Fat-suppressed MRI Research Articles

Deep Learning Approach for Evaluating Knee MR Images: Achieving High Diagnostic Performance for Cartilage Lesion Detection.

Purpose To determine the feasibility of using a deep learning approach to detect cartilage lesions (including cartilage softening, fibrillation, fissuring, focal defects, diffuse thinning due to cartilage degeneration, and acute cartilage injury) within the knee joint on MR images. Materials and Methods A fully automated deep learning-based cartilage lesion detection system was developed by using segmentation and classification convolutional neural networks (CNNs). Fat-suppressed T2-weighted fast spin-echo MRI data sets of the knee of 175 patients with knee pain were retrospectively analyzed by using the deep learning method. The reference standard for training the CNN classification was the interpretation provided by a fellowship-trained musculoskeletal radiologist of the presence or absence of a cartilage lesion within 17 395 small image patches placed on the articular surfaces of the femur and tibia. Receiver operating curve (ROC) analysis and the κ statistic were used to assess diagnostic performance and intraobserver agreement for detecting cartilage lesions for two individual evaluations performed by the cartilage lesion detection system. Results The sensitivity and specificity of the cartilage lesion detection system at the optimal threshold according to the Youden index were 84.1% and 85.2%, respectively, for evaluation 1 and 80.5% and 87.9%, respectively, for evaluation 2. Areas under the ROC curve were 0.917 and 0.914 for evaluations 1 and 2, respectively, indicating high overall diagnostic accuracy for detecting cartilage lesions. There was good intraobserver agreement between the two individual evaluations, with a κ of 0.76. Conclusion This study demonstrated the feasibility of using a fully automated deep learning-based cartilage lesion detection system to evaluate the articular cartilage of the knee joint with high diagnostic performance and good intraobserver agreement for detecting cartilage degeneration and acute cartilage injury. © RSNA, 2018 Online supplemental material is available for this article .

Filling the dead-time gap in zero echo time MRI: Principles compared.

MRI of tissues with short coherence lifetimes T2 or T2* can be performed efficiently using zero echo time (ZTE) techniques such as algebraic ZTE, pointwise encoding time reduction with radial acquisition (PETRA), and water- and fat-suppressed proton projection MRI (WASPI). They share the principal challenge of recovering data in central k-space missed due to an initial radiofrequency dead time. The purpose of this study was to compare the three techniques directly, with a particular focus on their behavior in the presence of ultra-short-lived spins. The most direct comparison was enabled by aligning acquisition and reconstruction strategies of the three techniques. Image quality and short- T2* performance were investigated using point spread functions, 3D simulations, and imaging of phantom and bone samples with short (<1 ms) and ultra-short (<100 μs) T2*. Algebraic ZTE offers favorable properties but is limited to k-space gaps up to approximately three Nyquist dwells. At larger gaps, PETRA enables robust imaging with little compromise in image quality, whereas WASPI may be prone to artifacts from ultra-short T2* species. For small k-space gaps (<4 dwells) and T2* much larger than the dead time, all techniques enable artifact-free short- T2* MRI. However, if these requirements are not fulfilled careful consideration is needed and PETRA will generally achieve better image quality. Magn Reson Med 79:2036-2045, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Fat-suppressed T2-weighted MRI appearance of subchondral insufficiency fracture of the femoral head

Our aims were to investigate the imaging appearance of subchondral insufficiency fracture (SIF) of the femoral head based on fat-suppressed T2-weighted MRI, and evaluate its correlation with the clinical outcomes following conservative treatment. We retrospectively evaluated 40 hips in 37 patients with SIF of the femoral head (12 males and 25 females; mean age 55.8years, range 22-78years). MRI examinations were performed within 3months after the onset of hip pain. Using fat-suppressed T2-weighted imaging, we evaluated the hips for the intensity of the subchondral bone (corresponding to the area superior to the low intensity band on T1-weighted images) as well as bone marrow edema, joint effusion, and presence of the band lesion. We then correlated the intensity of the subchondral bone with clinical outcomes. The hips were classified into three types based on subchondral intensity on fat-suppressed T2-weighted images: type 1 (21 hips) showed high intensity, type 2 (eight hips) showed heterogeneous intensity, and type 3 (11 hips) showed low intensity. The mean period between pain onset and MRI examination was significantly longer for type 2 hips than for type 1. Healing rates were 86% for type 1, 75% for type 2, and 18% for type 3. SIF cases were classified into three types based on subchondral intensity on fat-suppressed T2-weighted imaging performed within 3months after pain onset. Type 3 SIF tended to be intractable to conservative treatment compared to type 1 and type 2.

