Muscle T2 Research Articles

Using magnetic resonance imaging to map the hidden burden of muscle involvement in systemic sclerosis

BackgroundSkeletal muscle can be directly affected by systemic sclerosis (SSc); however, a significant burden of SSc-associated myopathy is undetected because clinical parameters such as weakness and creatine kinase (CK) are unreliable biomarkers of muscle involvement. This study presents qualitative and quantitative magnetic resonance imaging (MRI) findings that quantify the prevalence of myopathy and evaluate any association between skeletal and cardiac muscle involvement in SSc.MethodsThirty-two patients with SSc who fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism classification criteria underwent skeletal muscle MRI in addition to cardiac MRI. Skeletal muscles were independently assessed by two musculoskeletal radiologists for evidence of oedema, fatty infiltration and atrophy. Skeletal muscle T2 mapping times and percentage fat fraction were calculated. Linear regression analysis was used to evaluate the clinical and myocardial associations with skeletal muscle oedema and fatty infiltration. Cardiac MRI was performed using post gadolinium contrast imaging and parametric mapping techniques to assess focal and diffuse myocardial fibrosis.ResultsThirteen participants (40.6%) had MRI evidence of skeletal muscle oedema. Five (15.6%) participants had fatty infiltration. There was no association between skeletal muscle oedema and muscle strength, creatine kinase, inflammatory markers or fibroinflammatory myocardial disease. Patients with skeletal muscle oedema had higher T2-mapping times; there was a significant association between subjective assessments of muscle oedema and T2-mapping time (coef 2.46, p = 0.02) and percentage fat fraction (coef 3.41, p = 0.02). Diffuse myocardial fibrosis was a near-universal finding, and one third of patients had focal myocardial fibrosis. There was no association between skeletal myopathy detected by MRI and burden of myocardial disease.ConclusionsMRI is a sensitive measure of muscle oedema and systematic assessment of SSc patients using MRI shows that myopathy is highly prevalent, even in patients without symptoms or other signs of muscle involvement. Similarly, cardiac fibrosis is highly prevalent but occurs independently of skeletal muscle changes. These results indicate that novel quantitative MRI techniques may be useful for assessing sub-clinical skeletal muscle disease in SSc.

Quantitative magnetic resonance imaging measures as biomarkers of disease progression in boys with Duchenne muscular dystrophy: a phase 2 trial of domagrozumab

Duchenne muscular dystrophy (DMD) is a progressive, neuromuscular disorder caused by mutations in the DMD gene that results in a lack of functional dystrophin protein. Herein, we report the use of quantitative magnetic resonance imaging (MRI) measures as biomarkers in the context of a multicenter phase 2, randomized, placebo-controlled clinical trial evaluating the myostatin inhibitor domagrozumab in ambulatory boys with DMD (n = 120 aged 6 to < 16 years). MRI scans of the thigh to measure muscle volume, muscle volume index (MVI), fat fraction, and T2 relaxation time were obtained at baseline and at weeks 17, 33, 49, and 97 as per protocol. These quantitative MRI measurements appeared to be sensitive and objective biomarkers for evaluating disease progression, with significant changes observed in muscle volume, MVI, and T2 mapping measures over time. To further explore the utility of quantitative MRI measures as biomarkers to inform longer term functional changes in this cohort, a regression analysis was performed and demonstrated that muscle volume, MVI, T2 mapping measures, and fat fraction assessment were significantly correlated with longer term changes in four-stair climb times and North Star Ambulatory Assessment functional scores. Finally, less favorable baseline measures of MVI, fat fraction of the muscle bundle, and fat fraction of lean muscle were significant risk factors for loss of ambulation over a 2-year monitoring period. These analyses suggest that MRI can be a valuable tool for use in clinical trials and may help inform future functional changes in DMD.Trial registration: ClinicalTrials.gov identifier, NCT02310763; registered December 2014.

Elevated magnetic resonance imaging measures of adipose tissue deposition in women with breast cancer treatment-related lymphedema.

