scholarly journals Quantitative T2 mapping accelerated by GRAPPATINI for evaluation of muscles in patients with myositis

2019 ◽  
Vol 92 (1102) ◽  
pp. 20190109 ◽  
Author(s):  
Fengdan Wang ◽  
Haiping Zhang ◽  
Chanyuan Wu ◽  
Qian Wang ◽  
Bo Hou ◽  
...  
Keyword(s):  
T2 Mapping ◽  
Quantitative Information ◽  
Thigh Muscle ◽  
Mapping Technique ◽  
Acquisition Time ◽  
T2 Relaxation ◽  
Muscle Enzymes ◽  
Scanning Time ◽  
Conventional Mri ◽  
Thigh Muscles

Objective: Dermatomyositis (DM) and polymyositis (PM) make up the largest group of potentially treatable myopathies and require early diagnosis. This study investigates whether the edema of thigh muscles in DM/PM can be quantitatively assessed by a novel accelerated T2 mapping technique—GRAPPATINI. Methods: Three conventional MR sequences and GRAPPATINI accelerated T2 mapping of bilateral thighs from 20 patients (7 DM and 13 PM) and 10 healthy volunteers were prospectively carried out on a 3 T MR scanner. Afterwards, T2 values of 477 thigh muscles from the patients and the healthy controls were manually measured. In addition, the correlations between T2 values and serum muscle enzymes in patients were also analyzed. Results: The new GRAPPATINI technique made quantitative T2 mapping of bilateral thighs feasible with a scanning time of only 2 min 18 s. Moreover, GRAPPATINI-generated T2 values of muscles from patients were markedly higher than those from healthy subjects (p < 0.001). GRAPPATINI accelerated T2 mapping appeared a more sensitive technique in that some DM/PM muscles appearing normal per conventional MRI had increased T2 relaxation time. Furthermore, GRAPPATINI-generated T2 values of DM/PM thigh muscles positively correlated with serum enzyme levels (p < 0.001), which reflected the severity of myopathy. Conclusion: GRAPPATINI can significantly shorten acquisition time of T2 mapping and may potentially be applied clinically in DM and PM. Advances in knowledge: GRAPPATINI acceleration makes T2 mapping feasible in clinical practice in providing quantitative information regarding thigh muscle inflammation in DM and PM.

Assessment of Meniscal Healing Status by Magnetic Resonance Imaging T2 Mapping After Meniscal Repair

2020 ◽  
Vol 48 (4) ◽  
pp. 853-860
Author(s):  
Shinya Yamasaki ◽  
Yusuke Hashimoto ◽  
Yohei Nishida ◽  
Takanori Teraoka ◽  
Shozaburo Terai ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
T2 Mapping ◽  
Meniscal Tear ◽  
Meniscal Repair ◽  
T2 Relaxation Time ◽  
Resonance Imaging ◽  
T2 Relaxation ◽  
Conventional Mri ◽  
Meniscal Healing ◽  
The Mean

Background: Although the sensitivity and specificity of magnetic resonance imaging (MRI) for the diagnosis of primary meniscal tears are high, these values are lower for the assessment of healing status of repaired menisci. Purpose: To compare the accuracy of MRI T2 mapping and conventional MRI in assessing meniscal healing after repair. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients who underwent meniscal repair with concurrent anterior cruciate ligament reconstruction between 2012 and 2016 and had a follow-up second-look arthroscopy were enrolled. The patients were divided into healed and incompletely/not healed groups based on the second-look arthroscopy findings. For the repaired menisci, the following were compared between the groups, (1) Stoller and Crues classification on conventional MRI with a proton density-weighted fat-saturated sequence and (2) the remaining colored meniscal tear line on T2 mapping coincident with the high signal line showing the primary tear on conventional MRI were compared. The change of T2 relaxation time (ΔT2) of the colored meniscal tear line pre- to postoperatively was compared between the groups. The mean T2 relaxation time of the whole area of the postoperative meniscus at each slice was also compared with that of control menisci to assess the whole quality of the repaired meniscus. Results: A total of 26 menisci from 24 knees were assessed (16 healed menisci, 10 incompletely/not healed menisci). According to the Crues classification on conventional MRI, 8 of 16 healed menisci and 3 of 10 incompletely/not healed menisci improved from grade 3 to 2, with there being no significant difference between the groups ( P = .43). However, the colored meniscal tear line remained in only 3 of the 16 healed menisci as compared with 9 of the 10 incompletely/not healed menisci, and the presence of this colored line allowed differentiation between healed menisci and incompletely/not healed menisci (sensitivity, 81.3%; specificity, 90.0%; odds ratio, 39.0; P = .001). The mean (SD) ΔT2 was −31.1 ± 3.2 and −19.9 ± 4.4 ms in the healed and incompletely/not healed groups, respectively ( P < .001). Receiver operating characteristic curve analysis showed a cutoff ΔT2 value of −22.3 ms for separation of meniscal healing ( P < .001). The T2 relaxation times of the whole area of the repaired menisci were 31.7 ± 3.4 and 32.8 ± 3.8 ms in the healed and incompletely/unhealed groups, respectively ( P = .69), with these values being significantly longer than the 26.9 ± 2.2 ms in the controls ( P < .001). Conclusion: MRI T2 mapping allowed the differentiation of healing status after meniscal repair, with high sensitivity and specificity as compared with conventional MRI.

