記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: The turbulent kinetic energy (TKE) estimation based on 4D flow MRI has been currently developed and can be used to estimate the pressure gradient. The objective of this study was to validate the clinical value of 4D flow-based TKE measurement in patients with hypertrophic cardiomyopathy (HCM). METHODS: From April 2018 to March 2019, we recruited 28 patients with HCM. Based on echocardiography, they were divided into obstructed HCM (HOCM) and non-obstructed HCM (HNCM). Triple-velocity encoding 4D flow MRI was performed. The volume-of-interest from the left ventricle to the aortic arch was drawn semi-automatically. We defined peak turbulent kinetic energy (TKEpeak) as the highest TKE phase in all cardiac phases. RESULTS: TKEpeak was significantly higher in HOCM than in HNCM (14.83 ± 3.91 vs. 7.11 ± 3.60 mJ, P < 0.001). TKEpeak was significantly higher in patients with systolic anterior movement (SAM) than in those without SAM (15.60 ± 3.96 vs. 7.44 ± 3.29 mJ, P < 0.001). Left ventricular (LV) mass increased proportionally with TKEpeak (P = 0.012, r = 0.466). When only the asymptomatic patients were extracted, a stronger correlation was observed (P = 0.001, r = 0.842). CONCLUSION: TKE measurement based on 4D flow MRI can detect the flow alteration induced by systolic flow jet and LV outflow tract geometry, such as SAM in patients with HOCM. The elevated TKE is correlated with increasing LV mass. This indicates that increasing cardiac load, by pressure loss due to turbulence, induces progression of LV hypertrophy, which leads to a worse prognosis.

DOI： 10.2463/mrms.mp.2022-0051

PubMed

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記述言語：日本語   出版者・発行元：(株)メジカルビュー社  

＜文献概要＞心臓MRIを用いた血流解析として,古くから流速/流量の定量が可能な2D phase-contrast MRIを用いた検討が行われてきた。近年,同撮影を三次元方向に拡張した4D Flow MRIが汎用化され,10分程度の撮像時間で撮影が可能となってきている。本稿では,4D Flow MRIの基本的な考え方および各種疾患における活用例を述べる。

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その他リンク： https://search.jamas.or.jp/default/link?pub_year=2023&ichushi_jid=J01843&link_issn=&doc_id=20230428080015&doc_link_id=10.18885%2FCI.0000001303&url=https%3A%2F%2Fdoi.org%2F10.18885%2FCI.0000001303&type=%E5%8C%BB%E6%9B%B8.jp_%E3%82%AA%E3%83%BC%E3%83%AB%E3%82%A2%E3%82%AF%E3%82%BB%E3%82%B9&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Although the high-attenuating crescent (HAC) sign can indicate aortic aneurysm (AA) impending rupture, the relation of its computed tomography (CT) value to the aneurysmal status remains unclear. This study compared the HAC sign CT-attenuation values among rupture, impending rupture, and non-rupture AA cases.Methods and Results:This included 76 patients (mean age: 77.0 years) diagnosed with HAC sign-associated AA between January 2005 and July 2015. The CT-attenuation values of the HAC sign (H) and aortic lumen (A) using region-of-interest methodology were measured and the H/A ratio was calculated. The study classified patients into the rupture group (R-G, n=36), impending rupture group (IR-G, n=16), and non-rupture group (NR-G, n=24); the H and the H/A ratio were compared among them. Additionally, the H and the H/A ratio cut-offs between the IR-G and NR-G groups were evaluated. The H and the H/A ratio were significantly higher in the R-G and IR-G than in the NR-G (both P<0.001); the H/A ratio was significantly higher in the R-G than in the IR-G (P=0.038). The optimal cut-off for H between the IR-G and NR-G was 50.3 Hounsfield units (area under the curve [AUC]=0.875; sensitivity=87.5%; specificity=87.5%), and that for the H/A ratio was 1.3 (AUC=0.909; sensitivity=91.7%; specificity=87.5%). CONCLUSIONS: Among patients with AA, the H and the H/A ratio were significantly higher in cases of rupture and impending rupture than in those of non-rupture.

