Nationwide prevalence and incidence study of neuromyelitis optica spectrum disorder in Denmark.

OBJECTIVES: To estimate the nationwide population-based incidence, prevalence, and geographical distribution of neuromyelitis optica (NMO) spectrum disorder (NMOSD) in Denmark based on the 2015 International Panel for NMO Diagnosis (IPND) criteria. METHODS: We conducted a multicentre, historically prospective study. Data were sourced from the Danish National Patient Registry, the Danish Multiple Sclerosis Registry, departments of neurology, and laboratories providing aquaporin-4 antibody test. Cases were selected based on the 2006 Wingerchuk and the 2015 IPND criteria and were individually validated by an expert panel. RESULTS: We confirmed NMO in 30 cases (2006 criteria) and NMOSD in 56 cases (2015 IPND criteria) between 2007 and 2014. Defined by the 2006 criteria, the incidence of NMO was 0.029 per 100,000 person-years (95% confidence interval [CI] 0.014-0.051), and the prevalence (aged 16 years and older) was 0.566 per 100,000 (95% CI 0.370-0.830). Based on the 2015 IPND criteria, the incidence of NMOSD was 0.070 per 100,000 person-years (95% CI 0.046-0.102), and the prevalence (aged 16 years and older) was 1.09 per 100,000 (95% CI 0.808-1.440), without regional differences. CONCLUSIONS: Our estimates of incidence and prevalence are similar to other Caucasian population-based studies using the 2015 IPND criteria. We found no geographical clustering in Denmark.

Evaluation and optimization of administered activity, scanning parameters and hydration at (99m) Tc hydroxymethylene diphosphonate adult whole-body bone imaging.

PURPOSE: To find out the method of optimal activity administration and scanning parameters to fulfil guidelines and diagnostic reference levels and to reach a maximal contrast-to-noise ratio (CNR) in bone imaging. We also investigate the influence on CNR and bladder activity in well-hydrated patients. METHODS: A total of 225 patients were included. The first group of 101 patients was used to find out the optimal method to administer activity in terms of optimized CNR. The next two groups with 62 patients each were hydrated with 1500 ml water in two different time periods. CNR, bladder area and content were calculated. RESULTS: An administrated activity per metre body height gave the highest CNR (5·43). A standard activity had the lowest percentage (2%) of images with < 1·5 million counts. Early hydration decreased CNR from 5·41 to 4·85 (P = 0·06), with late hydration to 5·29 (NS). Studies with too few pulses were increased from 2 to 11% to a level of 15-26% and 11-21%, respectively. Early hydration reduced the bladder activity from 20·7 to 10·1 MBq (P< 0·01), late hydration to 14·8 MBq (P = 0·08). The bladder size was enlarged from the no hydrated group (1406 mm(2) ) to the early hydrated group (2406 mm(2) , P< 0·000) and between the early and late hydrated group (3183 mm(2) , P< 0·05). CONCLUSION: A standard activity in sufficient quantity is the most practical method, in addition to have the lowest percentage of images with too few pulses. A high fluid intake is not recommended because of problems with disturbing bladder content.

Longitudinal peak strain detects a smaller risk area than visual assessment of wall motion in acute myocardial infarction.

BACKGROUND: Opening of an occluded infarct related artery reduces infarct size and improves survival in acute ST-elevation myocardial infarction (STEMI). In this study we performed tissue Doppler analysis (peak strain, displacement, mitral annular movement (MAM)) and compared with visual assessment for the study of the correlation of measurements of global, regional and segmental function with final infarct size and transmurality. In addition, myocardial risk area was determined and a prediction sought for the development of infarct transmurality >or=50%. METHODS: Twenty six patients with STEMI submitted for primary percutaneous coronary intervention (PCI) were examined with echocardiography on the catheterization table. Four to eight weeks later repeat echocardiography was performed for reassessment of function and magnetic resonance imaging for the determination of final infarct size and transmurality. RESULTS: On a global level, wall motion score index (WMSI), ejection fraction (EF), strain, and displacement all showed significant differences (p or=50%, but strain added no significant information to that obtained with WMSI in a logistic regression analysis. CONCLUSIONS: In patients with acute STEMI, WMSI, EF, strain, and displacement showed significant changes between the pre- and post PCI exam. In a ROC-analysis, strain had 64% sensitivity at 80% specificity and WMSI around 90% sensitivity at 80% specificity for the detection of scar with transmurality >or=50% at follow-up.

Image quality and myocardial scar size determined with magnetic resonance imaging in patients with permanent atrial fibrillation: a comparison of two imaging protocols.