scholarly journals Differentiating Brucella Spondylitis from Tuberculous Spondylitis by the Conventional MRI and MR T2 Mapping: A Prospective Study

2021 ◽  
Author(s):  
Hui Guo ◽  
Siqin Lan ◽  
Yuanlin He ◽  
Maijudan Tiheiran ◽  
Wenya Liu
Keyword(s):  
Mr Imaging ◽  
T2 Mapping ◽  
Quantitative Information ◽  
Tuberculous Spondylitis ◽  
Distinctive Features ◽  
Qualitative And Quantitative ◽  
Conventional Mri ◽  
Dead Bone ◽  
Granulomatous Lesions ◽  
A Prospective Study

Abstract Background Brucellar spondylitis (BS) and tuberculous spondylitis (TS) which cause initial bacteremia and show granulomatous lesions are the two leading types of spinal inflammatory. BS is easy to miss or maybe misdiagnosed as TS. Our purpose differentiates brucella spondylitis (BS) from tuberculous spondylitis (TS) in conventional MR imaging and MR T2 mapping.Methods We performed on 26 BS and 27 TS patients in conventional MR imaging and MR T2 mapping. We analyzed the features in conventional MR imaging and also measured T2 values of the lesion vertebrae (LV) and unaffected adjacent vertebrae (UAV) in BS and TS patients, respectively.Results There were no significant differences in sex, age, national between BS and TS. It was significantly lower of the severe vertebral destruction, vertebral posterior convex deformity, dead bone, and abscess scope in BS when compared to TS (p < 0.001, p = 0.005, p = 0.048, p < 0.001, p < 0.001, respectively). The vertebral hyperplasia was significantly higher in BS when compared to TS (p < 0.001). The T2 value of the LV with BS was markedly higher than that in the UAV with BS and that in the LV and UAV with TS (p < 0.001, p < 0.037, p < 0.001, respectively). The T2 value of the LV with TS was significantly higher than that of the UAV in TS and BS (p < 0.001, p < 0.001, respectively). There were no significant differences in the T2 value of the UAV between BS and TS (P = 0.568). Conclusions The qualitative and quantitative evaluation may differentiate BS from TS. The conventional MR imaging helps to distinguish BS from TS by several distinctive features. MR T2 mapping has the additional potential to provide quantitative information between BS and TS.

T2 mapping in orbital masses: preliminary study on differential diagnostic ability of T2 relaxation time

2019 ◽  
Vol 61 (5) ◽  
pp. 668-674
Author(s):  
Yan Zhou ◽  
Xiao-Quan Xu ◽  
Hao Hu ◽  
Guo-Yi Su ◽  
Hu Liu ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Predictive Value ◽  
T2 Mapping ◽  
Characteristic Curve ◽  
Preoperative Assessment ◽  
Diagnostic Value ◽  
Quantitative Information ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Orbital Masses

Background T2 mapping has been proven to be useful in tumor characterization. As to orbital masses, its diagnostic value needs to be investigated. Purpose To evaluate the usefulness of T2 mapping in orbital masses and the ability of T2 relaxation time in differentiating malignant from benign orbital masses. Material and Methods Forty-seven patients with solid orbital masses (33 benign and 14 malignant) who underwent T2 mapping examination for preoperative assessment were enrolled in the current study. T2 mapping was acquired using 16 TE values (range 12–192 ms; delta TE 12 ms). Mean T2 relaxation time was calculated based on the whole mass region of interest and compared between the malignant and benign groups using the unpaired t-test. Receiver operating characteristic curve analysis was adopted to calculate its diagnostic value. Results Malignant orbital masses showed significantly lower T2 relaxation time than benign masses (76.4 ± 13.0 ms vs. 119.1 ± 20.4 ms; P < 0.001). If setting a T2 relaxation time of 89.5 ms as the threshold value, optimal differentiating performance could be achieved (area under the curve 0.936; sensitivity 100.0%; specificity 87.9%; accuracy 91.5%; positive predictive value 77.8%; negative predictive value 100%). Conclusion T2 mapping and its derived T2 relaxation time could provide quantitative information and serve as a supplementary imaging marker for differentiating malignant from benign orbital masses.

