Prolonged T2 Relaxation Times Research Articles

Systematic review of cardiovascular magnetic resonance imaging T1 and T2 mapping in patients with Takotsubo syndrome

BackgroundCurrent imaging advancements quantify the use of cardiovascular magnetic resonance (CMR) derived T1 and T2 tissue characterization as robust indicators for cardiomyopathies, but limited literature exists on its clinical application in Takotsubo syndrome (TTS). This systematic review evaluated the T1 and T2 parametric mapping to delineate the current diagnostic and prognostic CMR imaging outcomes in TTS. MethodsA comprehensive literature search until October 2023 was performed on ScienceDirect, PubMed, Web of Science, and Cochrane Library by two independent reviewers adhering to the PRISMA framework. The Newcastle-Ottawa Scale (NOS) was used to evaluate the methodological quality of studies. ResultsOut of 198 results, 8 studies were included in this qualitative synthesis, accounting for a total population of 399 subjects (TTS = 201, controls = 175, acute myocarditis = 14, and acute regional myocardial oedema without infarction = 9). Approximately 50.4 % were TTS patients aged between 61 and 73 years, whereof, females (n = 181, 90.0 %) and apical variants (n = 180, 89.6 %) were significantly higher, and emotional stressor (n = 42; 20.9 %) was more prevalent than physical (n = 27; 13.4 %). The NOS identified 62.5 % of studies as moderate and 37.5 % as high quality. Parametric tissue mapping revealed significantly prolonged T1 and T2 relaxation times at 1.5T and 3T respectively in TTS (1053–1164 msec, 1292–1438 msec; and 56–67 msec, 60–90 msec) with higher extracellular volume (ECV) fraction (29–36 %), compared to healthy subjects (944–1211 msec, 1189–1251 msec; and 46–54 msec, 32–68 msec; 23–29 %) and myocarditis (1058 msec, 60 msec). Other significant myocardial abnormalities included increased left ventricular (LV) end-systolic and diastolic volume and reduced global longitudinal strain. Overall, myocardial oedema, altered LV mass and strain, and worse LV systolic function, with higher native T1, T2, and ECV values were consistent. ConclusionsFuture research with substantially larger clinical trials is vital to explore the CMR imaging findings in diverse TTS patient cohorts and correlate the T1 and T2 mapping outcomes with demographic/clinical covariates. CMR is a valuable imaging tool for TTS diagnosis and prognostication. T1 and T2 parametric mapping facilitates the quantification of oedema, inflammation, and myocardial injury in Takotsubo.

Quantitative evaluation of the lumbar ligamentum flavum using MRI T2-mapping: Efficacy of its clinical application in patients with lumbar spinal stenosis

ObejectiveTo perform a magnetic resonance imaging T2-mapping of the ligamentum flavum in healthy individuals and patients with lumbar spinal stenosis scheduled for surgery and compare the T2 relaxation times. Subjects and MethodsThe T2 relaxation time of the ligamentum flavum was compared among 3 groups, healthy young individuals (H group (age< 50)), healthy middle-aged and older individuals (H group (age≥50)), and patients with lumbar spinal stenosis (L group). Additionally, the thickness of the ligament was measured in the axial image plane, and the occupied area ratio of each fiber was measured by staining the surgically obtained ligament, and each was correlated with the T2 relaxation time. We also evaluated the adhesion of the ligamentum flavum with the dura mater during the surgery. ResultsThe T2 relaxation times were significantly prolonged in H group (age ≥50) and L group (P < 0.001) compared to H group (age<50). The relationship between collagen fiber and T2 relaxation times was significantly positive (r = 0.720, P < 0.001). Moreover, the relaxation times were significantly prolonged in those with adhesion of the ligamentum flavum with the dura mater (P < 0.05). The cut-off for the relaxation time was 50 ms (sensitivity: 62.50%, false positive rate: 10.8%). ConclusionHealthy middle-aged and older individuals and patients with lumbar spinal stenosis and adhesion of the ligamentum flavum with the dura mater have prolonged T2 relaxation times. Hence, the adhesion between the ligamentum flavum and dura mater should be considered in cases with a relaxation time ≥50 ms.

Cardiac adverse reactions of COVID-19 vaccination: cardiac MRI findings.

