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Purpose: To assess whether magnetic resonance (MR) angiography can be used as a noninvasive alternative to intraarterial digital subtraction angiography (DSA) to indicate additional treatment in the follow-up of patients with coil-treated intracranial aneurysms., Materials and Methods: This was an ethics committee-approved multicenter study. Consecutive patients who were scheduled for follow-up intraarterial DSA after coil placement were invited for additional MR angiography after providing written informed consent. Interventional neuroradiologists gave treatment advice (additional treatment, extended follow-up imaging, or discharge from follow-up) for each imaging modality. Agreement between treatment advices based on intraarterial DSA and MR angiographic findings and interobserver agreement were assessed with weighted κ statistics., Results: Agreement between intraarterial DSA- and MR angiography-based treatment recommendations was substantial (κ = 0.73; 95% confidence interval [CI]: 0.66, 0.80). In 34 of the 310 patients (11%), the advice was additional treatment based on findings of both modalities. In six patients (2%), the advice based on intraarterial DSA findings was additional treatment, while that based on MR angiographic findings was extended follow-up imaging; therefore, none of these patients were discharged from follow-up on the basis of MR angiographic findings. In six other patients (2%), the advice based on MR angiographic findings was additional treatment, while that based on intraarterial DSA findings was extended follow-up imaging (four patients), discharge from follow-up (one patient), and noninterpretable DSA (one patient). Extended follow-up imaging was suggested for 37 patients (12%) after intraarterial DSA and for 49 patients (16%) after MR angiography (difference: 4%; 95% CI: -0.6%, 8.4%). Interobserver agreement was substantial for intraarterial DSA (κ = 0.73; 95% CI: 0.64, 0.82) and moderate for MR angiography (κ = 0.53; 95% CI: 0.36, 0.70)., Conclusion: The overall proportion of patients advised to undergo additional treatment is similar based on intraarterial DSA and MR angiographic findings, with only few individual discrepancies. MR angiography can therefore be used for therapeutic decision making in the follow-up of patients with coil-treated aneurysms., Supplemental Material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112608/-/DC1., (© RSNA, 2012.)

Purpose: To determine the test characteristics of magnetic resonance (MR) angiography in the assessment of occlusion of aneurysms treated with coil placement., Materials and Methods: This was an ethics committee-approved multicenter study. written informed consent was obtained in 311 patients with 343 aneurysms, who had been treated with coil placement and were scheduled for routine follow-up with intraarterial digital subtraction angiography (DSA). Thirty-five patients participated two or three times. Either 3.0- or 1.5-T time-of-flight (TOF) and contrast material-enhanced MR angiography were performed in addition to intraarterial DSA. Aneurysm occlusion was evaluated by independent readers at DSA and MR angiography. The test characteristics of MR angiography were assessed by using DSA as the standard. The area under the receiver operating characteristic curve (AUC) was calculated for 3.0- versus 1.5-T MR angiography and for TOF versus contrast-enhanced MR angiography, and factors associated with discrepancies between MR angiography and DSA were assessed with logistic regression., Results: Aneurysm assessments (n = 381) at DSA and MR angiography were compared. Incomplete occlusion was seen at DSA in 88 aneurysms (23%). Negative predictive value of MR angiography was 94% (95% confidence interval [CI]: 91%, 97%), positive predictive value was 69% (95% CI: 60%, 78%), sensitivity was 82% (95% CI: 72%, 89%), and specificity was 89% (95% CI: 85%, 93%). AUCs were similar for 3.0- (0.90 [95% CI: 0.86, 0.94]) and 1.5-T MR (0.87 [95% CI: 0.78, 0.95]) and for TOF MR (0.86 [95% CI: 0.81, 0.91]) versus contrast-enhanced MR (0.85 [95% CI: 0.80, 0.91]). A small residual lumen (odds ratio, 2.1 [95% CI: 1.1, 4.3]) and suboptimal projection at DSA (odds ratio, 5.5 [95% CI: 1.5, 21.0]) were independently associated with discordance between intraarterial DSA and MR angiography., Conclusion: Documentation of good diagnostic performance of TOF MR angiography at both 1.5 and 3.0 T in the current study represents an important step toward replacing intraarterial DSA with MR angiography in the follow-up of patients with aneurysms treated with coils.

Purpose: To evaluate the effects of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) on the human brain by using diffusion and perfusion magnetic resonance (MR) imaging., Materials and Methods: Eight abstinent ecstasy users and six ecstasy nonusers underwent diffusion and perfusion MR imaging. Apparent diffusion coefficient and relative cerebral volume maps were reconstructed. Differences in apparent diffusion coefficient values and relative cerebral volume ratios between the groups were analyzed with the Mann-Whitney-Wilcoxon test. The relationship between apparent diffusion coefficient and relative cerebral volume and the extent of previous ecstasy use was investigated with Spearman rank correlation., Results: Apparent diffusion coefficient values (0.84 vs 0.65 x 10(-5) cm(2)/sec, P <.025) and relative cerebral volume ratios (1.22 vs 1.01, P <.025) were significantly higher in the globus pallidus of ecstasy users compared with nonusers, respectively. Increases in pallidal relative cerebral volume were positively correlated with the extent of previous use of ecstasy (rho = 0.73, P <.04)., Conclusion: Ecstasy use is associated with tissue changes in the globus pallidus. These findings are in agreement with findings in case reports, suggesting that the globus pallidus is particularly sensitive to the effects of ecstasy.

