Magnetic Resonance Exams Research Articles

Monitoring the progression of renal fibrosis by T2-weighted signal intensity and diffusion weighted magnetic resonance imaging in cisplatin induced rat models.

Background:Diffusion weighted imaging (DWI), with the applying of intravoxel incoherent motion model, has showed promising results in obtaining additional information about microperfusion and tubular flow associated with morphologic changes in chronic kidney diseases. The study aims to evaluate the potential of T2-weighted signal intensity (SI) and DWI with mono- and bi-exponential models to reflect the serial changes on cisplatin (CP) induced rat renal fibrosis models.Methods:Magnetic resonance exams were performed prior to and 2nd day, 4th day, 6th day, 8th day, 2nd week, 3rd week and 4th week after CP injection at a 3.0T with an animal coil. Besides T2-weighted images (T2WI), DWI of 13 b values from 0 to 1500 s/mm2 was acquired. Apparent diffusion coefficient (ADC), fluid fraction f, pure diffusivity D and pseudodiffusivity D* values were calculated. The regions of interest were placed on cortex (CO), outer stripe of the outer medulla (OM) and inner stripe of the outer medulla (OM), parameters were measured and compared among different time points. Five rats were scarified at each time point for pathological examination.Results:OM revealed remarkable hyperintense and broadened before it became an obscure thread, while CO demonstrated moderate hyperintense and IM didn’t show significant change on T2WI. On all three stripes, ADC values decreased firstly then kept increasing since the 4th day; f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn’t achieve statistical significance; D* values increased at the 2nd day then tended to be steady thereafter. Pathological findings revealed tubules epitheliums swelling followed by inflammation cells infiltration, interstitial fibrosis was observed since the 2nd week.Conclusions:All of T2-weighted SI, ADC, and biexponential models parameters vary during fibrotic process; biexponential model is superior to monoexponential model in separating changes of microperfusion together with tubular flow from pure diffusion.

Associations between native myocardial T1 and diastolic function evaluated by PC-CMR in patients with severe aortic valve stenosis

Background To assess the relationship between the presence of myocardial interstitial fibrosis as reflected by the increase in native T1 values and alterations in left ventricular (LV) diastolic function evaluated by phase contrast cardiac magnetic resonance (PC-CMR), in subjects with severe aortic valve stenosis (AVS). Methods We studied 20 subjects (71±10 years) with severe AVS including 19 with a preserved ejection fraction. All patients underwent transthoracic echocardiogram (TTE) and cardiac magnetic resonance (CMR) exams. CMR included conventional LV systolic function and delayed enhancement evaluations as well as a native T1 mapping acquisition using the modified Look-Locker inversion recovery sequence and velocity encoding data of the transmitral inflow for the evaluation of LV diastolic function. These latter CMR data were analyzed using custom software resulting in segmental T1 values and diastolic parameters such as transmitral peak velocities (E, A), peak flow rates (Ef, Af), filling volume (FV), and myocardial peak velocities. Results For all patients, TTE revealed the presence of severe AVS according to ESC criteria (aortic valve area indexed to BSA= 0.43±0.09 cm2/m2 and mean gradient 54 ±14mmHg). When compared to CMR data of 34 elderly controls (60±8 years) despite the preserved ejection fraction (patients=66±10%; controls=66±4%), diastolic parameters indicated an impaired LV relaxation in patients with severe AVS. Importantly, while dense fibrosis volume quantified from delayed enhancement images was not related to diastolic function parameters, a significant relation was found between native myocardial T1 values and parameters of LV filling such as: the ratio between the peak filling rate and the peak atrial rate EfMR/AfMR (r=0.51; p<0.05); the ratio between the peak atrial rate and the filling volume Af/FVMR (r=0.67; p<0.05); and the peak atrial rate Af (r=0.63; p<0.05). Conclusions Interstitial myocardial fibrosis assessed non-invasively by native T1 is related to the severity of diastolic dysfunction in subjects with severe AVS.

