Abstract 366: Cardiac Strain From Magnetic Resonance Imaging Offers Sensitive Detection of Therapeutic Efficacy Following Transplantation of Tissue Engineered Heart Muscles

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Xulei Qin ◽  
Johannes Riegler ◽  
Malte Tiburcy ◽  
Thomas Denney ◽  
Wolfram Zimmermann ◽  
...  

Background: Myocardial infarction (MI) leads to gradually decreased cardiac contractility that can ultimately cause heart failure or sudden death. One potential therapy to recover this MI-impaired contractile function is the regenerative approach that integrates both tissue engineering and exogenously produced cardiomyocytes. Although this contractile recovery has been assessed by different imaging methods in previous studies, these assessments in global cardiac performance are plagued by their relatively low sensitivity. As this treatment is locally performed, the sensitivity of its therapeutic assessment can be improved by myocardial strain imaging that assesses regional contractility. Methods: We first made tissue engineered heart muscles (EHMs) by casting human embryonic stem cell-derived cardiomyocytes (ESC-CMs) with collagen in preformed molds. Then we transplanted these EHMs (n=12) into the post-MI rat hearts one month after this injure. We also performed sham surgeries on a control group (n=9) without EHM transplantation. Meanwhile, strain imaging from cardiac magnetic resonance imaging (MRI) and ultrasound were performed prior to and four weeks after EHM transplantations. In addition, global cardiac performance such as left ventricular ejection fraction (EF) was estimated from cardiac MRI. Results: Based on the measurements, regional myocardial strain measured from tagged MRI detected the preserved systolic function in the EHM-treated group compared to control group (P=0.04). In contrary, the global function EF was unable to detect this significant difference between both groups (P=0.38). Similarly, myocardial strain measured from cardiac ultrasound also failed to detect the significance between both treatment and control groups (P=0.24). Conclusions: This study for the first time confirmed that regional assessment of contractile function offered higher sensitivity compared to the conventional measure of global systolic performance. This finding highlights the feasibility and sensitivity of cardiac strain derived from tagged MRI as a sensitive method to assess the efficacy of regenerative therapies in both preclinical and clinical studies.

2020 ◽  
pp. 028418512093837
Author(s):  
Sunay Sibel Karayol ◽  
Kudret Cem Karayol

Background The aim of this study is to investigate the role of diffusion-weighted imaging (DWI) in the differential diagnosis of sacroiliitis. Purpose To compare the sacroiliac magnetic resonance imaging (MRI) examinations of patients with suspected active sacroiliitis with patients with acute SpA MR findings and the DWI examinations of patients with acute brucella sacroiliitis, and thereby determine whether DWI can contribute to the differential diagnosis. Material and Methods A total of 84 patients were included in the study and were separated into three groups: group 1 (13 women, 6 men) comprised cases with brucella positive for sacroiliitis; group 2 (17 women, 19 men) comprised cases negative for brucella but with sacroiliitis; and group 3 (16 women, 13 men) comprised cases negative for brucella and sacroiliitis. Results The mean bone marrow apparent diffusion coefficient (ADC) values independently of edema were determined as 0.71 × 10−3 in sacroiliitis and brucella-positive patients, as 0.53 × 10−3 in brucella-negative and sacroiliitis-positive patients, and as 0.43 × 10−3 in the control group of brucella-negative sacroiliitis-negative patients. In the ADC measurements taken from areas of evident edema in patients with sacroiliitis, the mean values were 0.13 × 10−3 in the brucella-positive group and 0.12 × 10−3 in the brucella-negative group. Conclusion By adding DWI, which is a rapid MR sequence, to sacroiliac joint MR examination, normal bone marrow and bone marrow with sacroiliitis can be objectively differentiated with ADC measurements in addition to visual evaluation.


2005 ◽  
Vol 25 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Guangliang Ding ◽  
Quan Jiang ◽  
Li Zhang ◽  
Zheng Gang Zhang ◽  
Lian Li ◽  
...  