The rapid development of COVID-19 vaccines in the wake of the COVID-19 pandemic has led to an equally expediently deployed vaccination campaign with more than 12billion vaccinations administered worldwide. Reports of vaccine-associated adverse reactions (VAARs) have ranged from headaches and pain at the injection site to potentially life-threatening events such as cerebral venous sinus thrombosis. The heart has also not been spared of VAARs, as vaccine-associated myocardial infarction and more commonly, albeit still rare, myocarditis and perimyocarditis have been reported in predominantly young male recipients. Cardiac magnetic resonance imaging findings of vaccine-associated myocarditis such as prolonged T1 and T2 relaxation times, increased T2 signal intensity ratio, and subepicardial late gadolinium enhancement have been demonstrated to be similar to those in virus-induced myocarditis, enabling the use of the modified 2018 Lake Louise Criteria for diagnostic purposes to confirm vaccination-associated myocardial inflammation. Other reported cardiac findings such as cardiomyopathies and arrhythmias were confined to case reports. The incidence of myocardial infarction was not noted to be higher than in the overall population. The overall preliminary prognosis of vaccine- associated myocarditis seems to be good as suggested by initial reports, but long-term follow-up is needed to sufficiently assess possible sequelae and consequences.

Unique Random-Block Polymer Architecture for Site-Specific Mitochondrial Sequestration-Aided Effective Chemotherapeutic Delivery and Enhanced Fluorocarbon Segmental Mobility-Facilitated 19F Magnetic Resonance Imaging.

The elevation of the chemotherapeutic efficacy and attenuation of its side effects on healthy cells and tissues become one of the prime targets for the treatment of cancer. Toward this direction, a sequential receptor and mitochondria dual-targeting strategy was implemented in the DX TP PG BN 19F theranostic polymer that was anchored with the chemotherapeutic agent doxorubicin, receptor-targeting biotin, and mitochondria-targeting triphenylphosphonium cations. The polymer was flourished with a unique 19F magnetic resonance imaging (MRI) tracer that exhibited high segmental mobility and eventually led to prolonged T2 relaxation time. Furthermore, for the sake of amphiphilicity, the DX TP PG BN 19F polymer spontaneously aggregated into nano-sphere with positive zeta potential, where the MRI tracer and biotin embedded at the exterior and displayed site-specific targeting and remarkable 19F MRI capability simultaneously. The mitochondria-targeting competency of the DX TP PG BN 19F theranostic polymer was investigated by comparing the non-mitochondrial-targeting DX PG BN 19F polymer using fluorescence microscopic cell imaging in human cervical, HeLa, and breast MCF-7 carcinoma cell lines. Moreover, cytotoxicity experiments of the aforementioned theranostic polymers clarified the enhancement of the chemotherapeutic efficacy of DX TP PG BN 19F theranostic polymers through effective and precise mitochondrial doxorubicin delivery that forced to follow the apoptotic path.

Cardiac MRI findings in patients with Crohn's disease.

Early cardiac death is more common in patients with Crohn's disease (CD) than in healthy adults, but the exact cause is unknown. The aim of this study is to investigate the cardiac magnetic resonance imaging (MRI) findings in patients with CD and compare the MRI findings with healthy controls (HCs). This study also aimed to demonstrate the possible cardiac involvement in patients with CD using MRI. In this prospective study, participants with CD (n = 20) and HC (n = 20) underwent cardiac MRI. Erythrocyte sedimentation rate (ESR) and hematocrit levels were investigated before MRI in both groups. Two observers evaluated the ventricular functional and morphological parameters in consensus. Myocardial T1/T2-relaxation times were calculated by two observers independently using two different software, and hematocrit-corrected left ventricle extracellular volume (LV-ECV) was calculated. Observer-2 also performed histogram analysis for T1/T2-mapping images. Patients with CD had a significantly higher LV-ECV, mildly decreased right ventricle ejection fraction, and prolonged T2-relaxation time than HC. Moreover, histogram analysis showed that the maximum and mean T2-relaxation times were higher in patients with CD. There was an excellent agreement between observers for the assessment of mean native and post-contrast T1-relaxation time (intraclass correlation coefficient (ICC) of 0.991 and ICC of 0.941, respectively) and mean T2-relaxation time measurements (ICC of 0.983). Moreover, mean T2-relaxation time was found to be significantly correlated with ESR. This study suggests visually undetectable myocardial involvement due to chronic systemic inflammation in patients with Crohn's disease. Cardiac MRI can help assess and monitor cardiac involvement in patients with CD.

