Efficacy of DynaCT digital angiography in the detection of the fistulous point of dural arteriovenous fistulas.

BACKGROUND AND PURPOSE: Identifying the precise hemodynamic features, including the fistulous point, is essential for treatments of dural arteriovenous fistulas (DAVFs). This study illustrates the efficacy of DynaCT digital angiograms obtained from a 3D C-arm CT to directly visualize the location of the fistulous points in DAVFs. MATERIALS AND METHODS: This retrospective study observed 14 consecutive patients with DAVFs, which included 7 cavernous sinuses, 4 transverse-sigmoid sinuses, 2 convexity-superior sagittal sinuses, and 1 tentorial sinus. In the assessment of the practical applicability for the diagnosis of DAVFs, images obtained from 2D digital subtraction angiography (DSA) and DynaCT were comparatively evaluated. RESULTS: In all patients, DynaCT digital angiography could clearly demonstrate the feeding arteries, the fistulous points, and the draining veins. Significant anatomic landmarks for the fistulous points with relationships to osseous structures were also provided. Compared with 2D DSA, DynaCT digital angiograms demonstrated 12 additional findings in 8 patients (57%), including the detection of the fistulous points (n = 7), the feeders (n = 1), the retrograde leptomeningeal drainage (n = 1), the draining veins (n = 1), and the venous anomaly (n = 2). CONCLUSIONS: In comparison with 2D DSA, DynaCT may provide more detailed information to evaluate DAVFs. DynaCT digital angiograms have a high contrast and isotropic spatial resolution, allowing a reliable visualization of small vessels and fine osseous structures. Such detailed information, especially for the location of the fistulous points, could be very useful for either the endovascular or the surgical treatments of DAVFs

Long-term follow-up of endovascular coil embolization for cerebral aneurysms using three-dimensional time-of-flight magnetic resonance angiography.

OBJECTIVES: As endovascular treatment becomes more prevalent, aneurysm recurrence from neck remnants, recanalization, incomplete obliteration and bleeding remain major concerns. In the current analysis, we attempted to identify factors related to disease progression and clinical outcome in patients treated with coil embolization. METHODS: This study included 58 patients who underwent endovascular coil embolization for treatment of intracranial aneurysm. The result of embolization was evaluated with three-dimensional time-of-flight magnetic resonance angiography (TOF MRA) and classified as a complete occlusion, a residual neck (minor, central and marginal types), a residual dome (central and marginal types). Patients were followed up clinically and radiologically. Statistical analyses were performed to establish factors that influenced the occurrence of adverse events such as recurrence of aneurysm. RESULTS: Overall, the complete occlusion rate was 18.8%, the occurrence of a residual neck was 67.2%, and the residual dome rate was 14.1%. The mean clinical follow-up was 31.2 months. Recurrences were found in 18 aneurysms, and major recurrences were retreated with coiling or surgery. The post-treatment study revealed that the marginal-type aneurysm filling has a significant impact on outcome. Thus, perianeurysmal edema was correlated with recurrence of the aneurysm. CONCLUSIONS: Three-dimensional TOF MRA was a sensitive tool for visualizing residual filling of embolized aneurysm and is useful for long-term follow-up of patients

Quantitative Chemical Exchange Saturation Transfer Imaging of Amide Proton Transfer Differentiates between Cerebellopontine Angle Schwannoma and Meningioma: Preliminary Results

Vestibular schwannomas are the most common tumor at the common cerebellopontine angle, followed by meningiomas. Differentiation of these tumors is critical because of the different surgical approaches required for treatment. Recent studies have demonstrated the utility of amide proton transfer (APT)-chemical exchange saturation transfer (CEST) imaging in evaluating malignant brain tumors. However, APT imaging has not been applied in benign tumors. Here, we explored the potential of APT in differentiating between schwannomas and meningiomas at the cerebellopontine angle. We retrospectively evaluated nine patients with schwannoma and nine patients with meningioma who underwent APT-CEST MRI from November 2020 to April 2022 pre-operation. All 18 tumors were histologically diagnosed. There was a significant difference in magnetization transfer ratio asymmetry (MTRasym) values (0.033 ± 0.012 vs. 0.021 ± 0.004; p = 0.007) between the schwannoma and meningioma groups. Receiver operative curve analysis showed that MTRasym values clearly differentiated between the schwannoma and meningioma groups. At an MTRasym value threshold of 0.024, the diagnostic sensitivity, specificity, positive predictive value, and negative predictive values for MTRasym were 88.9%, 77.8%, 80.0%, and 87.5%, respectively. Our results demonstrated the ability of MTRasym values on APT-CEST imaging to discriminate patients with schwannomas from patients with meningiomas

