Anxiety during magnetic resonance imaging of the spine in relation to scanner design and size.

INTRODUCTION: Magnetic resonance imaging in closed-bore scanners sometimes provokes anxiety but closed-bore designs have gradually become wider and shorter. Open scanners may be easier to tolerate. The aim was to compare patient anxiety during MRI between bore diameters of 60 cm and 70 cm, and to determine the current level of patient anxiety and experience in open scanners in a clinical setrting. METHODS: Consecutive patients referred for examination of the spine in 60 cm and 70 cm bores and one open scanner participated. Four established/validated questionnaires, answered before, directly after (N = 155) and one week after (N = 109) the MRI-examination were used, measuring anxiety, fear and depression. RESULTS: No difference was found in the patient scores of anxiety between the 60 cm and the 70 cm scanners on the examination day. At follow-up, patients in the 70 cm bore rated their examination experience better (p < 0.025), compared to patients in the 60 cm bore. Patients in the open scanner rated higher levels of anxiety (p < 0.001) before, directly after and one week after the examination, compared to the closed bore scanners. CONCLUSION: Scanners with a 70 cm diameter bore seem more tolerable than those with a 60 cm bore. Patients referred to the open scanner had on average a higher tendency to express anxiety. Still, patient anxiety in MRI is challenging and further research required. IMPLICATIONS FOR PRACTICE: Patients prefer to be examined in 70 cm bore scanners compared with 60 cm. If open scanners aren't available extended support may be necessary for the most anxious patients.

The impact of using sagittal abdominal diameter to predict major cardiovascular events in European patients with type 2 diabetes.

BACKGROUND AND AIMS: Obesity is associated with diabetes type 2 and one of the most important risk factors for cardiovascular disease. We explored if sagittal abdominal diameter (SAD) is a better predictor of major cardiovascular events than waist circumference (WC) and body mass index (BMI) in type 2 diabetes. METHODS AND RESULTS: The CARDIPP study consists of a cohort of patients with type 2 diabetes. In this study we used data from 635 participants with no previous myocardial infarction or stroke, with a mean follow-up time of 7.1 years. SAD, WC and BMI were measured at baseline and the end-point was first cardiovascular event, measured as a composite of ICD-10 codes for acute myocardial infarction, stroke or cardiovascular mortality. SAD was significantly higher in the major cardiovascular event group compared to participants that did not suffer a major cardiovascular event during follow-up (p < 0.001). SAD >25 cm was the only anthropometric measurement that remained associated with major cardiovascular events when adjusted for modifiable and non-modifiable factors (hazard ratio 2.81, 95% confidence interval 1.37-5.76, p = 0.005). CONCLUSION: SAD with the cut off level of >25 cm, if confirmed in larger studies, may be used as a more independent risk-assessment tool compared with WC in clinical practice, to identify persons with type 2 diabetes at high cardiovascular risk. ClinicalTrials.gov: NCT01049737.

The Swedish CArdioPulmonary BioImage Study: objectives and design.

Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.

Microalbuminuria, but not reduced eGFR, is associated with cardiovascular subclinical organ damage in type 2 diabetes.

