Late gadolinium enhancement (LGE) is a widely used magnetic resonance imaging method for assessing cardiac disease. However, the relationship between different LGE signal thresholds and microscopic tissue staining images is unclear. In this study, we performed cardiovascular MRI on myocardial infarction (MI) model rats and evaluated the relationship between LGE with different signal thresholding methods and tissue staining images.
View Article and Find Full Text PDFThis study aimed to evaluate an intracerebral hemorrhage (ICH) model using quantitative susceptibility mapping (QSM) and chemical exchange saturation transfer (CEST) with preclinical 7T-magnetic resonance imaging (MRI) and determine the potential of amide proton transfer-CEST (APT-CEST) for use as a biomarker for the early detection of ICH. Six Wistar male rats underwent MRI, and another six underwent histopathological examinations on postoperative days 0, 3, and 7. The ICH model was created by injecting bacterial collagenase into the right hemisphere of the brain.
View Article and Find Full Text PDFPelizaeus−Merzbacher disease (PMD) is an X-linked recessive disorder of the central nervous system. We performed 7 Tesla magnetic resonance imaging of the brain in Tama rats, a rodent PMD model, and control rats, as well as evaluated the diagnostic values. In the white matter of the Tama rats, the T2 values were prolonged, which is similar to that observed in patients with PMD (60.
View Article and Find Full Text PDFThis study is to observe a thioacetamide (TAA) administered Hepatic encephalopathy (HE) model rats at three and ten days after TAA administration using liver MRI and brain MR Spectroscopy (MRS) by use of 7T-MRI. Forty-two Wistar rats (control group, n = 14) were intraperitoneally administered at 300 mg/kg (low-dose group, n = 14) or 400 mg/kg (high-dose group, n = 14) doses of TAA for induced of HE. At three days after TAA administration, glutamine (Gln) measured by MRS in high-dose and low-dose TAA groups showed significant increases in comparison to those of the control group (p < 0.
View Article and Find Full Text PDFChemical exchange saturation transfer (CEST) imaging is a non-invasive molecular imaging technique for indirectly measuring low-concentration endogenous metabolites. Conventional CEST has low specificity, owing to the effects of spillover, magnetization transfer (MT), and T relaxation, thus necessitating an inverse Z-spectrum analysis. We aimed to investigate the usefulness of inverse Z-spectrum analysis in creatine (Cr)-CEST in mice, by conducting preclinical 7T-magnetic resonance imaging (MRI) and comparing the conventional analysis metric magnetization transfer ratio () with the novel metric apparent exchange-dependent relaxation ().
View Article and Find Full Text PDFThis study aimed to evaluate tumor changes due to chemotherapy with temozolomide (TMZ) in terms of quantitative values measured by APT imaging and NODDI. We performed TMZ treatment (administered orally by gavage to the TMZ-40 mg and TMZ-60 mg groups) on 7-week-old male Wistar rats with rat glioma C6 implanted in the right brain. TWI, APT imaging, diffusion tensor imaging (DTI), and NODDI were performed on days 7 and 14 after implantation using 7T-MRI, and the calculated quantitative values were statistically compared.
View Article and Find Full Text PDFPurpose: We measured the T and T values the liver of acute liver inflammation model mice administered carbon tetrachloride (CCl) after 3 days and 6 days after dispensed, and we compared and examined whether each relaxation time can be used for detect acute liver inflammation.
Methods: To create an acute liver inflammation model, a mixture of 0.2 ml / 100 g of CCl with an equal amount of Sesame Oil was administered once intraperitoneally to C57BL / 6JJmsSlc mice (n = 15).
Nihon Hoshasen Gijutsu Gakkai Zasshi
December 2021
Purpose: This study aims to investigate inflammatory changes and osteophyte formation in a rat osteoarthritis (OA) model longitudinally by using 7 T-magnetic resonance imaging (MRI) and micro-computed tomography (CT).
Method: This OA model is induced surgically by removing the medial collateral ligament and medial meniscus of the right knee joint. Using 7 T-MRI, we compared the relative signal value of the medial collateral site and the area (mm) of the upper end of the tibia at the right knee joint to those of the left knee joint on TWI.
Nihon Hoshasen Gijutsu Gakkai Zasshi
November 2021
Purpose: This study aimed to perform longitudinal observation using 4D-computed tomography (CT) and compare images acquired by 3D-CT and 3D-ultrashort echo time (UTE) for evaluation of bleomycin-induced lung fibrosis model.
Method: The pulmonary fibrosis model was induced by instilling intratracheally with 50 μl of bleomycin. 4D-CT images were classified into four phases after acquisition and analyzed.