scholarly journals Two-kidney one-clip is a pertinent approach to integrate arterial hypertension in animal models of stroke: Serial magnetic resonance imaging studies of brain lesions before and during cerebral ischemia

2017 ◽  
Vol 38 (10) ◽  
pp. 1769-1780 ◽  
Author(s):  
Benjamin Ménard ◽  
Laurent Chazalviel ◽  
Simon Roussel ◽  
Myriam Bernaudin ◽  
Omar Touzani
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Arterial Hypertension ◽  
Brain Lesions ◽  
Cortical Lesions ◽  
Resonance Imaging ◽  
Spontaneously Hypertensive ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Magnetic Resonance Imaging Mri

Although chronic arterial hypertension (CAH) represents the major comorbid factor in stroke, it is rarely integrated in preclinical studies of stroke. The majority of those investigations employ spontaneously hypertensive rats (SHR) which display a susceptibility to ischemic damage independent of hypertension. Here, we used a renovascular model of hypertension (RH) to examine, with magnetic resonance imaging (MRI), brain alterations during the development of hypertension and after brain ischemia. We also examined whether MRI-derived parameters predict the extent of ischemia-induced brain damage. RH was induced according to the two-kidney one-clip model and multiparametric MRI was performed at 3, 6, 9, and 12 weeks after hypertension and also at 10, 50, and 60 min following stroke. Blood pressure values increased progressively and reached a plateau at 6 weeks after RH induction. At 12 weeks, all hypertensive animals displayed spontaneous brain lesions (hemorrhages, deep and cortical lesions, ventricular dilatation), increased apparent diffusion coefficient (ADC) values in the corpus callosum and higher fractional anisotropy in the cortex. Following ischemia, these animals showed larger brain lesions (406 ± 82 vs. 179 ± 36 mm3, p < 0.002) which correlated with ADC values at chronic stage of hypertension. This model of hypertension displays many characteristics of the neuropathology of human CAH. The use of this model in stroke studies is relevant and desirable.

scholarly journals Effect of Methylprednisolone on Experimental Brain Edema in Magnetic Resonance Imaging

2020 ◽  
pp. 919-926
Author(s):  
P KOZLER ◽  
V HERYNEK ◽  
D MAREŠOVÁ ◽  
P PEREZ ◽  
L ŠEFC ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brain Edema ◽  
Vasogenic Edema ◽  
Water Intoxication ◽  
Control Group ◽  
Resonance Imaging ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Experimental Brain Edema

Magnetic resonance imaging has been used for evaluating of a brain edema in experimental animals to assess cytotoxic and vasogenic edema by the apparent diffusion coefficient (ADC) and T2 imaging. This paper brings information about the effectiveness of methylprednisolone (MP) on experimental brain edema. A total of 24 rats were divided into three groups of 8 animals each. Rats with cytotoxic/intracellular brain edema induced by water intoxication were assigned to the group WI. These rats also served as the additional control group CG when measured before the induction of edema. A third group (WIMP) was intraperitoneally administered with methylprednisolone 100 mg/kg during water intoxication treatment. The group WI+MP was injected with methylprednisolone 50 mg/kg into the carotid artery within two hours after the water intoxication treatment. We evaluated the results in four groups. Two control groups (CG, WI) and two experimental groups (WIMP, WI+MP). Rats were subjected to MR scanning 24 h after edema induction. We observed significantly increased ADC values in group WI in both evaluated areas – cortex and hippocampus, which proved the occurrence of experimental vasogenic edema, while ADC values in groups WIMP and WI+MP were not increased, indicating that the experimental edema was not developed and thus confirming the protective effect of MP.

scholarly journals Value of Minimum Apparent Diffusion Coefficient on Magnetic Resonance Imaging as a Biomarker for Predicting Progression of Disease Following Surgery and Radiotherapy in Glial Tumors from a Tertiary Care Center in Northern India

2017 ◽  
Vol 08 (02) ◽  
pp. 185-193 ◽  
Author(s):  
Pramod Kumar Gupta ◽  
Rishi Awasthi ◽  
Shalini Singh ◽  
Sanjay Behari ◽  
K. J. Maria Das ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Progressive Disease ◽  
Resonance Imaging ◽  
Glial Tumors ◽  
Apparent Diffusion ◽  
Adc Values