AIM: This study explored the association between reduced estimated glomerular filtration rate (eGFR) and microalbuminuria vs. subclinical organ damage in patients with type 2 diabetes. METHODS: Data from middle-aged patients with type 2 diabetes (n=706) treated in primary care were analyzed for microalbuminura, defined as a urinary albumin/creatinine ratio (uACR)≥3.0mmol/mol, and reduced eGFR, defined as<60mL/min/1.73m(2), in relation to blood pressure, pulse wave velocity (PWV), left ventricular mass index (LVMI), and carotid intima-media thickness (IMT) and lumen diameter (LD). RESULTS: Patients with microalbuminuria had significantly higher 24-h ambulatory systolic blood pressure (ASBP) compared with subjects with uACR<3mg/mmol: 137 vs. 128mmHg (P<0.001). There were no differences in ASBP in patients with eGFR<60mL/min/1.73m(2). However, patients with vs. without microalbuminuria had increased PWV (11.4 vs. 10.1m/s; P<0.001), LVMI (134.4 vs. 118.6g/m(2); P<0.001), LD (7.01±0.93 vs. 6.46±0.74mm; P<0.001) and IMT (0.78 vs. 0.74mm; P=0.047), respectively. The associations between uACR vs. PWV and LVMI were more robust after adjusting for age, diabetes duration, ASBP, HbA1c, LDL-cholesterol, and antihypertensive and lipid-lowering therapy compared with uACR vs. IMT. There were no statistically significant differences in PWV, LVMI or IMT between patients with reduced (<60mL/min/1.73m(2)) vs. normal eGFR. CONCLUSION: Levels of urinary albumin excretion, but not reduced eGFR, were associated with increased arterial stiffness, left ventricular mass and atherosclerosis in patients with type 2 diabetes.

Soft tissue discrimination ex vivo by dual energy computed tomography.

PURPOSE: Dual Energy Computed Tomography (DECT) may provide additional information about the chemical composition of tissues compared to examination with a single X-ray energy. The aim of this in vitro study was to test whether combining two energies may significantly improve the detection of soft tissue components commonly present in arterial plaques. METHODS: Tissue samples of myocardial and psoas muscle, venous and arterial thrombus as well as fat from different locations were scanned using a SOMATOM Definition Dual Source CT system (Siemens AG, Medical Solutions, Forchheim, Germany) with simultaneous tube voltages of 140 and 80 kV. The attenuation (Hounsfield units, HU) at 80 and 140 kV was measured in representative regions of interest, and the association between measured HU values and tissue types was tested with logistic regression. RESULTS: The combination of two energy levels (80 and 140 kV) significantly improved (p<0.001) the ability to correctly classify venous thrombus vs arterial thrombus, myocardium or psoas; arterial thrombus vs myocardium or psoas; myocardium vs psoas; as well as the differentiation between fat tissue from various locations. Single energy alone was sufficient for distinguishing fat from other tissues. CONCLUSION: DECT offers significantly improved in vitro differentiation between soft tissues occurring in plaques. If this corresponds to better tissue discrimination in vivo needs to be clarified in future studies.

Carotid intima-media thickness and apolipoprotein B/apolipoprotein A-I ratio in middle-aged patients with Type 2 diabetes.

AIMS: To explore the association between carotid intima-media thickness (IMT) and the apolipoprotein B (apoB)/apolipoprotein A-I (apoA-I) ratio compared with conventional lipids in middle-aged patients with Type 2 diabetes. METHODS: We analysed data from 247 patients with Type 2 diabetes, aged 55-66 years, in the Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care (CARDIPP-1) study. Primary care nurses measured blood pressure and anthropometric characteristics. Blood samples were taken for laboratory analyses. The carotid IMT was determined by ultrasonography at the University Hospital in Linköping and at the County Hospital Ryhov, Jönköping, Sweden. RESULTS: The ApoB/apoA-I ratio (r = 0.207, P = 0.001), apoB (r = 0.166, P = 0.009) and non-high-density lipoprotein cholesterol (non-HDL-c) (r = 0.129, P = 0.046) correlated with IMT. Conventional lipids, high-sensitivity C-reactive protein (hsCRP), glycated haemoglobin (HbA(1c)) and systolic blood pressure were not significantly correlated to IMT. A stepwise logistic regression analysis was conducted with IMT as the dependent variable and the apoB/apoA-I ratio, HbA(1c), hsCRP, low-density lipoprotein cholesterol (LDL-c), total cholesterol, non-HDL-c and treatment with statins as independent variables. Following adjustment for age and gender, only the apoB/apoA-I ratio remained significantly associated with IMT (odds ratio 4.3, 95% confidence intervals 1.7-10.8, P = 0.002). CONCLUSIONS: We conclude that there was a significant association between the apoB/apoA-I ratio and IMT in middle-aged patients with Type 2 diabetes. The association was independent of conventional lipids, hsCRP, glycaemic control and use of statins.

