scholarly journals Signal Intensity of Contrast Enhancement according to TE in 3.0T MRI T1 Imaging

2018 ◽  
Vol 8 (7) ◽  
pp. 1138
Author(s):  
Hyun Jeong ◽  
Kwon Lee ◽  
Min Kim ◽  
Sung Kim ◽  
Min Kim ◽  
...  
Keyword(s):  
Clinical Study ◽  
Magnetic Resonance ◽  
Contrast Enhancement ◽  
Signal Intensity ◽  
Mr Contrast Agents ◽  
Peak Point ◽  
Contrast Enhanced ◽  
Echo Time ◽  
3.0T Mri ◽  
Peak Signal Intensity

Normal body tissue or lesion characteristics in T1 images have been evaluated; however, how external parameters effect the change in signal intensity by gadolinium-based contrast agent remains unknown. We investigated how contrast enhancement changed according to echo time (TE) in 3.0T magnetic resonance (MR) T1 imaging and determined the optimal settings for TE in contrast-enhanced T1 imaging. Since there are no guidelines regarding parameters for T1 enhancement when using MR-contrast agents, we analyzed results from varying TEs (between 25 and 7 msec) in both a phantom and clinical study. We obtained the following results: contrast percentage of fat to saline increased from 740.0–1003.6%, response start point increased from 30–90 mmol, max peak signal intensity increased from 1771–2425 a.u., max peak point increased from 2–4 mmol, enhancement percentage of the max peak signal intensity (MPSI) to saline increased from 1671.0–2065.2%, the average of SI on each mol as TE increased from 600.8–996.6 a.u., the average of SI as TE on each molar concentration increased from 378–845 a.u., the AEPSS increased from 44.3–140.3%, and the AEPSC increased from 224.3–647.8%. We confirmed that TE can affect contrast enhancement, and the lowest TE has faster and higher effects on contrast enhancement.

Lipoma in olecranon bursa: A case report

2021 ◽  
Vol 3 ◽  
pp. 67-69
Author(s):  
Shalini Agarwal ◽  
Jyoti Siwach ◽  
Ramneet Wadi ◽  
Nipun Gupta
Keyword(s):  
Magnetic Resonance Imaging ◽  
Case Report ◽  
Magnetic Resonance ◽  
Contrast Enhancement ◽  
Local Anesthesia ◽  
Signal Intensity ◽  
Ultrasound Examination ◽  
Fat Cells ◽  
Resonance Imaging ◽  
Diffusion Weighted Images

We report a case of a 55-year-old male patient who presented with swelling over his right elbow of 5-year duration. An ultrasound examination revealed an echogenic mass within the olecranon bursa. On magnetic resonance imaging, the mass revealed the signal intensity of fat, and it was attached to the bursal lining by means of a pedicle. There was no restriction on diffusion-weighted images and no significant contrast enhancement. Excision was performed under local anesthesia. The excised specimen revealed mature fat cells on histopathology.

scholarly journals Correlative Magnetic Resonance Imaging and Histopathology in Small Ruminant Listeria Rhombencephalitis

2020 ◽  
Vol 11 ◽  
Author(s):  
Christina Precht ◽  
Peter Vermathen ◽  
Diana Henke ◽  
Anne Staudacher ◽  
Josiane Lauper ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Enhancement ◽  
Signal Intensity ◽  
Small Ruminants ◽  
Large Animal ◽  
Resonance Imaging ◽  
Post Contrast ◽  
Mri Features ◽  
Inflammatory Infiltrates

