Diffusion-weighted imaging of the dentate nucleus after repeated application of gadolinium-based contrast agents in multiple sclerosis

Following a previous study with diffusion tensor imaging, we investigated the correlation between diffusion-weighted imaging (DWI) and cognitive dysfunction in multiple sclerosis (MS). We studied 60 MS patients (mean age 45.8±9.0 years) using 1.5-T MRI. Disease course was RR=40 and SP = 20. Mean disease duration was 12.8±8.7 years. Mean EDSS was 3.4±1.7. Whole brain, gray and white matter normalized volumes were calculated on 3D SPGR T1-WI using a fully automated Hybrid SIENAX method. Parenchymal mean diffusivity (PMD) maps were created after automated segmentation of the brain parenchyma and cerebrospinal fluid using T2-WI and DW images. Histogram analysis was performed and DWI indices of peak position (PP), peak height (PH), mean parenchymal diffusivity (MPD) and entropy were obtained. Neuropsychological (NP) evaluation emphasized auditory/verbal and visual/spatial memory, as well as processing speed and executive function. We found significant correlations between DWI and performance in all cognitive domains. Overall, stronger correlations emerged for MPD and entropy than other DWI measures, although all correlations were in the expected direction. The strongest association was between DWI entropy and performance on the Symbol Digit Modalities Test, which assesses processing speed and working memory (r = -0.54). Fisher r to z transformations revealed that DWI, gray matter (GMF) and whole brain (BPF) atrophy, T1-lesion volume (LV) and T2-LV all accounted for similar amounts of variance in NP testing. Stepwise regression models determined whether multiple MRI measures predicted unique additive variance in test performance. GMF (R2 = 0.35, F =30.82, P <0.01) and entropy (ΔR2 =0.06, ΔF=5.47, P <0.05) both accounted for unique variance in processing speed. Our data make a stronger case for the clinical validity of DWI in MS than heretofore reported. DWI has very short acquisition times, and the segmentation method applied in the present study is reliable and fully automated. Given its overall simplicity and moderate correlation with cognition, DWI may offer several logistic advantages over more traditional MRI measures when predicting the presence of NP impairment. Multiple Sclerosis 2007; 13: 722-730. http://msj.sagepub.com

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Signal Intensity Changes in the Dentate Nucleus and Globus Pallidus of Multiple Sclerosis Patients Undergoing Multiple Brain Magnetic Resonance Imaging with Gadolinium-Based Contrast Agents

The Journal of Tepecik Education and Research Hospital ◽

10.5222/terh.2021.60490 ◽

2021 ◽

Author(s):

Yasin Ertuğ Çekdemir ◽

Nuri Karabay

Keyword(s):

Magnetic Resonance Imaging ◽

Multiple Sclerosis ◽

Magnetic Resonance ◽

Contrast Agents ◽

Signal Intensity ◽

Dentate Nucleus ◽

Resonance Imaging ◽

Mri Scans ◽

Intensity Ratios ◽

Multiple Sclerosis Patients

Objective: To investigate the correlation between cumulative doses of gadolinium-based contrast agents and increased signal intensity (SI) in the dentate nucleus (DN) and globus pallidus (GP). Methods: Our retrospective trial involved 21 multiple sclerosis patients (11 women, 10 men; mean age: 39.21±10.24, range: 20 to 57 years) who underwent a serial number of multiple cranial magnetic resonance imaging (MRI) examinations in the radiology department of our tertiary care center. Average signal intensities on the DN, pons, GP and thalamus on unenhanced T1-weighted magnetic resonance images were taken into account. The signal intensity in the DN was proportioned to the signal intensity in the pons, whereas the signal intensity in GP to the signal intensity in the thalamus. Any relationship between the DN-to-pons or GP-to-thalamus signal intensity ratios and previous gadolinium-based contrast administrations was sought by means of repeated measures ANOVA. Results: Increases in both DN-to-pons and GP-to-thalamus signal intensity ratios displayed a significant correlation with previous administrations of gadolinium-based contrast agents (p<0.001 for both). A remarkable increase was detected in DN-to-pons and GP-to-thalamus signal intensity ratios between the first and last MRI examinations (p<0.001 for both). Conclusion: Our results support the association between increase in the SI of the DN and GP to the number of gadolinium-enhanced MRI scans in MS patients. The increase in T1 SI seems to be linked with the number of enhanced MRI scans.

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Detection of Active Plaques in Multiple Sclerosis Using 3 and 12 Directional Diffusion-weighted Imaging: Comparison with Gadolinium-enhanced MR Imaging

Journal of Biomedical Physics and Engineering ◽

10.31661/jbpe.v0i0.925 ◽

2018 ◽

Author(s):

S Rahimi ◽

A Azari ◽

P Ghaemmaghami ◽

G H Meftahi ◽

G Pirzad Jahromi

Keyword(s):

Multiple Sclerosis ◽

Correlation Coefficient ◽

Intraclass Correlation Coefficient ◽

Diffusion Weighted Imaging ◽

Diffusion Tensor ◽

Intraclass Correlation ◽

Neurological Dysfunction ◽

Lower Sensitivity ◽

Diffusion Weighted ◽

Cost Effective Treatment

Background: Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) characterized by exacerbations of neurological dysfunction due to inflammatory demyelination. MRI is the most sensitive method to make adiagnosis of multiple sclerosis. contrast-enhanced T1-weighted imaging (CE T1WI) is used as a gold standard to distinguish active and inactive MS lesions. However, Gadolinium based contrast agents (GBCAs) have some contraindications. Diffusion-weighted imaging (DWI) can detect diffusion alterations in active inflammatory lesions. The purpose of this study is to investigate whether common DWI (3 directional) and 12 directional DWI which is used in Diffusion tensor imaging can be an alternative to CE T1WI so as to demonstrat active (enhanced) MS lesions.Methods: In this cross sectional study, at two different hospitals, 138 patients who presented with CNS symptoms suggestive of demyelinating disease were examined. CE T1WI using 0.1 mmol/kg gadolinium as well as 3 & 12 directional DWI was done for all patients. To determine the reliability and accuracy of 3 & 12 directional DWI for delineating the enhancement of demyelinating lesions on CET1W, Intraclass correlation coefficient (ICC) and the plot of sensitivity versus specifity is called receiver operating characteristic (ROC) curve and the area under the curve (AUC) were calculated.Results: 114 patients (82.6%)revealed contrast enhancement in CE T1WI, 117 (84.7%) and 107 (77.5%) patients demonstrated hyper intense lesions on DWI 12 & DWI 3 respectively. The intraclass correlation coefficient (ICC) for DWI 12 was higher than 0.92; however, for DWI 3 was less than 0.64. The DWI 12 data generated a sensitivity and specificity of 94.7% and 62.5%, combined with an AUC of 84%. Besides the sensitivity, specificity and AUC for DWI 3 CE were 86%, 62.5 and 79%, respectively.Conclusion: Among 2 different DWI sequences, 12 directional DWI images have higher reliability and accuracy. Therefore, despite lower sensitivity compared to CE T1WI, it can be a practical diagnostic sequence in discriminating enhancing lesions from non-enhancing lesions when performing CE-MRI is a concern for the patient. concerning the cons and pros of CE T1WI and DWI 12, these two sequences can be used in combination in order to reach higher sensitivities, leading to earlier diagnosis and more cost effective treatment.

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