Retracted: Brain Susceptibility Weighted Imaging Signal Changes in Acute Hemorrhagic Anemia: An Experimental Study Using a Rabbit Model.

The Editors of Medical Science Monitor wish to inform you that the above manuscript has been retracted from publication due to concerns with the credibility and originality of the study, the manuscript content, and the Figure images. Reference: Jun Xia, Ni Xie, Yuning Feng, Anyu Yin, Pinni Liu, Ruming Zhou, Fan Lin, Guozhao Teng, Yi Lei. Brain Susceptibility Weighted Imaging Signal Changes in Acute Hemorrhagic Anemia: An Experimental Study Using a Rabbit Model. Med Sci Monit, 2014; 20: 1291-1297. DOI: 10.12659/MSM.890641.

Quantitative Analysis of Lipid-Rich Necrotic Core in Carotid Atherosclerotic Plaques by In Vivo Magnetic Resonance Imaging and Clinical Outcomes.

BACKGROUND The aim of this study was to explore the accuracy of in vivo magnetic resonance imaging (MRI) in the quantitative evaluation of lipid-rich necrotic core (LRNC) in carotid atherosclerotic plaques compared with histopathology, and to assess the association of LRNC size with cerebral ischemia symptoms. MATERIAL AND METHODS Thirty patients were enrolled and 19 patients (16 men and 3 women) were analyzed. All the patients were submitted to MRI on a Siemens Avanto (1.5-Tesla) device before carotid endarterectomy (CEA). The scanning protocol included three-dimensional time of flight (3D TOF), T1-weighted image (T1WI), T2-weighted image (T2WI), turbo spin-echo T2-weighted (T2-TSE), and contrast-enhanced T1-weighted image. MRI images were reviewed for quantitative measurements of LRNC areas. LRNC specimens were collected for histology. Percentages of LRNC area to total vessel area were assessed to determine the association of MRI with histological findings. RESULTS There were 151 pairs of matched MRI and pathological sections. LRNC area percentages (LRNC area/vessel area) measured by MRI and histology were 20.6±9.0% and 18.7±9.5%, respectively (r=0.69, p<0.001). Twelve out of 19 patients had symptoms (S-group; 3 had recent stroke, 3 had a recent stroke and a history of transient ischemic attack (TIA), and 6 had TIA); the remaining 7 subjects showed no symptoms (NS-group). LRNC area percentages in the S- and NS-groups were 22.2±5.8% and 12.6±10.7%, respectively (p<0.05). CONCLUSIONS MRI can quantitatively measure LRNC in carotid atherosclerotic plaques, and may be useful in predicting the rupture risk of plaques. These findings provide a basis for imaging use in individualized treatment plan.

Brain susceptibility weighted imaging signal changes in acute hemorrhagic anemia: an experimental study using a rabbit model.

BACKGROUND: The aim of this study was to investigate susceptibility-weighted imaging (SWI) signal changes in different brain regions in a rabbit model of acute hemorrhagic anemia. MATERIAL/METHODS: Ten New Zealand white rabbits were used for construction of the model of acute hemorrhagic anemia. Signal intensities of SWI images of the bilateral frontal cortex, frontal white matter, temporal lobe, and thalamic nuclei were measured. In addition, the cerebral gray-white contrast and venous structures of the SWI images were evaluated by an experienced physician. RESULTS: Repeated bloodletting was associated with significant reductions in red blood cell count, hemoglobin concentration, hematocrit, pH, and PaCO2, and elevations of blood lactate and PaO2. In normal status, the SWI signal intensity was significantly higher in the frontal cortex than in the frontal white matter (63.10±22.82 vs. 52.50±20.29; P<0.05). Repeated bloodletting (5 occasions) caused significant (P<0.05) decreases in the SWI signals of the frontal cortex (from 63.10±22.82 to 37.70±4.32), temporal lobe (from 52.50±20.29 to 42.60±5.54), and thalamus (from 60.40±20.29 to 39.40±3.47), but was without effect in the frontal white matter. The cerebral white-gray contrast and venous structures were clearer after bloodletting than before bloodletting. CONCLUSIONS: The effect of hemorrhage on the brain is reflected by SWI signal changes in the cerebral cortex and gray matter nuclei.