Breast cancer treatment-related lymphedema (BCRL) is a common co-morbidity of breast cancer therapies, yet factors that contribute to BCRL progression remain incompletely characterized. We investigated whether magnetic resonance imaging (MRI) measures of subcutaneous adipose tissue were uniquely elevated in women with BCRL. MRI at 3.0T of upper extremity and torso anatomy, fat and muscle tissue composition, and T2 relaxometry were applied in left and right axillae of healthy control (n = 24) and symptomatic BCRL (n = 22) participants to test the primary hypothesis that fat-to-muscle volume fraction is elevated in symptomatic BCRL relative to healthy participants, and the secondary hypothesis that fat-to-muscle volume fraction is correlated with MR relaxometry of affected tissues and BCRL stage (significance criterion: two-sided p < 0.05). Fat-to-muscle volume fraction in healthy participants was symmetric in the right and left sides (p = 0.51); in BCRL participants matched for age, sex, and BMI, fat-to-muscle volume fraction was elevated on the affected side (fraction = 0.732 ± 0.184) versus right and left side in controls (fraction = 0.545 ± 0.221, p < 0.001). Fat-to-muscle volume fraction directly correlated with muscle T2 (p = 0.046) and increased with increasing level of BCRL stage (p = 0.041). Adiposity quantified by MRI is elevated in the affected upper extremity of women with BCRL and may provide a surrogate marker of condition onset or severity. NCT02611557.

PENATALAKSANAAN FISIOTERAPI PADA OSTEOARTHRITISGENU BILATERAL DENGAN MODALITAS ULTRASOUND, TENS, DAN TERAPI LATIHAN DI RSUD CILILIN KABUPATEN BANDUNG BARAT

Osteoarthritis is a degenerative health disorder where there is stiffness and inflammation in the joints which is characterized by damage to joint cartilage so that it can cause pain in the joints of the hands, neck, back, waist, and most often the knee joints. After doing therapy 6 times, the results of the assessment of increasing functional values ​​in both knees, namely right knee tenderness T1 = 60mm to T6 = 50mm, right knee motion pain T1 = 70mm to T6 = 60mm, and silent pain T1-T6 = 10mm, and the left knee showed tenderness T1=30mm to T6=10mm, motion pain T1=65mm to T6=60mm, and silent pain T1-T6=10mm. Increased muscle value in both legs, namely the right knee flexor muscle T1= 3 to T6=4, on the left knee T1=4 becomes T6=5, and the right knee extensor muscle T1=3 becomes T6=4, and the left knee T1= 30mm becomes T6=3, becomes T6=4. Ultrasound, Trancutaneous Electrical Nerve Stimulation (TENS) and Exercise Therapy can help reduce pain, improve basic functional and increase muscle strength in cases of Bilateral Genu Osteoarthritis

Inter-rater and inter-session reliability of lumbar paraspinal muscle composition in a mobile MRI device.

Objective:To assess the reliability of measurements of paraspinal muscle transverse relaxation times (T2 times) between two observers and within one observer on different time points.Methods:14 participants (9f/5m, 33 ± 5 years, 176 ± 10 cm, 73 ± 12 kg) underwent 2 consecutive MRI scans (M1,M2) on the same day, followed by 1 MRI scan 13–14 days later (M3) in a mobile 1.5 Tesla MRI. T2 times were calculated in T2 weighted turbo spin-echo-sequences at the spinal level of the third lumbar vertebrae (11 slices, 2 mm slice thickness, 1 mm interslice gap, echo times: 20, 40, 60, 80, 100 ms) for M. erector spinae (ES) and M. multifidius (MF). The following reliability parameter were calculated for the agreement of T2 times between two different investigators (OBS1 & OBS2) on the same MRI (inter-rater reliability, IR) and by one investigator between different MRI of the same participant (intersession variability, IS): Test–Retest Variability (TRV, Differences/Mean*100); Coefficient of Variation (CV, Standard deviation/Mean*100); Bland–Altman Analysis (systematic bias = Mean of the Differences; Upper/Lower Limits of Agreement = Bias+/−1.96*SD); Intraclass Correlation Coefficient 3.1 (ICC) with absolute agreement, as well as its 95% confidence interval.Results:Mean TRV for IR was 2.6% for ES and 4.2% for MF. Mean TRV for IS was 3.5% (ES) and 5.1% (MF). Mean CV for IR was 1.9 (ES) and 3.0 (MF). Mean CV for IS was 2.5% (ES) and 3.6% (MF). A systematic bias of 1.3 ms (ES) and 2.1 ms (MF) were detected for IR and a systematic bias of 0.4 ms (ES) and 0.07 ms (MF) for IS. ICC for IR was 0.94 (ES) and 0.87 (MF). ICC for IS was 0.88 (ES) and 0.82 (MF).Conclusion:Reliable assessment of paraspinal muscle T2 time justifies its use for scientific purposes. The applied technique could be recommended to use for future studies that aim to assess changes of T2 times, e.g. after an intense bout of eccentric exercises.