Masked nocturnal hypertension--a novel marker of risk in type 2 diabetes.

AIMS/HYPOTHESIS: This study was designed to evaluate the prevalence of masked nocturnal hypertension (MNHT) and its impact on arterial stiffness and central blood pressure in patients with type 2 diabetes. METHODS: Middle-aged patients (n = 414) with type 2 diabetes underwent clinic and ambulatory BP measurements and applanation tonometry. RESULTS: MNHT (clinic BP < 130/80 mmHg and night-time BP > or = 120/70 mmHg) was found in 7.2% of patients (n = 30). Compared with patients with both clinical and nocturnal normotension (n = 70), patients with MNHT had higher aortic pulse wave velocity (PWV) (10.2 +/- 1.8 m/s vs 9.4 +/- 1.7 m/s; p = 0.03) and higher central BP (117.6 +/- 13.9/74.0 +/- 9.1 mmHg vs 110.4 +/- 16.4/69.7 +/- 9.6 mmHg, p = 0.04). In patients with clinical normotension, night-time systolic BP correlated significantly with PWV. CONCLUSIONS/INTERPRETATION: Thirty per cent of patients with clinical normotension had nocturnal hypertension. This was accompanied by increased arterial stiffness and higher central BP. We conclude that in clinically normotensive patients with type 2 diabetes, ambulatory BP measurement may help clinicians to identify patients with increased cardiovascular risk.

Increasing incidence of childhood thyrotoxicosis in a population-based area of central Sweden.

AIM: To study the incidence, prevalence and clinical characteristics of childhood thyrotoxicosis in a population-based area comprising five counties in central Sweden. METHODS: Retrospective analysis of the medical records of all children below 16 y of age with thyrotoxicosis during a 10-y study period. RESULTS: Forty-six children were identified with thyrotoxicosis. The median age at onset was 11.7 y and 85% were females. At the end of the study period on 31 December 1999, the prevalence was 0.08 per 1000. The mean annual incidence was four times higher in the second 5-y period than in the first (2.7 and 0.7 per 100000, respectively; p < 0.001). A first-degree relative with thyrotoxicosis was found in 21% of the children and 11/46 children (24%) showed autoimmune-related co-morbidity. Increased heart rate was observed in 95%, goitre in 67% and exophthalmos in 33% of the children. TSH was completely suppressed and free T4 was clearly above the upper reference limit in all children. TSH receptor-stimulating antibodies and peroxidase antibodies were observed in 80% and 71% of the children, respectively. CONCLUSION: This study indicates an increase in the incidence of childhood thyrotoxicosis in a population-based area of central Sweden. A prospective study aimed at identifying specific aetiological risk factors for development of thyrotoxicosis has been initiated.

Non-invasive diagnosis of coronary artery disease by quantitative stress echocardiography: optimal diagnostic models using off-line tissue Doppler in the MYDISE study.

AIMS: To develop optimal methods for the objective non-invasive diagnosis of coronary artery disease, using myocardial Doppler velocities during dobutamine stress echocardiography. METHODS AND RESULTS: We acquired tissue Doppler digital data during dobutamine stress in 289 subjects, and measured myocardial responses by off-line analysis of 11 left ventricular segments. Diagnostic criteria developed by comparing 92 normal subjects with 48 patients with coronary disease were refined in a prospective series of 149 patients referred with chest pain. Optimal diagnostic accuracy was achieved by logistic regression models, using systolic velocities at maximal stress in 7 myocardial segments, adjusting for independent correlations directly with heart rate and inversely with age and female gender (all p<0.001). Best cut-points from receiver-operator curves diagnosed left anterior descending, circumflex and right coronary disease with sensitivities and specificities of 80% and 80%, 91% and 80%, and 93% and 82%, respectively. All models performed better than velocity cut-offs alone (p<0.001). CONCLUSION: Non-invasive diagnosis of coronary artery disease by quantitative stress echocardiography is best performed using diagnostic models based on segmental velocities at peak stress and adjusting for heart rate, and gender or age.