Diabetic Myonecrosis: A Case Study

Abstract Background: Diabetic myonecrosis is a rare complication of diabetes mellitus with less than 200 cases reported in the literature since initial description in 19651. Diabetic myonecrosis most commonly affects the thigh and usually presents with acute muscle pain, edema, and erythema in the absence of trauma or fever1. The pathogenesis has yet to be elucidated—atherosclerosis, microangiopathy, vasculitis, and ischemia-reperfusion injury have been theorized. Laboratory findings are relatively nonspecific—of the findings reported in a systematic review, CRP was elevated in 90%, ESR elevated in 83.3%, WBC elevated in 42.5%, and CK elevated in 31.6%1. Definitive diagnosis can be made by muscle biopsy which demonstrates muscle necrosis and edema; however, it is not routinely recommended due to procedural complications. MRI is the diagnostic modality of choice for diabetic myonecrosis which is both sensitive and specific for the diagnosis2. Clinical Case: 76-year-old male with T2DM presented to regional hospital with severe right lower leg pain in the absence of fever, tachycardia, hypotension, or recent trauma. Physical exam demonstrated discrete erythema of distal 2/3 of posterior right lower leg extending to the ankle distally. Labs demonstrated normal CK, elevated ESR, HgbA1c 8.2%, and negative blood cultures. MRI of the right lower extremity demonstrated abnormal prolongation of T2 relaxation time involving posterior muscle compartment including soleus and gastrocnemius with associated perifacial and subcutaneous edema. These findings were consistent with diabetic myonecrosis without evidence of osteomyelitis or abscess. Rest, optimal glycemic control, and aspirin were recommended and patient improved gradually with complete clinical resolution on outpatient follow-up. Conclusions: Diabetic myonecrosis is a rare complication of diabetes and should be considered in patients presenting with acute muscle pain. Among cases described in literature, 5.7% have affected the soleus and 5% have affected the gastrocnemius respectively1. The diagnostic modality of choice is contrast enhanced MRI with typical findings including hyperintense signal on T2 weighted images with associated muscular, perifascial, and/or subcutaneous edema3. The optimal treatment is yet unknown, but reasonable strategies based on case series include rest, glycemic control, and NSAID therapy1.

Diagnosis of lumbar radiculopathy using simultaneous MR neurography and apparent T2 mapping

We sought to assess the utility of simultaneous apparent T2 mapping and neurography with the nerve-sheath signal increased by inked rest-tissue rapid acquisition of relaxation-enhancement imaging (SHINKEI-Quant) for the quantitative evaluation of compressed nerves in patients with lumbar radiculopathy.Thirty-two patients with lumbar radiculopathy and 5 healthy subjects underwent simultaneous apparent T2 mapping and neurography with SHINKEI-Quant. Regions of interest (ROIs) were placed in the lumbar dorsal root ganglia (DRG) and the spinal nerves distal to the lumbar nerves bilaterally at L4-S1. The T2 relaxation times were measured on the affected and unaffected sides. The T2 ratio was calculated as the affected side/unaffected side. Pearson correlation coefficients were calculated to determine the correlation between the T2 relaxation times or T2 ratio and clinical symptoms. An ROC curve was used to examine the diagnostic accuracy and threshold of the T2 relaxation times and T2 ratio.We observed no significant differences in the T2 relaxation times between the nerve roots on the left and right at each spinal level in healthy subjects. In patients, lumbar neurography revealed swelling of the involved nerve, and prolonged T2 relaxation times compared with that of the contralateral nerve. The T2 ratio correlated with leg pain. The ROC analysis revealed that the T2 relaxation time threshold was 127 ms and the T2 ratio threshold was 1.07.To our knowledge, this is the first study to show the utility of SHINKEI-Quant for the quantitative evaluation of lumbar radiculopathy.