Additive value of magnetic resonance neurography in diagnosis of brachial plexopathy: a cross-section descriptive study

BackgroundManagement of brachial plexopathy requires proper localization of the site and nature of nerve injury. Nerve conduction studies and electrophysiological studies (ED) are crucial when diagnosing brachial neuropathy but these do not determine the actual site of the lesion. Conventional MRI has been used to evaluate the brachial plexus. Still, it carried the disadvantage of the inability to provide multi-planar images that depict the entire length of the neural plexus .It might be difficult to differentiate the brachial plexus nerves from adjacent vascular structures. Magnetic resonance neurography (MRN) is an innovative imaging technique for direct imaging of the spinal nerves. Our study aims to detect the additive role of MRN in the diagnosis of brachial plexopathy over ED. Forty cases of clinically suspected and proved by clinical examination and ED—traumatic (N = 30) and non-traumatic (N = 10)—were included in our study. We compared MRN finding with results of clinical examination and ED.ResultsMRN findings showed that the root was involved in 80% of cases, trunks in 70% of cases affecting the middle trunk in 40% of cases, the middle and posterior cord in 25%, lateral cord in 50%, and terminal branches on 10% of cases. Ten percent of cases were normal according to MRN, and 90% had abnormal findings in the form of preganglionic nerve root avulsion in 30% of cases, mild perineural edema surrounding C6/7 nerve roots in 20%, lower brachial trunk high signal in 10%, complicated with pseudo meningocele in 20%, and with increased shoulder muscle T2 signal intensity with muscle atrophy in 10%. There were minimal differences between clinical examination finding and MRN findings, with very good agreement between electromyography and nerve conduction (p value < 0.05, with sensitivity and specificity values of 94.44% and 100%, respectively).ConclusionMRN is important in differentiating different types of nerve injuries, nerve root avulsion, and nerve edema, playing an important role in differentiating the site of nerve injury, both preganglionic or postganglionic and planning for treatment of the cause of nerve injury, either medical or surgical.

Musculoskeletal magnetic resonance imaging in the DE50-MD dog model of Duchenne muscular dystrophy

The DE50-MD canine model of Duchenne muscular dystrophy (DMD) has a dystrophin gene splice site mutation causing deletion of exon 50, an out-of-frame transcript and absence of dystrophin expression in striated muscles. We hypothesized that the musculoskeletal phenotype of DE50-MD dogs could be detected using Magnetic Resonance Imaging (MRI), that it would progress with age and that it would reflect those in other canine models and DMD patients. 15 DE50-MD and 10 age-matched littermate wild type (WT) male dogs underwent MRI every 3 months from 3 to 18 months of age. Normalized muscle volumes, global muscle T2 and ratio of post- to pre-gadolinium T1-weighted SI were evaluated in 7 pelvic limb and 4 lumbar muscles bilaterally. DE50-MD dogs, compared to WT, had smaller volumes in all muscles, except the cranial sartorius; global muscle T2 was significantly higher in DE50-MD dogs compared to WT. Muscle volumes plateaued and global muscle T2 decreased with age. Normalized muscle volumes and global muscle T2 revealed significant differences between groups longitudinally and should be useful to determine efficacy of therapeutics in this model with suitable power and low sample sizes. Musculoskeletal changes reflect those of DMD patients and other dog models.