Three dimensional flow in the human left atrium.

BACKGROUND: Abnormal flow patterns in the left atrium in atrial fibrillation or mitral stenosis are associated with an increased risk of thrombosis and systemic embolisation; the characteristics of normal atrial flow that avoid stasis have not been well defined. OBJECTIVES: To present a three dimensional particle trace visualisation of normal left atrial flow in vivo, constructed from flow velocities in three dimensional space. METHODS: Particle trace visualisation of time resolved three dimensional magnetic resonance imaging velocity measurements was used to provide a display of intracardiac flow without the limitations of angle sensitivity or restriction to imaging planes. Global flow patterns of the left atrium were studied in 11 healthy volunteers. RESULTS: In all subjects vortical flow was observed in the atrium during systole and diastolic diastasis (mean (SD) duration of systolic vortex, 280 (77) ms; and of diastolic vortex, 256 (118) ms). The volume incorporated and recirculated within the vortices originated predominantly from the left pulmonary veins. Inflow from the right veins passed along the vortex periphery, constrained between the vortex and the atrial wall. CONCLUSIONS: Global left atrial flow in the normal human heart comprises consistent patterns specific to the phase of the cardiac cycle. Separate paths of left and right pulmonary venous inflow and vortex formation may have beneficial effects in avoiding left atrial stasis in the normal subject in sinus rhythm.

Estimation of relative cardiovascular pressures using time-resolved three-dimensional phase contrast MRI.

Accurate, easy-to-use, noninvasive cardiovascular pressure registration would be an important addition to the diagnostic armamentarium for assessment of cardiac function. A novel noninvasive and three-dimensional (3D) technique for estimation of relative cardiovascular pressures is presented. The relative pressure is calculated using the Navier-Stokes equations along user-defined lines placed within a time-resolved 3D phase contrast MRI dataset. The lines may be either straight or curved to follow an actual streamline. The technique is validated in an in vitro model and tested on in vivo cases of normal and abnormal transmitral pressure differences and intraaortic flow. The method supplements an intuitive visualization technique for cardiovascular flow, 3D particle trace visualization, with a quantifiable diagnostic parameter estimated from the same dataset.

Major and minor axes of the normal mitral annulus.

BACKGROUND AND AIM OF THE STUDY: A dilated or abnormally shaped mitral annulus is a common cause of mitral valve regurgitation, and may be cured by annuloplastic surgery. Multiplane transesophageal echocardiography (TEE) is the diagnostic technique of choice. Our aim was to evaluate and suggest two-dimensional TEE reference values from a standardized procedure of measuring the mitral annular major and minor axes, and their cyclic changes. METHODS: The annulus was approximated elliptic in the horizontal plane. The intercommissural (IC, major axis) and anteroposterior (AP, minor axis) distances were measured at end-systole (ES), at maximal valve opening (MO), and at end-diastole (ED) from a mid-esophageal view, in 13 men and eight women with normal echocardiographic findings. Indexed values and reproducibility were calculated. RESULTS: The success rate was 100% at ES, 90% at MO, and 29% at ED. ES distances were largest (p <0.001) and most reproducible (5-5.9%). Body weight, but not height or age, had a significant impact. ES 95% prediction intervals for IC were 27 to 46 mm (16-23 mm/m2) and 22 to 36 mm (13-18 mm/m2) for AP (p <0.001). Corresponding body weight-corrected intervals were 0.39 to 0.59 (IC) and 0.32 to 0.48 (AP) mm/kg. No subject had IC:AP <1.1 together with an AP >0.45 mm/kg. CONCLUSION: Among measurements made at ES, MO and ED, those at ES provided the most reproducible results, and high-quality images were obtained in normal, non-obese subjects. The distances should be judged in relation to body weight or surface area and each other. The largest IC distance and the most elliptic shape were at ES, while the annulus was minimal at ED. The procedure and normal ranges presented may contribute to the evaluation of patients with mitral regurgitation.