Background: Listeria rhombencephalitis, infection of the brainstem with Listeria monocytogenes, occurs mainly in humans and farmed ruminants and is associated with high fatality rates. Small ruminants (goats and sheep) are a large animal model due to neuropathological similarities. The purpose of this study was to define magnetic resonance imaging (MRI) features of listeria rhombencephalitis in naturally infected small ruminants and correlate them with histopathology. Secondly, the purpose of this study was to compare the results with MRI findings reported in humans.Methods: Twenty small ruminants (13 sheep and 7 goats) with listeria rhombencephalitis were prospectively enrolled and underwent in vivo MRI of the brain, including T2-weighted, fluid attenuation inversion recovery, and T1-weighted sequences pre- and post-contrast administration and postmortem histopathology. In MRI, lesions were characterized by location, extent, border definition, signal intensity, and contrast enhancement. In histopathology, the location, cell type, severity, and chronicity of inflammatory infiltrates and signs of vascular damage were recorded. In addition, histopathologic slides were matched to MRIs, and histopathologic and MRI features were compared.Results: Asymmetric T2-hyperintense lesions in the brainstem were observed in all animals and corresponded to the location and pattern of inflammatory infiltrates in histopathology. Contrast enhancement in the brainstem was observed in 10 animals and was associated with vessel wall damage and perivascular fibrin accumulation in 8 of 10 animals. MRI underestimated the extension into rostral brain parts and the involvement of trigeminal ganglia and meninges.Conclusion: Asymmetric T2-hyperintense lesions in the brainstem with or without contrast enhancement can be established as criteria for the diagnosis of listeria rhombencephalitis in small ruminants. Brainstem lesions were similar to human listeria rhombencephalitis in terms of signal intensity and location. Different from humans, contrast enhancement was a rare finding, and abscessation was not observed.

scholarly journals Basic knowledge for hepatic MRI interpretation

2019 ◽  
Vol 2 (1) ◽  
pp. 9-12
Author(s):  
Wanwarang Teerasamit
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Tissue Characterization ◽  
Basic Knowledge ◽  
Liver Lesions ◽  
Resonance Imaging ◽  
Mr Contrast Agents ◽  
Magnetic Resonance Imaging Mri ◽  
Weighted Sequences

Nowadays, Magnetic resonance imaging (MRI) has an important role for diagnosis of liver lesions due to excellent tissue characterization, radiation-free technique and continuous development of MRI technology, causing an increased use of MRI. This article focuses on basic knowledge of MRI liver interpretation for non-radiologist. The basic techniques including T1-weighted and T2-weighted sequences as well as additional techniques such as 2D dual GRE in-phase and opposed-phase, fat suppression or heavily T2-weighted sequences were introduced. Types of MR contrast agents for liver including extracellular and hepatocyte-specific agents were also described.   Figure 1  เป็นภาพ MRI ของตับเทคนิค T1W โดยอวัยวะส่วนใหญ่ที่ปรากฏในภาพจะให้ลักษณะ signal intensity ไปในทางhypointense ซึ่งจะเห็นว่าม้าม (spleen=S) ดำกว่าตับ (liver=L) และตับจะดำกว่าตับอ่อน (pancreas=P) โดยลูกศรสีดำชี้ให้เห็น signal intensity ของน้ำไขสันหลังที่เป็นลักษณะ hypointense

scholarly journals Contrast-enhanced dynamic magnetic resonance imaging of the rat kidney.

1996 ◽  
Vol 7 (3) ◽  
pp. 424-430
Author(s):  
R Fransen ◽  
H J Muller ◽  
W H Boer ◽  
K Nicolay ◽  
H A Koomans
Keyword(s):  
Magnetic Resonance Imaging ◽  
Angiotensin Ii ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Rat Kidney ◽  
Magnetic Resonance Images ◽  
Resonance Imaging ◽  
Water Reabsorption ◽  
Gadolinium Dtpa ◽  
Contrast Enhanced

This study was designed to assess whether contrast-enhanced dynamic 1H magnetic resonance imaging (DMRI) can be used to detect the effects of the loop diuretic furosemide and the vasoactive peptide angiotensin II on tubular water reabsorption in the rat kidney. A bolus of gadolinium-DTPA-dimeglumine (Gd-DTPA) (0.025 or 0.1 mmol/kg) was used as a contrast agent. The signal intensity in the magnetic resonance images relative to the precontrast signal intensity (RSI) was assessed as a function of time in the cortex and medulla. In the cortex, no differences were observed between high and low bolus injection, and between different treatment groups and controls. In the medulla, RSI patterns were different between high and low bolus, with the high bolus showing lower RSI values, because of T2 shortening at high Gd-DTPA concentrations. No difference was observed between controls and angiotensin II-infused animals. This is in line with the finding that angiotensin II did not alter medullary water reabsorption, as evidenced by unchanged urine flow and osmolality compared with controls. Medullary RSI patterns during furosemide infusion differed markedly from controls, in a manner suggesting that a lower concentration of Gd-DTPA was present compared with controls. This agrees with the well-known inhibiting effect of furosemide on medullary water reabsorption. It was concluded that, with the method used, small concentration differences of Gd-DTPA in the cortex resulting from small changes of plus or minus 20% in tubular water reabsorption, previously found to be present by direct micropuncture measurements, cannot be detected in rats. However, large changes in renal concentrating ability do result in different RSI patterns in the medulla.

