scholarly journals Reperfusion after Thrombolytic Therapy of Embolic Stroke in the Rat: Magnetic Resonance and Biochemical Imaging

1998 ◽  
Vol 18 (4) ◽  
pp. 407-418 ◽  
Author(s):  
Elmar Busch ◽  
Karsten Krüger ◽  
Peter R. Allegrini ◽  
Christian M. Kerskens ◽  
Michael L. Gyngell ◽  
...  
Keyword(s):  
Blood Flow ◽  
Magnetic Resonance ◽  
Thrombolytic Therapy ◽  
Autologous Blood ◽  
Sharp Decrease ◽  
Tissue Type ◽  
Gradual Improvement ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Clot Material

The effect of thrombolytic therapy was studied in rats submitted to thromboembolic stroke by intracarotid injection of autologous blood clots. Thrombolysis was initiated after 15 minutes with an intracarotid infusion of recombinant tissue-type activator (10 mg/kg body weight). Reperfusion was monitored for 3 hours using serial perfusion- and diffusion magnetic resonance imaging, and the outcome of treatment was quantified by pictorial measurements of ATP, tissue pH, and blood flow. In untreated animals, clot embolism resulted in an immediate decrease in blood flow and a sharp decrease in the apparent diffusion coefficient (ADC) that persisted throughout the observation period. Thrombolysis successfully recanalized the embolized middle cerebral artery origin and led to gradual improvement of blood flow and a slowly progressing reversal of ADC changes in the periphery of the ischemic territory, but only to transient and partial improvement in the center. Three hours after initiation of thrombolysis, the tissue volume with ADC values less than 80% of control was 39 ± 22% as compared to 61 ± 20% of ipsilateral hemisphere in untreated animals (means ± SD, P = .03) and the volume of ATP-depleted brain tissue was 25 ± 31% as compared to 46 ± 29% in untreated animals. Recovery of ischemic brain injury after thromboembolism is incomplete even when therapy is started as early as 15 minutes after clot embolism. Possible explanations for our findings include downstream displacement of clot material, microembolism of the vascular periphery, and events associated with reperfusion injury.

scholarly journals Late Reversal of Cerebral Perfusion and Water Diffusion after Transient Focal Ischemia in Rats

2002 ◽  
Vol 22 (3) ◽  
pp. 253-261 ◽  
Author(s):  
Lei Wang ◽  
Victor E. Yushmanov ◽  
Serguei M. Liachenko ◽  
Pei Tang ◽  
Ronald L. Hamilton ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Focal Ischemia ◽  
Artery Occlusion ◽  
Tissue Water ◽  
Apparent Diffusion ◽  
Reperfusion Period ◽  
Adc Values ◽  
Transient Focal Ischemia ◽  
Late Reperfusion

Region-specific cerebral blood flow (CBF) and the apparent diffusion coefficient (ADC) of tissue water in the rat brain were quantified by high-field magnetic resonance imaging at 9.4 T in the rat suture occlusion model. Cerebral blood flow and ADC were compared during the short- (4.5 hours) and long-term (up to 6 days) reperfusion after 80 minutes of transient middle cerebral artery occlusion, and correlated with the histology analysis. On occlusion, average CBF fell from ∼100 to less than 50 mL 100 g−1 min−1 in the cortex, and to less than 20 mL 100 g−1 min−1 in the caudate putamen (CP). Corresponding ADC values decreased from (6.98 ± 0.82) × 10−4 to (5.49 ± 0.54) × 10−4 mm2/s in the cortex, and from (7.16 ± 0.58) × 10−4 to (4.86 ± 0.62) × 10−4 mm2/s in the CP. On average, CBF recovered to ∼50% of baseline in the first 24 hours of reperfusion. After 2 to 4 days, a strong hyperperfusion in the ipsilateral cortex and CP, up to ∼300 mL 100 g−1 min−1, was observed. The ADC ratio in the ipsilateral and contralateral CP was also inverted in the late reperfusion period. Histology revealed more severe tissue damage at the late stage of reperfusion than at 4.5 hours. Significant reversal of CBF and ADC during the late reperfusion period may reflect the impairment of autoregulation in the ischemic regions. Vascular factors may play an important role in the infarct development after 80-minute focal ischemia.

scholarly journals Diffusion-Weighted Magnetic Resonance Imaging as a Noninvasive Parameter for Differentiating Benign and Malignant Intraperitoneal Collections