Usability of Magnetic Resonance Equipment

A product usability is related to the way it can be used by specific users to achieve its goals with effectiveness and satisfaction in a specific use context. This paper had as an objective to evaluate the usability in a magnetic resonance (MR) equipment in some health services in the city of Recife, Pernambuco, Brazil. This study was performed in the second semester of 2014 and their participants were radiology technicians that performed the magnetic resonance exam. The evaluation occurred in services where you can find machines of same size and label. There were performed field observations and semi-structured interviews, with the help of some instruments: interview script, field journey, camera for photographic and filming records and a recorder. The MR exam occurs in two rooms: in the 1st, where you can find the machine studied in this paper (magnet and patient table); and, in the 2nd room, the command, where there was the computer with the record software and computer for image treatment. The collected data were analyzed accordingly to the usability indicators. The usability of the equipment was evaluated much more positively than negatively by its users, with acknowledge of the improvements by the technological advances. Nevertheless, there were some difficulties observed and pointed. It was identified the possibility of solutions both in the organizational point of view, from the partnership with the radiologist doctor, logistic in the distribution of exams and capacitation contributing in the technicians decision making process; and redesign of some bobbin that presents weight excess and grip inadequacy.

Free-breathing myocardial T2* mapping using GRE-EPI and automatic non-rigid motion correction.

BackgroundMeasurement of myocardial T2* is becoming widely used in the assessment of patients at risk for cardiac iron overload. The conventional breath-hold, ECG-triggered, segmented, multi-echo gradient echo (MGRE) sequence used for myocardial T2* quantification is very sensitive to respiratory motion and may not be feasible in patients who are unable to breath-hold. We propose a free-breathing myocardial T2* mapping approach that combines a single-shot gradient-echo echo-planar imaging (GRE-EPI) sequence for T2*-weighted image acquisition with automatic non-rigid motion correction (MOCO) of respiratory motion between single-shot images.MethodsECG-triggered T2*-weighted images at different echo times were acquired by a black-blood, single-shot GRE-EPI sequence during free-breathing. A single image at a single TE is acquired in each heartbeat. Automatic non-rigid MOCO was applied to correct for in-plane respiratory motion before pixel-wise T2* mapping. In a total of 117 patients referred for clinical cardiac magnetic resonance exams, the free-breathing MOCO GRE-EPI sequence was compared to the breath-hold segmented MGRE approach. Image quality was scored independently by 2 experienced observers blinded to the particular image acquisition strategy. T2* measurements in the interventricular septum and in the liver were compared for the two methods in all cases with adequate image quality.ResultsT2* maps were acquired in all 117 patients using the breath-hold MGRE and the free-breathing MOCO GRE-EPI approaches, including 8 patients with myocardial iron overload and 25 patients with hepatic iron overload. The mean image quality of the free-breathing MOCO GRE-EPI images was scored significantly higher than that of the breath-hold MGRE images by both reviewers. Out of the 117 studies, 21 breath-hold MGRE studies (17.9 % of all the patients) were scored to be less than adequate or very poor by both reviewers, while only 2 free-breathing MOCO GRE-EPI studies were scored to be less than adequate image quality. In a comparative evaluation of the images with at least adequate quality, the intra-class correlation coefficients for myocardial and liver T2* were 0.868 and 0.986 respectively (p < 0.001), indicating that the T2* measured by breath-hold MGRE and free-breathing MOCO GRE-EPI were in close agreement. The coefficient of variation between the breath-hold and free-breathing approaches for myocardial and liver T2* were 9.88 % and 9.38 % respectively. Bland-Altman plots demonstrated good absolute agreement of T2* in the interventricular septum and the liver from the free-breathing and breath-hold approaches (mean differences -0.03 and 0.16 ms, respectively).ConclusionThe free-breathing approach described for T2* mapping using MOCO GRE-EPI enables accurate myocardial and liver T2* measurements and is insensitive to respiratory motion.

Validation of quantitative magnetic resonance imaging-based apparent bone volume fraction in peri-articular tibial bone of cadaveric knees.