ABSTRACT Purpose: Studies have shown that cellularity of glial tumors are inversely correlated to minimum apparent diffusion coefficient (ADC) values derived on diffusion-weighted imaging (DWI). The purpose of this prospective exploratory study was to evaluate whether temporal change in “minimum ADC” values during follow-up predict progressive disease in glial tumors post radiotherapy and surgery. Materials and Methods: Adult patients of glial tumors, subjected to surgery followed by Radiotherapy (RT), were included in the study. Serial conventional magnetic resonance imaging with DWI at the following time points – presurgery, pre-RT, post-RT imaging at 3, 7, and 15 months were done. For “minimum ADC” values, multiple regions of interest (ROI) were identified on ADC maps derived from DWI. A mean of 5 minimum ADC values was chosen as “minimum ADC” value. The correlation was drawn between histology and minimum ADC values and time trends were studied. Results: Fourteen patients were included in this study. Histologies were low-grade glioma (LGG) - 5, anaplastic oligodendroglioma (ODG) -5, and glioblastoma multiforme (GBM) - 4. Minimum ADC values were significantly higher in LGG and GBM than ODG. Presurgery, the values were 0.812, 0.633, and 0.787 × 10−3 mm2/s for LGG, ODG, and GBM, respectively. DWI done at the time of RT planning showed values of 0.786, 0.636, 0.869 × 10−3 mm2/s, respectively. During follow-up, the increasing trend of minimum ADC was observed in LGG (P = 0.02). All these patients were clinically and radiologically stable. Anaplastic ODGs, however, showed an initial increase followed by the fall of minimum ADC in all the 5 cases (P = 0.00). Four of the five cases developed progressive disease subsequently. In all the 4 GBM cases, a consistent fall of minimum ADC values was observed (P = 0.00), and they all progressed in spite of RT. Conclusions: The DWI-derived minimum ADC values are an important yet simple quantitative tool to assess the treatment response and disease progression before they are evident on conventional imaging during the follow-up of glial tumors.

scholarly journals A Predictor of Tumor Recurrence in Patients With Endometrial Carcinoma After Complete Resection of the Tumor: The Role of Pretreatment Apparent Diffusion Coefficient

2018 ◽  
Vol 28 (5) ◽  
pp. 861-868 ◽  
Author(s):  
Ryo Kuwahara ◽  
Aki Kido ◽  
Shiro Tanaka ◽  
Kaoru Abiko ◽  
Kyoko Nakao ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Endometrial Cancer ◽  
Magnetic Resonance ◽  
Tumor Recurrence ◽  
Operating Characteristic ◽  
Complete Resection ◽  
Resonance Imaging ◽  
Apparent Diffusion ◽  
Adc Values

ObjectivesThe aim of this study was to assess the prognostic and incremental value of pretreatment apparent diffusion coefficient (ADC) values of tumors for the prediction of tumor recurrence after complete resection of the tumor in patients with endometrial cancer.MethodsThis study enrolled 210 patients with stages IA to IIIC endometrial cancer who had undergone complete resection of the tumor and pretreatment magnetic resonance imaging. The minimum and mean ADC values (ADCmin, ADCmean) of tumors and normalized ADC (nADCmin, nADCmean) were calculated from magnetic resonance imaging. The primary outcome was recurrence-free survival (RFS). Receiver operating characteristic analysis was performed to compare the diagnostic performance of ADC values of 4 types. The Kaplan-Meier method, log-rank tests, and Cox regression were used to explore associations between recurrence and the ADC values with adjustment for clinicopathological factors.ResultsIn receiver operating characteristic curve analysis, the areas under the curve were significant for ADCmean and nADCmean predicting tumor recurrence but were not significant for ADCmin and nADCmin. Regarding univariate analysis, ADCmean and nADCmean were significantly associated with increased risk of recurrence. Multivariate analysis showed that ADCmean and nADCmean remained independently associated with shorter RFS. In the high-risk group, the RFS of patients with lower ADC values (ADCmean and nADCmean) was significantly shorter than that of patients in the higher ADC value group.ConclusionsPretreatment tumor ADCmean and nADCmean were important imaging biomarkers for predicting recurrence in patients after complete resection of the tumor. They might improve existing risk stratification.

scholarly journals Evaluation of MRI Orthogonal Planes in Differential Diagnosis of Non-Tumour Brain Lesions

2021 ◽  
Vol 10 (40) ◽  
pp. 3543-3547
Author(s):  
Smitha H. ◽  
Meena Devi V. N. ◽  
Sreekanth K. S. ◽  
Vinoo Jacob
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Sagittal Plane ◽  
Tumour Volume ◽  
Brain Lesions ◽  
Resonance Imaging ◽  
Anatomical Structures ◽  
Precise Diagnosis ◽  
Magnetic Resonance Imaging Mri

