The aim of this study was to determine the feasibility and usefulness of contrast-enhanced magnetic resonance angiography (CE-MRA) and 3-dimensional (3D) time-of-flight (TOF) MRA for follow-up of intracranial aneurysms treated using the Enterprise stent.
Five aneurysm cases using the Enterprise stent were prospectively analyzed and were followed up with CE-MRA, 3D TOF MRA, and digital subtraction angiography (DSA). Depictions of parent artery lumen and the aneurysm neck with 3D TOF MRA and CE-MRA were compared with those of DSA.
In all cases, on 3D TOF MRA, it was difficult to evaluate the parent artery lumen and aneurysm neck owing to the significant artifacts from the stent. Contrast-enhanced MRA sufficiently demonstrated parent artery lumen and aneurysm neck distinctly and as clear as DSA did in all cases.
For follow-up after coiling with an Enterprise stent, CE-MRA may be necessary to avoid susceptibility artifacts caused by the stent.
"According to our data, there was a 12.7% chance of in-stent stenosis (more than a 33% luminal loss), as demonstrated by DSA (9). Recently, there have been some reports that contrast-enhanced (CE) MRA had better image quality of the stented parent arteries than the TOF MRA (2, 4, 5, 18, 19). They also insisted that, especially in large residual aneurysms, the sensitivity of the CE MRA might be superior to the TOF MRA. "
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine the interobserver and intermodality agreement in the interpretation of time-of-flight (TOF) MR angiography (MRA) for the follow-up of coiled intracranial aneurysms with the Enterprise stent.
Two experienced neurointerventionists independently reviewed the follow-up MRA studies of 40 consecutive patients with 44 coiled aneurysms. All aneurysms were treated with assistance from the Enterprise stent and the radiologic follow-up intervals were greater than 6 months after the endovascular therapy. Digital subtraction angiography (DSA) served as the reference standard. The degree of aneurysm occlusion was determined by an evaluation of the maximal intensity projection (MIP) and source images (SI) of the TOF MRA. The capability of the TOF MRA to depict the residual flow within the coiled aneurysms and the stented parent arteries was compared with that of the DSA.
DSA showed stable occlusions in 25 aneurysms, minor recanalization in 8, and major recanalization in 11. Comparisons between the TOF MRA and conventional angiography showed that the MIP plus SI had almost perfect agreement (κ = 0.892, range 0.767 to 1.000) and had better agreement than with the MIP images only (κ = 0.598, range 0.370 to 0.826). In-stent stenosis of more than 33% was observed in 5 cases. Both MIP and SI of the MRA showed poor depiction of in-stent stenosis compared with the DSA.
TOF MRA seemed to be reliable in screening for aneurysm recurrence after coil embolization with Enterprise stent assistance, especially in the evaluation of the SI, in addition to MIP images in the TOF MRA.
Korean journal of radiology: official journal of the Korean Radiological Society 01/2014; 15(1):161-8. DOI:10.3348/kjr.2014.15.1.161 · 1.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PurposeTo assess the usefulness of TOF MRA in evaluation of coil embolized cerebral aneurysms, detection of possible complications such as incomplete occlusion (residual aneurysm) and recurrence and peri-aneurysmal edema.Patients and methodsThis study included 23 patients with coil embolized cerebral aneurysm who underwent follow up by TOF MRA for 2 years. Findings were classified as complete occlusion, incomplete occlusion and recurrence. Recurrent and residual cases were correlated with neurosurgical assessment.ResultsSixteen patients (69.6%) had complete persistent occlusion, 4 patients (17.4%) had recurrent aneurysms and 3 patients (13%) had residual aneurysms. Among the 7 patients of residual/recurrent aneurysms: 5 were dome and 2 were neck shaped. All recurrent cases showed peri-aneurysmal edema in the initial after coil scan. Recurrent cases were significantly correlated with initial size (more than 6 mm) and presence of peri-aneurysmal edema.ConclusionMRA is a safe and accurate non-invasive follow-up imaging method that can be used for evaluation of cerebral aneurysms after embolization. It had the same accuracy of DSA. Three-dimensional TOF MRA clearly demonstrates residual/recurrent aneurysm neck and sac. MRA source images yields more information about cerebral infarction, bleeding and atrophy.
Egyptian Journal of Radiology and Nuclear Medicine 03/2012; 43(1):33–40. DOI:10.1016/j.ejrnm.2011.11.005
[Show abstract][Hide abstract] ABSTRACT: The use of contrast media and the time-resolved imaging of contrast kinetics (TRICKS) technique have some theoretical advantages over time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment. We prospectively compared the diagnostic performance of TRICKS and TOF-MRA with digital subtracted angiography (DSA) in the assessment of occlusion of embolized aneurysms.
Seventy-two consecutive patients with 72 aneurysms were examined 3 months after embolization. Test characteristics of TOF-MRA and TRICKS were calculated for the detection of residual flow. The results of quantification of flow were compared with weighted kappa. Intraobserver and interobserver reproducibility was determined.
The sensitivity of TOF-MRA was 85% (95% CI, 65-96%) and of TRICKS, 89% (95% CI, 70-97%). The specificity of both methods was 91% (95% CI, 79-98%). The accuracy of the flow quantification ranged from 0.76 (TOF-MRA) to 0.83 (TRICKS). There was no significant difference between the methods in the area under the ROC curve regarding both the detection and the quantification of flow. Intraobserver reproducibility was very good with both techniques (kappa, 0.86-0.89). The interobserver reproducibility was moderate for TOF-MRA and very good for TRICKS (kappa, 0.74-0.80).
In this study, TOF-MRA and TRICKS presented similar diagnostic performance; therefore, the use of time-resolved contrast-enhanced MRA is not justified in the follow-up of embolized aneurysms.
Medical science monitor: international medical journal of experimental and clinical research 06/2012; 18(7):MT60-5. DOI:10.12659/MSM.883199 · 1.43 Impact Factor
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