Giant Cell Arteritis Presenting with Bilateral Subdural Haematomas of Arterial Origin.

Giant cell arteritis or temporal arteritis is an inflammatory condition affecting medium to large sized vessels, particularly the cranial arteries. A 76-year-old man with no significant past medical history presented to the emergency department with a 3-week history of diffuse headaches associated with fever, loss of appetite, weight loss and general malaise. A CT scan of the brain showed bilateral shallow chronic low density subdural haematomas. A complete laboratory panel was unremarkable except for a raised erythrocyte sedimentation rate and elevated C-reactive protein. A transthoracic echocardiogram and CT scan of the body were unremarkable. MRI of the brain confirmed bilateral old subdural collections and showed marked vessel wall enhancement in the frontal branches of the left superficial temporal artery. A left temporal artery biopsy confirmed giant cell temporal arteritis. We speculate that a vasculitic process in the small subdural arteries may have contributed to our patient’s spontaneous subdural haematomas.LEARNING POINTSA contrast-enhanced T1 axial fat-suppressed MRI of the brain is a non-invasive modality of diagnostic value in giant cell arteritis (GCA); increased access to high resolution MRI technology may reduce the requirement for invasive temporal artery biopsy in the future.Subdural hematomas may be of arterial origin; GCA has been reported in association with subdural hematomas but causation is not proven.GCA must be suspected in patients presenting with headaches and raised inflammatory markers even in the absence of classic features or dual pathology as failure to recognize and treat promptly could lead to permanent visual loss.

Serum levels of resistin and interleukin-17 are associated with increased cartilage defects and bone marrow lesions in patients with knee osteoarthritis

Objectives: To investigate cross-sectional associations between serum levels of resistin and interleukin-17 (IL-17) and cartilage defects and bone marrow lesions (BMLs) in patients with knee symptomatic osteoarthritis (OA).Methods: One hundred and ninety-four consecutively-selected patients with knee symptomatic OA (mean 55.4 years, range 34–74, 87% females) were included in Anhui Osteoarthritis (AHOA) Study. Knee cartilage defects and BMLs were determined at different sites using T2-weighted fat-suppressed fast spin echo MRI. Serum resistin, IL-17, and high-sensitivity C-reactive protein (hs-CRP) levels were measured using ELISA.Results: In multivariable analyses, serum resistin was positively associated with cartilage defects at lateral femoral, lateral tibial, and medial tibial (all p < 0.05) sites. The significant associations were also present with BMLs at lateral femoral and tibial sites (ORs: 1.13–1.19, both p < 0.05). In patients with the highest quartile of hs-CRP (>2.45 pg/ml), IL-17 was positively and significantly associated with cartilage defect score at nearly all sites (ORs: 1.33–1.44, all p < 0.05), and BMLs at lateral and medial femoral sites (ORs: 1.26–1.51, both p < 0.05).Conclusions: Serum levels of resistin were positively and independently associated with cartilage defects and BMLs in patients with knee OA. Serum IL-17 was significantly associated with cartilage defects and BMLs in patients with an increased inflammatory status. These suggest that metabolic and inflammatory mechanisms may have a role to play in knee OA.

Evaluation of T1-Weighted MRI to Detect Intratumoral Hemorrhage Within Papillary Renal Cell Carcinoma as a Feature Differentiating From Angiomyolipoma Without Visible Fat.