BackgroundIn the knee, high-resolution magnetic resonance (MR) imaging has demonstrated that increased apparent bone volume fraction (trabecular bone volume per total volume; BV/TV) in the peri-articular proximal medial tibia is associated with joint space narrowing and the presence of bone marrow lesions. However, despite evidence of construct validity, MR-based apparent BV/TV has not yet been cross-validated in the proximal medial tibia by comparison with a gold standard (e.g., micro-computed tomography [microCT]). In this cadaveric validation study we explored the association between MR-based apparent BV/TV and microCT-based BV/TV in the proximal peri-articular medial tibia.MethodsFresh cadaveric whole knee specimens were obtained from individuals 51 to 80 years of age with no knee pathology other than osteoarthritis. Ten knees were collected from five cadavers within 10 hours of death and underwent a 3-Tesla MR exam including a coronal-oblique 3-dimensional fast imaging with steady state precession (3D FISP) sequence within 36 hours of death. The specimens were placed in a 4% paraformaldehyde in phosphate buffer within 58 hours of death. After preservation, a subchondral region from the tibial plateau was collected and underwent microCT imaging with a voxel size of 9 μm x 9 μm x 9 μm. A single reader analyzed the microCT images in a similar volume of interest as selected in the MR measures. A different reader analyzed the MR-based trabecular morphometry using a custom analysis tool. To analyze the MR-based trabecular morphometry, a rectangular region of interest (ROI) was positioned on the 20 central images in the proximal medial tibial subchondral bone. The primary outcome measures were MR-based and microCT-based trabecular BV/TV in the proximal medial tibia.ResultsThe MR-based apparent BV/TV was strongly correlated with microCT-based BV/TV (r = 0.83, confidence interval = 0.42 to 0.96), despite the MR-based apparent BV/TV being systematically lower than measured using microCT.ConclusionsMR-based apparent BV/TV in the proximal peri-articular medial tibia has good construct validity and may represent an alternative for CT-based BV/TV.

MR elastography following focused ultrasound treatment of uterine fibroids

Background Magnetic Resonance Elastography (MRE) is a technique in which shear waves are induced in soft tissues and are imaged by Magnetic Resonance (MR) is to assess tissue stiffness. While gadolinium has served as the standard for assessing immediate post treatment changes in the fibroids, some patients may have allergies to gadolinium preventing use of this contrast agent. Additionally, some patients may experience transient reduction in vascularity to non-treated fibroid tissue due to vessel spasm or other factors, which could possibly lead to overestimation of the treated volume. As of now, no studies have been performed to assess the mechanical changes associated with thermal damage to fibroid tissues induced by the MRguided focused ultrasound (MRgFUS) treatment. The purpose of this feasibility study was to evaluate whether shear waves can be propagated through the uterus and distinguish fibroids from normal uterine tissue and to evaluate for any post changes in follow up MR exams.

ANALYSIS OF REPORTS OF BRAIN MAGNETIC RESONANCE IMAGING EXAMS OF PATIENTS WITH MULTIPLE SCLEROSIS OF THE INSTITUTO DE NEUROLOGIA DE GOIÂNIA

Multiple sclerosis is the most common of the demyelinating diseases of the central nervous system and is characterized by its nonspecific clinical aspects which makes the diagnosis difficult. The magnetic resonance is a highly sensitive method for detection of typical lesions of multiple sclerosis, for this reason the aim of this study was to evaluate retrospectively the reports of brain magnetic resonance exams of patients attended at the resonance service of the Instituto de Neurologia de Goiânia, in order to determine the incidence of positive cases for multiple sclerosis, and trace the epidemiological and socioeconomic profile of these patients. From the data analyzed, it was found that the incidence of diagnosis of multiple sclerosis was quite relevant in our sample, because not long ago the disease was considered rare in Brazil. There was a predominance in females and caucasians and the mean age observed among the patients of the study was 35.2 years. The socioeconomic conditions of patients analyzed in general are good. It is hoped that this study could contribute to a better understanding of the epidemiological characteristics of brazilian patients with multiple sclerosis, and also mobilize entities able to offer free magnetic resonance exams for the entire population.