Cardiac MRI in Suspected Acute COVID-19 Myocarditis.

Keywords: COVID-19; coronavirus; myocarditis; cardiac MRI; T1 mapping; T2 mapping

Patients with episodic migraine show increased T2 values of the trapezius muscles - an investigation by quantitative high-resolution magnetic resonance imaging.

BackgroundNeck pain is frequent in patients with migraine. Likewise, evidence for inflammatory processes in the trapezius muscles is accumulating. However, non-invasive and objectively assessable correlates are missing in vivo.MethodsTwenty-one subjects with episodic migraine (mean age: 24.6 ± 3.1 years, 18 females) and 22 controls (mean age: 23.0 ± 2.2 years, 17 females) without any history of headache prospectively underwent physical examination and quantitative magnetic resonance imaging of the trapezius muscles. A T2‐prepared turbo spin-echo sequence was acquired for manual segmentation of the trapezius muscles and extraction of mean T2 values.ResultsThere were no statistically significant differences regarding age, sex, body mass index, or number of myofascial trigger points (mTrPs) between groups. All patients with migraine presented with mTrPs in the trapezius muscles. T2 of the entire trapezius muscles was significantly higher in the migraine group when compared to controls (31.1 ± 0.8 ms vs. 30.1 ± 1.1 ms; p = 0.002).ConclusionsElevated T2 values of the trapezius muscles may indicate subtle inflammatory processes within musculature among patients with migraine because T2 increase is likely to stem from edematous changes. Future work may validate this finding in larger cohorts, but muscle T2 might have potential to develop into a viable in vivo biomarker for muscular affection in migraine.

Quantification of 1.5 TT1 and T2* Relaxation Times of Fetal Tissues in Uncomplicated Pregnancies.

Despite its many advantages, experience with fetal magnetic resonance imaging (MRI) is limited, as is knowledge of how fetal tissue relaxation times change with gestational age (GA). Quantification of fetal tissue relaxation times as a function of GA provides insight into tissue changes during fetal development and facilitates comparison of images across time and subjects. This, therefore, can allow the determination of biophysical tissue parameters that may have clinical utility. To demonstrate the feasibility of quantifying previously unknown T1 and T2* relaxation times of fetal tissues in uncomplicated pregnancies as a function of GA at 1.5 T. Pilot. Nine women with singleton, uncomplicated pregnancies (28-38 weeks GA). All participants underwent two iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) acquisitions at different flip angles (6° and 20°) at 1.5 T. Segmentations of the lungs, liver, spleen, kidneys, muscle, and adipose tissue (AT) were conducted using water-only images and proton density fat fraction maps. Driven equilibrium single pulse observation of T1 (DESPOT1 ) was used to quantify the mean water T1 of the lungs, intraabdominal organs, and muscle, and the mean water and lipid T1 of AT. IDEAL T2* maps were used to quantify the T2* values of the lungs, intraabdominal organs, and muscle. F-tests were performed to assess the T1 and T2* changes of each analyzed tissue as a function of GA. No tissue demonstrated a significant change in T1 as a function of GA (lungs [P= 0.89]; liver [P= 0.14]; spleen [P= 0.59]; kidneys [P= 0.97]; muscle [P= 0.22]; AT: water [P= 0.36] and lipid [P= 0.14]). Only the spleen and muscle T2* showed a significant decrease as a function of GA (lungs [P= 0.67); liver [P= 0.05]; spleen [P< 0.05]; kidneys [P= 0.70]; muscle [P< 0.05]). These preliminary data suggest that the T1 of the investigated tissues is relatively stable over 28-38 weeks GA, while the T2* change in spleen and muscle decreases significantly in that period. 3 TECHNICAL EFFICACY STAGE: 2.