The objective of the present study is to determine whether hemorrhage within papillary renal cell carcinoma (RCC) can be detected using T1-weighted MRI and to ascertain whether it can be used to differentiate papillary RCC from angiomyolipoma (AML) without visible fat. A retrospective case-control study compared 11 AMLs without visible fat with 58 papillary RCCs smaller than 5 cm that were evaluated using MRI between 2003 and 2015. Two blinded radiologists subjectively evaluated MR images to identify the presence of intratumoral hemorrhage on the basis of a decrease in signal intensity (SI) on in-phase, compared with opposed-phase, chemical-shift MRI and also on the basis of the SI of the lesion compared with that of the renal cortex on fat-suppressed T1-weighted MRI. A third radiologist established consensus and measured the ratio of the SI of the lesion to that of the renal cortex (hereafter referred to as the "SI ratio") on T2-weighted MRI; the SI loss index, as calculated using the equation [(SItumorIP - SItumorOP) / SItumorOP] × 100, where IP denotes the in-phase image and OP denotes the opposed-phase image; and the SI ratio on fat-suppressed T1-weighted MRI. Analyses were performed using tests of association and ROCs. When AMLs without visible fat were compared with papillary RCCs, no statistically significant difference in the T2-weighted SI ratio was noted (p = 0.08). Papillary RCCs had a lower mean (± SD) SI loss index (-3.7% ± 17.3%; range, -51.3% to 31.3%) than did AMLs without visible fat (37.8% ± 76.1%; range, -15.6% to 184.4%) (p < 0.001). A mean SI loss index of less than -16% resulted in an AUC of 0.71 (95% CI, 0.52-0.91), with a sensitivity and specificity of 22.8% and 100%, respectively, for the diagnosis of papillary RCC. After consensus review, none of the AMLs without visible fat and 16 of the 58 papillary RCCs (27.6%) were found to have a decrease in SI on subjective analysis (p = 0.06, κ = 0.60). Between groups, no differences were noted in the SI ratio on fat-suppressed T1-weighted MRI (p = 0.58) or in the SI observed on subjective analysis of fat-suppressed T1-weighted MRI (p = 0.20, κ = 0.48). The presence of intratumoral hemorrhage within papillary RCC is a specific feature that differentiates papillary RCCs from AMLs without visible fat. Subjective analysis may be more clinically appropriate than chemical-shift MRI because of limitations in the quantitative measurement of T2* signal with the use of chemical-shift MRI.

Evaluation of Adhesive Capsulitis of the Shoulder With Fat-Suppressed T2-Weighted MRI: Association Between Clinical Features and MRI Findings.

The purpose of this study was to examine the association between clinical features and MRI findings in adhesive capsulitis of the shoulder. This study included 103 patients (41 men, 62 women) with adhesive capsulitis. The MRI findings were correlated with pain intensity, range of motion, and clinical stage. Joint capsule edema in the axillary recess, extracapsular edema, obliteration of the subcoracoid fat triangle, and effusion in the long head biceps tendon sheath were assessed by two radiologists using fat-suppressed T2-weighted images. Joint capsule thickness in the axillary recess and degree of external rotation during MRI were also measured. Intraclass correlation coefficient and kappa values were obtained. Associations between MRI findings and clinical features were assessed by statistical analyses. Anterior extracapsular edema was associated with range of motion on external rotation and abduction (p < 0.01). Joint capsule edema in the humeral portion of the axillary recess was associated with range of motion on external rotation (p = 0.01). Joint capsule thickness in the humeral portion of the axillary recess and height of the axillary recess were associated with pain intensity (p < 0.05). Joint capsule edema in the humeral portion of the axillary recess and obliteration of the subcoracoid fat triangle were significantly more common in the early stages of adhesive capsulitis (p < 0.05). Joint capsule thickness in the humeral portion of the axillary recess at stage 1 (4.67 ± 1.73 mm) was significantly different from the thickness at the later stages (stage 2, 3.73 ± 1.49 mm; stages 3 and 4, 3.67 ± 1.44 mm) (p < 0.05). MRI is useful for assessing clinical impairment and predicting the clinical stage of adhesive capsulitis.