Medicina ◽  
2020 ◽  
Vol 56 (5) ◽  
pp. 217
Author(s):  
Paul-Andrei Ștefan ◽  
Csaba Csutak ◽  
Andrei Lebovici ◽  
Georgeta Mihaela Rusu ◽  
Carmen Mihaela Mihu
Keyword(s):  
Magnetic Resonance ◽  
Tumor Staging ◽  
Abdominal Mass ◽  
Final Diagnosis ◽  
Malignant Ascites ◽  
Characteristic Analysis ◽  
Apparent Diffusion ◽  
Malignant Group ◽  
Adc Values ◽  
The Difference

Background and Objective: The imaging differentiation of benign from malignant intraperitoneal collections (IPCs) relies on the tumoral morphological modifications of the peritoneum, which are not always advocating for malignancy. We aimed to assess ascitic fluid with the apparent diffusion coefficient (ADC) to determine non-invasive, stand-alone, differentiation criteria for benign and malignant intraperitoneal effusions. Materials and Methods: Sixty-one patients with known IPCs who underwent magnetic resonance examinations for reasons such as tumor staging, undetermined abdominal mass and disease follow up were retrospectively included in this study. All subjects had a final diagnosis of the fluid based on pathological examinations, which were divided into benign (n = 37) and malignant (n = 24) IPCs groups. ADC values were measured separately by two radiologists, and the average values were used for comparing the two groups by consuming the independent samples t-test. The receiver operating characteristic analysis was performed to test the ADC values’ diagnostic ability to distinguish malignant from benign collections. Results: The differentiation between benign and malignant IPCs based on ADC values was statistically significant (p = 0.0034). The mean ADC values were higher for the benign (3.543 × 10−3 mm2/s) than for the malignant group (3.057 × 10−3 mm2/s). The optimum ADC cutoff point for the diagnosis of malignant ascites was <3.241 × 10−3 mm2/s, with a sensitivity of 77.78% and a specificity of 80%. Conclusions: ADC represents a noninvasive and reproducible imaging parameter that may help to assess intraperitoneal collections. Although successful in distinguishing malignant from benign IPCs, further research must be conducted in order to certify if the difference in ADC values is a consequence of the physical characteristics of the ascitic fluids or their appurtenance to a certain histopathological group.

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 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 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.

Prediction of Neurological Recovery Using Apparent Diffusion Coefficient in Cases of Incomplete Spinal Cord Injury

Neurosurgery ◽  
2011 ◽  
Vol 68 (2) ◽  
pp. 329-336 ◽  
Author(s):  
Toshiki Endo ◽  
Shinsuke Suzuki ◽  
Akihiro Utsunomiya ◽  
Hiroshi Uenohara ◽  
Teiji Tominaga
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Cervical Spinal Cord ◽  
Postoperative Recovery ◽  
Cavity Formation ◽  
Cord Injury ◽  
Apparent Diffusion ◽  
Adc Values

Abstract BACKGROUND: Magnetic resonance imaging is useful in evaluating acute spinal cord injury. Apparent diffusion coefficient (ADC) values obtained by diffusion-weighted imaging can differentiate cytotoxic edema from vasogenic edema through microscopic motion of water protons. OBJECTIVE: To determine whether ADC values in the cervical spinal cord match neurological grades and thus predict functional recovery in patients suffering from cervical spinal cord injury. METHODS: Diffusion-weighted images were obtained using 15 axial slices covering the cervical spinal cord from 16 consecutive patients. ADC values were determined for both gray and white matter. All patients were treated surgically. Patient neurological status was evaluated preoperatively and postoperatively with the Frankel classification and neurosurgical cervical spine scale. One patient had complete spinal cord injury and showed no recovery. Using 15 patients with incomplete injury, we analyzed correlations between preoperative ADC values and neurological grading, degree of postoperative recovery, or cavity formation in follow-up magnetic resonance images. For comparison, ADC values of 11 healthy volunteers were also calculated. RESULTS: There was significant correlation between ADC values and degree of postoperative recovery (P = .02). ADC values of patients showing cavity formation were significantly lower than those of patients without cavity formation (0.70 vs 0.96 × 10−3 mm2/s; P = .01). The cutoff ADC value of 0.80 × 10−3 mm2/s resulted in 75% sensitivity and 81.8% specificity for predicting cavity formation. CONCLUSION: Low ADC values in acute spinal cord injury may indicate postoperative cavity formation in the injured spinal cord and predict poor functional recovery.

scholarly journals Do Intratumoral And Peritumoral Apparent Diffusion Coefficient (ADC) Values Have A Role In The Diagnosis Of Pediatric Brain Tumors?

