Changes in Apparent Diffusion Coefficient ( ADC) during Cardiac Cycle of the Brain in Idiopathic Normal Pressure Hydrocephalus Before and After Cerebrospinal Fluid Drainage

2020 ◽  
Author(s):  
Tomoshi Osawa ◽  
Naoki Ohno ◽  
Mitsuhito Mase ◽  
Tosiaki Miyati ◽  
Ryoko Omasa ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Normal Pressure Hydrocephalus ◽  
Cardiac Cycle ◽  
Normal Pressure ◽  
Cerebrospinal Fluid Drainage ◽  
Before And After ◽  
Apparent Diffusion ◽  
The Brain

Evaluation of extraocular muscles in patients with thyroid associated ophthalmopathy using apparent diffusion coefficient measured by magnetic resonance imaging before and after radiation therapy

2021 ◽  
pp. 028418512110340
Author(s):  
Wu Yu ◽  
Lao Zheng ◽  
Zhang Shuo ◽  
Liu Xingtong ◽  
Jiang Mengda ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Radiation Therapy ◽  
Apparent Diffusion Coefficient ◽  
Extraocular Muscles ◽  
Clinical Activity ◽  
Inferior Rectus ◽  
Thyroid Associated Ophthalmopathy ◽  
Before And After ◽  
Apparent Diffusion ◽  
The Mean

Background Thyroid-associated ophthalmopathy (TAO) is an autoimmune orbital disease characterized by edema of extraocular muscles (EOMs). Purpose To characterize the inflammation of EOMs in patients with TAO before and after radiation therapy using apparent diffusion coefficient (ADC) and to analyze the correlation between ADC and clinical activity of TAO. Material and Methods The ADCs of superior rectus (SR), inferior rectus (IR), medial rectus (MR), and lateral rectus (LR) muscles were measured in 52 eyes of 26 patients with TAO before and three months after orbital radiation therapy. In addition, 38 eyes of 20 healthy volunteers were included. The clinical activity score (CAS) was evaluated. The ADC maps were reconstructed and measured on the coronal diffusion-weighted imaging (DWI) sequence and calculated in mm2/s. Results The mean ADCs of EOMs before treatment were 1.42 ± 0.23 in SR, 1.37 ± 0.23 in IR, 1.41 ± 0.21 in MR, and 1.28 ± 0.25 in LR. The mean ADCs after treatment were 1.27 ± 0.18, 1.22 ± 0.26, 1.30 ± 0.22, and 1.15 ± 0.21, respectively. The ADCs were significantly decreased after treatment (all P < 0.001). The ADCs of patients with TAO were significantly higher than those of controls. There was a statistically significant correlation between the mean ADCs and the CAS in each patient with TAO both before and after treatment (before: r = 0.520; P < 0.001; after: r = 0.625; P < 0.001). Conclusion The ADC values of EOMs can be exploited as a quantitative indicator to evaluate the clinical activity and monitor the therapeutic responses of patients with TAO.

Quantitative brain histogram of canine epilepsy using magnetic resonance imaging

2020 ◽  
pp. 028418512091403
Author(s):  
Somkiat Huaijantug ◽  
Paranee Yatmark ◽  
Phanupong Chinnabrut ◽  
Nutruja Rueangsawat ◽  
Avirut Wongkumlue ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Imaging ◽  
Idiopathic Epilepsy ◽  
Resonance Imaging ◽  
Mr Images ◽  
Apparent Diffusion ◽  
The Brain

Background Quantitative magnetic resonance imaging (MRI) is used to study the anatomy of the brain in dogs with idiopathic epilepsy. Purpose To quantitate MRI images in terms of volumetric ratios and histogram analyses of the following regions of interest (ROI) in dogs with idiopathic epilepsy: frontal; parietal; temporal; piriform; thalamic; and hippocampal regions. Material and Methods Nine dogs with epilepsy and four healthy controls were evaluated. We examined the volumetric ratios and histogram analyses of six ROIs in all dogs. Results MR images, in T1-weighted, T2-weighted, FLAIR, diffusion-weighted imaging, and apparent diffusion coefficient sequences detected changes in 4/9 (44%) epileptic dogs found in 5/6 regions: frontal; parietal; temporal; piriform; and hippocampal regions. However, no such changes were observed in the thalamic region. Interestingly, the frontal and piriform volumetric ratios of epileptic dogs were significantly lower than those of control dogs. The histogram analyses in 4/6 regions were significantly increased in epileptic dogs. Conclusion Our results demonstrated MRI finding abnormalities in several regions of the brain in several sequences including T1-weighted, T2-weighted, FLAIR, diffusion-weighted imaging, and apparent diffusion coefficient in epileptic dogs. In several regions of the brain, atrophy may exist, and hyperintensity may be present on MR images in epileptic dogs. These findings suggest that the diagnostic yield of MRI, which is an advanced neuroimaging technique, is high in epileptic dogs and has good reliability and sensitivity in detecting abnormal areas in patients.

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