Quantitative MRI reveals decelerated fatty infiltration in muscles of active FSHD patients

To investigate the effects of aerobic exercise training (AET) and cognitive-behavioral therapy (CBT), directed towards an increase in daily physical activity, on the progression of fatty infiltration and edema in skeletal muscles of patients with facioscapulohumeral muscular dystrophy (FSHD) type 1 by T2 MRI. Quantitative T2 MRI (qT2 MRI) and fat-suppressed T2 MRI of the thigh were performed at 3T on 31 patients, 13 of whom received usual care (UC), 9 AET, and 9 CBT. Muscle-specific fat fractions (%), derived from qT2 MRI, were recorded pretreatment and posttreatment. Intervention effects were analyzed by comparing fat fraction progression rates of the UC with the treated groups using Mann-Whitney tests, and intermuscle differences by a linear mixed model. Edematous hyperintense lesions were identified on the fat-suppressed T2 MRI. The intraclass correlation coefficient for reproducibility of qT2 MRI fat assessment was 0.99. In the UC group, the fat fraction increased by 6.7/year (95% confidence interval [CI] 4.3 to 9.1). This rate decreased to 2.9/year (95% CI 0.7 to 5.2) in the AET (p = 0.03) and 1.7/year (95% CI -0.2 to 3.6) in the CBT group (p = 0.00015). The treatment effect differed among individual muscles. Fewer new edematous lesions occurred after therapy. Fat fraction derived from qT2 MRI is a reproducible and sensitive biomarker to monitor the effects of increased physical activity in individual muscles. This biomarker reports a favorable effect of AET and CBT on the rate of muscular deterioration in FSHD as reflected in decelerated fat replacement. This study provides Class II evidence that for patients with FSHD type 1, both AET and CBT decrease the rate of fatty infiltration in muscles.

The relation of patellofemoral joint alignment and trochlear morphology to superolateral Hoffa’s fat pad edema: the most study

Purpose: The infrapatellar or Hoffa’s fat pad (HFP) is an intracapsular but extrasynovial fat tissue in the knee joint located inferior to the patella and posterior to the patellar tendon. It is highly innervated and may be a source of knee pain. Impingement of HFP between the lateral femoral condyle and the patellar tendon is hypothesized to cause inflammation/edema in the superolateral region of HFP. This impingement may be a result of patellofemoral joint (PFJ) alignment and abnormal trochlear morphology. Previous studies in young individuals have demonstrated conflicting results as to which measures of PFJ alignment and trochlear morphology are related to superolateral HFP edema. More generalized inflammation/edema in HFP is present in older individuals with knee osteoarthritis (OA). The aim of the current study was to assess whether measures of PFJ alignment and trochlear morphology are related to superolateral HFP edema and if superolateral HFP edema is related to knee pain in older individuals with or at risk for knee OA. Methods: The Multicenter Osteoarthritis (MOST) study is a NIH-funded longitudinal cohort study of older individuals with or at risk for knee OA. For the current cross-sectional study we used data from the 60-month study visit where all eligible subjects had their knee MRI assessed for other structural features of knee OA. Signal changes in three areas (superolateral, infrapatellar and intercondylar) of HFP were assessed on sagittal proton density-weighted fat-suppressed MRI images from 0 to 3 (0 = normal, 1 = mild, 2 = moderate, 3 = severe) by two musculoskeletal radiologists and dichotomized into presence (>1) and absence (=0). PFJ alignment (bisect offset and patellar tilt angle) and trochlear morphology (lateral trochlear inclination, sulcus angle and trochlear angle) were assessed on axial MRI images and divided into quintiles. Subjects were also queried about the presence of frequent knee pain (FKP) defined as pain on most days of the last month. We determined the relation of measures of PFJ alignment and trochlear morphology to the presence of superolateral HFP edema using logistic regression, adjusting for age, sex and body mass index. We additionally determined the relation of superolateral HFD edema to FKP using logistic regression, adjusting for age, sex, body mass index, depressive symptoms, catastrophizing and presence of signal changes in the infrapatellar/intercondylar HFP. Results: To date, 433 knees have been assessed for PFJ alignment, trochlear morphology and superolateral HFP edema. Superolateral HFP edema was present in 63 (17.7%) of knees. Compared with knees in the lowest quartile of bisect offset, those in the highest had 6.4 (2.6, 15.7) times the odds of having superolateral HFP edema. Compared with knees in the lowest quartile of trochlear angle, those in the highest had 2.7 (1.2, 6.3) times the odds of having superolateral HFP edema. There was no relation of other PFJ alignment/trochlear morphology measures to superolateral HFP edema. There was also no relation of superolateral HFP edema to FKP. Conclusions: Knees with the greatest lateral displacement of the patella had the greatest odds of superolateral HFP edema. Treatments that attempt to normalize PFJ alignment may help to reduce the prevalence of superolateral HFP edema.Tabled 1Table. Relation of PFJ alignment and trochlear morphology to superolateral HFP edema% Patella lateral to midline (Bisect Offset)Quartile 1Quartile 2Quartile 3Quartile 4Range33.91–52.5952.6–58.1658.17–64.664.61–92.79# of knees108109109108Superolateral HFP edema%≥16.511.113.828.7Adjusted OR* (95% CI)1.0 (reference)1.9 (0.70, 5.0)2.5 (0.95, 6.4)6.4 (2.6, 15.7)Trochlear Morpholgy (Trochlear Angle)Quartile 1Quartile 2Quartile 3Quartile 4 (flat trochlea)Range−5.32–0.940.95–3.553.56–5.835.84–26.57# of knees108109109108Superolateral HFP edema%≥18.313.814.724.3Adjusted OR* (95% CI)1.0 (reference)1.6 (0.65, 3.8)1.6 (0.67, 3.9)2.7 (1.2, 6.3)∗Adjusted for age, sex and BMI Open table in a new tab ∗Adjusted for age, sex and BMI

