CT perfusion in Moyamoya disease

Transcription

1 CT perfusion in Moyamoya disease Poster No.: C-1726 Congress: ECR 2015 Type: Scientific Exhibit Authors: K. C. Lam, C. P. Tsang, K. K. Wong, R. LEE ; HK, Hong Kong/HK Keywords: Hemodynamics / Flow dynamics, Computer ApplicationsDetection, diagnosis, CT-Angiography, CT, Neuroradiology brain DOI: /ecr2015/C Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 9

2 Aims and objectives To describe and demonstrate the characteristic CT perfusion feature in Moyamoya disease. To investigate the role of CT perfusion reassessment scan in Moyamoya disease after revascularization surgery. Methods and materials Between December 2009 and November 2014, 31 consecutive patients (age 6-48, mean age 35) with angiographic or MRI evidence of MoyaMoya disease were referred for CT perfusion studies. CT perfusion studies were performed with Lightspeed, Lightspeed16, Lightspeed VCT 64 (General Electric, Milwaukee, USA) or Aquilion One 320 (Toshiba Medical Systems Corporation, Tochigi-ken, Japan). A 20 gauge angiocatheter was inserted at the antecubital fossae. Contrast (1ml/kg Iopamiro 370 Bracco Milano) injection was made at a rate of 2-3ml/second. Dynamic volumetric aquisition was performed by Toshiba 320-slice CT scanner. In other GE scanners, perfusion scan of 4-cm thickness of brain tissue at the level of basal ganglia was acquired. CT perfusion images were processed with Vitrea version 6 (Vital Imges Inc), generating the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP) and delayed flow functional maps by SVD (Singular value decomposition) or SVD+ algorithm. All the images were reviewed by two radiologists independently with consensus made by agreement. Results Demographic data and clinical aspects: Page 2 of 9

3 Twelve of the 31 patients (39%) had both pre-operative and post-operative CT perfusion scan performed. There are a total of 17 revascularized hemispheres. Presenting symptoms include (number of patient; percentage): Weakness (23; 74%) Facial or limb numbness (9; 29%) Slurring of speech (8; 26%) Headache (3; 10%) Dizziness (3; 10%) Seizure (3; 10%) Amnesia (1; 3%) Some of the patients presented with multiple neurological symptoms. Four out of 31 patients (13%) had intraventicular bleeding found during their first presentation. One of them was due to ruptured posterior choroidal aneurysm. No obvious aneurysm was seen in remaining three patients. Two patients had Down's syndrome. Radiological Findings: Twelve of out 36 patients had both pre-operative and post-operative CT perfusion scan for comparison. These scans include 17 re-vascularized hemispheres for us to study CT perfusion parameters change after operation. The perfusion scans demonstrated prolonged MTT with reduced CBF over the deep white matter of bilateral anterior watershed areas (between ACA and MCA territories) in all 31 patients (100%). The posterior watershed areas also showed similar involvement in 6 patients (19%) of the patients. Twelve of the 31 patients (39%) had both pre-operative and post-operative CT perfusion scan performed. All but one patients showed interval improvement of CT perfusion parameters, i.e. increased CBF, reduced CBV, shortened MTT, shortened TTP or reduced delayed flow. Five out of the 12 patients (42%) had moyamoya vessels visualized in lentiform nuclei in pre-operative CT angiogram. Four out of the 5 patients had regression of moyamoya vessel, reduction of CBV and shortening of MTT in lentiform nuclei. Case Illustration: A 33-year-old lady with Moyamoya disease underwent left superficial temporal arterymiddle cerebral artery (STA-MCA) bypass surgery and subsequently right STA-MCA bypass. First re-assessment CT perfusion scan was performed 6 months after left bypass surgery and second scan was performed 2.5 years after right STA-MCA bypass surgery. Page 3 of 9

4 Interval improvement of CBF, CBV and MTT was seen. Gradual reduction of delayed flow from collaterals was also observed. Magnetic resonance angiography (MRA) also confirmed regression of moyamoya vessels at bilateral basal ganglia. Images for this section: Fig. 1: This is a 33-year-old lady who presented with right sided weakness and slurring of speech. CT angiogram showed extensive moyamoya vessels bilaterally. Bilateral anterior, middle and posterior cerebral arteries are markedly attenuated (not shown). Rest of the following images belong to the same patient. Fig. 2: MRA was performed after bilateral superficial temporal artery - middle cerebral artery (STA-MCA) bypass and significant regression of the moyamoya vessels was evident. Page 4 of 9

5 Fig. 3: (CBF) Five sets of CT perfusion images without azetazolamide challenge. Increased CBF is seen after revascularization especially over right hemispheres. Fig. 4: (CBV) Interval reduction of CBV is seen at both cortical region and basal ganglia. This is in keeping with regression of cortical collaterals and moyamoya vessels at basal ganglia. Reduced vasodilation may also play a role. Page 5 of 9

6 Fig. 5: (MTT) Serial improvement of mean transit time. Fig. 6: (TTP) Time to peak is dependent on the size or shape of the arterial time density curve. Delay map is more useful for quantitative comparison and follow-up studies as it is insensitive to the arterial curve. Page 6 of 9

7 Fig. 7: (Delayed flow) Gradual reduction of delayed flow due to collateral vessels. Page 7 of 9

8 Conclusion CT perfusion study can be a tool to assess perfusion change after revascularization in Moyamoya disease. Future study can focus on quantitative aspect of CT perfusion scan and to correlate radiological with clinical findings. Personal information Address correspondence to Dr KC Lam, Resident of Department of Radiology, Queen Mary Hospital, Pokfulam, Hong Kong SAR, China ( lkc347@ha.org.hk). Co-authors: Dr CP Tsang, Associate Consultant of Department of Neurosurgery, Queen Mary Hospital, Hong Kong Dr KK Wong and Dr Raymand Lee, Consultants of Department of Radiology, Queen Mary Hospital, Hong Kong References Page 8 of 9

9 Lee M, Zaharchuk G, Guzman R, Achrol A, Bell-Stephens T, Steinberg GK. Quantitative hemodynamic studies in moyamoya disease: a review. Neurosurg Focus. 2009;26(4):E5. Tian B, Xu B, Liu Q, Hao Q, Lu J. Adult Moyamoya disease: 320-multidetector row CT for evaluation of revascularization in STA-MCA bypasses surgery. Eur J Radiol. 2013;82(12): Dai DW, Zhao WY, Zhang YW, Yang ZG, Li Q, Xu B, et al. Role of CT perfusion imaging in evaluating the effects of multiple burr hole surgery on adult ischemic Moyamoya disease. Neuroradiology. 2013;55(12): Angel E. SVD+ Dynamic Volume CT: Delay insensitive Brain Perfusion Analysis. Page 9 of 9