽

Experimental Studies ◽

Three Dimensional ◽

Time Of Flight ◽

Imaging Parameters

Download Full-text

Three-dimensional volume rendering for magnetic resonance angiography in the screening and preoperative workup of intracranial aneurysms

Journal of Neurosurgery ◽

10.3171/jns.1996.85.6.1050 ◽

1996 ◽

Vol 85 (6) ◽

pp. 1050-1055 ◽

Cited By ~ 40

Author(s):

Philippe P. Maeder ◽

Reto A. Meuli ◽

Nicolas de Tribolet

Keyword(s):

Magnetic Resonance ◽

Volume Rendering ◽

Intracranial Aneurysms ◽

Mr Angiography ◽

Three Dimensional ◽

Time Of Flight ◽

Conventional Angiography ◽

Content Type ◽

Aneurysm Neck ◽

Fine Print

✓ This study was undertaken to evaluate the capacity of three-dimensional (3-D) time-of-flight (TOF) magnetic resonance (MR) angiography with VoxelView (VV) 3-D volume rendering to detect and characterize intracranial aneurysms and to compare this rendering technique with that of maximum intensity projection (MIP). Forty patients with a total of 53 intracranial aneurysms (10 giant and subgiant, 43 saccular) were consecutively admitted to University Hospital, Lausanne, Switzerland, and investigated with 3-D TOF MR angiography. Source images of the 43 saccular aneurysms were processed with both MIP and VV. The aneurysm detection rate of the two techniques and their ability to characterize features of an aneurysm, such as its neck and its relation to the parent vessel, were compared. Intraarterial digital subtraction angiography was used as the gold standard to which these techniques could be compared and evaluated. Four aneurysms, less than 3 mm in size, were missed using MIP compared to three missed using VV. The representation of aneurysmal morphology using VV was superior to that found using conventional angiography in nine cases, equal in 16 cases, and inferior in seven cases. The representation of the aneurysm neck using VV was superior to MIP in 21 cases, equal in 17 cases, and inferior in one case; it was superior to that shown using conventional angiography in 10 cases, equal in 18 cases, and inferior in four cases. Time-of-flight MR angiography in conjunction with both MIP and VV 3-D reconstruction was able to visualize all aneurysms that were larger than 3 mm. Compared to MIP, VV provides a better definition of the aneurysm neck and the morphology of saccular aneurysms, making VV valuable for use in a preoperative diagnostic workup.

Download Full-text