Evaluation of lesser metatarsophalangeal joint plantar plate tears with contrast-enhanced and fat-suppressed MRI.

To present findings of plantar plate (PP) lesions from MRI with administration of gadolinium and to differentiate PP lesions from others causes of metatarsalgia. Two musculoskeletal radiologists reviewed 249 contrast-enhanced forefoot MRI scans from patients with metatarsalgia between June 2012 and June 2013. Evaluations focused on hyper-vascularized/fibrous tissue and other findings associated with PP tears. Fifty-nine patients had PP tears, 59 % were female. Most of these patients, 48/59 (81.4 %), had a single metatarsophalangeal (MTP) PP lesion in one foot, although 7/59 patients had one lesion in each foot, 3/59 (5.1 %) had two in one foot, and 1/59 (1.7 %) had three lesions in one foot. The second MTP joint was the most common location for PP tears (n = 56), followed by the third (n = 12) and fourth (n = 3) MTP joints. Lateral (n = 33) and full thickness (n = 28) PP lesions were the most frequent, and central (n = 3) and lateral/central (n = 7) tears were less prevalent. Fifty (70.5 %) PP lesions showed pericapsular fibrosis in pre-contrast sequences, and 21 (29.5 %) were visible only after administration of gadolinium. All PP lesions had collateral ligament involvement. Others findings included interosseous tendon lesions (n = 29), interosseous tendon rupture (n = 29), synovitis (n = 49), flexor tenosynovitis (n = 28), crossover toe (n = 2), hammertoe (n = 1), intermetatarsal space (IS) neuromas (n = 11), and third IS neuromas (n = 12). PP tears are a common cause of metatarsalgia, accounting for more than 20 % of cases in our sample. A substantial portion of the lesions (29.5 %) became visible only after the administration of gadolinium.

Change in knee structure and change in tibiofemoral joint space width: a five year longitudinal population–based study