Simultaneous MR neurography and apparent T2 mapping of cervical nerve roots before microendoscopic surgery to treat patient with radiculopathy due to cervical disc herniation: Preliminary results

There is no imaging modality to quantitatively evaluate compressed cervical nerve roots in cervical radiculopathy. Here we sought to evaluate the usefulness of simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation-enhancement imaging (SHINKEI-Quant) to evaluate compressed nerves quantitatively in patients with cervical radiculopathy due to cervical disc hernia before microendoscopic surgery.One patient with cervical radiculopathy due to cervical disc hernia before microendoscopic surgery and 5 healthy subjects underwent simultaneous apparent T2 mapping and neurography with SHINKEI-Quant. The patient was a 49-year-old man with severe right upper arm pain and numbness. Based on MRI images, we suspected right C7 radiculopathy due to C6-7 cervical disc hernia. The T2 relaxation times of the cervical dorsal root ganglia of the brachial plexus bilaterally at C5–C8 were measured.We observed no significant differences in T2 relaxation times between the nerve roots on the left and right at each spinal level with values in healthy subjects. In our patient, neurography revealed swelling of the right C7 nerve, and a prolonged T2 relaxation time compared with that of the contralateral, unaffected C7 nerve. We performed microendoscopic surgery and the symptoms improved.We were able to evaluate the injured nerve root quantitatively in a patient with cervical radiculopathy using the SHINKEI-Quant technique, being the first study to our knowledge to show the usefulness of this technique to evaluate cervical radiculopathy quantitatively before microendoscopic surgery.

Clinical efficacy of transcutaneous triamcinolone acetonide injection for upper eyelid retraction and swelling in patients with thyroid eye disease.

AimTo evaluate the efficacy of transcutaneous triamcinolone acetonide (TA) injection for the treatment of upper eyelid retraction and swelling in thyroid eye disease (TED) patients.Patients and methodsThis is a case series. Three euthyroid TED patients with features of both upper eyelid retraction and swelling were recruited. TED signs appeared within 6 months prior to treatment. Next, 0.5 mL of TA (40 mg/mL) was transcutaneously injected targeting the orbital fat around the levator palpebrae superioris (LPS) muscle. At each visit, eyelid retraction was evaluated by palpebral fissure height and the presence of scleral show above the superior corneoscleral limbus. Eyelid swelling was judged by the appearance of upper eyelid bulging and the lack of an eyelid sulcus. In addition, the LPS muscle, orbital and retro-orbicularis oculi fat were observed using MRI before and after treatment.ResultsTwo patients had resolution of their upper lid retraction and swelling within 12 months. In the other patient who had proptosis, eyelid retraction resolved, while eyelid swelling remained mild. In all cases, MRI revealed that treatment resulted in thinner LPS muscle and reduced fat swelling. In addition, both high-intensity signals on T2 images and prolonged T2 relaxation time were normalized. No adverse signs were observed.ConclusionTranscutaneous TA injection was effective as a treatment for upper eyelid retraction and swelling in euthyroid TED patients who had signs within 6 months prior to treatment. Transcutaneous TA injection induced reduction of LPS muscle enlargement and fat tissue swelling. These reductions by transcutaneous TA injection were verified using MRI.

T2 relaxation times of the anterolateral femoral cartilage in patients after ACL-reconstruction with and without a deep lateral femoral notch sign

PurposeTo quantitatively assess T2 relaxation times of the anterolateral femoral cartilage following anterior cruciate ligament (ACL)-reconstruction with and without a positive deep lateral femoral notch sign (DLNS) at post-traumatic MRI. Materials and MethodsIn 52 patients post-traumatic MRI as well as 12 months after ACL-rupture (ACLR) and surgical treatment were analysed. In 28 patients a positive DLNS was present at post-traumatic MRI.For quantitative analysis, T2 relaxation time measurements (7 TE: 10–70 ms) were performed at time of re-evaluation. Three polygonal ROIs encompassing the full cartilage layer were placed in the anterolateral femoral cartilage. Clinical assessment included Lysholm-Tegner-Activity-Score, Rasmussen's clinical score and modified Cincinnati-Rating-System-Questionnaire. Description and differences were calculated as means and confidence intervals of means, controlled for the cluster effect of person, if appropriate. ResultsIn patients with a positive DLNS after ACLR, relaxation times in the notch region were significantly prolonged compared to patients without a positive DLNS (Δ 7.4 ms, CI: 5.6–9.2; p-value <0.001) as well as to the adjacent anterior (Δ 5.7 ms, CI: 4.7–6.7; p-value <0.001) and central femoral cartilage (Δ 6.6 ms, CI: 5.7–7.6; p-value <0.001).Solely insignificant differences were noticed in the performed clinical scores comparing the two groups (p > 0.05). ConclusionSignificantly prolonged T2 relaxation times of the anterolateral femoral cartilage were found in patients with a positive DLNS following ACL-reconstruction compared to patients without a DLNS. Based on these results, it has to be assumed that a positive DLNS is associated with higher cartilage degradation.