2020 ◽  
Author(s):  
Güleç Mert Doğan ◽  
Ahmet Sığırcı ◽  
Sevgi Taşolar ◽  
Aslınur Cengiz ◽  
Hilal Er Ulubaba ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Brain Tumors ◽  
Magnetic Resonance Image ◽  
Pediatric Patients ◽  
Pediatric Brain Tumors ◽  
Low Grade ◽  
High Grade ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Pediatric Brain

INTRODUCTION: The motion of water particles within biological tissues, which is called random Brownian motion, is detected at the microscopic level by Diffusion-Weighted Imaging (DWI) sequence of Magnetic Resonance Image technique. The Apparent Diffusion Coefficient (ADC) calculated on DWI has been used for tumor diagnosis and grading. The purpose of this study was to evaluate of ADC values in the differential diagnosis of supratentorial and infratentorial pediatric brain tumors and to reveal the difference of peritumoral ADC measurements of pediatric patients from adult patients. METHODS: All of the 56 pediatric patients included in this retrospective study had lesions >1 cm in diameter on magnetic resonance image and all of the diagnosies were confirmed by histopathology. Intratumoral and peritumoral ADC values and ratios were measured in diffusion weighted Magnetic Resonance Image. RESULTS: The 58.9% (n=33) of these tumors were supratentorial and 41.1% (n=23) were infratentorial. ADC values and ADC ratios were significantly lower in high-grade tumors than low-grade tumors (p<0.05). Peritumoral ADC values in high-grade tumors were lower than low grade tumors (p<0.05). The cut-off value of the ADC ratio between these two groups was 1 and the ADC cut-off value was 1.1*10-3 mm2/s. DISCUSSION AND CONCLUSION: In the differentiation of low and high-grade pediatric brain tumors, cut-off values of 1.1*10_3mm2/s for ADC Value and 1.0 for ADC Ratio may be useful. Although, peritumoral ADC values differ in children compared to the adult group, both intratumoral and peritumoral ADC values can help for grading pediatric brain tumors.

scholarly journals Diffusion-weighted imaging and apparent diffusion coefficient values for evaluating terminal ileitis in patients with Crohn’s disease

2019 ◽  
Vol 52 (6) ◽  
pp. 361-367 ◽  
Author(s):  
Evandra Durayski ◽  
Guilherme Watte ◽  
Gabriel Sartori Pacini ◽  
Diego Hermindo Roman ◽  
Marta Brenner Machado ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Crohn’S Disease ◽  
Magnetic Resonance ◽  
Crohn's Disease ◽  
Diffusion Weighted Imaging ◽  
Inactive Disease ◽  
Terminal Ileitis ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Active Inflammation

Abstract Objective: To determine the accuracy of diffusion-weighted imaging (DWI) in identifying terminal ileitis in patients with Crohn’s disease. Materials and Methods: This was a retrospective study of 38 consecutive patients with Crohn’s disease who underwent magnetic resonance enterography with DWI in a 3.0 T scanner. The patients were divided into two groups, on the basis of colonoscopy and biopsy findings: active inflammation; and inactive disease. Apparent diffusion coefficient (ADC) values were determined, as were the magnetic resonance index of activity (MaRIA) and the Clermont score. Results: Of the 38 patients evaluated, 18 (47%) had active inflammation. The patients with active inflammation showed greater restricted diffusion, more pronounced mucosal edema, greater wall thickening, a higher MaRIA, and a higher Clermont score than did those with inactive disease. The level of interobserver agreement (intraclass correlation coefficient) was excellent for the MaRIA and the Clermont score, whereas it was substantial for the ADC values. For identifying colonoscopy-proven inflammation, the best ADC cut-off point was 2.1 × 10−3 mm2/s, which had a sensitivity of 88.8% and a specificity of 95.0%, whereas DWI presented an overall accuracy of 89.4%, with a sensitivity of 88.9% and a specificity of 90.0%. Conclusion: Visual analysis of the DWI sequence has good accuracy in detecting terminal ileitis in patients with Crohn’s disease. In addition, low ADC values have good sensitivity for detecting colonoscopy-proven inflammation.

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.

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