BackgroundChange in knee cartilage volume is frequently used as a proxy for change in knee joint space width over time, but longitudinal data on these associations is limited. We aimed to determine whether change in knee cartilage volume, new or worsening meniscal extrusion (ME), meniscal tears and cartilage defects over 2.4 years correlated with change in joint space width (JSW) over 5 years in older community dwelling adults.MethodsParticipants (n = 153) had their right knee imaged using MR imaging and x-ray at baseline, and after 2.4 years (MRI) and 5 years (x-ray). Cartilage volume, cartilage defects, meniscal extrusions and meniscal tears were assessed on sagittal T1-weighted fat-suppressed MRI. JSW was assessed using standard fixed semi-flexed view radiographs, and scored on those with adequate alignment.ResultsParticipants were 51–79 (mean 62) years old; 48 % were female. Cartilage volume reduced over time (medial −134 ± 202 μL/year, lateral −106 ± 165 μL/year, p < 0.001), as did JSW (medial −0.05 ± 0.16 mm/year, lateral −0.12 ± 0.24 mm/year, p < 0.001). In multivariable analysis, the only consistent predictor of change in JSW was new or worsening ME (medial tibia R2 3.1 %, p = 0.031; medial femur R2 3.2 %, p = 0.024); change in cartilage volume correlated with change in JSW laterally (R2 4.8 %, p = 0.007) and was borderline medially (R2 2.2 %, p = 0.064); there was no association for meniscal tears or cartilage defects. The magnitude of these associations were similar albeit somewhat greater for ME in participants with radiographic OA (R2 6.2 %, p = 0.017).ConclusionChange in ME and cartilage volume weakly predict change in JSW, but the vast majority of the variation remains unexplained. Since MRI examines cartilage directly while radiographs examine it indirectly, these results cast doubt on the validity of using JSW as a proxy measure of cartilage loss.

Utility of unenhanced fat-suppressed T1-weighted MRI in children with sickle cell disease -- can it differentiate bone infarcts from acute osteomyelitis?

Children with sickle cell disease (SCD) are at risk of bone infarcts and acute osteomyelitis. The clinical differentiation between a bone infarct and acute osteomyelitis is a diagnostic challenge. Unenhanced T1-W fat-saturated MR images have been proposed as a potential tool to differentiate bone infarcts from osteomyelitis. To evaluate the reliability of unenhanced T1-W fat-saturated MRI for differentiation between bone infarcts and acute osteomyelitis in children with SCD. We retrospectively reviewed the records of 31 children (20 boys, 11 girls; mean age 10.6 years, range 1.1-17.9 years) with SCD and acute bone pain who underwent MR imaging including unenhanced T1-W fat-saturated images from 2005 to 2010. Complete clinical charts were reviewed by a pediatric hematologist with training in infectious diseases to determine a clinical standard to define the presence or absence of osteomyelitis. A pediatric radiologist reviewed all MR imaging and was blinded to clinical information. Based on the signal intensity in T1-W fat-saturated images, the children were further classified as positive for osteomyelitis (low bone marrow signal intensity) or positive for bone infarct (high bone marrow signal intensity). Based on the clinical standard, 5 children were classified as positive for osteomyelitis and 26 children as positive for bone infarct (negative for osteomyelitis). The bone marrow signal intensity on T1-W fat-saturated imaging was not significant for the differentiation between bone infarct and osteomyelitis (P = 0.56). None of the additional evaluated imaging parameters on unenhanced MRI proved reliable in differentiating these diagnoses. The bone marrow signal intensity on unenhanced T1-W fat-saturated MR images is not a reliable criterion to differentiate bone infarcts from osteomyelitis in children.

Multiple Symmetric Lipomatosis Presenting with Bilateral Brachial Plexopathy.