BACKGROUND Magnetic resonance imaging (MRI) provides structural characterization of brain lesions, by measuring volume of axial, sagittal and coronal planes through two dimensional slices. The purpose of this study was to characterize and identify the orthogonal imaging planes to detect non tumour lesions of brain through MRI. METHODS This study included 81 patients, both males and females, suspected of brain lesions and underwent MRI for diagnosis. The variations in the volume of the anatomical structures were measured and compared the planes as axial and sagittal, axial and coronal and coronal and sagittal for non-tumour brain lesions. RESULTS The present study revealed the differences in the measurement of volume in nontumour lesions (N = 81) in axial, sagittal and coronal planes. It was found that the volume of axial planes (9.2) is more dominant than the sagittal (9.1) and coronal planes (8.8) in non-tumour lesions. Statistical analysis was done by Statistical Package for Social Sciences (SPSS version 16 software). Two way/Friedman test were used for comparing the three groups. CONCLUSIONS This study concluded that, in most of the brain lesions irrespective of the type of tumours, axial planes helps more in the detection of tumour volume as compared to sagittal and coronal planes for precise diagnosis of brain lesions. KEY WORDS Axial Plane; Coronal Plane; Magnetic Resonance Imaging; Non-Tumour Brain Lesions; Sagittal Plane.

Quantitative magnetic resonance imaging for focal liver lesions: bridging the gap between research and clinical practice

2021 ◽  
pp. 20210220
Author(s):  
Roberto Cannella ◽  
Riccardo Sartoris ◽  
Jules Grégory ◽  
Lorenzo Garzelli ◽  
Valérie Vilgrain ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Clinical Practice ◽  
Magnetic Resonance ◽  
Quantitative Mri ◽  
Focal Liver Lesions ◽  
Liver Lesions ◽  
Resonance Imaging ◽  
Apparent Diffusion ◽  
Magnetic Resonance Imaging Mri ◽  
Diagnostic Work

Magnetic resonance imaging (MRI) is highly important for the detection, characterization, and follow-up of focal liver lesions. Several quantitative MRI-based methods have been proposed in addition to qualitative imaging interpretation to improve the diagnostic work-up and prognostics in patients with focal liver lesions. This includes DWI with apparent diffusion coefficient measurements, intravoxel incoherent motion, perfusion imaging, MR elastography, and radiomics. Multiple research studies have reported promising results with quantitative MRI methods in various clinical settings. Nevertheless, applications in everyday clinical practice are limited. This review describes the basic principles of quantitative MRI-based techniques and discusses the main current applications and limitations for the assessment of focal liver lesions.

scholarly journals A piglet model for detection of hypoxic-ischemic brain injury with magnetic resonance imaging

2008 ◽  
Vol 49 (9) ◽  
pp. 1049-1057 ◽  
Author(s):  
B. H. Munkeby ◽  
C. De Lange ◽  
K. E. Emblem ◽  
A. Bjørnerud ◽  
G. A. B. Kro ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Basal Ganglia ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Therapeutic Interventions ◽  
Resonance Imaging ◽  
Prognostic Information ◽  
Proton Mrs ◽  
Apparent Diffusion ◽  
Magnetic Resonance Imaging Mri

Background: Early detection of hypoxic-ischemic (HI) injury in the asphyxic newborn is important because present prognostic factors are inadequate. Furthermore, therapeutic interventions may have additional benefit if initiated in time. Purpose: To assess whether the use of a combined protocol including conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and proton MR spectroscopy (MRS) could detect pathological findings in a piglet model 7 hours after HI. Material and Methods: Ten piglets were submitted to HI for 30 min followed by reoxygenation with 21% O2 for 7 hours. MRI at 1.5T was done prior to and 7 hours after the HI. Single-voxel proton MRS was performed, and apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in the basal ganglia. MRS identified N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and lactate (Lac). Histology and microtubule-associated protein 2 (MAP-2) staining was performed in the basal ganglia at the end of the experiment. Results: Compared to baseline, ADC, NAA/Cho, and NAA/Cr were significantly reduced after 7 hours ( P<0.001, P=0.01, and P=0.05, respectively) and FA values were increased ( P<0.025). The ratios of Lac/Cho and Lac/NAA were significantly higher after 7 hours compared to baseline ( P<0.001). Presence of necrosis correlated well with reduced ADC ( RS=0.91) and presence of Lac ( RS=0.80). Histology and MAP-2 staining showed more than 90% necrosis in eight piglets, 60% in one piglet, and no necrosis in one piglet. Conclusion: Diffusion MRI and proton MRS can detect HI injury in the piglet brain 7 hours after hypoxia. DWI and MRS can be used to give useful prognostic information. This piglet model may potentially be used to mimic clinical situations and is suitable for further research investigating HI injury.

scholarly journals Accuracy of apparent diffusion coefficient values and magnetic resonance imaging in differentiating suprasellar germinomas from chiasmatic/hypothalamic gliomas

