The aim of the present study was to apply hyperpolarised (HP) 3 He magnetic resonance imaging (MRI) to identify patients with chronic obstructive pulmonary disease (COPD) and a 1 -antitrypsin deficiency (a 1 -ATD) from healthy volunteers and compare HP 3 He MRI findings with high-resolution computed tomography (HRCT) in a multicentre study. Quantitative measurements of HP 3He MRI (apparent diffusion coefficient (ADC)) and HRCT (mean lung density (MLD)) were correlated with pulmonary function tests.A prospective three centre study enrolled 122 subjects with COPD (either acquired or genetic) and age-matched never-smokers. All diagnostic studies were completed in 94 subjects (52 with COPD; 13 with a 1 -ATD; 29 healthy subjects; 63 males; and 31 females; median age 62 yrs). The consensus assessment of radiologists, blinded for other test results, estimated nonventilated lung volume (HP Using lung function tests as a reference, regional analysis of HP 3 He MRI and HRCT correctly categorised normal volunteers in 100% and 97%, COPD in 42% and 69% and a 1 -ATD in 69% and 85% of cases, respectively. Direct comparison of HP 3 He MRI and CT revealed 23% of subjects with moderate/severe structural abnormalities had only mild ventilation defects. In comparison with lung function tests, ADC was more effective in separating COPD patients from healthy subjects than MLD (p,0.001 versus 0.038). ADC measurements showed better correlation with DL,CO than MLD (r50.59 versus 0.29). Hyperpolarised 3 He MRI correctly categorised patients with COPD and normal volunteers. It offers additional functional information, without the use of ionising radiation whereas HRCT gives better morphological information. We showed the feasibility of a multicentre study using different magnetic resonance systems.
PAS occurs relatively often among patients of an endocrinological centre, with a 3:1 female to male ratio. Because there is usually a long interval between the onset of the various endocrine diseases, regular monitoring of patients with an endocrine autoimmune disease is indicated, specific tests to be performed if additional immune diseases are suspected.
Somatostatin-receptor (SSTR) scintigraphy using the single photon emission computed tomography (SPECT) technique allows the assessment of orbital inflammation in patients with Graves' disease. Previous studies showed differences in orbital octreotide uptake already 4 hr after injection. In this study, analysis of inter-/intra-observer variance and reproducibility in the evaluation of orbital SPECT images was performed. First, SPECT data of one representative female patient with clinically active Graves' ophthalmopathy (GO), obtained 4 hr after intravenous injection of 110 MBq 111In-pentetreotide and processed by filtered backprojection, were analyzed. Transverse SPECT images were reconstructed, an optimal orbital image was selected and predetermined regions of interests (ROIs) for both orbits were positioned by three independent observers 15 to 19 times each. In a second step, SPECT data of 8 different patients with GO were evaluated in the same manner by four independent observers 3 to 4 times each. Variance component partitioning was used to compare the order of intra- and inter-observer variation. For the right and the left orbit, the inter-observer variance proportion was 90% and 79%, whereas intra-observer variance partition was 10% and 21%, respectively. The corresponding ratios 0.11 and 0.27 summarize the comparison of sources of variance. The overall reliability was 84%, representing the patients influence on the total variance. Intra-observer reliability for both orbits was 88%, 89%, 97% and 98% (mean over orbits), respectively for observers I to IV. Using the Spearman Brown prophecy formula it follows that two replications per patient are sufficient to ensure a minimum reproducibility of 90%, which is also confirmed by the low intra-observer variation. Furthermore, intra-class correlation as a measure of (multiple) observer reproducibility was 94%. In conclusion, due to the increased inter-observer variance proportion and the high variation in intra-observer reliability, evaluations of orbital SSTR scintigraphy have to be done by the same and experienced observer leading to comparable data. But an automatic and quantitative computerized technique for evaluation of these SPECT data should be exactly reproducible and probably lead to more accurate and representative results.
Diagnostic image quality of the thoracic aorta can be achieved without application of intravenous contrast media. Images of the aortic root using ECG-gated non-CE-MRA are superior to standard CE-MRA. This technique might be applicable in NSF patients.
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