Dear Editor, Multiple symmetric lipomatosis (MSL), also called Madelung's disease, is a rare disease characterized by the growth of nonencapsulated masses of adipose tissue.1 The disease causes not only cosmetic issues but also various clinical problems depending on the location and extent of the lesion,2 with neuromuscular manifestations such as polyneuropathy, myopathy, and ataxia having been reported.3 Herein we report on a case of bilateral brachial plexopathy caused by extensive lipoma associated with MSL. A 55-year-old man presented with progressive bilateral hand weakness. He first noticed a weak grip with his right hand 2 years before the presentation. The symptom progressed slowly, and his left hand also became weak a few months later. The patient often experienced paresthesia in both arms, but did not complain of proximal arm or leg weakness. He had been drinking about 200 mL of alcohol every day for 30 years. A physical examination revealed excessive soft tissues around his neck, shoulder, and forearm (Fig. 1A). His hand grip, finger abduction, wrist flexion/extension, and elbow extension were extremely weak (Medical Research Council scale grades from 1 to 3) on both sides with muscle atrophy in the first dorsal interossei, hypothenar, and pectoralis major muscles. Deep tendon reflexes were absent in both arms. A nerve conduction study revealed no potentials in the ulnar and radial motor nerves or the medial and lateral antebrachial cutaneous nerves of the left arm. Electromyography revealed positive sharp waves and fibrillation potentials in the first dorsal interosseous, abductor pollicis longus, and extensor carpi radialis of the left arm. Long-duration, high-amplitude motor unit action potentials (MUPs) were present in all muscles of the left arm with reduced recruitment of MUPs. Magnetic resonance images showed extensive fat proliferation and infiltration at the face, neck, shoulder, and axilla that resulted in compression of the brachial plexus (Fig. 1B). He was diagnosed with bilateral brachial plexopathy secondary to MSL, and was operated on to relieve the compression of the brachial plexus. After the surgery, the weaknesses in his hands were slightly improved. Fig. 1 A: Excessive fatty tissues around the neck and shoulder. B: Coronal fat-suppressed T2-weighted MRI reveals the brachial plexus (thick arrow) compressed by lipoma (thin arrow). The incidence of MSL is highest in Mediterranean countries, and it is uncommon in Asia (including Korea). A case-series study of Korean MSL patients found that most patients visited hospital because of a mass lesion and some of them were complicated with peripheral neuropathy.4 The etiology of the disease is not fully understood, but most patients included in previous studies have had a history of chronic excessive alcohol consumption.5 While the exact role of alcohol in the pathophysiology remains elusive, defects in adrenergic stimulated lipolysis or hypertrophy of the brown fat cells have been proposed as an alternative explanation for the pathomechanism.6 The differential diagnosis should include other forms of generalized lipomatosis such as Bannayan-Zonana syndrome, Cowden syndrome, Proteus syndrome, and Dercum disease.7 Familial multiple lipomatosis manifests as multiple encapsulated lipomas with autosomal dominant inheritance, but with relative sparing of the head and shoulders.8 Surgical excision is the treatment of choice. Liposuction can be applied alone9 or in combination with lipectomy.10

A longitudinal study of the association between infrapatellar fat pad maximal area and changes in knee symptoms and structure in older adults

BackgroundThe infrapatellar fat pad (IPFP) is of uncertain significance for knee osteoarthritis. The aim of this study was to describe the longitudinal associations between baseline IPFP maximal area and changes...

Bone-seeking superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic resonance imaging of bone turnover in early osteoarthritis

Bone-seeking superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic resonance imaging of bone turnover in early osteoarthritis

Characterization of early cartilage degeneration associated with anterior cruciate ligament injury using T1-rho mapping magnetic resonance imaging

Characterization of early cartilage degeneration associated with anterior cruciate ligament injury using T1-rho mapping magnetic resonance imaging

Magnetic Resonance Evaluation of Multiple Myeloma at 3.0 Tesla: How Do Bone Marrow Plasma Cell Percentage and Selection of Protocols Affect Lesion Conspicuity?

PurposeTo compare various pulse sequences in terms of percent contrast and contrast-to-noise ratio (CNR) for detection of focal multiple myeloma lesions and to assess the dependence of lesion conspicuity on the bone marrow plasma cell percent (BMPC%).Materials and MethodsSagittal T1-weighted FSE, fat-suppressed T2-weighted FSE (FS- T2 FSE), fast STIR and iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging of the lumbar spine were performed (n = 45). Bone marrow (BM)-focal myeloma lesion percent contrast and CNR were calculated. Spearman rank correlation coefficients were obtained between percent contrast, CNR and BMPC%. Percent contrasts and CNRs were compared among the three imaging sequences.ResultsBM-focal lesion percent contrasts, CNRs and BMPC% showed significant negative correlations in the three fat-suppression techniques. Percent contrast and CNRs were significantly higher for FS- T2 FSE than for STIR (P<0.01, P<0.05, respectively), but no significant differences were found among the three fat-suppression methods in the low tumor load BM group.ConclusionThe higher BMPC% was within BM, the less conspicuous the focal lesion was on fat-suppressed MRI. The most effective protocol for detecting focal lesions was FS- T2 FSE. In the high tumor load BM group, no significant differences in lesion conspicuity were identified among the three fat-suppression techniques.