Purpose: To investigate whether coronal multiplanar reconstruction (MPR) images of the petrosal bone from axial spiral computed tomographic (CT) data obtained with 0.5-mm collimation can replace direct coronal sequential CT scans obtained with 0.5- or 1.0-mm collimation., Materials and Methods: The differences in diagnostic quality between thin-section coronal sequential CT scans of 24 petrosal bones in 12 patients and matched MPR images were assessed by five observers. The matched MPR images were calculated with both trilinear and tricubic interpolation. Image resolution was determined by measuring the three-dimensional point spread function., Results: All observers preferred tricubically interpolated MPR images over trilinearly interpolated images. Subjective differences in image quality between direct coronal scans and matched tricubically interpolated MPR images were small. Only the direct coronal scans with the highest image quality (0.5-mm collimation, 465 mAs) were judged to be slightly better than the matched MPR images. With regard to direct coronal scans obtained at 245 mAs and/or 1.0-mm collimation, either there was no preference or the MPR images were preferred., Conclusion: Coronal MPR images from axial spiral CT obtained with 0.5-mm collimation can replace direct coronal sequential CT scans.

Purpose: To assess the diagnostic yield of magnetic resonance (MR) imaging in patients with symptoms and signs related to the trigeminal nerve., Materials and Methods: Medical records and MR imaging studies in 112 consecutive patients referred for MR imaging over 5 years were evaluated. MR images were independently reviewed by two neuroradiologists unaware of the clinical findings. Signs and symptoms at presentation were associated with either a positive or negative MR imaging outcome. Logistic regression analysis was performed to identify clinical variables related to imaging results., Results: Sixty-eight (61%) patients had positive MR imaging findings related to symptoms and signs. Trigeminal neuralgia was correlated with a negative MR imaging outcome (P < .001). Numbness (P < .01), impaired sensation (P < .001), other neurologic symptoms and signs (P < .01), progression of symptoms and signs (P < .001), and duration of symptoms of less than 1 year (P < .001) corresponded to a positive MR imaging outcome. Two regression models, each with three clinical parameters (progression, duration < 1 year, and trigeminal neuralgia or impaired sensation), had comparable accuracy for prediction of the MR imaging outcome., Conclusion: Clinical findings can be used to identify groups in which a high or a low yield of MR imaging is correlated with symptoms and signs related to the trigeminal nerve.

Purpose: To compare two magnetic resonance (MR) imaging techniques for demonstration of vascular contact with the trigeminal nerve., Materials and Methods: Thirteen patients with unilateral trigeminal neuralgia and 50 control subjects underwent three-dimensional fast inflow with steady-state precession (FISP) and contrast material-enhanced magnetization-prepared rapid acquisition gradient-echo (MP-RAGE) MR imaging. The images were independently reviewed by two neuroradiologists, who were blinded to the clinical details. Six of the 13 patients underwent surgery., Results: Vascular contact with the trigeminal nerve at the root entry zone was seen on FISP images in 10 of 13 (77%) symptomatic nerves and in eight of 113 (7%) asymptomatic nerves (P < .001). MP-RAGE and FISP images demonstrated arterial contacts equally well. MP-RAGE images demonstrated one additional venous contact at the root entry zone in a patient with ipsilateral trigeminal neuralgia. Interobserver agreement was good for both FISP (kappa = 0.69) and MP-RAGE (kappa = 0.78) images. The presence of vascular contact at the root entry zone, seen on preoperative MR images, was confirmed in all six patients who underwent surgery., Conclusion: Both FISP and MP-RAGE MR imaging are useful in demonstrating vascular contact with the trigeminal nerve at the root entry zone in patients with trigeminal neuralgia.

Neuropathy of the trigeminal nerve can involve its full course, from its nuclei in the brain stem to its peripheral branches. The nerve can be divided into four segments--brain stem, cistern, the Meckel cave and cavernous sinus, and extracranial--and consideration of the pathologic entities by these locations simplifies the differential diagnosis. Multiple sclerosis, infarct, and glioma are the most common abnormalities in the brain stem leading to trigeminal neuropathy. The most common cisternal cause is neurovascular compression, followed by acoustic and trigeminal schwannomas, meningiomas, epidermoid cysts, lipomas, and metastases. Trigeminal neuropathy arising from the Meckel cave and cavernous sinus is frequently due to meningiomas, trigeminal schwannomas, epidermoid cysts, metastases, pituitary adenomas, and aneurysms. Malignant tumors, which may demonstrate perineural tumor spread, are the most common extracranial cause. Because the clinical findings do not permit accurate lesion localization, magnetic resonance imaging must be used to visualize the entire course of the fifth cranial nerve. The standard study should include T2-weighted images of the whole brain and high-resolution axial and coronal T1-weighted images of the skull base obtained with and without contrast material enhancement.