MR Diffusional Kurtosis Imaging–Based Assessment of Brain Microstructural Changes in Patients with Moyamoya Disease before and after Revascularization

Introduction —It is well known that surgical revascularization can improve cerebral hemodynamics and prevent further ischemic cerebrovascular events in moyamoya disease. However, a certain subgroup of patients repeats ischemic attacks even after surgery because of insufficient surgery or disease progression during follow-up periods. Hypothesis —Relevant designs and techniques in additional bypass surgery can resolve ischemic cerebrovascular events in patients with moyamoya disease refractory to previous bypass surgery. Methods —This study included totally 7 patients (9 hemispheres) with moyamoya disease refractory to previous bypass surgery. There were 5 children and 2 adults. They underwent previous bypass surgery in Japan and Europe 6 to 240 months before admission. Based on precise clinical and radiological analysis, cerebrovascular events were considered to occur because of insufficient bypass surgery in 5 patients and disease progression in the ipsilateral posterior cerebral artery in 2. Surgical strategies included wide craniotomy to cover the area where cerebral hemodynamics is still impaired and appropriate bypass procedures such as STA-MCA anastomosis, OA-PCA anastomosis, and indirect bypass. Using [123]I-IMP SPECT or [15]O-gas PET, cerebral hemodynamics was precisely examined before and after surgery Results —Postoperative course was uneventful and cerebral hemodynamics significantly improved in all 7 patients. Postoperative cerebral angiography revealed that additional bypass provided collateral blood flow to ischemic area before surgery. Ischemic cerebrovascular events rapidly resolved in 5 patients and gradually decreased in 2. Conclusion —This study strongly suggests adequate surgical design and procedures can resolve ischemic cerebrovascular events in patients with moyamoya disease refractory to previous bypass surgery.

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Application value of diffusional kurtosis imaging (DKI) in evaluating microstructural changes in the spinal cord of patients with early cervical spondylotic myelopathy

Clinical Neurology and Neurosurgery ◽

10.1016/j.clineuro.2017.03.015 ◽

2017 ◽

Vol 156 ◽

pp. 71-76 ◽

Cited By ~ 3

Author(s):

Daowei Li ◽

Xiaoming Wang

Keyword(s):

Spinal Cord ◽

Cervical Spondylotic Myelopathy ◽

Microstructural Changes ◽

Diffusional Kurtosis Imaging

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Posterior cerebral artery stenosis and posterior circulation revascularization surgery in pediatric patients with moyamoya disease

Journal of Neurosurgery Pediatrics ◽

10.3171/2018.1.peds17367 ◽

2018 ◽

Vol 21 (6) ◽

pp. 632-638 ◽

Cited By ~ 3

Author(s):

Tomomi Kimiwada ◽

Toshiaki Hayashi ◽

Reizo Shirane ◽

Teiji Tominaga

Keyword(s):

Moyamoya Disease ◽

Cerebral Artery ◽

Pediatric Patients ◽

Posterior Cerebral Artery ◽

Posterior Circulation ◽

Initial Diagnosis ◽

Occipital Artery ◽

Anterior Circulation ◽

Before And After ◽

Revascularization Surgery

OBJECTIVESome pediatric patients with moyamoya disease (MMD) present with posterior cerebral artery (PCA) stenosis before and after anterior circulation revascularization surgery and require posterior circulation revascularization surgery. This study evaluated the factors associated with PCA stenosis and assessed the efficacy of posterior circulation revascularization surgery, including occipital artery (OA)–PCA bypass, in pediatric patients with MMD.METHODSThe presence of PCA stenosis before and after anterior circulation revascularization surgery and its clinical characteristics were investigated in 62 pediatric patients (< 16 years of age) with MMD.RESULTSTwenty-three pediatric patients (37%) with MMD presented with PCA stenosis at the time of the initial diagnosis. A strong correlation between the presence of infarction and PCA stenosis before anterior revascularization was observed (p < 0.001). In addition, progressive PCA stenosis was observed in 12 patients (19.4%) after anterior revascularization. The presence of infarction and a younger age at the time of initial diagnosis were risk factors for progressive PCA stenosis after anterior revascularization (p < 0.001 and p = 0.002, respectively). Posterior circulation revascularization surgery, including OA-PCA bypass, was performed in 9 of the 12 patients with progressive PCA stenosis, all of whom showed symptomatic and/or radiological improvement.CONCLUSIONSPCA stenosis is an important clinical factor related to poor prognosis in pediatric MMD. One should be aware of the possibility of progressive PCA stenosis during the postoperative follow-up period and consider performing posterior circulation revascularization surgery.