The Role of 3 Tesla Diffusion-Weighted Imaging in the Differential Diagnosis of Benign versus Malignant Cervical Lymph Nodes in Patients with Head and Neck Squamous Cell Carcinoma

Objective. The aim of this study was to validate the role of diffusion-weighted imaging (DWI) at 3 Tesla in the differential diagnosis between benign and malignant laterocervical lymph nodes in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods. Before undergoing surgery, 80 patients, with biopsy proven HNSCC, underwent a magnetic resonance exam. Sensitivity (Se) and specificity (Spe) of conventional criteria and DWI in detecting laterocervical lymph node metastases were calculated. Histological results from neck dissection were used as standard of reference. Results. In the 239 histologically proven metastatic lymphadenopathies, the mean apparent diffusion coefficient (ADC) value was 0.903 × 10−3 mm2/sec. In the 412 pathologically confirmed benign lymph nodes, an average ADC value of 1.650 × 10−3 mm2/sec was found. For differentiating between benign versus metastatic lymph nodes, DWI showed Se of 97% and Spe of 93%, whereas morphological criteria displayed Se of 61% and Spe of 98%. DWI showed an area under the ROC curve (AUC) of 0.964, while morphological criteria displayed an AUC of 0.715. Conclusions. In a DWI negative neck for malignant lymph nodes, the planned dissection could be converted to a wait-and-scan policy, whereas DWI positive neck would support the decision to perform a neck dissection.

Reproducibility of small animal cine and scar cardiac magnetic resonance imaging using a clinical 3.0 tesla system

BackgroundTo evaluate the inter-study, inter-reader and intra-reader reproducibility of cardiac cine and scar imaging in rats using a clinical 3.0 Tesla magnetic resonance (MR) system.MethodsThirty-three adult rats (Sprague–Dawley) were imaged 24 hours after surgical occlusion of the left anterior descending coronary artery using a 3.0 Tesla clinical MR scanner (Philips Healthcare, Best, The Netherlands) equipped with a dedicated 70 mm solenoid receive-only coil. Left-ventricular (LV) volumes, mass, ejection fraction and amount of myocardial scar tissue were measured. Intra-and inter-observer reproducibility was assessed in all animals. In addition, repeat MR exams were performed in 6 randomly chosen rats within 24 hours to assess inter-study reproducibility.ResultsThe MR imaging protocol was successfully completed in 32 (97%) animals. Bland-Altman analysis demonstrated high intra-reader reproducibility (mean bias%: LV end-diastolic volume (LVEDV), -1.7%; LV end-systolic volume (LVESV), -2.2%; LV ejection fraction (LVEF), 1.0%; LV mass, -2.7%; and scar mass, -1.2%) and high inter-reader reproducibility (mean bias%: LVEDV, 3.3%; LVESV, 6.2%; LVEF, -4.8%; LV mass, -1.9%; and scar mass, -1.8%). In addition, a high inter-study reproducibility was found (mean bias%: LVEDV, 0.1%; LVESV, -1.8%; LVEF, 1.0%; LV mass, -4.6%; and scar mass, -6.2%).ConclusionsCardiac MR imaging of rats yielded highly reproducible measurements of cardiac volumes/function and myocardial infarct size on a clinical 3.0 Tesla MR scanner system. Consequently, more widely available high field clinical MR scanners can be employed for small animal imaging of the heart e.g. when aiming at serial assessments during therapeutic intervention studies.

An Electronic Safety Screening Process during Inpatient Computerized Physician Order Entry Improves the Efficiency of Magnetic Resonance Imaging Exams

Delays between order and magnetic resonance (MR) exam often result when using the conventional paper-based MR safety screening process. The impact of an electronic MR safety screening process imbedded in a computerized physician order entry (CPOE) system was evaluated. Retrospective chart review of 4 months of inpatient MR exam orders and reports was performed before and after implementation of electronic MR safety documentation. Time from order to MR exam completion, time from MR exam completion to final radiology report, and time from first order to final report were analyzed by exam anatomy. Length of stay (LOS) and date of service within the admission were also analyzed. We evaluated 1947 individual MR orders in 1549 patients under an institutional review board exemption and a waiver of informed consent. Implementation of the electronic safety screening process resulted in a significant decrease of 1.1 hours (95% confidence interval 1.0-1.3 hours) in the mean time between first order to final report and a nonsignificant decrease of 0.8 hour in the median time from first order to exam end. There was a 1-day reduction (P = .697) in the time from admission to the MR exam compared to the paper process. No significant change in LOS was found except in neurological intensive care patients imaged within the first 24 hours of their admission, where a mean 0.9-day decrease was found. Benefits of an electronic process for MR safety screening include enabling inpatients to have decreased time to MR exams, thus enabling earlier diagnosis and treatment and reduced LOS.