Daytime ambulatory blood pressure correlates strongly with the echocardiographic diameter of aortic coarctation.

OBJECTIVE: To relate the echocardiographic aortic arch-diameter to ambulatory and clinic blood pressure (BP) in patients with aortic coarctation. DESIGN: Eighteen adult patients (50% men) were recruited from the coarctation registry of the Linkoping Heart Centre. Biplane-trans-oesophageal echocardiography (TEE) was performed with Acuson XP 128/10, ambulatory BP was recorded with Spacelab models 90202/90205. RESULTS: Systolic clinic and ambulatory BP levels were higher in patients than in the 36 controls (clinic BP: 146 +/- 25 mmHg vs 119 +/- 10 mmHg, p = 0.0009, ambulatory BP: 140 +/- 18 mmHg vs 124 +/- 11 mmHg, p = 0.009). The differences in diastolic BP levels were less obvious (clinic BP: 87 +/- 16 mmHg vs 76 +/- 8 mmHg, p = 0.02, ambulatory BP: 84 +/- 13 mmHg vs 77 +/- 9 mmHg, p = 0.052). Daytime ambulatory BP was more strongly related than clinic BP to the coarctation diameter (AD) (systolic BP r= -0.73, p = 0.0006 and r = -0.61, p = 0.007, respectively). In surgically corrected patients (n = 14) only the correlations between ambulatory systolic daytime (r = -0.61, p = 0.02) and night-time (r = -0.58, p = 0.03) BP to AD was statistically significant. CONCLUSION: Ambulatory BP correlates strongly with aortic coarctation measured by TEE and would thus be the preferred technique for evaluating BP in this patient category.

Correction for acceleration-induced displacement artifacts in phase contrast imaging.

The acceleration-induced displacement artifact impairs the accuracy of MR velocity measurements. This study proposes a post processing method for correction of this artifact. Velocity measurements were performed in a flow phantom containing a constriction. Velocity curves were obtained from streamlines parallel to the frequency, phase, and slice directions, respectively. The acceleration-induced displacement artifact was most prominent when the frequency encoding direction was aligned with the flow direction. After correction, velocity assignment improved and a more accurate description of the flow was obtained. In vivo measurements were performed in the aorta in a patient with a repaired aortic coarctation. The correction method was applied to velocity data along a streamline parallel to the frequency encoding direction. The result after correction was a new location of the peak velocity and improved estimates of the velocity gradients.

Pitfalls in Doppler evaluation of diastolic function: insights from 3-dimensional magnetic resonance imaging.

Ultrasound-Doppler assessment of diastolic function is subject to velocity errors caused by angle sensitivity and a fixed location of the sample volume. We used 3-dimensional phase contrast magnetic resonance imaging (MRI) to evaluate these errors in 10 patients with hypertension and in 10 healthy volunteers. The single (Doppler) and triple (MRI) component velocity was measured at early (E) and late (A) inflow along Doppler-like sample lines or 3-dimensional particle traces generated from the MRI data. Doppler measurements underestimated MRI velocities by 9.4% +/- 8.6%; the effect on the E/A ratio was larger and more variable. Measuring early and late diastolic inflows from a single line demonstrated the error caused by their 3-dimensional spatial offset. Both errors were minimized by calculating the E/A ratio from maximal E and A values without constraint to a single line. Alignment and spatial offset are important sources of error in Doppler diastolic parameters. Improved accuracy may be achieved with the use of maximal E and A velocities from wherever they occur in the left ventricle.

Particle trace visualization of intracardiac flow using time-resolved 3D phase contrast MRI.