Non-invasive assessment of peripheral skeletal muscle weakness in idiopathic pulmonary fibrosis: a pilot study with multiparametric MRI of the rectus femoris muscle

BackgroundTo investigate differences in magnetic resonance imaging (MRI) features of rectus femoris muscle between idiopathic pulmonary fibrosis (IPF) patients and healthy volunteers.MethodsThirteen IPF patients with GAP Index stage II disease were subjected to pulmonary function tests, 6-minute walk test (6MWT), quadriceps femoris muscle strength measurement and MRI of the thigh at rest. At MRI, muscle cross-sectional areas, T2 and T2* relaxometry, and 3-point Dixon fat fraction were measured. The results were compared to those of eight healthy sedentary volunteers.ResultsIPF patients had significantly lower %predicted FVC, FEV1 and DLCO (p<0.001 for the three variables) and walked significantly less in the 6MWT (p=0.008). Mean quadriceps femoris muscle strength also was significantly lower in IPF patients (p=0.041). Rectus femoris muscle T2* measurements were significantly shorter in IPF patients (p=0.027). No significant intergroup difference was found regarding average muscle cross-sectional areas (p=0.790 for quadriceps and p=0.816 for rectus femoris) or rectus femoris fat fraction (p=0.901). Rectus femoris T2 values showed a non-significant trend to be shorter in IPF patients (p=0.055).ConclusionsOur preliminary findings suggest that, besides disuse atrophy, other factors such as hypoxia (but not inflammation) may play a role in the peripheral skeletal muscle dysfunction observed in IPF patients. This might impact the rehabilitation strategies for IPF patients and warrants further investigation.

MUSCLE IMAGING – MRI: P.167 Last but not least: preserved thenar muscles in non-ambulant Duchenne muscular dystrophy patients

Hand function in Duchenne muscular dystrophy (DMD) is preserved relatively long, and is crucial for daily-life activities of non-ambulant patients such as operating a wheelchair. As a potential target for therapy, it is important to know to what extent intrinsic hand muscles are affected. We used quantitative MRI (qMRI) to study the relation between thenar muscle fat fraction (FF), total volume (TV), contractile volume (CV), T2 of muscle (T2water) and pinch strength. Seventeen non-ambulant DMD patients (range 10.2-24.1 years) and 13 healthy controls (HC; range 9.5-25.4 years) underwent qMRI of the right hand at 3T while positioned on their right side.

The Role of Imaging Biomarkers in the Assessment of Sarcopenia.

Background: The diagnosis of sarcopenia through clinical assessment has some limitations. The literature advises studies that include objective markers along with clinical assessment in order to improve the sensitivity and specificity of current diagnostic criteria. The decrease of muscle quality precedes the loss of quantity, so we studied the role magnetic resonance imaging biomarkers as indicators of the quantity and quality of muscle in sarcopenia patients. Methods: a cross-sectional analysis was performed to analyze what MR-derived imaging parameters correlate better with sarcopenia diagnostic criteria in women of 70 years of age and over (independent walking and community-dwelling women who were sarcopenic in accordance with EWGSOP criteria with muscle mass adjusted to Spanish population were chosen). Results: The study included 26 women; 81 ± 8 years old. A strong correlation was obtained between cineanthropometric variables (BMI; thigh perimeter and fat mass) and imaging biomarkers (muscle/fat ratio, fatty infiltration, muscle T2*, water diffusion coefficient, and proton density fat fraction) with coefficients around 0.7 (absolute value). Conclusions: Knowing the correlation of clinical parameters and imaging-derived muscle quality indicators can help to identify older women at risk of developing sarcopenia at an early stage. This may allow taking preventive actions to decrease disability, morbidity, and mortality in sarcopenia patients.

Evaluation of inflammatory lesions over 2 years in facioscapulohumeral muscular dystrophy.

