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Purpose: We aimed to compare apparent diffusion coefficient (ADC) values among magnetic resonance imaging (MRI) scanners from different vendors., Materials and Methods: We used a custom-made phantom solution consisting of distilled water, 0.9% NaCl, 25% NaCl, and shampoo for diffusion-weighted MRI (DW-MRI) examinations. DW-MRI was performed with similar sequence parameters using six different 1.5 Tesla MR scanners (scanners A-F). ADC maps were automatically constructed for all DW-MR images (b factors of 0 and 1000 s/mm(2)). ADC measurements were performed using regions of interest and seven different software programs, including four different postprocessing workstations, two different picture archiving and communication systems, and operator console software for each MR scanner., Results: The ADC values generated by scanners A and F were higher and those of scanner B were lower than those generated by the other scanners (P = 0.002). The intravendor difference in the ADC values averaged from scanners D, E, and F was statistically significant (P < 0.001). The difference between the ADC values obtained by scanners C and E was not statistically different (P = 0.15)., Conclusion: ADC values may differ among different MRI systems used for DW-MRI. Thus, the MRI vendor should be considered when using DW-MRI in a clinical setting.

Purpose: There are two well-known indications for first-pass perfusion in the literature. First is the evaluation of myocardial ischemia, and the other is the evaluation of tumor vascularity. Our aim was to assess the value of a first-pass contrast bolus tracking sequence (FPCBTS) for cases unrelated to these pathologies., Materials and Methods: A total of 35 patients (age range, 1 day to 66 years; mean age, 10.4±19.2 years; median age, 4.5 months) with suspected congenital (n=31) and acquired (n=4) heart and great vessel disease were included in the study. All the patients underwent cardiac magnetic resonance imaging (MRI) and FPCBTS, and 20 patients underwent contrast enhanced magnetic resonance angiography (CE-MRA). We used cardiac MRI and CEMRA for anatomic evaluation and FPCBTS for dynamic flow evaluation., Results: Truncus arteriosus, double outlet right ventricle, tetralogy of Fallot, corrected transposition of great arteries, atrial and ventricular septal defect, aortic rupture, cardiac hydatid cyst, tricuspid atresia, anomalous pulmonary venous return, and interrupted aorta were detected using the technique described here. Septal defects in six patients and atrial aneurysm in two patients were excluded. The shunt gap and flow direction of the septal defects, a ruptured wall in a dissected aorta, a hydatid cyst, and the atrial relationship in two cases with paracardiac masses were diagnosed easily using this dynamic evaluation technique., Conclusion: FPCBTS can be performed in addition to cardiac MRI and CEMRA to reveal flow dynamics and morphology.

Purpose: Myocardial iron overload remains an important problem and results in cardiac dysfunction in patients with thalassemia major (TM). The ratio of color M-mode flow propagation velocity to early diastolic transmitral flow velocity (E/Vp) in echocardiography is a marker of increased left ventricular filling pressure, which is independent of preload, afterload, and heart rate. We examined the relationship between E/Vp and iron loading in patients with TM using cardiac magnetic resonance imaging (MRI)., Materials and Methods: Twenty-one TM patients and 21 age-matched healthy controls were enrolled in the study. Transmitral flow, pulmonary vein velocities, and Vp were obtained by two blinded echocardiographers. Left ventricular isovolumetric relaxation time (IVRT) was measured in the apical long axis by echocardiography. All patients also underwent MRI for cardiac T2* evaluation of iron overload. An increased E/Vp was defined as > 1.5., Results: The E/Vp ratio was increased in TM patients compared with control subjects (1.7±0.4 and 1.2±0.2, P < 0.01, respectively). There was no correlation between E/Vp and cardiac T2* value. E/Vp was significantly correlated with IVRT (r=0.51, P = 0.02). In addition, the cardiac T2* value was comparable in patients with an E/Vp > 1.5 and E/Vp ≤1.5 (21.1±9.8 ms vs. 22.3±8.0 ms, P = 0.80, respectively)., Conclusion: E/Vp may be a marker of diastolic abnormality that is independent from myocardial iron load in TM patients with preserved left ventricular function.