scholarly journals Magnetic Resonance Diffusion W Imaging in Cerebral Fat Embolism

Author(s):  
G.B. Marshall ◽  
V.R. Heale ◽  
L. Herx ◽  
A. Abdeen ◽  
L. Mrkonjic ◽  
...  

The use of diffusion weighted imaging with apparent diffusion coefficient mapping in the diagnosis of cerebral fat embolism is shown here to demonstrate infarcts secondary to fat emboli more intensely than T2 weighted sequences 24 hours after the onset of symptoms. Embolic foci are hypointense on apparent diffusion coefficient mapping consistent with cytotoxic edema associated with cell death and restricted water diffusion. This technique increases the sensitivity for detecting cerebral fat embolism and offers a potentially important tool in its diagnosis.

2020 ◽  
pp. 028418512091403
Author(s):  
Somkiat Huaijantug ◽  
Paranee Yatmark ◽  
Phanupong Chinnabrut ◽  
Nutruja Rueangsawat ◽  
Avirut Wongkumlue ◽  
...  

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.


2019 ◽  
Vol 18 ◽  
pp. 153303381985326
Author(s):  
Haisong Chen ◽  
Zengjie Wu ◽  
Wenjian Xu ◽  
Jing Pang ◽  
Meng Jia ◽  
...  

Background: It is very important for surgeons to know the accurate borders of malignant bone tumors before they can precisely resect the tumors. The objective of the study is to investigate the usefulness of apparent diffusion coefficient value for estimating the extent of malignant bone tumor. Methods: VX2 tumor fragments were implanted into the tibiae of 30 rabbits. After 4 weeks, magnetic resonance plain scans were performed and then tumor specimens were cut into sagittal sections and partitioned into histology slices for dot-to-dot comparisons with microscopic findings. The sizes of the tumors measured separately on specimen, conventional magnetic resonance imaging sequences, and diffusion-weighted imaging (by measuring apparent diffusion coefficient value on apparent diffusion coefficient mapping) were compared statistically with each other. Results: The mean tumor sizes measured on specimen and apparent diffusion coefficient mapping (by calculating apparent diffusion coefficient value) were 5.20 ± 0.89 cm and 5.31 ± 0.87 cm, respectively; there was no significant difference between the 2 ( P > .05). The tumor sizes measured on T1WI, T2WI, T2WI with fat suppression were 4.82 ± 0.87 cm, 5.58 ± 0.87 cm, 5.63 ± 0.85 cm, respectively, and these values were significantly different from that measured on specimen (5.20 ± 0.89 cm, P < .05). Conclusion: The extent of the VX2 malignant bone tumor can be estimated accurately by measurement of apparent diffusion coefficient value.


2019 ◽  
Vol 60 (4) ◽  
pp. 202-207
Author(s):  
Saba Q . Issa ◽  
Khaleel I. Mohson ◽  
Nawras K. Fadhil

Background: Ovarian malignancy is considered to score the highest fatality among women due to lack of significant symptoms. Early diagnosis and treatment lead to good prognosis. Magnetic resonance imaging (MRI) plays a major role in the diagnosis by detecting the lesions and assessing their appearance and consistency. Objective: To determine the accuracy of MRI in the diagnosis of ovarian malignancy and comparing this to histopathology as a gold standard test. Patients and methods: A follow up study was conducted in the MRI unit of the Radiology Department in Baghdad Teaching Hospital / Baghdad Medical City Complex during the period from 1st of February to 31st of December, 2017 on a group of thirty women with clinically suspected adnexal mass(es). All patients were examined with MRI including the diffusion-weighted imaging. Surgical specimens were taken for histopathology assessment. Results: A total of 30 women with adnexal mass were included in this study, with a mean age of 46.8±14.9 years. The MRI T1W image of the cystic part was dark in (60%), while the T2W image of the cystic part was bright (80%), T2W of the solid part was bright in (53.3%), T2W fat saturation of the solid part was bright in the majority (73.3%). T1W fat suppression contrast-enhanced of the solid part was avid in 66.7% of women with an adnexal mass; DWI of the solid part was bright in (76.7%). The mean apparent diffusion coefficient (ADC) value by MRI for women with adnexal mass was 0.9±0.3x103 mm2/sec. Histopathology mainly revealed mucinous cystadenocarcinoma in (10%) and low-grade serous adenocarcinoma in (10%).Validity of the results of MRI regarding malignant adnexal mass were sensitivity (90.9%), specificity (75%), +ve predictive value (90.9%), -ve predictive value (75%) and accuracy (86.6%). The appropriate cutoff value for apparent diffusion coefficient in differentiation between malignant and benign adnexal mass was 0.97 with 100% sensitivity and 90.9% specificity. Conclusions: MRI and diffusion-weighted imaging is a valid and reliable technique in the diagnosis and characterization of ovarian malignancy.


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