The flow patterns in the human heart are complex and difficult to visualize using conventional two-dimensional (2D) modalities, whether they depict a single velocity component (Doppler echocardiography) or all three components in a few slices (2D phase contrast MRI). To avoid these shortcomings, a temporally resolved 3D phase contrast technique was used to derive data describing the intracardiac velocity fields in normal volunteers. The MRI data were corrected for phase shifts caused by eddy currents and concomitant gradient fields, with improvement in the accuracy of subsequent flow visualizations. Pathlines describing the blood pathways through the heart were generated from the temporally resolved velocity data, starting from user-specified locations and time frames. Flow trajectories were displayed as 3D particle traces, with simultaneous demonstration of morphologic 2D slices. This type of visualization is intuitive and interactive and may extend our understanding of dynamic and previously unrecognized patterns of intracardiac flow.

Regional mean systolic myocardial velocity estimation by real-time color Doppler myocardial imaging: a new technique for quantifying regional systolic function.

A new color Doppler myocardial imaging (CDMI) system with high spatial and temporal resolution and novel postprocessing modalities has been developed that could allow quantifiable stress echocardiography. The purpose of this study was to determine whether regional myocardial systolic velocities could be accurately and reproducibly measured both at rest and during bicycle ergometry by using CDMI. Thirty normal subjects were examined with CDMI at rest, and peak mean systolic myocardial velocities (MSV) were measured for 34 predetermined left ventricular myocardial segments. Interobserver variability and intraobserver variability were established for all segments. Submaximal bicycle ergometry was performed in 20 normal subjects by using standardized weight-related increases in workload. MSV were measured at each step of exercise for 16 left ventricular stress echo segments. At rest, a base-apex gradient in regional MSV was recorded with highest longitudinal shortening velocities at the base. A similar pattern was noted for circumferential shortening MSV. Measurements were predictable and highly reproducible with low interobserver and intraobserver variability for 26 of 34 segments. Reproducibility was poor for basal anteroseptal segments in all views and mid anterior, anteroseptal, and septal segments in the short-axis views. During exercise, mid and basal segments of all walls showed a significant increase of MSV between each workload step and for apical segments between alternate steps. The resting base-apex velocity gradient observed at rest remained in all walls throughout ergometry. Thus a CDMI system with improved spatial and temporal resolution and postprocessing analysis modalities provided reproducible and accurate quantification of segmental left ventricular circumferential and longitudinal contraction both at rest and during exercise.

Case management and patient reactions: a study of STD care in a province in Zambia.

Sexually transmitted disease (STD) case management was evaluated through observation and interviews at 2 urban and 4 rural health centres and 2 district hospital STD clinics in one urban and 2 rural districts in Central Province, Zambia. The analysis was limited to 59 patients (42 men and 17 women) who paid first visits for their disease and were managed by a clinical officer. The evaluation suffered from the lack of a standard for case management. Results showed that the patients engaged in risky sexual behaviour without being aware of the risks. At the health institutions, few patients were informed about condoms, the risk of HIV, and abstinence from sex during treatment and few were asked to notify their partners. Clinical officers with special STD training performed better than others but sill informed only one-fifth of the patients. Few clinical officers managed patients according to the syndromic approach recommended by the STD control programme.

PIP: Sexually transmitted disease (STD) case management was evaluated through observation and interviews at two urban and four rural health centers and two district hospital STD clinics in one urban and two rural districts in Central Province, Zambia. The analysis was limited to 59 patients (42 men and 17 women) who made first visits for their disease and were managed by a clinical officer. The evaluation suffered from the lack of a standard for case management. Results showed that the patients engaged in risky sexual behavior without being aware of the risks. At the health institutions, few patients were informed about condoms, the risk of HIV, and abstinence from sex during treatment and few were asked to notify their partners. Clinical officers with special STD training performed better than others, but still informed only one-fifth of the patients. Few clinical officers managed patients according to the syndromic approach recommended by the STD control program.