Cardiac complications and diabetes in thalassaemia major: a large historical multicentre study

The relationship between diabetes mellitus (DM) and cardiac complications has never been systematically studied in thalassaemia major (TM). We evaluated a large retrospective historical cohort of TM to determine whether DM is associated with a higher risk of heart complications. We compared 86 TM patients affected by DM with 709 TM patients without DM consecutively included in the Myocardial Iron Overload in Thalassaemia database where clinical/instrumental data are recorded from birth to the first cardiovascular magnetic resonance (CMR) exam. All of the cardiac events considered were developed after the DM diagnosis. In DM patients versus non-DM patients we found a significantly higher frequency of cardiac complications (46.5% vs. 16.9%, P < 0.0001), heart failure (HF) (30.2% vs. 11.7%, P < 0.0001), hyperkinetic arrhythmias (18.6% vs. 5.5%, P < 0.0001) and myocardial fibrosis assessed by late gadolinium enhancement (29.9% vs. 18.4%, P = 0.008). TM patients with DM had a significantly higher risk of cardiac complications [odds ratio (OR) 2.84, P < 0.0001], HF (OR 2.32, P = 0.003), hyperkinetic arrhythmias (OR 2.21, P = 0.023) and myocardial fibrosis (OR 1.91, P = 0.021), also adjusting for the absence of myocardial iron overload assessed by T2* CMR and for the covariates (age and/or endocrine co-morbidity). In conclusion, DM significantly increases the risk for cardiac complications, HF, hyperkinetic arrhythmias and myocardial fibrosis in TM patients.

Mean platelet volume is associated with infarct size and microvascular obstruction estimated by cardiac magnetic resonance in ST segment elevation myocardial infarction

Introduction: Mean platelet volume (MPV) is an indicator of platelet activation. High MPV has been recently considered as an independent risk factor for poor outcomes after ST-segment elevation myocardial infarction (STEMI). Methods: We analyzed 128 patients diagnosed with first STEMI successfully reperfused during three consecutive years. MPV was measured on admission and a cardiac magnetic resonance (CMR) exam was performed within the first week in all patients. Myocardial necrosis size was estimated by the area of late gadolinium enhancement (LGE), identifying microvascular obstruction (MVO) if present. Clinical outcomes were recorded at one year follow-up. High MPV was defined as a value in the third tertile (≥ 9.5 fL), and a low MPV, as a value in the lower two. Results: We found a slight but significant correlation between MPV and infarct size (r=0.287, p=0.008). Patients with high MPV had more extensive infarcted area (percentage of necrosis by LGE: 17.6 vs 12.5%, p=0.021) and more presence of MVO (patients with MVO pattern: 44.4 vs 25.3%, p=0.027). In a multivariable analysis, HR for MACE was 3.35 (95% CI 1.1-9.9, p 0.03) in patients with high MPV (Table). View this table: Multivariable Cox analysis for MACE Conclusions: High MPV in patients with first STEMI is associated with higher infarct size and more presence of MVO measured by CMR.

Contrast-enhanced three-dimensional MR imaging using T 1-weighted high-resolution isotropic volume examination (THRIVE): Focus on endometrial cancer

The present study sought to provide optimized radiographic information regarding endometrial cancer by comparing dynamic contrast-enhanced images obtained using the 3-dimensional T1-weighted high-resolution isotropic volume examination (3D-THRIVE) technique to existing 2-dimensional magnetic resonance (MR) images to provide data regarding the radiological advantages and the technical aspects of 3D-THRIVE. This study included 30 patients with suspected endometrial cancer who were referred for an MR exam for disease characterization and staging. A 3.0T MR scanner was used to obtain 2D turbo spin echo (2D-TSE) images prior to injection of the contrast medium. After the injection, 3D-THRIVE images and 2D spectral pre-saturation inversion recovery (2D-SPIR) images were obtained. The imaging methods were quantitatively compared using the signal-to-noise ratios (SNRs) of the uterus and the endometrial cancer, the contrast-to-noise ratio (CNR) between tissue pairs, and the time-intensity curve. Comparative qualitative analyses were also conducted using an MR image evaluation tool. Comparison of the pre- and post-contrast enhancement images showed that the SNRs measured from the uterus and the endometrial cancer (SNRuterus and SN Rec) were relatively higher and more optimized for the contrast-enhanced 3D-THRIVE and 2D-SPIR images than they were for the pre-contrast 2D-TSE images (p 0.05). The time-intensity curve was obtained with the 3D-THRIVE sequence and provided data that enabled a differentiation between malignant tumors and normal tissue. The overall image quality, artifacts, and lesion definition and representation were superior for contrast-enhanced 3D-THRIVE images compared to pre- and post-contrast enhancement of 2D-TSE and 2D-SPIR images (p < 0.05). In conclusion, 3D-THRIVE images had better image quality than 2D-TSE and SPIR images. In addition to 3D-THRIVE being an alternative to 2D-TSE and SPIR in terms of endometrial cancer characterization and staging, it also provides superior data for the differentiation between malignant tumors and normal tissue.

