ABSTRACT Background We discovered a novel finding of ribbon-like signal hyperintensity of the cerebral cortical gyri, named the ribbon sign, after reperfusion therapy. Herein, we report the significance and clinical characteristics of ribbon signs. Methods Data from consecutive patients with acute ischemic stroke and anterior large-vessel occlusion were prospectively extracted from the Tokushima University Hospital Stroke Registry between January 2011 and March 2020. Diffusion-weighted imaging (DWI) was retrospectively assessed in patients with acute ischemic stroke with large-vessel occlusion, with or without treatment. Results A total of 140 patients (78 males, Average age: 75.7 years) were enrolled in the study. The mean DWI-Alberta Stroke Program Early Computed Tomography Score (DWI- ASPECTS) was 7.0. Among the patients, 113 (80.7%) underwent reperfusion therapy and 95 (67.9%) had unfavorable outcomes. Eighty-one (57.9%) patients underwent successful recanalization. The ribbon sign was more common in patients with successful recanalization than in the patients with unsuccessful recanalization (53.1% vs. 8.5%, respectively; p <0.01). Conclusion Our study is the first to report that the ribbon sign is a specific finding after successful recanalization in patients with acute ischemic stroke.
OBJECTIVE Subarachnoid hemorrhage (SAH) due to intracranial aneurysm (IA) rupture is often a devastating event. Since the incidence of SAH increases especially in menopause, it is crucial to clarify the detailed pathogenesis of these events. The activation of vascular nucleotide-binding oligomerization domain–like receptor family pyrin domain–containing 3 (NLRP3) inflammasomes has been studied in ischemic stroke and cardiovascular disease. However, the role of NLRP3 in IA rupture still needs to be explained. The authors sought to test their hypothesis that, under estrogen-deficient conditions, activation of NLRP3 inflammasomes via downregulation of the estrogen receptor (ER) facilitates IA rupture. METHODS Ten-week-old female Sprague Dawley rats with and without oophorectomy were subjected to hemodynamic changes and hypertension (OVX + /HT and OVX − /HT, respectively) and fed a high-salt diet. Separately, using human brain endothelial cells (HBECs) and human brain smooth muscle cells (HBSMCs), the authors tested the effect of NLRP3 under estrogen-free conditions and in the presence of estradiol or of ER agonists. RESULTS In OVX + /HT rats, the frequency of IA rupture was significantly higher than in OVX − /HT rats (p = 0.03). In the left posterior cerebral artery prone to rupture in OVX + /HT rats, the levels of the mRNAs encoding ERα and Sirt1 , but not of that encoding ERβ , were decreased, and the levels of the mRNAs encoding NLRP3 , interleukin-1β ( IL-1β ), and matrix metalloproteinase 9 ( MMP-9 ) were elevated. Immunohistochemical analysis demonstrated that the expression profiles of these proteins correlated with their mRNA levels. Treatment with an ER modulator, bazedoxifene, normalized the expression profiles of these proteins and improved SAH-free survival. In HBECs and HBSMCs under estrogen-free conditions, the depletion of ERα and Sirt1 and the accumulation of NLRP3 were counteracted by exposure to estradiol or to an ERα agonist but not to an ERβ agonist. CONCLUSIONS To the authors’ knowledge, this work represents the first demonstration that, in an aneurysm model under estrogen-deficient conditions, the depletion of ERα and Sirt1 may contribute to activation of the NLRP3/IL-1β/MMP-9 pathway, facilitating the rupture of IAs in the estrogen-deficient rat IA rupture model.
From the Department of Radiology, Kobe City General Hospital, 4-6 Minatojima-nakamachi, Chuo-ku, Kobe, 650, Japan. Address correspondence and reprint requests to Dr. N. Usuki.
<b><i>Background:</i></b> Although mechanical thrombectomy is a standard endovascular therapy for patients with acute ischemic stroke (AIS), the incidence of and risk factors for contrast-induced nephropathy (CIN) following mechanical thrombectomy are infrequently reported. <b><i>Objectives:</i></b> The aim of this study was to investigate the incidence and risk factors for CIN following mechanical thrombectomy for AIS, and whether the incidence of CIN is related to a poor prognosis. <b><i>Methods:</i></b> We examined consecutive patients who underwent a mechanical thrombectomy in the period from January 2014 to March 2018. The patients’ clinical backgrounds, treatments, and clinical prognoses were analyzed. CIN was defined as an increase in the serum creatinine level of ≥44.2 μmol/L (0.5 mg/dL) or 25% above baseline within 72 h after exposure to the contrast medium. <b><i>Results:</i></b> In total, 80 patients (46 men and 34 women aged 74.5 ± 11.5 years) who met our inclusion criteria were analyzed. CIN occurred in 8.8% (7/80) of the patients following mechanical thrombectomy. Although no patients needed permanent dialysis, 1 required temporary dialysis. The median amount of contrast medium was 109 mL. A comparison between the groups with and without CIN showed a significant difference in white blood cell (WBC) count at the time of admission (11.6 ± 2.7 × 10<sup>3</sup>/μL and 8.1 ± 2.7 × 10<sup>3</sup>/μL; <i>p</i> < 0.01) and the cut-off value was 9.70 × 10<sup>3</sup>/μL. In multivariate analysis, contrast volume/estimated glomerular filtration rate by creatinine and WBC count were significantly associated with the incidence of CIN, with odds ratios of 1.64 (95% CI 1.02–2.65; <i>p</i> = 0.04) and 1.61 (95% CI 1.15–2.25; <i>p</i> < 0.01), respectively. <b><i>Conclusions:</i></b> This study found that CIN occurred in 8.8% of patients with AIS following mechanical thrombectomy. High WBC count was associated with an increased risk of CIN and may be helpful for predicting CIN.
Purpose: Our goal was to evaluate the usefulness of MR cholangiopancreatography (MRCP) for intraductal mucin-producing tumor of the pancreas (MPT). Method: Eleven patients with intraductal MPTs (six main duct type; five branch duct type) underwent MRCP. The findings of MRCP were compared with those of endoscopic retrograde cholangiopancreatography (ERCP). Results: In all of the cases, MRCP could disclose all dilated pancreatic ducts and cysts, some of which were not demonstrated by ERCP. MRCP did not show a signal void of mucin in any of the cases. In the two cases of the main duct type, ERCP showed filling defects of excrescent nodules, which were not seen by MRCP. In the two cases of the main duct type, nodules were seen more clearly by ERCP than by MRCP. Conclusion: MRCP and ERCP are complementary imaging modalities for intraductal MPT.
