scholarly journals Diagnostic Efficacy of Signal Intensity Ratio and Apparent Diffusion Coefficient Measurements in Differentiating Cerebellopontine Angle Meningioma and Schwannoma

2020 ◽  
Author(s):  
Ali Er
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Cerebellopontine Angle ◽  
Signal Intensity Ratio ◽  
Diagnostic Efficacy ◽  
Apparent Diffusion

scholarly journals Apparent Diffusion Coefficient Signal Intensity Ratio Predicts the Effect of Revascularization on Ischemic Cerebral Edema

2018 ◽  
Vol 45 (3-4) ◽  
pp. 93-100 ◽  
Author(s):  
Matthew B. Bevers ◽  
Thomas W.K. Battey ◽  
Ann-Christin Ostwaldt ◽  
Reza Jahan ◽  
Jeffrey L. Saver ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Cerebral Edema ◽  
Signal Intensity ◽  
Intensity Ratio ◽  
Response To Therapy ◽  
Signal Intensity Ratio ◽  
Edema Formation ◽  
Post Stroke ◽  
Apparent Diffusion

Background: Apparent diffusion coefficient (ADC) imaging is a biomarker of cytotoxic injury that predicts edema formation and outcome after ischemic stroke. It therefore has the potential to serve as a “tissue clock” to describe the extent of ischemic injury and potentially predict response to therapy. The goal of this study was to determine the relationship between baseline ADC signal intensity, revascularization, and edema formation. Methods: We examined the ADC signal intensity ratio (ADCr) of the stroke lesion (defined as the baseline DWI hyperintense region) compared to the contralateral normal hemisphere in 65 subjects from the Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy trial. The associations between ADCr, neurologic outcome, and cerebral edema were examined. Finally, we explored the interaction between baseline ADCr and vessel recanalization at day 7 on post-stroke edema. Results: We found that lower initial ADCr was associated with a worse outcome on the modified Rankin Scale (mRS) at 90 days (52.2% of those with ADCr <64% were mRS 5–6 vs. 19.1% with ADCr ≥64%, p = 0.006). Those subjects with reconstitution of flow distal to the initial vessel occlusion showed greater normalization of ADCr on follow-up scan (increase in ADCr of 16.4 ± 2.07 vs. 1.99 ± 4.33%, p = 0.0039). In those patients with low baseline ADCr, successful revascularization was associated with reduced edema (median swelling volume 164 mL [interquartile range (IQR) 53.3–190 mL] vs. 20.7 mL [IQR 3.20–55.1 mL], p = 0.024). Conclusions: This study reaffirms the association of ADCr with outcome after stroke, supports the idea that reperfusion may attenuate rather than enhance post-stroke edema, and indicates that the degree of edema with and without revascularization may be predicted by ADCr.

scholarly journals T2 and DWI in Pilocytic and Pilomyxoid Astrocytoma with Pathologic Correlation

2012 ◽  
Vol 39 (4) ◽  
pp. 491-498 ◽  
Author(s):  
M. Horger ◽  
M. N. Vogel ◽  
R. Beschorner ◽  
U. Ernemann ◽  
J. Wörner ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Signal Intensity ◽  
Imaging Features ◽  
Pilomyxoid Astrocytoma ◽  
Diffusion Weighted Images ◽  
Significant Difference ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Myxoid Matrix

Objective:To quantify and compare T2 signal and apparent diffusion coefficient (ADC) in pilocytic and pilomyxoid astrocytoma (PA and PMA) and correlate results with myxoid content.Methods:Echo-planar diffusion weighted images (DWI) and standard magnetic resonance imaging (MRI) findings were reviewed retrospectively in patients with PA (n=34) and PMA (n=8). Regions of interest (ROIs) were drawn on ADC maps within tumor parts with lowest ADC values. Apparent diffusion coefficient values in tumor were normalized to those in cerebrospinal fluid (ADC/CSF). The ratio of T2 signal intensity in solid tumor parts to CSF (T2/CSF) was registered. Myxoid matrix was histologically quantified retrospectively in 8 PMAs and 17 PAs and correlated with imaging findings.Results:Mean ADC/CSF for PA and PMA was 0.53±0.10 and 0.69±0.10 (p<0.01). Mean T2/CSF for PA and PMA was 0.78±0.19 and 0.93±0.09 (p<0.01). Mean proportion of myxoid tumor matrix in PA was 50% (range, 10-100%) and 93% (range, 90-100%) in PMA (p=0.004). Eight patients (32%; all PA) had less than 50% myxoid content and 17 (68%; 8 PA; 9 PMA) had more. There was positive correlation of ADC/CSF, T2/CSF and ADC (r2=0.61, 0.65 and 0.60 respectively) and significant difference between the groups with more and less than 50% myxoid content (p=0.01 for ADC/CSF and T2/CSF and p=0.02 for ADC).Conclusions:General imaging features of PA and PMA are non-specific, ADC values and T2 signal intensity are generally higher in the latter, reflecting the proportion of myxoid matrix in these tumors.

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