2020 ◽  
Vol 33 (3) ◽  
pp. 201-209
Author(s):  
Theeraphol Panyaping ◽  
Piyakarn Taebunpakul ◽  
Oranan Tritanon
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Pituitary Gland ◽  
Contrast Enhancement ◽  
Resonance Imaging ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Mri Characteristics

Objective The aim of this study was to differentiate suprasellar germinomas from chiasmatic/hypothalamic gliomas (CHGs) using apparent diffusion coefficient (ADC) values and magnetic resonance imaging (MRI) characteristics. Materials and methods A cross-sectional study was conducted on 11 patients with suprasellar germinomas and 11 patients with CHGs who underwent pretreatment MRI. The ADC values (minimum and average ADC values) of the tumors were measured and the MRI characteristics were evaluated. Results The average and minimum ADC values of suprasellar germinomas were significantly lower than those of CHGs ( p = 0.016 and 0.004 respectively). The selection of 941.15 × 10−6 mm2/s as a cutoff value of the minimum ADC value was used to differentiate suprasellar germinomas and CHGs; the best results were obtained with area under the curve of 0.889, sensitivity of 87.5%, specificity of 77.8% and accuracy of 82.4%. MRI characteristics suggested the diagnosis of suprasellar germinomas were T2W hypointensity and involvement of pituitary gland and/or stalk. MRI characteristics suggested the diagnosis of CHGs was higher degree of contrast enhancement and presence of macrocysts. Conclusion ADC values have a role in differentiating suprasellar germinomas and CHGs, especially when imaging findings on conventional MRI are inconclusive. Furthermore, some MRI features are in favor of differentiation between these tumor entities including tumor location, cyst pattern, T2W hypointensity, degree of contrast enhancement, stalk and pituitary gland involvement.

scholarly journals P.002 Neurodevelopment at 2 years in asphyxiated newborns treated with hypothermia can be predicted by early neuroimaging markers

2016 ◽  
Vol 43 (S2) ◽  
pp. S22-S22
Author(s):  
FJ Al Amrani ◽  
P Wintermark
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Cerebral Palsy ◽  
Neurodevelopmental Outcome ◽  
Resonance Imaging ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Measurements

Background: Brain imaging in asphyxiated newborns treated with hypothermia has shown that brain injury can be identified as early as day 2 of life and continue to evolve over the first month of life. Methods: Asphyxiated newborns treated with hypothermia were enrolled prospectively. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured on magnetic resonance imaging (MRI) performed over the first month of life. Neurodevelopment was evaluated around 2 years of age. Results: Twenty-six asphyxiated newborns treated with hypothermia were enrolled. In asphyxiated newborns treated with hypothermia, who developed cerebral palsy, ADC values were significantly decreased on day 1 of life, on day 2-3 and around day 10 of life in the thalamus. In the same newborns, the FA values were significantly decreased on day 10 of life. Conclusions: Early MRI measurements permitted to identify the newborns developing cerebral palsy as early as on day 1 of life and could thus be used in the future to predict the long-term neurodevelopmental outcome asphyxiated newborns treated with hypothermia.

scholarly journals Apparent Diffusion Coefficient Decreases and Magnetic Resonance Imaging Perfusion Parameters are Associated in Ischemic Tissue of Acute Stroke Patients

2001 ◽  
Vol 21 (5) ◽  
pp. 577-584 ◽  
Author(s):  
Jens Fiehler ◽  
René Knab ◽  
Jürgen R. Reichenbach ◽  
Clemens Fitzek ◽  
Cornelius Weiller ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Resonance Imaging ◽  
Time To Peak ◽  
Ischemic Tissue ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Weighted Magnetic Resonance Imaging

Perfusion-and diffusion-weighted magnetic resonance imaging scans are thought to allow the characterization of tissue at risk of infarction. The authors tested the hypothesis that the apparent diffusion coefficient (ADC) decrease should be associated with the severity of the perfusion deficit in ischemic tissue of acute stroke patients. Perfusion-and diffusion-weighted scans were performed in 11 patients with sudden onset of neurologic deficits within the last 6 hours and T2-weighted magnetic resonance imaging scans were obtained after 6 days. Parameter images of the maximum of the contrast agent concentration, time to peak, relative cerebral blood volume, relative cerebral blood flow, and relative mean transit time were computed from the perfusion-weighted data. A threshold function was used to identify tissue volumes with stepwise ADC decreases. An onionlike distribution of successively decreasing ADC values was found, with the lowest ADC in the center of the ischemic region. Correspondingly, tissue perfusion decreased progressively from the periphery toward the ischemic core. This effect was most pronounced in the time-to-peak maps, with a linear association between ADC decrease and time-to-peak increase. Apparent diffusion coefficient values decreased from the periphery toward the ischemic core, and this distribution of ADC values was strongly associated with the severity of the perfusion deficit.

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