Cross-sectional and longitudinal associations between circulating leptin and knee cartilage thickness in older adults

To investigate cross-sectional and longitudinal associations between serum leptin levels and knee cartilage thickness in older adults. A prospective cohort of 163 randomly selected subjects (mean 63 years, range 52-78, 46% women) was studied. Knee cartilage thickness at medial tibial, lateral tibial, femoral and patellar sites was determined using T1-weighted fat-suppressed MRI. Serum leptin levels were measured by radioimmunoassay. Radiographic osteoarthritis, body fat (%), trunk fat (%), weight and height were measured, and body mass index (BMI) was calculated. Cross-sectionally, serum levels of leptin were negatively associated with femoral (β: -0.013, 95% CI -0.022 to -0.003), medial tibial (β: -0.009, 95% CI -0.018 to -0.001), lateral tibial (β: -0.012, 95% CI -0.021 to -0.003) and patellar (β: -0.014, 95% CI -0.026 to -0.002) cartilage thickness after adjustment for covariates. Moreover, BMI, trunk fat and total body fat were negatively associated with cartilage thickness, and the significant associations disappeared after further adjustment for leptin. Longitudinally, both baseline leptin and change in leptin were associated with greater changes in medial tibial cartilage thickness (β: -0.004, 95% CI -0.007 to -0.001 and β: -0.009, 95% CI -0.018 to -0.001, respectively) in multivariable analyses. Serum levels of leptin are independently and consistently associated with reduced cartilage thickness cross-sectionally and longitudinally. In addition, the associations between adiposity measures and cartilage thickness are mediated by leptin, suggesting leptin may play a key role in cartilage thinning.

Cross-sectional and longitudinal associations between systemic, subchondral bone mineral density and knee cartilage thickness in older adults with or without radiographic osteoarthritis

ObjectivesTo investigate cross-sectional and longitudinal associations between systemic bone mineral density (BMD), subchondral BMD (sBMD) and knee cartilage thickness in older adults with or without radiographic osteoarthritis (ROA).MethodsA prospective cohort...

Breast MRI at 7 Tesla with a bilateral coil and T1-weighted acquisition with robust fat suppression: image evaluation and comparison with 3 Tesla

To evaluate the image quality of T1-weighted fat-suppressed breast MRI at 7 T and to compare 7-T and 3-T images. Seventeen subjects were imaged using a 7-T bilateral transmit-receive coil and 3D gradient echo sequence with adiabatic inversion-based fat suppression (FS). Images were graded on a five-point scale and quantitatively assessed through signal-to-noise ratio (SNR), fibroglandular/fat contrast and signal uniformity measurements. Image scores at 7 and 3 T were similar on standard-resolution images (1.1 × 1.1 × 1.1-1.6 mm(3)), indicating that high-quality breast imaging with clinical parameters can be performed at 7 T. The 7-T SNR advantage was underscored on 0.6-mm isotropic images, where image quality was significantly greater than at 3 T (4.2 versus 3.1, P ≤ 0.0001). Fibroglandular/fat contrast was more than two times higher at 7 T than at 3 T, owing to effective adiabatic inversion-based FS and the inherent 7-T signal advantage. Signal uniformity was comparable at 7 and 3 T (P < 0.05). Similar 7-T image quality was observed in all subjects, indicating robustness against anatomical variation. The 7-T bilateral transmit-receive coil and adiabatic inversion-based FS technique produce image quality that is as good as or better than at 3 T. • High image quality bilateral breast MRI is achievable with clinical parameters at 7 T. • 7-T high-resolution imaging improves delineation of subtle soft tissue structures. • Adiabatic-based fat suppression provides excellent fibroglandular/fat contrast at 7 T. • 7- and 3-T 3D T1-weighted gradient-echo images have similar signal uniformity. • The 7-T dual solenoid coil enables bilateral imaging without compromising uniformity.