Comparison of Techniques for EELS Mapping in Biology

1996 ◽  
Vol 54 ◽  
pp. 300-301
Author(s):  
R.D. Leapman ◽  
S.B. Andrews
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Image Data ◽  
Beam Current ◽  
Quantitative Information ◽  
Acquisition Time ◽  
Uniform Thickness ◽  
Electron Dose ◽  
Array Detectors ◽  
Transmission Electron

Elemental mapping of biological specimens by electron energy loss spectroscopy (EELS) can be carried out both in the scanning transmission electron microscope (STEM), and in the energy-filtering transmission electron microscope (EFTEM). Choosing between these two approaches is complicated by the variety of specimens that are encountered (e.g., cells or macromolecules; cryosections, plastic sections or thin films) and by the range of elemental concentrations that occur (from a few percent down to a few parts per million). Our aim here is to consider the strengths of each technique for determining elemental distributions in these different types of specimen.On one hand, it is desirable to collect a parallel EELS spectrum at each point in the specimen using the ‘spectrum-imaging’ technique in the STEM. This minimizes the electron dose and retains as much quantitative information as possible about the inelastic scattering processes in the specimen. On the other hand, collection times in the STEM are often limited by the detector read-out and by available probe current. For example, a 256 x 256 pixel image in the STEM takes at least 30 minutes to acquire with read-out time of 25 ms. The EFTEM is able to collect parallel image data using slow-scan CCD array detectors from as many as 1024 x 1024 pixels with integration times of a few seconds. Furthermore, the EFTEM has an available beam current in the µA range compared with just a few nA in the STEM. Indeed, for some applications this can result in a factor of ~100 shorter acquisition time for the EFTEM relative to the STEM. However, the EFTEM provides much less spectral information, so that the technique of choice ultimately depends on requirements for processing the spectrum at each pixel (viz., isolated edges vs. overlapping edges, uniform thickness vs. non-uniform thickness, molar vs. millimolar concentrations).

scholarly journals Association of Thigh Muscle Strength with Texture Features Based on Proton Density Fat Fraction Maps Derived from Chemical Shift Encoding-Based Water–Fat MRI

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 302
Author(s):  
Michael Dieckmeyer ◽  
Stephanie Inhuber ◽  
Sarah Schläger ◽  
Dominik Weidlich ◽  
Muthu R. K. Mookiah ◽  
...  
Keyword(s):  
Chemical Shift ◽  
Muscle Strength ◽  
Neuromuscular Disorders ◽  
Texture Features ◽  
Thigh Muscle ◽  
Proton Density ◽  
Proton Density Fat Fraction ◽  
Thigh Muscles ◽  
Fat Fraction ◽  
Flexion Strength

Purpose: Based on conventional and quantitative magnetic resonance imaging (MRI), texture analysis (TA) has shown encouraging results as a biomarker for tissue structure. Chemical shift encoding-based water–fat MRI (CSE-MRI)-derived proton density fat fraction (PDFF) of thigh muscles has been associated with musculoskeletal, metabolic, and neuromuscular disorders and was demonstrated to predict muscle strength. The purpose of this study was to investigate PDFF-based TA of thigh muscles as a predictor of thigh muscle strength in comparison to mean PDFF. Methods: 30 healthy subjects (age = 30 ± 6 years; 15 females) underwent CSE-MRI of the lumbar spine at 3T, using a six-echo 3D spoiled gradient echo sequence. Quadriceps (EXT) and ischiocrural (FLEX) muscles were segmented to extract mean PDFF and texture features. Muscle flexion and extension strength were measured with an isokinetic dynamometer. Results: Of the eleven extracted texture features, Variance(global) showed the highest significant correlation with extension strength (p < 0.001, R2adj = 0.712), and Correlation showed the highest significant correlation with flexion strength (p = 0.016, R2adj = 0.658). Multivariate linear regression models identified Variance(global) and sex, but not PDFF, as significant predictors of extension strength (R2adj = 0.709; p < 0.001), while mean PDFF, sex, and BMI, but none of the texture features, were identified as significant predictors of flexion strength (R2adj = 0.674; p < 0.001). Conclusions: Prediction of quadriceps muscle strength can be improved beyond mean PDFF by means of TA, indicating the capability to quantify muscular fat infiltration patterns.