Suppression of platelet activation improves the efficacy of thrombolytic therapy for stroke. Thus, combination treatment with recombinant tissue plasminogen activator (r-tPA) and 7E3 F(ab′)2, a GPIIb/IIIa inhibitor that binds the platelet to fibrin, may improve the efficacy of thrombolytic therapy in embolic stroke. Magnetic resonance imaging (MRI) was used to monitor treatment response in rats subjected to embolic middle cerebral artery (MCA) occlusion (MCAo). Animals were randomized into treated ( n = 12) and control ( n = 10) groups and received intravenous combination therapy or saline, respectively, 4 hours after MCAo. Magnetic resonance imaging (MRI) measurements performed 1 hour after MCAo showed no difference between groups. However, an increased incidence (50%) of MCA recanalization was found in the treated group at 24 hours compared with 20% in the control group. The area of low cerebral blood flow at 24 and 48 hours was significantly smaller in the combination treatment group, and the lesion size, as indicated from the T2 and T1 maps, differed significantly between groups. Fluorescence microscopy measurements of cerebral microvessels perfused with fluorescein isothiocyanate-dextran and measurements of infarct volume revealed that the combination treatment significantly increased microvascular patency and reduced infarct volume, respectively, compared with the control rats. The efficacy of combination treatment 4 hours after ischemia is reflected by MRI indices of tissue perfusion, MCA recanalization, and reduction of lesion volume. The treatment also reduced secondary microvascular perfusion deficits.


2019 ◽  
Vol 33 (08) ◽  
pp. 768-776 ◽  
Author(s):  
Si Heng Sharon Tan ◽  
Beatrice Ying Lim ◽  
Kiat Soon Jason Chng ◽  
Chintan Doshi ◽  
Francis K.L. Wong ◽  
...  

AbstractThe tibial tubercle–trochlear groove (TT–TG) distance was originally described for computed tomography (CT) but has recently been used on magnetic resonance imaging (MRI) without sufficient evidence demonstrating its validity on MRI. The current review aims to evaluate (1) whether there is a difference in the TT–TG distances measured using CT and MRI, (2) whether both the TT–TG distances measured using CT and MRI could be used to differentiate between patients with or without patellofemoral instability, and (3) whether the same threshold of 15 to 20 mm can be applied for both TT–TG distances measured using CT and MRI. The review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRSIMA) guidelines. All studies that compared TT–TG distances either (1) between CT and MRI or (2) between patients with and without patellofemoral instability were included. A total of 23 publications were included in the review. These included a total of 3,040 patients. All publications reported the TT–TG distance to be greater in patients with patellofemoral instability as compared to those without patellofemoral instability. This difference was noted for both TT–TG distances measured on CT and on MRI. All publications also reported the TT–TG distance measured on CT to be greater than that measured on MRI (mean difference [MD] = 1.79 mm; 95% confidence interval [CI]: 0.91–2.68). Pooling of the studies revealed that the mean TT–TG distance for the control group was 12.85 mm (95% CI: 11.71–14.01) while the mean TT–TG distance for patients with patellofemoral instability was 18.33 mm (95% CI: 17.04–19.62) when measured on CT. When measured on MRI, the mean TT–TG distance for the control group was 9.83 mm (95% CI: 9.11–10.54), while the mean TT–TG distance for patients with patellofemoral instability was 15.33 mm (95% CI: 14.24–16.42). Both the TTTG distances measured on CT and MRI could be used to differentiate between patients with and without patellofemoral instability. Patients with patellofemoral instability had significantly greater TT–TG distances than those without. However, the TT–TG distances measured on CT were significantly greater than that measured on MRI. Different cut-off values should, therefore, be used for TT–TG distances measured on CT and on MRI in the determination of normal versus abnormal values. Pooling of all the patients included in the review then suggest for 15.5 ± 1.5 mm to be used as the cut off for TT–TG distance measured on CT, and for 12.5 ± 2 mm to be used as the cut-off for TT–TG distance measured on MRI. The Level of evidence for this study is IV.


2013 ◽  
Vol 29 (11) ◽  
pp. 1531.e9-1531.e11 ◽  
Author(s):  
Shintaro Nakano ◽  
Fumiko Kimura ◽  
Nael Osman ◽  
Keiki Sugi ◽  
Jun Tanno ◽  
...  

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