Amide proton transfer MRI differentiates between progressive multifocal leukoencephalopathy and malignant brain tumors: a pilot study

Background: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nerve system caused by the John Cunningham virus. On MRI, PML may sometimes appear similar to primary central nervous system lymphoma (PCNSL) and glioblastoma multiforme (GBM). The purpose of this pilot study was to evaluate the potential of amide proton transfer (APT) imaging for differentiating PML from PCNSL and GBM. Methods: Patients with PML (n = 4; two men; mean age 52.3 ± 6.1 years), PCNSL (n = 7; four women; mean age 74.4 ± 5.8 years), or GBM (n = 11; 6 men; mean age 65.0 ± 15.2 years) who underwent APT-CEST MRI between January 2021 and September 2022 were retrospectively evaluated. Magnetization transfer ratio asymmetry (MTRasym) values were measured on APT imaging using a region of interest within the lesion. Receiver operating characteristics curve analysis was used to determine diagnostic cutoffs for MTRasym. Results: The mean MTRasym values were 0.005 ± 0.005 in the PML group, 0.025 ± 0.005 in the PCNSL group, and 0.025 ± 0.009 in the GBM group. There were significant differences in MTRasym between PML and PCNSL (P = 0.023), and between PML and GBM (P = 0.015). For differentiating PML from PCNSL, an MTRasym threshold of 0.0165 gave diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of 100% (all). For differentiating PML from GBM, an MTRasym threshold of 0.015 gave diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 90.9%, 80.0%, and 100%, respectively. Conclusion: MTRasym values obtained from APT imaging allowed patients with PML to be clearly discriminated from patients with PCNSL or GBM

Recurrence of the cavernous sinus dural arteriovenous fistula at adjacent sinuses following repeated transvenous embolizations: case report and literature review.

We present a unique case of a cavernous sinus (CS) dural arteriovenous fistula (DAVF), which recurred at adjacent sinuses following repeated transvenous embolizations (TVEs). A 68-year-old woman presented with progressive left conjunctival chemosis and diplopia. Cerebral angiography revealed a left CS DAVF, which was completely obliterated by TVE via the left inferior petrosal sinus (IPS). Two years later, the DAVF recurred in the left IPS, and again in the left sigmoid sinus (SS) 3 years after the initial treatment in spite of a second TVE. Moreover, the left SS and the left internal jugular vein, which had been previously stenotic, had been occluded. The third TVE resulted in the complete obliteration of the SS DAVF. CS DAVFs may recur at adjacent sinuses even after complete obliteration by TVE. Careful follow-up is necessary to check for the recurrence of DAVFs, especially in cases with venous flow changes, such as sinus occlusion, following endovascular treatment.The original publication is available at www.springerlink.co

Progressing takayasu arteritis successfully treated by common carotid-internal carotid crossover bypass grafting: technical case report.

OBJECTIVE: This report describes a unique case of Takayasu arteritis with occlusion of the left common carotid artery (CCA) and the right internal carotid artery (ICA), which was successfully treated by right CCA-left ICA crossover bypass grafting using the saphenous vein. The histological findings of the original occluded prosthetic graft are also described. CLINICAL PRESENTATION: A 63-year-old woman with a history of Takayasu arteritis was admitted to our hospital with a history of progressive dizziness, frequent syncopal attacks, and repetitive blurred vision in the left eye. She had undergone repeat transthoracic bypass surgeries, including grafting with the use of a Gore-Tex (W.L. Gore & Associates, Inc., Flagstaff, AZ) prosthesis between the left external ilioaxillary bypass and the left CCA. However, cerebral angiography demonstrated total occlusion of the left CCA, the right ICA, and the bilateral subclavian arteries. On admission, I-iodoamphetamine single-photon emission computed tomography showed a decreased cerebrovascular reactivity to acetazolamide in the bilateral cerebral hemispheres. Moreover, cerebral angiography revealed an occlusion of the Gore-Tex graft, whereas the left ICA was opacified through the retrograde filling in the left external carotid artery. INTERVENTION: Crossover bypass grafting was performed using the saphenous vein between the right CCA and the left ICA. The Gore-Tex graft was partially removed, and myointimal hypertrophy with an inflammatory response around the wall was found histologically. The postoperative course was uneventful. A normalized cerebrovascular reserve in both cerebral hemispheres was demonstrated on I-iodoamphetamine single-photon emission computed tomography. CONCLUSION: Although it is not frequently indicated, crossover bypass grafting using the saphenous vein between bilateral carotid arteries is considered to be a feasible alternative procedure in patients with Takayasu arteritis.This is a non-final version of an article published in final form in Neurosurgery, 65(5), pp.1178-1179; 2008