Effects of Surgical Factors on Cartilage Can Be Detected Using Quantitative Magnetic Resonance Imaging After Anterior Cruciate Ligament Reconstruction

Background: Quantitative magnetic resonance (qMR) can be used to measure macromolecules in tissues and is a potential method of observing early cartilage changes in the development of posttraumatic osteoarthritis. Hypothesis/Purpose: We hypothesized that specific patient and surgical factors affecting cartilage matrix composition after anterior cruciate ligament (ACL) reconstruction (ACLR) can be detected using T1ρ and T2 relaxation times. Our purpose was to demonstrate this ability in a multicenter feasibility study. Study Design: Case series; Level of evidence, 4. Methods: A total of 54 patients who underwent ACLR underwent bilateral MRI at baseline before surgery and 6 months postoperatively. Operative findings were recorded. T1ρ and T2 relaxation times were calculated for 6 cartilage regions: the medial femur, lateral femur, medial tibia, lateral tibia, patella, and trochlea. A paired t test compared relaxation times at baseline and 6 months, univariate regression identified regions that influenced patient-reported outcome measures, and analysis of covariance was used to determine the surgical factors that resulted in elevated relaxation times at 6 months. Results: The injured knee had significantly prolonged T1ρ and T2 relaxation times in the tibiofemoral compartment at baseline and 6 months but had shorter values in the patellofemoral compartment compared with the uninjured knee. Prolonged T1ρ and T2 times at 6 months were noted for both the injured and uninjured knees. At 6 months, prolongation of T1ρ and T2 times in the tibial region was associated with lower patient-reported outcome measures. ACLR performed within 30 days of injury had significantly shorter T1ρ times in the tibial regions, and lateral meniscal tears treated with repair had significantly shorter T1ρ times than those treated with excision. Conclusion: Prolonged relaxation times in multiple regions demonstrate how the injury affects the entire joint after an ACL tear. Changes observed in the uninjured knee may be caused by increased loading during rehabilitation, especially in the patellofemoral articular cartilage and distal femur. Relaxation times in the tibial regions may be predictive of patient symptoms at 6 months. These same regions are affected by surgical timing as early as 30 days after injury, but this may partially be reflective of the severity of the preoperative injury and the choice of treatment of meniscal tears.

Feasibility of fat fraction quantification by measuring J-coupling related signal modulation in multi echo fast spin echo sequences

Introduction Echo spacing in Fast Spin Echo techniques can affect signal intensity mainly of fatty tissue and is presented as effectively prolonged T2 relaxation time (magnetic fat liquefaction). Purpose The aim of this study is to measure signal intensity in multi echo Fast Spin Echo techniques with variable echo spacing in order to examine the feasibility of fat quantification from J-coupling related signal modulation. T2 maps were calculated from all different acquisition schemes. Materials and methods A phantom containing porcine fat, vegetable oils, gadolinium doped agarose gels that mimic fat magnetic relaxation properties, double distilled water at controlled temperature of 36–38 °C was scanned at 1.5 T utilizing a single slice multi echo SE technique with equidistant echoes of variable TE intervals (6.7–40 ms). Results Fat signal modulation as a function of echo spacing varied significantly between short and long echo spacing acquisitions (28.97–56.26%) and this dependence could be approximated by a linear sequence ( Δ S fat = S short ESP - S long ESP = 3.38*n*TE + 27.18, residual 7,88 for n ranging from 1 to 12) for a wide range of routinely used TEs in clinical practice (13.4–160.8 ms) while effect on water was minimal ( Δ S water = 22.11%, SD for same TE range: 0.53). Difference of calculated T2 relaxation times between sequences with different echo spacing ranged from 9.5 to 35%. Conclusion Echo spacing in MESE sequences may serve as a metric of signal manipulation and fat quantification. Bright fat sequences should be avoided for T2 relaxation parametric maps.

