Spatial distribution, source identification, and transportation paths of plutonium in the Beibu Gulf, South China Sea.

To investigate the spatial distribution and source of plutonium isotopes in the Beibu Gulf, surface sediments were collected and analyzed using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The activities of 239+240Pu in surface sediments ranged from 0.012 to 0.451 mBq/g (mean: 0.171 ± 0.138 mBq/g, n = 36), indicating a decreasing trend in a counterclockwise direction from the southern bay mouth. The counterclockwise decreasing trend in the south of the bay mouth is similar to the current in the Beibu Gulf. The 240Pu/239Pu atom ratios in surface sediments ranged from 0.156 to 0.283 (mean: 0.236 ± 0.031, n = 36), slightly higher than that of the global fallout value of 0.18. This suggests that the Pu in the Beibu Gulf was a combination of global fallout and Pacific Proving Ground (PPG). The average contribution of the plutonium (Pu) derived from the PPG in the sediment was estimated to be 52 % ± 24 %.

Discriminating Depth of Response to Therapy in Multiple Myeloma Using Whole-body Diffusion-weighted MRI with Apparent Diffusion Coefficient: Preliminary Results From a Single-center Study.

RATIONALE AND OBJECTIVES: This study aimed to measure apparent diffusion coefficient (ADC) in Chinese patients with newly diagnosed multiple myeloma by whole-body diffusion-weighted magnetic resonance imaging (WB-DWI MRI) and assess the diagnostic accuracy of ADC in the discrimination of deep response to induction chemotherapy. MATERIALS AND METHODS: Seventeen patients underwent WB-DWI MRI before and after induction chemotherapy (week 20). DWI images and ADC maps were produced and 89 regions of interest were chosen. ADC percent changes were compared between deep (complete response or very good partial response) and non-deep responders (partial response, minimal response, stable disease, or progressive disease) as International Myeloma Working Group criteria. Diagnostic accuracy of ADC was calculated using specific cut offs. Predictive positive value of ADC was calculated to predict deep response to consolidation therapy. RESULTS: Lesions reduced in size and number and signal intensity decreased in follow-up DWI, which did not differ between deep and non-deep responders. ADC percent changes were significantly higher in deep responders (36.79%) than in non-deep responders (11.50%) after induction therapy (P = .02) in per lesion analysis. ADC percent increases by 46.96%, 78.0% yielded specificity at 81.4%, 90.7% in discriminating deep response to induction therapy. Predictive positive value predicting deep response to consolidation therapy was 60.5% by using ADC cutoff >1.00 × 10-3 mm2/s at week 20. CONCLUSIONS: ADC from WB-DWI MRI increased remarkably in patients who achieved deep response at the end of induction chemotherapy, which represented a confirmatory diagnostic tool to discriminate deep response to induction therapy for patients with multiple myeloma. ADC may have a potential to predict deep response to consolidation therapy.

Pulmonary CT findings in relapsing polychondritis.

BACKGROUND: Relapsing polychondritis (RPC) is a rare rheumatic disease characterized by recurrent inflammation of cartilaginous structures, with airway involvement a major cause of morbidity and mortality. PURPOSE: To retrospectively evaluate airway and lung abnormalities in RPC with computed tomography (CT). MATERIAL AND METHODS: From January 2004 to May 2009, 21 patients with RPC (12 men, 9 women; 13-65 years old) underwent chest CT examinations. Two chest radiologists evaluated the CT images retrospectively. Abnormal findings, including airway stenosis, airway malacia, air trapping, and airway wall thickening with or without calcifications, were observed and noted. RESULTS: Major abnormal CT findings were observed in eight patients (38.1%), which included airway wall thickening (n=7), airway stenosis (n=6), airway malacia (n=6), airway wall calcification (n=8), and air trapping (n=3). Mediastinal lymph nodes were found in 12 patients. Lung infection was identified in four patients and interstitial lung disease in six patients. CONCLUSION: The CT findings in patients with RPC consisted mainly of airway wall thickening, airway stenosis, airway malacia, airway wall calcification, and air trapping.

Correlation of iron in the hippocampus with MMSE in patients with Alzheimer's disease.

PURPOSE: To investigate the brain iron deposits in patients with Alzheimer's disease (AD) and healthy age-matched controls using phase imaging. MATERIALS AND METHODS: Twenty-six AD patients and 24 healthy controls were recruited. A three-dimensional high-resolution, gradient-echo sequence was used to acquire phase data in the coronal plane. A high-pass filter was used to remove the phase variation caused by field inhomogeneity. The regions evaluated included the bilateral putamen, globus pallidus, and the head and body of the hippocampus. RESULTS: Significantly lower phase values in both the basal ganglion and hippocampus were revealed in the AD group compared to the normal controls (P < 0.05). The phase value in the right side of the head of the hippocampus had a moderate positive correlation with the MMSE score (r= 0.603, P = 0.000) and a negative correlation with the duration of the disease (r = -0.677, P = 0.013). Using -0.0972 radians as an optimal cutoff value, the sensitivity and specificity for differentiation between AD and normal controls reached 95.8 and 80.8%, respectively. CONCLUSION: Phase imaging proved to be a useful method for the differentiation between normal controls and AD patients. An investigation of the excessive accumulation of iron in the hippocampus may help us better understand the pathologic process and neuropsychological dysfunction of AD disease.

Preliminary application of whole body diffusion weighted imaging in screening metastasis.

OBJECTIVE: To investigate the feasibility of whole body diffusion weighted imaging (WB-DWI) in screening metastasis. METHODS: WB-DWI was performed in 24 patients diagnosed with various types of primary tumors. The three-dimensional maximum intensity projection reconstruction and black-and-white flip technique were used to observe metastatic lesions, and the results were compared with those of bone scintigraphy. RESULTS: By WB-DWI scanning sequence at b = 800 s/mm2, all the bone lesions found by bone scintigraphy in the cohort were well identified, and other lesions of soft tissue and organs were also well demonstrated. Its screening capability was equivalent with bone scintigraphy in screening metastases in bones (P = 0.062). CONCLUSION: WB-DWI was practicable with the parameter settings attempted in metastases screening.