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MR Angiography of Moyamoya Disease Before and After Encephaloduroarteriosynangiosis

American Journal of Roentgenology ◽

10.2214/ajr.174.1.1740195 ◽

2000 ◽

Vol 174 (1) ◽

pp. 195-200 ◽

Cited By ~ 28

Author(s):

Hye-Kyung Yoon ◽

Hyung-Jin Shin ◽

Munhyang Lee ◽

Hong Sik Byun ◽

Dong Gyu Na ◽

...

Keyword(s):

Moyamoya Disease ◽

Mr Angiography ◽

Before And After

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Physical and Magnetic Modification of Co/Pt Multilayers by Ion Irradiation

Microscopy and Microanalysis ◽

10.1017/s1431927602020275 ◽

2002 ◽

Vol 8 (4) ◽

pp. 319-332 ◽

Cited By ~ 10

Author(s):

G.J. Kusinski ◽

G. Thomas

Keyword(s):

Magnetic Anisotropy ◽

Ion Irradiation ◽

Strain Relaxation ◽

Magnetic Domain ◽

Perpendicular Magnetic Anisotropy ◽

Spin Reorientation ◽

Microstructural Changes ◽

Spin Reorientation Transition ◽

Before And After ◽

Magnetic Modification

The microstructure of Co/Pt multilayers with large perpendicular magnetic anisotropy (PMA) was investigated before and after energetic ion irradiation. No pronounced microstructural changes were detected at ion doses sufficient to completely reduce the PMA and cause a spin reorientation transition to in-plane. Ion-induced displacement of Co and Pt atoms near Co/Pt interfaces lead to local “roughening” and Co layer strain relaxation, reducing the PMA. The magnetic domain confinement induced by ion irradiation and magnetic patterning by selective ion irradiation were also investigated.

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Cerebral blood flow, transit time, and apparent diffusion coefficient in moyamoya disease before and after acetazolamide

Neuroradiology ◽

10.1007/s00234-016-1766-y ◽

2016 ◽

Vol 59 (1) ◽

pp. 5-12 ◽

Cited By ~ 15

Author(s):

Christian Federau ◽

Soren Christensen ◽

Zungho Zun ◽

Sun-Won Park ◽

Wendy Ni ◽

...

Keyword(s):

Blood Flow ◽

Diffusion Coefficient ◽

Cerebral Blood Flow ◽

Apparent Diffusion Coefficient ◽

Transit Time ◽

Moyamoya Disease ◽

Before And After ◽

Apparent Diffusion

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Abstract TMP40: Revascularization in Patients with Moyamoya Decreases Abnormally High Posterior Circulation Arterial Flows Measured by Quantitative Magnetic Resonance Angiography

Stroke ◽

10.1161/str.44.suppl_1.atmp40 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Ramon Navarro ◽

Robert Lober ◽

Abdullah Feroze ◽

Nadia Khan ◽

Gary K Steinberg

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Moyamoya Disease ◽

Basilar Artery ◽

Posterior Cerebral Artery ◽

Posterior Circulation ◽

Arterial Circulation ◽

Non Invasive ◽

Post Surgery ◽

Before And After

Introduction: Moyamoya disease and syndrome are well known to affect the anterior cerebral circulation by progressive steno-occlusive disease of the supraclinoid internal carotid arteries. Less attention has been paid to changes in posterior arterial circulation hemodynamics in this condition. We sought to better understand the latter by using a relatively novel non-invasive imaging technique: quantitative magnetic resonance angiography (qMRA). Hypothesis: We assessed the utility of qMRA to detect changes in arterial posterior arterial circulation flows before and after surgical revascularization. Methods: Retrospective review of patients who met the following inclusion criteria: (1) diagnosis of moyamoya disease or syndrome with revascularization surgery at the Stanford University between September 2008 and March 2012; (2) preoperative and postoperative qMRA scans on record within a two-year time frame; and (3) high-quality qMRA images without motion artifact. Cerebral blood-vessel flow was quantified after non-contrast magnetic resonance imaging through the use of a commercially available software tool: non-invasive optimal vessel analysis (NOVA, VasSol, Chicago, USA). Results: A total of 191 patients underwent 281 surgeries in this period of time. Of these, a cohort of 64 patients (78% female, mean age 38.5 years, 55% unilateral disease) had preoperative and postoperative qMRA studies. Preoperative arterial flows in the posterior circulation were markedly elevated compared to normative data. These flows significantly decreased after revascularization (94% direct STA-MCA bypass): right posterior cerebral artery 145 ml/min pre-surgery, 123 ml/min post-surgery, p=0.005; basilar artery 264 ml/min pre-surgery, 222ml/min post-surgery, p=0.0038. Conclusion: Quantitative MRA shows that posterior circulation arterial flows are markedly increased in patients with moyamoya. After revascularization, there is an overall decrease in these flows that is significant in the basilar artery and right posterior cerebral artery. Further use of qMRA might be warranted to better understand moyamoya hemodynamics before and after surgery.