We followed up patients with facioscapulohumeral muscular dystrophy (FSHD) with sequential examinations over 2 years to investigate whether inflammatory lesions always precede fat replacement, if inflammation can be resolved without muscle degeneration, and if inflammatory lesions in muscle are always followed by fat replacement. In this longitudinal study of 10 sequential MRI assessments over 2.5 years, we included 10 patients with FSHD. We used MRI with short TI inversion recovery to identify regions of interest (ROIs) with hyperintensities indicating muscle inflammation. Muscle T2 relaxation time mapping was used as a quantitative marker of muscle inflammation. Dixon sequences quantified muscle fat replacement. Ten healthy controls were examined with a magnetic resonance scan once for determination of normal values of T2 relaxation time. We identified 68 ROIs with T2 elevation in the patients with FSHD. New ROIs with T2 elevation arising during the study had muscle fat content of 6.4% to 33.0% (n = 8) and 47.0% to 78.0% lesions that resolved (n = 6). ROIs with T2 elevation had a higher increase in muscle fat content from visits 1 to 10 (7.9 ± 7.9%) compared to ROIs with normal muscle T2 relaxation times (1.7 ± 2.6%; p < 0.0001). Severe T2 elevations were always followed by an accelerated replacement of muscle by fat. Our results suggest that muscle inflammation starts in mildly affected muscles in FSHD, is related to a faster muscle degradation, and continues until the muscles are completely fat replaced. NCT02159612.

Changes In Paraspinal Muscle T2 Times And Creatine Kinase After A Bout Of Eccentric Exercise

Eccentric (ECC) exercises might cause muscle damage, characterized by delayed-onset muscle soreness, elevated creatine kinase (CK) levels and local muscle oedema, shown by elevated T2 times in magnet resonance imaging (MRI) scans. Previous research suggests a high inter-individual difference regarding these systemic and local responses to eccentric workload. PURPOSE: To analyze ECC exercise-induced muscle damage in lumbar paraspinal muscles assessed via MRI. METHODS: Ten participants (3f/7m; 33±6y; 174±8cm; 71±12kg) were included in the study. Quantitative paraspinal muscle constitution of M. erector spinae and M. multifidius were assessed in supine position before and 72h after an intense eccentric trunk exercise bout in a mobile 1.5 tesla MRI device. MRI scans were recorded on spinal level L3 (T2-weighted TSE echo sequences, 11 slices, 2mm slice thickness, 3mm gap, echo times: 20, 40, 60, 80, 100ms, TR time: 2500ms). Muscle T2 times were calculated for manually traced regions of interest of the respective muscles with an imaging software. The exercise protocol was performed in an isokinetic device and consisted of 120sec alternating ECC trunk flexion-extension with maximal effort. Venous blood samples were taken before and 72h after the ECC exercise. Descriptive statistics (mean±SD) and t-testing for pre-post ECC exercises were performed. RESULTS: T2 times increased from pre- to post-ECC MRI measurements from 55±3ms to 79±28ms in M. erector spinae and from 62±5ms to 78±24ms in M. multifidius (p<0.001). CK increased from 126±97 U/L to 1447±20579 U/L. High SDs of T2 time and CK in post-ECC measures could be due to inter-individual reactions to ECC exercises. 3 participants showed high local and systemic reactions (HR) with T2 time increases of 120±24% (M. erector spinae) and 73±50% (M. multifidius). In comparison, the remaining 7 participants showed increases of 11±12% (M. erector spinae) and 7±9% (M. multifidius) in T2 time. Mean CK increased 9.5-fold in the 3 HR subjects compared with the remaining 7 subjects. CONCLUSIONS: The 120sec maximal ECC trunk flexion-extension protocol induced high amounts of muscle damage in 3 participants. Moderate to low responses were found in the remaining 7 subjects, assuming that inter-individual predictors play a role regarding physiological responses to ECC workload.

Magnetic resonance imaging and bioimpedance evaluation of lymphatic abnormalities in patients with breast cancer treatment-related lymphedema.