T2 relaxometry improves detection of non-sclerotic epileptogenic hippocampus

ObjectThe use of T2 relaxometry was investigated to detect non-sclerotic epileptogenic abnormality of the hippocampus in presurgical evaluation of temporal lobe epilepsy (TLE). MethodsThis prospective study included 30 patients who underwent hippocampectomy as part of surgical treatment of refractory TLE. Ten patients had structural epileptogenic lesions in the extra-hippocampal temporal lobe. Twelve patients underwent intracranial electroencephalography (iEEG) study before surgery. Visual assessment of atrophy and increased T2 signal intensity, volumetry, and T2 relaxometry of hippocampus were performed pre-operatively using 3T magnetic resonance imaging, and compared with the neuropathological findings and iEEG findings. Magnetic resonance imaging of 30 age- and sex-matched healthy controls was used to establish normal values, which were defined as z score within 2. ResultsVisual assessment, volumetry, and T2 relaxometry detected hippocampal abnormalities on the surgical side in 16 (53%), 16 (53%), and 26 (87%) patients, respectively. Hippocampal volume loss was always associated with prolonged T2 relaxation time, and supported by histopathological diagnosis of HS in all cases except one. Hippocampal abnormality was detected only by T2 relaxometry in nine patients (30%). Pathological diagnosis of these cases included mild HS in one, microdysgenesis in one, and granule cell pathology in three. Four patients with normal hippocampal volume and T2 relaxation time had no HS or granule cell pathology. Prolonged T2 relaxation time was associated with medial temporal seizure onset in iEEG (p<0.05). ConclusionsT2 relaxometry improves the detection of non-sclerotic epileptogenic abnormality of the hippocampus.

Early Cartilage Changes After Anterior Cruciate Ligament Injury: Evaluation With Imaging and Serum Biomarkers—A Pilot Study

To determine if magnetic resonance imaging markers of cartilage matrix and morphology and circulating serum biomarkers of inflammation and matrix degradation differ over time in patients with anterior cruciate ligament (ACL) injury and bone marrow edema lesions (BMELs) when compared with matched control subjects. We performed a case-control study, in which 11 ACL-injured subjects scheduled to undergo reconstruction and 11 matched control subjects were scheduled for testing. Participants were selected for the ACL reconstruction (ACLR) group if they injured their ACL while participating in sports, were aged 14 to 30 years, had 1 or more BMELs, and were scheduled to undergo bone-patellar tendon-bone ACLR. Testing required patients to undergo magnetic resonance imaging for measurement of T2 relaxation times in standardized regions of interest over the medial and lateral tibial plateaus and femoral condyles and have blood drawn for measurement of cartilage oligomeric matrix protein (COMP) and C-reactive protein levels before ligament reconstruction and 1 year after surgery. ACL patients had prolonged T2 relaxation times, indicative of cartilage matrix degradation, in the superficial central lateral tibial plateau (P= .02) and deep medial tibial plateau when compared with control subjects (P= .0001). Prolonged T2 relaxation times were also noted over the lateral femoral condyle at baseline for ACL patients compared with control subjects (P= .001), but the differences resolved by 1 year (P= .98). Circulating serum COMP levels were greater in ACL patients (233.23 ± 88.26 ng/mL) compared with control subjects (169.05 ± 64.53 ng/mL, P= .05). T2 mapping showed prolonged relaxation times in the lateral compartment of the knee in ACLR patients with lateral BMELs. Furthermore, prolonged T2 relaxation times were apparent in the medial compartment of the knee in ACL-injured patients where bone marrow lesions were not present. Higher serum COMP levels were present in ACL-injured subjects when compared with control subjects. Level II, prospective case-control study.