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Assessment of wood microstructural changes after one-stage thermo-hydro treatment (THT) by micro X-ray computed tomography

Holzforschung ◽

10.1515/hf-2014-0337 ◽

2016 ◽

Vol 70 (2) ◽

pp. 167-177 ◽

Cited By ~ 4

Author(s):

Vladimirs Biziks ◽

Jan Van den Bulcke ◽

Juris Grinins ◽

Holger Militz ◽

Bruno Andersons ◽

...

Keyword(s):

Computed Tomography ◽

Cell Types ◽

Volume Reduction ◽

Fiber Volume ◽

Microstructural Changes ◽

X Ray ◽

Lumen Volume ◽

Before And After ◽

X Ray Computed ◽

The Individual

AbstractThe microstructural changes in a selection of softwoods and hardwoods resulting from thermo-hydro treatment (THT) at 160°C were examined by means of a state-of-the-art micro X-ray computed tomography. A dedicated X-ray scanning and volumetric processing protocol was developed. All reconstructed volumes had an approximate voxel pitch between 0.8 and 1.2 μm3. The microstructures of the same needle-shaped specimens before and after THT were visualized, and the individual parameters (maximum opening and lumen volume) for various cell types were quantified and compared. The highest values of substance volume were recorded for the ash sapwood (81%) and spruce specimens (72%). After THT, a significant correlation was found between the mass loss determined by gravimetry and the X-ray volume loss. The largest change occurred in the lumen volume of several tissue components, such as libriform fibers, tracheids, and ray parenchyma. The average aspen fiber volume reduction after THT was 31%, a value 2.6 times higher than the volume reduction of the average vessels. The porosity of ash sapwood increased from 41 to 56%, whereas the porosity of birch decreased from 34 to 29%.

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Morphologic Changes in the Foveal Photoreceptor Layer before and after Laser Treatment in Acute and Chronic Central Serous Chorioretinopathy Documented in Spectral-Domain Optical Coherence Tomography

Journal of Ophthalmology ◽

10.1155/2013/361513 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Dominik Odrobina ◽

Iwona Laudańska-Olszewska ◽

Piotr Gozdek ◽

Mariusz Maroszyński ◽

Michael Amon

Keyword(s):

Laser Treatment ◽

Central Serous Chorioretinopathy ◽

Subretinal Fluid ◽

Chronic Central Serous Chorioretinopathy ◽

Microstructural Changes ◽

Photoreceptor Layer ◽

Before And After ◽

Group A ◽

Group B

Purpose. To analyze microstructural changes in the external limiting membrane (ELM) and photoreceptor layer before and after early and late conventional laser treatment in central serous chorioretinopathy (CSC) in 12 months follow-up study.Methods. A retrospective observational study included Group A: 19 patients (19 eyes) with symptomatic acute CSC and Group B: 16 patients (16 eyes) with symptomatic chronic CSC. Retinal microstructural changes were analyzed with SD-OCT paying a particular role in examining the photoreceptor layer and ELM.Results. The length of the photoreceptors, prior to treatment, was approximately 84 μm in Group A and 82,5 μm in Group B. Twelve months after laser treatment, photoreceptor length was approximately 49 μm in Group A and 43 μm (range 20–55 μm) in Group B. No patients in Group A had noticeable photoreceptor defects nor ELM defects, but in 15 eyes in Group B photoreceptor and ELM defects were detected ().Conclusions. When analyzing the photoreceptor layer and ELM during active CSC, it is not possible to evaluate any irreversible changes which have already occurred in this layer. Damage to the photoreceptor layer and ELM in patients with chronic CSC was only found after laser treatment and the absorption of subretinal fluid.

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