Mean platelet volume is associated with infarct size and microvascular obstruction estimated by cardiac magnetic resonance in ST segment elevation myocardial infarction

Mean platelet volume (MPV) is an indicator of platelet activation. High MPV has been recently considered as an independent risk factor for poor outcomes after ST-segment elevation myocardial infarction (STEMI). We analyzed 128 patients diagnosed with first STEMI successfully reperfused during three consecutive years. MPV was measured on admission and a cardiac magnetic resonance (CMR) exam was performed within the first week in all patients. Myocardial necrosis size was estimated by the area of late gadolinium enhancement (LGE), identifying microvascular obstruction (MVO), if present. Clinical outcomes were recorded at 1 year follow-up. High MPV was defined as a value in the third tertile (≥9.5 fl), and a low MPV, as a value in the lower two. We found a slight but significant correlation between MPV and infarct size (r = 0.287, P = 0.008). Patients with high MPV had more extensive infarcted area (percentage of necrosis by LGE: 17.6 vs. 12.5%, P = 0.021) and more presence of MVO (patients with MVO pattern: 44.4 vs. 25.3%, P = 0.027). In a multivariable analysis, hazard ratio for major adverse cardiac events was 3.35 [95% confidence interval (CI) 1.1-9.9, P = 0.03] in patients with high MPV. High MPV in patients with first STEMI is associated with higher infarct size and more presence of MVO measured by CMR.

Radiofrequency (RF) coil impacts the value and reproducibility of cartilage spin–spin (T2) relaxation time measurements

T2 (spin-spin) relaxation time is frequently used for compositional assessment of articular cartilage. However little is known about the influence of magnetic resonance (MR) system components on these measurements. The reproducibility and range of cartilage T2 values were evaluated using different extremity radiofrequency (RF) coils with potential differences in flip angle uniformity and signal-to-noise ratio (SNR). Ten knees underwent 3T MR exams using RF coils with different SNR: quadrature transmit/receive (QTR); quadrature transmit/eight-channel phased-array receive (QT8PAR). Each knee was scanned twice per coil (four exams total). T2 values were calculated for the central medial and lateral femoral (cMF, cLF) and medial and lateral tibial (MT, LT) cartilage. The flip angle varied across a central 40mm diameter region-of-interest of each coil by <1.5%. However SNR was significantly higher using QT8PAR than QTR (P<0.001). T2 values for cMF (50.7msec/45.9msec) and MT (48.2msec/41.6msec) were significantly longer with QT8PAR than QTR (P<0.05). T2reproducibility was improved using QT8PAR for cMF and cLF (4.8%/5.8% and 4.1%/6.5%; P<0.001), similar for LT (3.8%/3.6%; P=1.0), and worse for MT (3.7%/3.3%; P<0.001). T2 varied spatially, with cLF having the longest (52.0msec) and the LT having the shortest (40.6msec) values. All deep cartilage had significantly longer, and less variable, T2 values using QT8PAR (higher SNR; P<0.03). SNR varied spatially (significant) depending upon coil, but refocusing flip angle only slightly. With higher SNR, significantly longer T2 values were measured for deep (all plates) and global (MT, cMF) cartilage. T2 values varied by depth and plate, in agreement with prior studies.