Breast cancer treatment-related lymphedema (BCRL) evaluation is frequently performed using portable measures of limb volume and bioimpedance asymmetry. Here quantitative magnetic resonance imaging (MRI) is applied to evaluate deep and superficial tissue impairment, in both surgical and contralateral quadrants, to test the hypothesis that BCRL impairment is frequently bilateral and extends beyond regions commonly evaluated with portable external devices. 3-T MRI was applied to investigate BCRL topographical impairment. Female BCRL (n = 33; age = 54.1 ± 11.2years; stage = 1.5 ± 0.8) and healthy (n = 33; age = 49.4 ± 11.0years) participants underwent quantitative upper limb MRI relaxometry (T2), bioimpedance asymmetry, arm volume asymmetry, and physical evaluation. Parametric tests were applied to evaluate study measurements (i) between BCRL and healthy participants, (ii) between surgical and contralateral limbs, and (iii) in relation to clinical indicators of disease severity. Two-sided p-value < 0.05 was required for significance. Bioimpedance asymmetry was significantly correlated with MRI-measured water relaxation (T2) in superficial tissue. Deep muscle (T2 = 37.6 ± 3.5ms) and superficial tissue (T2 = 49.8 ± 13.2ms) relaxation times were symmetric in healthy participants. In the surgical limbs of BCRL participants, deep muscle (T2 = 40.5 ± 4.9ms) and superficial tissue (T2 = 56.0 ± 14.8ms) relaxation times were elevated compared to healthy participants, consistent with an edematous micro-environment. This elevation was also observed in contralateral limbs of BCRL participants (deep muscle T2 = 40.3 ± 5.7ms; superficial T2 = 56.6 ± 13.8ms). Regional MRI measures substantiate a growing literature speculating that superficial and deep tissue, in surgical and contralateral quadrants, is affected in BCRL. The implications of these findings in the context of titrating treatment regimens and understanding malignancy recurrence are discussed.

Evaluation of the relationship between splenic iron overload and liver, heart and muscle features evident on T2*-weighted magnetic resonance imaging.

Splenic iron overload is the most common clinical condition in patients with thalassemia. However, few studies of the effects of splenectomy have been published. To evaluate the relationship between splenic iron overload and liver, heart and muscle features visible in T2*-weighted magnetic resonance imaging, and to investigate the effects of splenectomy on these tissues in patients with beta-thalassemia major (TM). We retrospectively included 131 patients (76 male and 55 female) diagnosed with TM. All radiological assessments were performed with the aid of a Philips Achieva 1.5T scanner running a multiecho gradient-echo sequence. Hepatic and splenic T2* values were assessed in the same gradient multiecho series. Muscle T2* values were assessed in the shoulder girdle muscles adjacent to the heart area. The relationships among splenic T2*, hepatic T2*, cardiac T2* and muscle T2* parameters, serum ferritin levels, age and other parameters were evaluated. The splenic T2* value correlated with serum ferritin level and the hepatic T2* value (p < 0.001 and p < 0.001, respectively). The splenic T2* value did not correlate with age, cardiac or muscle T2* values, or with spleen size (p = 0.27, 0.21, 0.99, and 0.39, respectively). The muscle T2* value correlated weakly with the serum ferritin level (p = 0.022). The cardiac T2* value was lower and the liver size greater in patients who had undergone splenectomy compared with those who had not (p < 0.001 and 0.001, respectively). Splenic iron overload correlated with hepatic overload and the serum ferritin level. Splenectomy increased cardiac iron overload and triggered liver enlargement. However, the muscle iron overload was low and the muscles were therefore unaffected by splenectomy.