BACKGROUND: Magnetic resonance imaging (MRI) of the heart generally requires breath holding and a regular rhythm. Single shot 2D steady-state free precession (SS_SSFP) is a fast sequence insensitive to arrhythmia as well as breath holding. Our purpose was to determine image quality, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios and infarct size with a fast single shot and a standard segmented MRI sequence in patients with permanent atrial fibrillation and chronic myocardial infarction. METHODS: Twenty patients with chronic myocardial infarction and ongoing atrial fibrillation were examined with inversion recovery SS_SSFP and segmented inversion recovery 2D fast gradient echo (IR_FGRE). Image quality was assessed in four categories: delineation of infarcted and non-infarcted myocardium, occurrence of artefacts and overall image quality. SNR and CNR were calculated. Myocardial volume (ml) and infarct size, expressed as volume (ml) and extent (%), were calculated, and the methodological error was assessed. RESULTS: SS_SSFP had significantly better quality scores in all categories (P = 0.037, P = 0.014, P = 0.021, P = 0.03). SNR(infarct) and SNR(blood) were significantly better for IR_FGRE than for SS_SSFP (P = 0.048, P = 0.018). No significant difference was found in SNR(myocardium) and CNR. The myocardial volume was significantly larger with SS_SSFP (170.7 versus 159.2 ml, P<0.001), but no significant difference was found in infarct volume and infarct extent. CONCLUSION: SS_SSFP displayed significantly better image quality than IR_FGRE. The infarct size and the error in its determination were equal for both sequences, and the examination time was shorter with SS_SSFP.

Late gadolinium uptake demonstrated with magnetic resonance in patients where automated PERFIT analysis of myocardial SPECT suggests irreversible perfusion defect.

BACKGROUND: Myocardial perfusion single photon emission computed tomography (MPS) is frequently used as the reference method for the determination of myocardial infarct size. PERFIT(R) is a software utilizing a three-dimensional gender specific, averaged heart model for the automatic evaluation of myocardial perfusion. The purpose of this study was to compare the perfusion defect size on MPS, assessed with PERFIT, with the hyperenhanced volume assessed by late gadolinium enhancement magnetic resonance imaging (LGE) and to relate their effect on the wall motion score index (WMSI) assessed with cine magnetic resonance imaging (cine-MRI) and echocardiography (echo). METHODS: LGE was performed in 40 patients where clinical MPS showed an irreversible uptake reduction suggesting a myocardial scar. Infarct volume, extent and major coronary supply were compared between MPS and LGE as well as the relationship between infarct size from both methods and WMSI. RESULTS: MPS showed a slightly larger infarct volume than LGE (MPS 29.6 +/- 23.2 ml, LGE 22.1 +/- 16.9 ml, p = 0.01), while no significant difference was found in infarct extent (MPS 11.7 +/- 9.4%, LGE 13.0 +/- 9.6%). The correlation coefficients between methods in respect to infarct size and infarct extent were 0.71 and 0.63 respectively. WMSI determined with cine-MRI correlated moderately with infarct volume and infarct extent (cine-MRI vs MPS volume r = 0.71, extent r = 0.71, cine-MRI vs LGE volume r = 0.62, extent r = 0.60). Similar results were achieved when wall motion was determined with echo. Both MPS and LGE showed the same major coronary supply to the infarct area in a majority of patients, Kappa = 0.84. CONCLUSION: MPS and LGE agree moderately in the determination of infarct size in both absolute and relative terms, although infarct volume is slightly larger with MPS. The correlation between WMSI and infarct size is moderate.

Computer-assisted calculation of myocardial infarct size shortens the evaluation time of contrast-enhanced cardiac MRI.

BACKGROUND: Delayed enhancement magnetic resonance imaging depicts scar in the left ventricle which can be quantitatively measured. Manual segmentation and scar determination is time consuming. The purpose of this study was to evaluate a software for infarct quantification, to compare with manual scar determination, and to measure the time saved. METHODS: Delayed enhancement magnetic resonance imaging was performed in 40 patients where myocardial perfusion single photon emission computed tomography imaging showed irreversible uptake reduction suggesting a myocardial scar. After segmentation, the semi-automatic software was applied. A scar area was displayed, which could be corrected and compared with manual delineation. The different time steps were recorded with both methods. RESULTS: The software shortened the average evaluation time by 12.4 min per cardiac exam, compared with manual delineation. There was good correlation of myocardial volume, infarct volume and infarct percentage (%) between the two methods, r = 0.95, r = 0.92 and r = 0.91 respectively. CONCLUSION: A computer software for myocardial volume and infarct size determination cut the evaluation time by more than 50% compared with manual assessment, with maintained clinical accuracy.