T2 Mapping and Fat Quantification of Thigh Muscles in Children with Duchenne Muscular Dystrophy

2019 ◽  
Vol 39 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Liang Yin ◽  
Zhi-ying Xie ◽  
Hai-yan Xu ◽  
Sui-sheng Zheng ◽  
Zhao-xia Wang ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
T2 Mapping ◽  
Fat Quantification ◽  
Thigh Muscles

scholarly journals Myocardial Mapping in Systemic Sarcoidosis: A Comparison of Two Measurement Approaches

2020 ◽  
Vol 193 (01) ◽  
pp. 68-76
Author(s):  
Darius Dabir ◽  
Julian Luetkens ◽  
Daniel Kuetting ◽  
Jennifer Nadal ◽  
Hans Heinz Schild ◽  
...  
Keyword(s):  
T1 Mapping ◽  
Tissue Characterization ◽  
Cardiac Involvement ◽  
T2 Mapping ◽  
Relaxation Times ◽  
Short Axis Slice ◽  
T2 Relaxation ◽  
Standard Mapping ◽  
Systemic Sarcoidosis ◽  
T1 And T2

Purpose To investigate if T1 and T2 mapping is able to differentiate between diseased and healthy myocardium in patients with systemic sarcoidosis, and to compare the standard mapping measurement (measurement within the whole myocardium of the midventricular short axis slice, SAX) to a more standardized method measuring relaxation times within the midventricular septum (ConSept). Materials and Methods 24 patients with biopsy-proven extracardiac sarcoidosis and 17 healthy control subjects were prospectively enrolled in this study and underwent CMR imaging at 1.5 T including native T1 and T2 mapping. Patients were divided into patients with (LGE+) and without (LGE–) cardiac sarcoidosis. T1 and T2 relaxation times were compared between patients and controls. Furthermore, the SAX and the ConSept approach were compared regarding differentiation between healthy and diseased myocardium. Results T1 and T2 relaxation times were significantly longer in all patients compared with controls using both the SAX and the ConSept approach (p < 0.05). However, LGE+ and LGE– patients showed no significant differences in T1 and T2 relaxation times regardless of the measurement approach used (ConSept/SAX) (p > 0.05). Direct comparison of ConSept and SAX T1 mapping showed high conformity in the discrimination between healthy and diseased myocardium (Kappa = 0.844). Conclusion T1 and T2 mapping may not only enable noninvasive recognition of cardiac involvement in patients with systemic sarcoidosis but may also serve as a marker for early cardiac involvement of the disease allowing for timely treatment. ConSept T1 mapping represents an equivalent method for tissue characterization in this population compared to the SAX approach. Further studies including follow-up examinations are necessary to confirm these preliminary results. Key Points:  Citation Format

scholarly journals Feasibility of T2 Mapping and Magnetic Transfer Ratio for Diagnosis of Intervertebral Disc Degeneration at the Cervicothoracic Junction: A Pilot Study

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Chao Zhang ◽  
Yuan Lin ◽  
Zhihua Han ◽  
Liang Gao ◽  
Ruipeng Guo ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
T2 Mapping ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
Cervicothoracic Junction ◽  
Magnetic Transfer ◽  
Pfirrmann Grade

Background. Intervertebral disc degeneration (IDD) at the cervicothoracic junction of spine is clinically relevant, however, little attention had been paid. T2 mapping and magnetic transfer ratio (MTR) are useful magnetic resonance imaging (MRI) techniques to quantitatively evaluate IDD, revealing the biochemical changes within the intervertebral disc. To compare T2 mapping with MTR imaging regarding their accuracy to quantitatively diagnose intervertebral disc degeneration at the cervicothoracic junction, influences of anatomical level, gender, age, and Pfirrmann grade of T2 relaxation time values and MTR values were evaluated. Methods. Sixty-seven patients with neck and upper back pain were included and examined with both T2 mapping and MTR imaging. The Pfirrmann grade, T2 relaxation time values, and MTR value of each disc between C7 and T3 were measured. Differences were investigated among different segmental levels, genders, age ranges, and Pfirrmann grades. The diagnostic accuracy of both MRI techniques was compared using the receiver operating characteristic (ROC) curves. Results. No significant difference was detected comparing T2 relaxation time values or MTR values among different anatomical levels, genders, and segmental levels. And we generally found that T2 relaxation time values decreased, while MTR value increased with increasing age. Importantly, we demonstrated the significant correlation between either T2 relaxation time values or MTR value and Pfirrmann grade. Conclusion. We proved the better accuracy of T2 mapping over MTR imaging to quantitatively evaluate the intervertebral disc degeneration of the cervicothoracic junction.

scholarly journals B1-insensitive T2 mapping of healthy thigh muscles using a T2-prepared 3D TSE sequence

PLoS ONE ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. e0171337 ◽  
Author(s):  
Elisabeth Klupp ◽  
Dominik Weidlich ◽  
Sarah Schlaeger ◽  
Thomas Baum ◽  
Barbara Cervantes ◽  
...  
Keyword(s):  
T2 Mapping ◽  
Thigh Muscles
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