Progressive perianeurysmal edema preceding the rupture of a small basilar artery aneurysm.

We herein report the first case of progressive perianeurysmal edema preceding the rupture of a small saccular aneurysm, without any intervention or intraluminal thrombosis. A 71-year-old woman was incidentally noted to have a cerebral aneurysm (5mm in diameter) at the lower basilar artery. Twelve months later, magnetic resonance (MR) imaging showed a T2-elongated area around a dome of the aneurysm buried in the brain stem, suggesting perianeurysmal edema formation. Interestingly, the edema progressed with the formation of a bleb, in addition to an increase in size of the aneurysm over the following 3-year period. The aneurysm eventually ruptured as a brain stem hemorrhage without any subarachnoid clots 3 days after the final check-up with MR imaging, by which a significant increase of edema formation with an increase in size of the aneurysm and a marked expansion of the bleb was observed. These findings raise the possibility that bleb formation and an enlargement of a small cerebral aneurysm might also be associated with perianeurysmal edema and a subsequent aneurysmal rupture. In addition to the pulsatile flow and/or compression from the expanded aneurysm, local inflammation in the aneurysm wall may play an important role in such edema formation

Observation of the embolus protection filter for carotid artery stenting

Background: Carotid artery stenting (CAS) in high-surgical-risk patients is considered as an effective alternative to carotid endarterectomy. Since the occurrence of distal embolization with CAS is still major concern, embolus protection device is usually employed during the procedure. We developed a technique for observation of embolus protection filter and evaluate the debris or thrombus microscopically, and the pathological findings were compared with preoperative imaging studies.Patients and Methods: After completing CAS, filter membrane was stained with hematoxylin & eosin (HE) solution and removed from filer strut. Mounting onto a glass slide, filter was evaluated under microscope. Plaque debris and appearance of filter membrane were evaluated and the covered area was measured. The pathological findings were compared with preoperative imaging studies.Results: Microscopical observation of the slide revealed atheromatous debris as well as thrombotic material to the filter membrane. HE stain facilitates the characterization of the debris composition, namely thrombotic debris, calicified debris, organized debris, fibrous debris, lipid-rich debris. The subtypes of debris were consistent with preoperative imaging studies. Thus. in cases of intraprocedural flow impairment, more than 50% of filter area was covered with debris or thrombotic material.Conclusion: Carotid plaque debris captured during carotid stenting with protection filter can be visualized with HE stain on the glass side. This simple method allows us to better understand plaque debris and appearance of embolus protection filter

Intracranial internal carotid artery stenosis with vulnerable plaques successfully treated by stenting under cerebral protection.

Percutaneous transluminal angioplasty with stenting (PTA/stenting) for intracranial atherosclerotic stenoses is usually performed without any protection devices. We report a unique case of atherothrombotic stenosis with the vulnerable plaque in the cavernous portion of the internal carotid artery (ICA), which was successfully treated by PTA/stenting under cerebral protection with the flow reversal system. A 68-year-old woman presented repetitive transient ischemic attacks in the right ICA territory. Cerebral angiography revealed 80% stenosis in the cavernous portion of the right ICA. High-resolution magnetic resonance imaging (HR-MRI) demonstrated lipid-rich plaques at this lesion. PTA/stenting was performed with a proximal protection device under flow reversal. A filter device captured much amount of atherothrombotic debris with lipid-rich macrophages and leukocytes, which was consistent with HR-MRI findings. Some selected cases of intracranial atherothrombotic ICA stenoses may need endovascular treatment with cerebral protection system. HR-MRI is useful to evaluate plaque characteristics even in the cavernous portion of the ICA