scholarly journals Signal Intensity Normalization of Multispectal Magnetic Resonance Images Obtained with Clinical Sequences

2021 ◽  
Author(s):  
Matthew Brier ◽  
biao xiang ◽  
Zhuocheng Li ◽  
Robert Naismith ◽  
Dmitriy Yablonskiy ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Magnetic Resonance Images ◽  
Clinical Settings ◽  
Alternative Technique ◽  
Tissue Integrity ◽  
T1 And T2 ◽  
Intensity Normalization ◽  
Tissue Biomarkers

Assessment of intrinsic tissue integrity is commonly accomplished via quantitative relaxometry or other specialized imaging, which requires sequences and analysis procedures not routinely available in clinical settings. We detail an alternative technique for extraction of quantitative tissue biomarkers based on intensity normalization of T1- and T2-weighted images. We develop the theoretical underpinnings of this approach and demonstrate its utility in imaging of multiple sclerosis.

scholarly journals Multiple Sclerosis Of The Spinal Cord: Is Gadolinium Irreplaceable In Assessing Lesion Activity?

2013 ◽  
Vol 59 (3) ◽  
pp. 158-161
Author(s):  
Constantina Andrada Treabă ◽  
M Buruian ◽  
Rodica Bălașa ◽  
Maria Daniela Podeanu ◽  
I P Simu ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Spinal Cord ◽  
Magnetic Resonance ◽  
Contrast Enhancement ◽  
Signs And Symptoms ◽  
Magnetic Resonance Images ◽  
Type I ◽  
Focal Lesions ◽  
Spinal Cord Lesions ◽  
Active Lesion

Abstract Purpose: To evaluate the relationship between the T2 patterns of spinal cord multiple sclerosis lesions and their contrast uptake. Material and method: We retrospectively reviewed the appearance of spinal cord lesions in 29 patients (with relapsing-remitting multiple sclerosis) who had signs and symptoms of myelopathy on neurologic examination and at least one active lesion visualized on magnetic resonance examinations performed between 2004 and 2011. We correlated the T2 patterns of lesions with contrast enhancement and calculated sensitivity and specificity in predicting gadolinium enhancement. Results: Only focal patterns consisting of a lesion’s center homogenously brighter than its periphery on T2-weighed images (type I) correlated significantly with the presence of contrast enhancement (p = 0.004). Sensitivity was 0.307 and specificity 0.929. In contrast, enhancement was not significantly related to uniformly hyperintense T2 focal lesions (type II) or diffuse (type III) pattern defined as poorly delineated areas of multiple small, confluent, subtle hyperintense T2 lesions (p > 0.5 for both). Conclusions: We believe that information about the activity of multiple sclerosis spinal cord lesions in patients with myelopathy may be extracted not only from contrast enhanced, but also from non-enhanced magnetic resonance images.

scholarly journals A vaginal fibroepithelial stromal polyp: a case report with magnetic resonance images

2022 ◽  
Author(s):  
Naoko Ogura ◽  
Mieko Inagaki ◽  
Ritsuko Yasuda ◽  
Shigeki Yoshida ◽  
Tetsuo Maeda
Keyword(s):  
Magnetic Resonance ◽  
Signal Intensity ◽  
Vaginal Wall ◽  
Magnetic Resonance Images ◽  
High Signal ◽  
Soft Tissue Tumour ◽  
Mri Findings ◽  
Vaginal Mass ◽  
Diffusion Weighted Images ◽  
Tissue Tumour

A fibroepithelial stromal polyp is a benign soft tissue tumour that can occur in the vagina, vulva and uterine cervix. Magnetic resonance imaging (MRI) findings have been reported in patients with vulvar fibroepithelial stromal polyps, not in those with vaginal polyps. We present MRI findings of vaginal fibroepithelial stromal polyp in a postmenopausal female. A 1 to 2 cm firm vaginal mass arising from the left side of the vaginal wall with hypointense signal changes on T1W MRI was identified. A well-defined vaginal mass (1 cm diameter) was detected with inhomogeneous signal intensity on T2W images. However, a major portion had high signal intensity on diffusion-weighted images. A benign vaginal lesion with oedematous changes or myxoid degeneration was suspected. Vaginal resection was performed, and fibroepithelial stromal polyp was pathologically diagnosed. MRI may be a useful non-invasive modality for preoperatively diagnosing vaginal fibroepithelial stromal polyps.