S283 – Invasive Fugal Sinusitis: Pathognomic Presentation in MRI

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P169-P169
Author(s):  
Jinyoung Min ◽  
Seung-Kyu Chung ◽  
Hun-Jong Dhong ◽  
Hyo-Yeol Kim ◽  
Yonggi Jung ◽  
...  
Keyword(s):  
High Risk ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Magnetic Resonance Image ◽  
Fungal Sinusitis ◽  
Mri Findings ◽  
Radiographic Findings ◽  
Invasive Fungal Sinusitis ◽  
Contrast Enhanced ◽  
Histopathologic Findings

Objectives The aim of this study was to evaluate the pathognomic findings of magnetic resonance image(MRI) and determine the benefit of MRI in early diagnosis of invasive fungal sinusitis(IFS). Methods We retrospectively reviewed 15 cases of biopsy-proven IFS. The preoperative MRI was reviewed to identify the pathognomic findings and correlation between radio-graphic and surgical findings were investigated. Results The MRI findings included decreased signal intensity on T1-weighted images with no enhancement on contrast-enhanced images and markedly decreased signal intensity on T2-weighted images in all cases. In our series, the interval between the onset of symptom and timing of MRI was from 48 hours to 2 weeks. Radiographic findings were correlated with histopathologic findings in 13 of 15 patients. Conclusions We could find typical MRI findings in IFS. MRI should be considered early in patients at high risk for IFS.

Biomechanical Properties and Vascularity of an Anterior Cruciate Ligament Graft can be Predicted by Contrast-Enhanced Magnetic Resonance Imaging

2001 ◽  
Vol 29 (6) ◽  
pp. 751-761 ◽  
Author(s):  
Andreas Weiler ◽  
Gunnar Peters ◽  
Jürgen Mäurer ◽  
Frank N. Unterhauser ◽  
Norbert P. Südkamp
Keyword(s):  
Magnetic Resonance Imaging ◽  
Tensile Strength ◽  
Anterior Cruciate Ligament ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Cruciate Ligament ◽  
Resonance Imaging ◽  
Contrast Enhanced ◽  
Load To Failure ◽  
Anterior Cruciate

Magnetic resonance imaging has been used to determine graft integrity and study the remodeling process of anterior cruciate ligament grafts morphologically in humans. The goal of the present study was to compare graft signal intensity and morphologic characteristics on magnetic resonance imaging with biomechanical and histologic parameters in a long-term animal model. Thirty sheep underwent anterior cruciate ligament reconstruction with an autologous Achilles tendon split graft and were sacrificed after 6, 12, 24, 52, or 104 weeks. Before sacrifice, all animals underwent plain and contrast-enhanced (gadolinium-diethylenetriamine pentacetic acid) magnetic resonance imaging (1.5 T, proton density weighted, 2-mm sections) of their operated knees. The signal/noise quotient was calculated and data were correlated to the maximum load to failure, tensile strength, and stiffness of the grafts. The vascularity of the grafts was determined immunohistochemically by staining for endothelial cells (factor VIII). We found that high signal intensity on magnetic resonance imaging reflects a decrease of mechanical properties of the graft during early remodeling. Correlation analyses revealed significant negative linear correlations between the signal/noise quotient and the load to failure, stiffness, and tensile strength. In general, correlations for contrast-enhanced measurements of signal intensity were stronger than those for plain magnetic resonance imaging. Immunohistochemistry confirmed that contrast medium enhancement reflects the vascular status of the graft tissue during remodeling. We conclude that quantitatively determined magnetic resonance imaging signal intensity may be a useful tool for following the graft remodeling process in a noninvasive manner.

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