Serial MR Findings and Comprehensive Review of Bilateral Lupus Mastitis with an Additional Case Report

Lupus Mastitis (LM) is a rare presentation of lupus panniculitis involving the breast. Because it often presents as a tender palpable mass, a workup for malignancy usually ensues. It is well documented that surgery may worsen the condition; therefore, it is important to consider LM in the differential of a palpable breast mass in patients with systemic lupus erythematosus (SLE). Currently, management of LM remains primarily medical. We discuss the multi-disciplinary work-up of LM, and further describe its appearance on serial Magnetic Resonance (MR) exams.

Correlation Between Trochlear Groove Depth and Patellar Position During Open and Closed Kinetic Chain Exercises in Subjects With Anterior Knee Pain

The purpose of this study was to correlate the trochlear shape and patellar tilt angle and lateral patellar displacement at rest and maximal voluntary isometric contraction (MVIC) exercises during open (OKC) and closed kinetic chain (CKC) in subjects with and without anterior knee pain. Subjects were all women, 20 who were clinically healthy and 19 diagnosed with anterior knee pain. All subjects were evaluated and subjected to magnetic resonance exams during OKC and CKC exercise with the knee placed at 15, 30, and 45 degrees of flexion. The parameters evaluated were sulcus angle, patellar tilt angle and patellar displacement using bisect offset. Pearson's r coefficient was used, with p < .05. Our results revealed in knee pain group during CKC and OKC at 15 degrees that the increase in the sulcus angle is associated with a tilt increase and patellar lateral displacement. Comparing sulcus angle, patellar tilt angle and bisect offset values between MVIC in OKC and CKC in the knee pain group, it was observed that patellar tilt angle increased in OKC only with the knee flexed at 30 degrees. Based on our results, we conclude that reduced trochlear depth is correlated with increased lateral patellar tilt and displacement during OKC and CKC at 15 degrees of flexion in people with anterior knee pain. By contrast, 30 degrees of knee flexion in CKC is more recommended in rehabilitation protocols because the patella was more stable than in other positions.

Automated Motion Estimation for 2-D Cine DENSE MRI

Cine displacement encoding with stimulated echoes (DENSE) is a magnetic resonance (MR) method that directly encodes tissue displacement into MR phase images. This technique has successfully interrogated many forms of tissue motion, but is most commonly used to evaluate cardiac mechanics. Currently, motion analysis from cine DENSE images requires manually delineated anatomical structures. An automated analysis would improve measurement throughput, simplify data interpretation, and potentially access important physiological information during the MR exam. In this paper, we present the first fully automated solution for the estimation of tissue motion and strain from 2-D cine DENSE data. Results using both simulated and human cardiac cine DENSE data indicate good agreement between the automated algorithm and the standard semi-manual analysis method.

025 Feasibility of combined cardiovascular MRI and percutaneous coronary intervention in a hybrid laboratory

BackgroundThe relationship between anatomy and associated pathophysiology in coronary artery disease (CAD) is complex and incompletely understood yet is important for patient management. This information cannot be comprehensively provided by...

Health consumption in Sami speaking municipalities and a control group with regard to medical imaging

Objectives: The Northern Norway Regional Health Authority trust aims to offer a high quality specialist health care to all inhabitants. The objective of this study was to document the consumption of medical imaging [conventional radiography (CR), computerised tomography (CT), magnetic resonance (MR), ultrasound (US)].Methods: The eight municipalities in northern Norway included in the administration area of the Sami language law (Sami group – 132,490 persons/year in the period 2003–2009, mean/year 19,363 inhabitants) were matched with a control group of 11 municipalities (non-Sami group – 135,539 persons/year, mean/year 18,927 inhabitants). Population data was accessed from Statistics Norway. Data on imaging exams were derived from a regional database including production data from all public and private institutions within the region. All four main modality groups (CR, CT, MR, US) were analysed. Variations for imaging frequency on each modality were compared between the Sami and non-Sami municipalities.Results: A total of 278,832 exams were performed during study period. The age adjusted exam rate (all modalities) was significantly higher (p < 0.001) in non-Sami (females and males) group. There was no difference with regard to conventional radiography (CR) (p = 0.855). Whereas MR (p < 0.001) imaging was more common in the Sami group, CT (p < 0.001) and US (p = 0.003) exams were more frequently used in the control group.Conclusion: People living in Sami speaking communities experienced significantly less CT and US exams, but had more MR exams than the control group. A relatively high physical activity, obesity and a lower risk of cancer may be explanations.