The diagnostic value of orbital magnetic resonance imaging T2-Mapping in patients with active Graves' ophthalmopathy

Objective To study the clinical value of orbital magnetic resonance imaging(MRI) in diagnosis and making a judgment about the curative effect of glucocorticoid in patients with Graves' ophthalmopathy(GO). Methods A total of 106 patients with GO were divided into active GO group or inactive GO group according to whether clinical activity score(CAS)≥3 or not, respectively. T2 relaxation times(T2RTs)(ms) and areas(mm2) of four extra-ocular muscles (EOMs) (superior, inferior, medial, and lateral rectus) were directly measured by MRI T2-Mapping. Correlation analysis of T2RTs and areas with eyeball motility, diplopia, exophthalmus, visual acuity and intraocular pressure(IOP) were also performed. The T2RTs and areas of EOMs before and after intravenous methylprednisolone(iv MP) pulse therapy were recorded, respectively. Results The mean T2RTs(88.9±13.8) and mean areas(58.1±23.8) of EOMs in active GO were significantly greater than those in inactive GO(80.6±10.0 and 46.2±18.6, respectively), bing both significantly greater than those in volunteers with normal eyes(76.2±4.7 and 30.3±6.1, respectively)(P<0.01). Maximal T2RTs and maximal areas of EOMs showed significant positive correlation(P<0.01), and both were positively correlated weakly with CAS, reduced movement of eyeball, diplopia, exophthalmus and loss of visual acuity(P<0.01). On the contrary, maximal T2RTs and maximal areas of EOMs showed negative correlation or no correlation with spontaneous retrobulbar pain, painful eye movement, redness of eyelids and abnormal IOP. Even if 1≤CAS<3, ophthalmic symptoms and signs also showed a positive responses to iv MP in patients with moderate to severe GO as long as prolonged T2RTs occurred at least in one of EOMs. The maximal T2RTs, maximal areas, mean T2RTs and mean areas of EOMs were significantly decreased at the end of iv MP treatment, meanwhile ophthalmic symptoms and signs were obviously improved. Conclusions Prolonged T2RTs, especially accompanied by enlarged area on the identical EOMs is an remarkable symbols of acute inflamed muscles. The findings suggested that the use of prolonged T2RTs can improve diagnostic sensitivity and predict the curative effect of iv MP in patients with moderate to severe GO and CAS≥1. (Chin J Endocrinol Metab, 2015, 31: 327-332) Key words: Graves' ophthalmopathy; Magnetic resonance imaging; Methylprednisolone

Diet-Induced and Age-Related Changes in the Quadriceps Muscle: MRI and MRS in a Rat Model of Sarcopenia

Background: Knowledge about the molecular pathomechanisms of sarcopenia is still sparse, especially with regard to nutritional risk factors and the subtype of sarcopenic obesity. Objective: The aim of this study was to characterize diet-induced and age-related changes on the quality and quantity of the quadriceps muscle in a rat model of sarcopenia by different magnetic resonance (MR) techniques. Methods: A total of 36 6-month-old male Sprague-Dawley rats were randomly subdivided into 2 groups and received either a high-fat diet (HFD) or a control diet (CD). At the age of 16 months, 15 HFD and 18 CD rats underwent MR at 1.5 T. T1-weighted images as well as T2 relaxation time maps were acquired perpendicular to the long axis of the quadriceps muscles. Maximum cross-sectional area (CSA) of the quadriceps muscle was measured on T1-weighted images, and T2 relaxation times of muscle were assessed in a region without visible intramuscular fat (T2_{lean muscle}) and across the complete CSA (T2_muscle). Furthermore, ¹H-MR spectroscopy was performed to evaluate the relative lipid content of the quadriceps muscles. These measurements were repeated 5 months later in the surviving 8 HFD and 14 CD rats. Results: HFD rats revealed significantly decreased CSA and CSA per body weight (BW) as well as prolonged T2 relaxation times of muscle. A higher weight gain (upper tertile during the first 6 months of diet in CD rats) resulted in a significant change of T2_muscle, but had no relevant impact on CSA. Advancing age up to 21 months led to significantly decreased BW, CSA and CSA/BW, significantly prolonged T2_muscle and T2_{lean muscle} and enlarged lipid content in the quadriceps muscle. Conclusions: In an experimental setting a chronically fat-enriched diet was shown to have a relevant and age-associated influence on both muscle quantity and quality. By translational means the employed MR techniques give rise to the possibility of an early detection and noninvasive quantification of sarcopenia in humans, which is highly relevant for the field of geriatrics.