DOI： 10.1253/circj.CJ-21-0541

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: The hemodynamic changes after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery are unclear. OBJECTIVE: To clarify the hemodynamics by comparing flow parameters obtained by 4-dimensional (4D) flow magnetic resonance imaging (MRI) and intraoperative MCA pressure measurement. METHODS: We recruited 23 patients who underwent STA-MCA bypass surgery for internal carotid artery (ICA) or MCA stenosis. We monitored intraoperative MCA, STA, and radial artery (RA) pressure. All patients underwent 4D flow MRI preoperatively and 3 wk after surgery to quantify the blood flow volume (BFV) of the ipsilateral ICA (BFViICA), contralateral ICA (BFVcICA), basilar artery (BFVBA), ipsilateral STA (BFViSTA), and contralateral STA (BFVcSTA). The sum of intracranial BFV was defined as BFVtotal. We compared BFV parameters and intraoperative pressure. RESULTS: BFViSTA significantly increased after surgery (P < .001). BFViICA and BFVBA significantly decreased after surgery (BFViICAP = .005; BFVBAP = .02). No significant difference was observed between BFVcICA before and after surgery. As a result, BFVtotal postoperatively increased by 6.8%; however, no significant difference was observed. Flow direction at M1 changed from antegrade to unclear after surgery in 5 patients. Intraoperative MCA pressure and MCA/RA pressure ratio significantly increased after surgery (P < .001). We found a stronger positive correlation between MCA pressure increase ratio and BFVtotal increase ratio in patients with lower pre-MCA pressure (r = 0.907, P < .001). CONCLUSION: The visual and quantitative assessment of 4D flow MRI revealed that intracranial blood flow changes complementarily after STA-MCA bypass surgery. 4D flow MRI may detect the improvement of cerebral perfusion pressure.

DOI： 10.1093/neuros/nyab305

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: MRI-based risk stratification should be established to identify patients with internal carotid artery stenosis (ICS) who require further PET or SPECT evaluation. This study assessed whether multiparametric flow analysis using time-resolved 3D phase-contrast (4D flow) MRI can detect cerebral hemodynamic impairment in patients with ICS. METHODS: This retrospective study analyzed 26 consecutive patients with unilateral ICS (21 men; mean age, 71 years) who underwent 4D flow MRI and acetazolamide-stress brain perfusion SPECT. Collateral flow via the Willis ring was visually evaluated. Temporal mean flow volume rate (Net), pulsatile flow volume (ΔV), and pulsatility index (PI) at the middle cerebral artery were measured. Cerebral vascular reserve (CVR) was calculated from the SPECT dataset. Patients were assigned to the misery perfusion group if the CVR was < 10% and to the nonmisery perfusion group if the CVR was ≥ 10%. Parameters showing a significant difference in both groups were statistically evaluated. RESULTS: Affected side ΔV, ratio of affected to contralateral side Net (rNet), and ratio of affected to contralateral side ΔV were significantly correlated to CVR (p = 0.030, p = 0.010, p = 0.015, respectively). Absence of retrograde flow at the posterior communicating artery was observed in the misery perfusion group (p = 0.020). Combined cut-off values of the affected side ΔV (0.18 ml) and rNet (0.64) showed a sensitivity and specificity of 100% and 77.8%, respectively. CONCLUSION: Multiparametric flow analysis using 4D flow MRI can detect misery perfusion by comprehensively assessing blood flow data, including blood flow volume, pulsation, and collateral flow.

DOI： 10.1007/s00234-020-02464-2

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記述言語：日本語   出版者・発行元：(一社)日本腹部救急医学会  

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記述言語：日本語   出版者・発行元：(公社)日本医学放射線学会  

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記述言語：日本語   出版者・発行元：(一社)日本磁気共鳴医学会  

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その他リンク： https://search.jamas.or.jp/default/link?pub_year=2020&ichushi_jid=J02090&link_issn=&doc_id=20200319090009&doc_link_id=10.2463%2Fjjmrm.2019-1700&url=https%3A%2F%2Fdoi.org%2F10.2463%2Fjjmrm.2019-1700&type=J-STAGE&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00007_3.gif

記述言語：日本語   出版者・発行元：日本医科大学医学会  

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記述言語：英語   出版者・発行元：(公社)日本医学放射線学会  

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