Lysability of arterial thrombi assessed by magnetic resonance imaging

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 262-265 ◽  
Author(s):  
Kozak ◽  
Mikac ◽  
Blinc ◽  
Sersa
Keyword(s):  
Magnetic Resonance ◽  
Signal Intensity ◽  
Magnetic Resonance Images ◽  
High Signal ◽  
Resonance Imaging ◽  
Gradient Echo ◽  
Catheter Directed Thrombolysis ◽  
Improve Patient Selection ◽  
Selection For ◽  
Improve Patient

Background: Intravascular thrombi change in time due to retraction and organization, which is reflected in the appearance of magnetic resonance images of clots. We have hypothesized that MRI has the potential to improve patient selection for thrombolytic treatment. The aim of our study was to analyze occlusive arterial thrombi with MRI, and to correlate the MRI parameters with the therapeutic outcome in patients with occlusive atherothrombotic disease of the superficial femoral artery who were treated with catheter-directed thrombolysis by streptokinase. Patients and methods: We included 13 patients with subacute (2 weeks to 3 months old) occlusive arterial thrombi and 4 patients with chronic (more than 6 months old) arterial occlusions. We measured the MRI signal intensity on gradient echo images of 98 axial slices of the subacute occlusive thrombi and in 45 slices of 4 chronic thrombi. Following MRI, the patients with subacute history were treated with catheter-directed thrombolysis. Results: Thrombolysis was successful in 11/13 patients. The normalized MRI signal intensity was significantly higher in the unsuccessfully treated thrombi than in the successfully treated thrombi (1.10 ± 0.08 vs. 0.72 ± 0.17, p < 0.003), but the subacute and chronic thrombi did not differ in signal intensity. Conclusions: High signal intensity of arterial thrombi on gradient echo MRI might predict resistance to thrombolytic therapy.

scholarly journals ADvanced IMage Algebra (ADIMA): a novel method for depicting multiple sclerosis lesion heterogeneity, as demonstrated by quantitative MRI

2012 ◽  
Vol 19 (6) ◽  
pp. 732-741 ◽  
Author(s):  
Marios C Yiannakas ◽  
Daniel J Tozer ◽  
Klaus Schmierer ◽  
Declan T Chard ◽  
Valerie M Anderson ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Quantitative Mri ◽  
Multiple Sclerosis Lesion ◽  
Proton Density ◽  
Image Algebra ◽  
Quantitative Magnetic Resonance ◽  
Magnetic Resonance Parameters ◽  
Mri Scans ◽  
T1 And T2

Background: There are modest correlations between multiple sclerosis (MS) disability and white matter lesion (WML) volumes, as measured by T2-weighted (T2w) magnetic resonance imaging (MRI) scans (T2-WML). This may partly reflect pathological heterogeneity in WMLs, which is not apparent on T2w scans. Objective: To determine if ADvanced IMage Algebra (ADIMA), a novel MRI post-processing method, can reveal WML heterogeneity from proton-density weighted (PDw) and T2w images. Methods: We obtained conventional PDw and T2w images from 10 patients with relapsing–remitting MS (RRMS) and ADIMA images were calculated from these. We classified all WML into bright (ADIMA-b) and dark (ADIMA-d) sub-regions, which were segmented. We obtained conventional T2-WML and T1-WML volumes for comparison, as well as the following quantitative magnetic resonance parameters: magnetisation transfer ratio (MTR), T1 and T2. Also, we assessed the reproducibility of the segmentation for ADIMA-b, ADIMA-d and T2-WML. Results: Our study’s ADIMA-derived volumes correlated with conventional lesion volumes ( p < 0.05). ADIMA-b exhibited higher T1 and T2, and lower MTR than the T2-WML ( p < 0.001). Despite the similarity in T1 values between ADIMA-b and T1-WML, these regions were only partly overlapping with each other. ADIMA-d exhibited quantitative characteristics similar to T2-WML; however, they were only partly overlapping. Mean intra- and inter-observer coefficients of variation for ADIMA-b, ADIMA-d and T2-WML volumes were all < 6 % and < 10 %, respectively. Conclusion: ADIMA enabled the simple classification of WML into two groups having different quantitative magnetic resonance properties, which can be reproducibly distinguished.

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