Quantitative MRI shows cerebral microstructural damage in hemolytic–uremic syndrome patients with severe neurological symptoms but no changes in conventional MRI

Severe neurological symptoms in Shiga toxin-producing Escherichia coli infection associated hemolytic-uremic syndrome (STEC-HUS) are often accompanied by none or only mild alterations of cerebral magnetic resonance imaging (MRI). This study aims to analyze if quantitative MRI is able to reveal cerebral pathological alterations invisible for conventional MRI. In nine patients with STEC-HUS associated severe neurological symptoms but inconspicuous cerebral MRI findings maps of the parameters T2 relaxation time, relative proton density (PD), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were generated. Quantitative values of these parameters were measured at the basal ganglia, thalamus, and white matter of the frontal and parietal lobe and compared to those of nine age- and sex-matched controls. Significant T2 prolongation (p < 0.01) was found in the basal ganglia of all patients compared to controls. PD and ADC were not significantly altered. A significant reduction of FA in patients was seen at caput nuclei caudati (p < 0.01). Prolonged T2 relaxation time indicates cerebral microstructural damages in these patients despite their inconspicuous MRI findings. T2 relaxometry could be used as a complementary tool for the assessment of metabolic-toxic brain syndromes.

Quantitative MRI Studies of Chronic Brain White Matter Hyperintensities in Migraine Patients

The aim of this study was to examine chronic brain white matter hyperintensities in migraine and to gain data on the characteristics of the lesions. Migraine associates with a higher incidence of magnetic resonance imaging (MRI)-visible white matter signal abnormalities. Several attack-related pathomechanisms have been proposed in the lesion development, including the effect of repeated intracerebral hemodynamic changes. Supratentorial white matter hyperintensities of 17 migraine patients were investigated interictally with quantitative MRI, including quantitative single voxel spectroscopy, diffusion, and perfusion MRI at 3.0-Tesla. The findings were compared with data measured in the contralateral, normal-appearing white matter of migraineurs and in the white matter of 17 healthy subjects. Significantly higher apparent diffusion coefficient values, prolonged T2 relaxation times, and decreased N-acetyl-aspartate and creatine/phosphocreatine concentrations were found in the white matter hyperintensities. The cerebral blood flow and blood volume values were mildly decreased inside the hyperintensities. Differences were not present between the migraine patients' normal-appearing white matter and the white matter of healthy subjects. The MRI measurements denote tissue damage with axonal loss, low glial cell density, and an enlarged extracellular space with an increased extracellular water fraction. These radiological features might be the consequences of microvascular ischemic changes during migraine attacks.

Descending corticospinal tract Wallerian degeneration after stroke: an old sign, a new prognostic marker?

right hemiplegia reached its plateau at month-3 (FIM motor score: 42/91). At that time, MRI revealed the signs of descending corticospinal tract Wallerian degeneration (DCST-WD) (Fig. 2). The MRI feature of DCST-WD is prolonged T2 relaxation times with or without shrinkage of ipsilateral cerebral peduncle and pons [1]. This feature is more evident 3–6 months after stroke but can appear as early as 5 weeks and could persist for more than 10 months [1]. Recent studies suggest that early or serial DCST-WD signs on MRI or diffusion weighted or diffusion tensor imaging might be new biological markers of motor prognosis after stroke [2].

Severe thyroid-associated orbitopathy in Hashimoto's thyroiditis. Report of 2 cases

Thyroid-associated orbitopathy (TAO) is characterized by immune-mediated inflammation of the extraocular muscles surrounding orbital connective tissue and adipose tissue. Severe orbitopathy related to autoimmune thyroid disease often occurs in patients with Grave's disease, but it is rare in patients with Hashimoto's thyroiditis. The pathogenesis of TAO is unclear. Several studies have noted a strong correlation between the levels of antibodies to thyrotropin receptor antibody (TRAb) and TAO in Graves' disease. Mild upper eyelid retraction has been reported to be common in Hashimoto's thyroiditis patients, however severe orbitopathy is rare. We report two cases of severe TAO in patients with Hashimoto's thyroiditis who required systemic glucocorticoid therapy and orbital irradiation to treat the TAO. The activity of the TAO was high in both patients, because their clinical activity scores (CAS) for the orbitopathy were high, and magnetic resonance imaging (MRI) showed enlargement of the extraocular muscles and an increase in T2 signal intensity and prolonged T2 relaxation time which indicate an active stage of inflammation. We tested the presence of TRAb by three different assays and were negative in both patients. Since the eye muscle damage cannot be due to TSH receptor antibodies, other pathogenetic mechanisms may be responsible for the orbitopathy in patients with Hashimoto's thyroiditis.