The Diagnostic Value of MR IVIM and T2 Mapping in Differentiating Autoimmune Myositis From Muscular Dystrophy

To confirm the feasibility and compare the accuracy of magnetic resonance imaging intravoxel incoherent motion (IVIM) and T2 mapping models for the differentiation of autoimmune myositis from muscular dystrophy. Fourty-two autoimmune myositis and 11 muscular dystrophy patients proven by diagnostic criteria were enrolled in the study. Conventional MR sequences, IVIM, and T2 mapping through the bilateral thighs were obtained as well as blood samples for all patients. IVIM and T2 mapping parameters as well as serum markers were compared between the autoimmune myositis and muscular dystrophy groups. Mann-Whitney U tests were performed for statistical analysis along with receiver operating characteristic curves. Spearman correlation coefficient models were constructed to analyze the correlation between IVIM and T2 mapping with serological parameters. The intramuscular apparent diffusion coefficient, tissue diffusivity (D), perfusion fraction (fp), and T2 relaxation time values were statistically significantly different between the autoimmune myositis and muscular dystrophy groups (p < 0.05). Pseudo diffusivity (Dp) values showed no statistical difference between the groups (p > 0.05). D parameter of IVIM sequences differentiated autoimmune and muscular dystrophy with a higher specificity of 75.60%. T2 values within the thighs were correlated with serum creatine kinase and lactate dehydrogenase levels (p < 0.05). Thigh muscle IVIM and T2 mapping parameters are useful in differentiating autoimmune myositis from muscular dystrophy, particularly the IVIM parameters.

Simultaneous Measurement of Perfusion and T2* in Calf Muscle at 7T with Submaximal Exercise using Radial Acquisition

Impairments in oxygen delivery and consumption can lead to reduced muscle endurance and physical disability. Perfusion, a measure of microvascular blood flow, provides information on nutrient delivery. T2* provides information about relative tissue oxygenation. Changes in these parameters following stress, such as exercise, can yield important information about imbalance between delivery and consumption. In this study, we implemented novel golden angle radial MRI acquisition technique to simultaneously quantify muscle perfusion and T2* at 7T with improved temporal resolution, and demonstrated assessment of spatial and temporal changes in these parameters within calf muscles during recovery from plantar flexion exercise. Nine healthy subjects participated the studies. At rest, perfusion and T2* in gastrocnemius muscle group within calf muscle were 5 ± 2 mL/100 g/min and 21.1 ± 3 ms respectively. Then the subjects performed plantar flexion exercise producing a torque of ~8ft-lb. Immediately after the exercise, perfusion was elevated to 79.3 ± 9 mL/100 g/min and T2* was decreased by 6 ± 3%. The time constants for 50% perfusion and T2* recovery were 54.1 ± 10 s and 68.5 ± 7 s respectively. These results demonstrate successful simultaneous quantification of perfusion and T2* in skeletal muscle using the developed technique.

Assessment of lumbar paraspinal muscle activation using fMRI BOLD imaging and T2 mapping.

Our study aimed to investigate the feasibility of functional magnetic resonance imaging [blood oxygen level-dependent (BOLD) imaging and T2 mapping] in monitoring the activation of lumbar paraspinal muscles before and after exercise. The ethics committee of the First Affiliated Hospital of Kunming Medical University approved our study. Both BOLD and T2 mapping of paraspinal muscles were performed in 50 healthy, young volunteers before and after upper-body extension exercises. The movement tasks included upper body flexion and extension using a simple Roman chair. Cross-sectional area (CSA), R2*, and T2 values were measured in various lower-back anatomical regions. The SPSS22.0 statistical software was used to analyze all the data. Post-exercise CSA and T2 values were higher than those recorded in the pre-exercise session for the three lower-back muscles that were evaluated (iliocostalis, longissimus, and multifidus) (P<0.01). However, R2* values of these muscles were significantly lower after exercise (P<0.01). A significant difference in the R2*, CSA, and T2 values of the iliocostalis occurred between males and females (P<0.05). No statistically significant differences were evident for R2*, CSA, and T2 of the lower-back muscles between L3 and L4 levels, or between the left and right sides. The total CSA of the iliocostalis was higher than that of the multifidus and longissimus (P<0.05). BOLD and T2 mapping are feasible non-invasive indirect assessments of lumbar paraspinal muscle activation before and after exercise.